/**
 * Looking Glass
 * Copyright © 2017-2026 The Looking Glass Authors
 * https://looking-glass.io
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc., 59
 * Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include "main.h"
#include "config.h"

#include <getopt.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <inttypes.h>
#include <string.h>
#include <stdint.h>
#include <stdbool.h>
#include <math.h>
#include <stdlib.h>
#include <stdatomic.h>
#include <linux/input.h>

#include "common/array.h"
#include "common/debug.h"
#include "common/crash.h"
#include "common/stringutils.h"
#include "common/thread.h"
#include "common/locking.h"
#include "common/event.h"
#include "common/time.h"
#include "common/version.h"
#include "common/paths.h"
#include "common/cpuinfo.h"
#include "common/ll.h"
#include "common/option.h"
#include "common/proctitle.h"

#include "message.h"
#include "core.h"
#include "app.h"
#include "audio.h"
#include "keybind.h"
#include "core/clipboard.h"
#include "kb.h"
#include "egl_dynprocs.h"
#include "gl_dynprocs.h"
#include "overlays.h"
#include "overlay_utils.h"
#include "util.h"
#include "render_queue.h"
#include "evdev.h"
#include "frame_scheduler.h"
#include "input.h"
#include "sw_surface.h"

#ifdef ENABLE_TESTS
#include "interface/test_capture.h"
_Static_assert((int)LG_CAPTURE_RGBA8 == (int)LG_TEST_CAPTURE_RGBA8,
    "capture format mismatch");
_Static_assert((int)LG_CAPTURE_RGB10_A2 == (int)LG_TEST_CAPTURE_RGB10_A2,
    "capture format mismatch");
_Static_assert((int)LG_CAPTURE_RGBA32F == (int)LG_TEST_CAPTURE_RGBA32F,
    "capture format mismatch");
#endif

#define TRANSPORT_LOST_PRIMARY  (1U << 0)
#define TRANSPORT_LOST_FALLBACK (1U << 1)
#define TRANSPORT_LOST_ALL \
  (TRANSPORT_LOST_PRIMARY | TRANSPORT_LOST_FALLBACK)
#define VIDEO_STATUS_ERROR_RETRY_NS 1000000U

// forwards
static int renderThread(void * unused);
static RenderQueueSource renderQueueSource(LG_VideoSource source);
static bool videoSourceInvalidate(LG_VideoSource source);
static void videoSourceShowSplashIfNeeded(void);
static bool fallbackRequestVideo(void);
static void primaryLost(void);
static bool videoComponentPayloadCurrent(const atomic_bool * available,
    const atomic_uint_least64_t * epoch, uint64_t payloadEpoch,
    bool trackEpoch);
static bool videoPayloadAccept(const atomic_bool * available,
    const atomic_uint_least64_t * epoch, uint64_t payloadEpoch,
    bool trackEpoch, uint64_t sourceGeneration);
static void videoPayloadRelease(void);
static bool videoFramePayloadAccept(const LG_TransportFrame * frame,
    uint64_t currentGeneration, bool trackEpoch,
    uint64_t * sourceGeneration, uint64_t * frameSerial,
    uint32_t * formatVersion, bool * sourceChanged);

static LGEvent  *e_startup       = NULL;
static LGEvent  *e_cursorRepaint = NULL;
static LGThread *t_render        = NULL;
static LGThread *t_cursorRepaint = NULL;

static struct
{
  LG_Lock  lock;
  uint64_t requestedSerial;
  uint64_t presentedSerial;
  uint64_t lastRenderTime;
  bool     rendering;
  bool     wakeArmed;
  bool     lastRenderCursorOnly;
}
l_cursorRepaint;

_Atomic(enum RunState) p_appState = APP_STATE_RUNNING;

struct AppState g_state = { 0 };
struct CursorState g_cursor;

// this structure is initialized in config.c
struct AppParams g_params = { 0 };

static bool videoStatusRetry(LG_TransportStatus status,
    bool statusAware, bool available)
{
  if (status == LG_TRANSPORT_TIMEOUT ||
      status == LG_TRANSPORT_UNAVAILABLE)
    return true;

  if (status != LG_TRANSPORT_ERROR || !statusAware || available)
    return false;

  nsleep(VIDEO_STATUS_ERROR_RETRY_NS);
  return true;
}

static void primaryWorkerFailed(void)
{
  /* A worker can still be handling an abandoned primary payload after the
   * session thread has initiated a restart. Preserve that restart so the
   * fallback video source can take over instead of terminating the client. */
  app_transitionState(APP_STATE_RUNNING, APP_STATE_SHUTDOWN);
}

#ifdef ENABLE_TESTS
static struct
{
  const char * path;
  uint64_t     targetSerial;
  uint64_t     lastSerial;
  unsigned     delay;
  unsigned     stableRenders;
  bool         enabled;
  bool         complete;
}
l_testCapture;

static atomic_uint_least64_t l_testFrameSerial;
static _Atomic(FrameType)    l_testFrameType;
#endif

static void lgInit(void)
{
  g_state.formatValid   = false;
  g_state.resizeDone    = true;

  core_setCursorInView(false);
  if (g_cursor.grab)
    core_setGrab(false);

  g_cursor.useScale      = false;
  g_cursor.scale.x       = 1.0;
  g_cursor.scale.y       = 1.0;
  g_cursor.draw          = false;
  g_cursor.inView        = false;
  g_cursor.viewReq       = false;
  g_cursor.exit          = false;
  g_cursor.surfaceExit   = false;
  g_cursor.guest.valid   = false;

  // if guest input is not in use, hide the local cursor
  if ((!lgInput_available() && g_params.hideMouse) || !g_params.showCursorDot)
    g_state.ds->setPointer(LG_POINTER_NONE);
  else
    g_state.ds->setPointer(LG_POINTER_SQUARE);
}

static bool fpsTimerFn(void * unused)
{
  static uint64_t last;
  if (!last)
  {
    last = nanotime();
    return true;
  }

  const uint64_t renderCount = atomic_exchange_explicit(&g_state.renderCount, 0,
      memory_order_acquire);

  float fps, ups;
  if (renderCount > 0)
  {
    const uint64_t frameCount = atomic_exchange_explicit(&g_state.frameCount, 0,
        memory_order_acquire);

    const uint64_t time      = nanotime();
    const uint64_t elapsedNs = time - last;
    const float    elapsedMs = (float)elapsedNs / 1e6f;

    last = time;
    fps  = 1e3f / (elapsedMs / (float)renderCount);
    ups  = 1e3f / (elapsedMs / (float)frameCount);
  }
  else
  {
    last = nanotime();
    fps  = 0.0f;
    ups  = 0.0f;
  }

  atomic_store_explicit(&g_state.fps, fps, memory_order_relaxed);
  atomic_store_explicit(&g_state.ups, ups, memory_order_relaxed);

  return true;
}

static bool tickTimerFn(void * unused)
{
  static unsigned long long tickCount = 0;

  bool needsRender = false;
  struct Overlay * overlay;
  ll_lock(g_state.overlays);
  ll_forEachNL(g_state.overlays, item, overlay)
  {
    if (overlay->ops->tick && overlay->ops->tick(overlay->udata, tickCount))
      needsRender = true;
  }
  ll_unlock(g_state.overlays);

  if (needsRender)
    app_invalidateWindow(false);

  ++tickCount;
  return true;
}

#define FRAME_TIMING_RECORD_COUNT       1024
#define FRAME_TIMING_PUBLISH_BATCH_SIZE 32
#define FRAME_TIMING_PRESENT_TIMEOUT_NS 500000000ULL
#define USB_REDIR_DISCONNECT_TIMEOUT_US 500000ULL

enum FrameTimingReady
{
  FRAME_TIMING_FRAME_READY   = 1 << 0,
  FRAME_TIMING_RENDER_READY  = 1 << 1,
  FRAME_TIMING_PRESENT_READY = 1 << 2,
};

struct FrameTimingRecord
{
  LG_RendererFrameToken token;
  uint64_t              frameSerial;
  uint32_t              scheduleGeneration;
  uint32_t              scheduleEpoch;
  uint32_t              scheduleDeadlineSerial;
  unsigned              readyMask;
  bool                  producerValid;
  bool                  providerValid;
  bool                  phaseValid;
  bool                  transportValid;
  bool                  presentValid;

  uint64_t captureTime;
  uint64_t postProcessTime;
  uint64_t copyTime;
  uint64_t readyTime;
  uint64_t holdTime;
  uint64_t readyLeadTime;
  uint64_t receiveTime;
  uint64_t providerPrepareTime;
  uint64_t importTime;
  uint64_t importWaitTime;
  uint64_t dispatchTime;
  uint64_t queueStart;

  uint64_t prepareStart;
  uint64_t prepareTime;
  uint64_t timestamp;
  uint64_t setupTime;
  uint64_t effectsTime;
  uint64_t desktopTime;
  uint64_t composeTime;
  uint64_t swapTime;
  uint64_t presentTime;
  uint64_t presentDeadline;
};

static struct
{
  LG_Lock                        lock;
  _Atomic(LG_RendererFrameToken) queuedToken;
  LG_RendererFrameToken          nextToken;
  LG_RendererFrameToken          retireToken;
  unsigned                       publishRead;
  unsigned                       publishWrite;
  unsigned                       publishCount;
  bool                           overflowWarning;
  LG_RendererFrameToken          publishToken[FRAME_TIMING_RECORD_COUNT];
  struct FrameTimingRecord       record[FRAME_TIMING_RECORD_COUNT];
}
l_frameTiming;

/* The frame and render threads complete records independently. A token is
 * published only after both halves have arrived, while queuedToken prevents a
 * renderer that woke for unrelated work from consuming an unqueued frame. */

static void frameTimingInit(void)
{
  LG_LOCK_INIT(l_frameTiming.lock);
  atomic_store_explicit(&l_frameTiming.queuedToken,
      LG_RENDERER_FRAME_TOKEN_NONE, memory_order_relaxed);
  l_frameTiming.nextToken       = LG_RENDERER_FRAME_TOKEN_NONE;
  l_frameTiming.retireToken     = 1;
  l_frameTiming.publishRead     = 0;
  l_frameTiming.publishWrite    = 0;
  l_frameTiming.publishCount    = 0;
  l_frameTiming.overflowWarning = false;
  memset(l_frameTiming.record, 0, sizeof(l_frameTiming.record));
}

static void frameTimingReset(void)
{
  INTERLOCKED_SECTION(l_frameTiming.lock, {
    memset(l_frameTiming.record, 0, sizeof(l_frameTiming.record));
    l_frameTiming.retireToken     = l_frameTiming.nextToken + 1;
    l_frameTiming.publishRead     = 0;
    l_frameTiming.publishWrite    = 0;
    l_frameTiming.publishCount    = 0;
    l_frameTiming.overflowWarning = false;
  });
  /* Tokens remain monotonic across reconnects so stale renderer state can
   * never alias a new frame. No frame is consumable until it is queued. */
  atomic_store_explicit(&l_frameTiming.queuedToken,
      LG_RENDERER_FRAME_TOKEN_NONE, memory_order_release);
}

static uint64_t frameTimingAdd(uint64_t lhs, uint64_t rhs)
{
  return rhs > UINT64_MAX - lhs ? UINT64_MAX : lhs + rhs;
}

static struct FrameTimingRecord * frameTimingRecord(
    LG_RendererFrameToken token)
{
  return &l_frameTiming.record[
    (token - 1) % FRAME_TIMING_RECORD_COUNT];
}

void main_framePresented(uint64_t frameToken, uint64_t presentTime,
    bool valid)
{
  if (!frameToken)
    return;

  INTERLOCKED_SECTION(l_frameTiming.lock, {
    struct FrameTimingRecord * record = frameTimingRecord(frameToken);
    if (record->token == frameToken)
    {
      record->presentTime  = presentTime;
      record->presentValid = valid;
      record->readyMask   |= FRAME_TIMING_PRESENT_READY;
    }
  });
}

static LG_RendererFrameToken frameTimingReserve(void)
{
  LG_RendererFrameToken token;

  LG_LOCK(l_frameTiming.lock);
  token = ++l_frameTiming.nextToken;
  if (unlikely(token == LG_RENDERER_FRAME_TOKEN_NONE))
    token = ++l_frameTiming.nextToken;

  struct FrameTimingRecord * record = frameTimingRecord(token);
  const bool recordActive =
    record->token != LG_RENDERER_FRAME_TOKEN_NONE &&
    ((record->readyMask & FRAME_TIMING_RENDER_READY) ||
     record->token >= l_frameTiming.retireToken);
  if (unlikely(recordActive && !l_frameTiming.overflowWarning))
  {
    DEBUG_WARN("Frame timing record pool exhausted; samples will be lost");
    l_frameTiming.overflowWarning = true;
  }
  *record = (struct FrameTimingRecord) { .token = token };
  LG_UNLOCK(l_frameTiming.lock);
  return token;
}

static void frameTimingCancel(LG_RendererFrameToken token)
{
  INTERLOCKED_SECTION(l_frameTiming.lock, {
    struct FrameTimingRecord * record = frameTimingRecord(token);
    if (record->token == token)
      *record = (struct FrameTimingRecord) {};
  });
}

static void frameTimingQueue(LG_RendererFrameToken token, uint64_t frameSerial,
    const LG_TransportFrameTiming * timing, uint64_t importTime,
    uint64_t importWaitTime, uint64_t dispatchStart, uint64_t queueStart)
{
  INTERLOCKED_SECTION(l_frameTiming.lock, {
    struct FrameTimingRecord * record = frameTimingRecord(token);
    if (record->token == token)
    {
      const uint64_t elapsed   = queueStart > dispatchStart ?
        queueStart - dispatchStart : 0;
      const uint64_t accounted =
        frameTimingAdd(importTime, importWaitTime);
      record->importTime             = importTime;
      record->importWaitTime         = importWaitTime;
      record->dispatchTime           = elapsed > accounted ?
        elapsed - accounted : 0;
      record->queueStart             = queueStart;
      record->frameSerial            = frameSerial;
      record->scheduleGeneration     = timing->scheduleGeneration;
      record->scheduleEpoch          = timing->scheduleEpoch;
      record->scheduleDeadlineSerial = timing->scheduleDeadlineSerial;
      record->phaseValid             = timing->phaseValid;
      if (record->timestamp < queueStart)
        record->timestamp = queueStart;
    }
  });

  atomic_store_explicit(
      &l_frameTiming.queuedToken, token, memory_order_release);
}

static LG_RendererFrameToken frameTimingQueuedToken(void)
{
  return atomic_load_explicit(
      &l_frameTiming.queuedToken, memory_order_acquire);
}

static void frameTimingFinishFrame(LG_RendererFrameToken token,
    const LG_TransportFrameTiming * timing)
{
  const uint64_t timestamp = nanotime();

  INTERLOCKED_SECTION(l_frameTiming.lock, {
    struct FrameTimingRecord * record = frameTimingRecord(token);
    if (record->token == token)
    {
      if (token < l_frameTiming.retireToken &&
          !(record->readyMask & FRAME_TIMING_RENDER_READY))
        *record = (struct FrameTimingRecord) {};
      else
      {
        record->producerValid   = timing->valid;
        record->captureTime     = timing->captureTime;
        record->postProcessTime = timing->postProcessTime;
        record->copyTime        = timing->copyTime;
        record->readyTime       = timing->readyTime;
        record->holdTime        = timing->holdTime;
        record->readyLeadTime   = timing->readyLeadTime;
        record->providerValid   = timing->providerValid;
        record->receiveTime     = timing->receiveTime;
        record->providerPrepareTime = timing->prepareTime;
        if (record->timestamp < timestamp)
          record->timestamp = timestamp;
        record->readyMask      |= FRAME_TIMING_FRAME_READY;
      }
    }
  });
}

static void frameTimingFinishRender(const LG_RendererFrameTiming * timing,
    uint64_t prepareStart, uint64_t prepareTime, uint64_t timestamp,
    LG_RendererFrameToken cadenceToken)
{
  uint64_t feedbackFrameSerial = 0;
  uint64_t feedbackQueueStart  = 0;
  uint32_t feedbackGeneration  = 0;
  uint32_t feedbackEpoch       = 0;
  uint32_t feedbackDeadline    = 0;
  bool     feedbackValid       = false;

  LG_LOCK(l_frameTiming.lock);
  if (l_frameTiming.retireToken <= timing->frameToken)
    l_frameTiming.retireToken = timing->frameToken + 1;

  struct FrameTimingRecord * record = frameTimingRecord(timing->frameToken);
  if (record->token == timing->frameToken)
  {
    record->prepareStart = prepareStart;
    record->prepareTime  = prepareTime;
    if (record->timestamp < timestamp)
      record->timestamp = timestamp;
    record->setupTime       = timing->setupTime;
    record->effectsTime     = timing->effectsTime;
    record->desktopTime     = timing->desktopTime;
    record->composeTime     = timing->composeTime;
    record->swapTime        = timing->swapTime;
    record->presentDeadline = timestamp + FRAME_TIMING_PRESENT_TIMEOUT_NS;
    if (!timing->presentTracked &&
        !(record->readyMask & FRAME_TIMING_PRESENT_READY))
    {
      record->presentTime  = 0;
      record->presentValid = false;
      record->readyMask   |= FRAME_TIMING_PRESENT_READY;
    }
    record->readyMask |= FRAME_TIMING_RENDER_READY;

    record->transportValid = record->phaseValid &&
      timing->frameToken == cadenceToken;

    feedbackFrameSerial = record->frameSerial;
    feedbackGeneration  = record->scheduleGeneration;
    feedbackEpoch       = record->scheduleEpoch;
    feedbackDeadline    = record->scheduleDeadlineSerial;
    feedbackValid       = record->transportValid;
    feedbackQueueStart  = record->queueStart;

    if (unlikely(
        l_frameTiming.publishCount == FRAME_TIMING_RECORD_COUNT))
    {
      if (!l_frameTiming.overflowWarning)
      {
        DEBUG_WARN("Frame timing publish queue exhausted; sample lost");
        l_frameTiming.overflowWarning = true;
      }
      *record = (struct FrameTimingRecord) {};
    }
    else
    {
      l_frameTiming.publishToken[l_frameTiming.publishWrite] =
        timing->frameToken;
      l_frameTiming.publishWrite =
        (l_frameTiming.publishWrite + 1) % FRAME_TIMING_RECORD_COUNT;
      ++l_frameTiming.publishCount;
    }
  }
  LG_UNLOCK(l_frameTiming.lock);

  if (g_state.jitRender && feedbackValid && feedbackFrameSerial &&
      feedbackGeneration && feedbackEpoch && feedbackDeadline &&
      feedbackQueueStart && prepareStart >= feedbackQueueStart)
  {
    frameScheduler_feedback(
        feedbackFrameSerial, feedbackGeneration, feedbackEpoch,
        feedbackDeadline, prepareStart - feedbackQueueStart);
  }
}

static void frameTimingPublishReady(void)
{
  struct FrameTimingRecord ready[FRAME_TIMING_PUBLISH_BATCH_SIZE];
  unsigned                 readyCount = 0;

  LG_LOCK(l_frameTiming.lock);
  const uint64_t now = nanotime();
  while (readyCount < FRAME_TIMING_PUBLISH_BATCH_SIZE &&
      l_frameTiming.publishCount)
  {
    const LG_RendererFrameToken token =
      l_frameTiming.publishToken[l_frameTiming.publishRead];
    struct FrameTimingRecord * record = frameTimingRecord(token);

    if (record->token != token ||
        !(record->readyMask & FRAME_TIMING_RENDER_READY))
    {
      l_frameTiming.publishRead =
        (l_frameTiming.publishRead + 1) % FRAME_TIMING_RECORD_COUNT;
      --l_frameTiming.publishCount;
      continue;
    }

    if (!(record->readyMask & FRAME_TIMING_FRAME_READY))
      break;

    if (!(record->readyMask & FRAME_TIMING_PRESENT_READY))
    {
      if (!record->presentDeadline || now < record->presentDeadline)
        break;

      record->presentTime  = 0;
      record->presentValid = false;
      record->readyMask   |= FRAME_TIMING_PRESENT_READY;
    }

    ready[readyCount++] = *record;
    *record = (struct FrameTimingRecord) {};
    l_frameTiming.publishRead =
      (l_frameTiming.publishRead + 1) % FRAME_TIMING_RECORD_COUNT;
    --l_frameTiming.publishCount;
  }
  LG_UNLOCK(l_frameTiming.lock);

  for (unsigned i = 0; i < readyCount; ++i)
  {
    const struct FrameTimingRecord * record    = &ready[i];
    const uint64_t                   queueTime =
      record->prepareStart > record->queueStart ?
      record->prepareStart - record->queueStart : 0;
    const uint64_t                   providerAccounted =
      record->providerValid ?
        frameTimingAdd(
          record->receiveTime, record->providerPrepareTime) : 0;
    const uint64_t                   transportAccounted =
      frameTimingAdd(frameTimingAdd(frameTimingAdd(providerAccounted,
            record->importTime), record->dispatchTime), queueTime);
    const uint64_t                   transportTime =
      record->readyLeadTime > transportAccounted ?
      record->readyLeadTime - transportAccounted : 0;
    uint32_t                         validMask =
      OVERLAY_FRAME_TIMING_VALID_ALL;
    if (!record->producerValid)
      validMask &= ~OVERLAY_FRAME_TIMING_VALID_PRODUCER;
    if (!record->producerValid || !record->transportValid)
      validMask &= ~OVERLAY_FRAME_TIMING_VALID_TRANSPORT;
    if (!record->providerValid)
      validMask &= ~OVERLAY_FRAME_TIMING_VALID_PROVIDER;
    if (!record->presentValid)
      validMask &= ~OVERLAY_FRAME_TIMING_VALID_PRESENT;

    const OverlayFrameTiming         timing = {
      .timestamp   = record->timestamp,
      .validMask   = validMask,
      .capture     = record->captureTime     * 1e-6f,
      .postProcess = record->postProcessTime * 1e-6f,
      .copy        = record->copyTime        * 1e-6f,
      .ready       = record->readyTime       * 1e-6f,
      .hold        = record->holdTime        * 1e-6f,
      .transport   = transportTime           * 1e-6f,
      .receive     = record->receiveTime     * 1e-6f,
      .providerPrepare = record->providerPrepareTime * 1e-6f,
      .import      = frameTimingAdd(record->importTime,
        record->producerValid ? 0 : record->importWaitTime) * 1e-6f,
      .dispatch    = record->dispatchTime    * 1e-6f,
      .queue       = queueTime               * 1e-6f,
      .prepare     = record->prepareTime     * 1e-6f,
      .setup       = record->setupTime       * 1e-6f,
      .effects     = record->effectsTime     * 1e-6f,
      .desktop     = record->desktopTime     * 1e-6f,
      .compose     = record->composeTime     * 1e-6f,
      .swap        = record->swapTime        * 1e-6f,
      .present     = record->presentTime     * 1e-6f,
    };
    ringbuffer_push(g_state.frameLatency, &timing);
  }
}

static void preSwapCallback(void * udata)
{
  (void)udata;

#ifdef ENABLE_TESTS
  if (!l_testCapture.enabled || l_testCapture.complete)
    return;

  const uint64_t serial =
    atomic_load_explicit(&l_testFrameSerial, memory_order_acquire);
  if (serial < l_testCapture.targetSerial)
    return;

  if (l_testCapture.lastSerial != serial)
  {
    l_testCapture.lastSerial    = serial;
    l_testCapture.stableRenders = 0;
    return;
  }

  if (l_testCapture.stableRenders++ < l_testCapture.delay)
    return;

  l_testCapture.complete = true;
  LG_RendererCapture capture;
  if (!g_state.lgr->ops.capture ||
      !RENDERER(capture, &capture))
  {
    DEBUG_ERROR("The selected renderer cannot capture its framebuffer");
    app_setState(APP_STATE_SHUTDOWN);
    return;
  }

  const FrameType sourceType =
    atomic_load_explicit(&l_testFrameType, memory_order_acquire);
  const LG_TestCaptureHeader header = {
    .magic         = LG_TEST_CAPTURE_MAGIC,
    .version       = LG_TEST_CAPTURE_VERSION,
    .headerSize    = sizeof(header),
    .frameSerial   = serial,
    .sourceType    = sourceType,
    .captureFormat = capture.format,
    .width         = capture.width,
    .height        = capture.height,
    .stride        = capture.stride,
    .flags         = (capture.hdr       ? LG_TEST_CAPTURE_HDR        : 0) |
                     (capture.hdrPQ     ? LG_TEST_CAPTURE_HDR_PQ     : 0) |
                     (capture.nativeHDR ? LG_TEST_CAPTURE_NATIVE_HDR : 0) |
                     LG_TEST_CAPTURE_BOTTOM_UP,
    .dataSize      = capture.dataSize,
  };

  FILE * file = fopen(l_testCapture.path, "wb");
  bool written = false;
  if (file)
  {
    written =
      fwrite(&header, sizeof(header), 1, file) == 1 &&
      fwrite(capture.data, capture.dataSize, 1, file) == 1;
    if (fclose(file) != 0)
      written = false;
  }
  free(capture.data);

  if (!written)
    DEBUG_ERROR("Failed to write test capture to: %s", l_testCapture.path);
  else
    DEBUG_INFO("Wrote test capture for frame %lu to: %s",
        serial, l_testCapture.path);
  app_setState(APP_STATE_SHUTDOWN);
#endif
}

static uint64_t cursorRepaintPeriod(void)
{
  uint64_t period = g_state.overlayFrameTime;
  uint64_t outputPeriod;
  if (g_state.ds->getFramePeriod &&
      g_state.ds->getFramePeriod(&outputPeriod) && outputPeriod)
    period = outputPeriod;

  if (overlaySplash_isFading())
    period = max(period, g_state.overlayFrameTime);

  return period;
}

static bool cursorRepaintNeeded(void)
{
  LG_LOCK(l_cursorRepaint.lock);
  const bool result =
    l_cursorRepaint.requestedSerial != l_cursorRepaint.presentedSerial &&
    !overlaySplash_isFading();
  LG_UNLOCK(l_cursorRepaint.lock);
  return result;
}

static void cursorRepaintRequest(void)
{
  LG_LOCK(l_cursorRepaint.lock);
  const bool wasDirty =
    l_cursorRepaint.requestedSerial != l_cursorRepaint.presentedSerial;
  ++l_cursorRepaint.requestedSerial;
  LG_UNLOCK(l_cursorRepaint.lock);

  if (!g_state.jitRender && !wasDirty)
    lgSignalEvent(e_cursorRepaint);
}

static bool queueCursorRedraw(void)
{
  if (!atomic_load_explicit(&g_cursor.redraw, memory_order_acquire))
    return false;

  const bool inputAvailable = lgInput_available();
  LG_LOCK(g_state.videoSourceLock);
  if (!atomic_exchange_explicit(
        &g_cursor.redraw, false, memory_order_acq_rel))
  {
    LG_UNLOCK(g_state.videoSourceLock);
    return false;
  }

  const LG_VideoSource source = atomic_load_explicit(
      &g_state.videoSourceApplied, memory_order_acquire);
  const uint64_t generation = atomic_load_explicit(
      &g_state.videoSourceAppliedGeneration, memory_order_acquire);
  if (source <= LG_VIDEO_SOURCE_NONE || source >= LG_VIDEO_SOURCE_COUNT)
  {
    LG_UNLOCK(g_state.videoSourceLock);
    return false;
  }

  const struct VideoSourceState * state = &g_state.videoSource[source];
  const bool valid = state->cursorStateValid &&
    atomic_load_explicit(&state->generation, memory_order_acquire) ==
      generation;
  const bool visible = state->cursorVisible &&
    (source == LG_VIDEO_SOURCE_FALLBACK ||
      g_cursor.draw || !inputAvailable);
  const int x  = state->cursorX;
  const int y  = state->cursorY;
  const int hx = state->cursorHX;
  const int hy = state->cursorHY;
  if (!valid)
  {
    LG_UNLOCK(g_state.videoSourceLock);
    return false;
  }

  renderQueue_sourceCursorState(renderQueueSource(source), generation,
      visible, x, y, hx, hy);
  LG_UNLOCK(g_state.videoSourceLock);
  return true;
}

static uint64_t cursorRepaintRenderBegin(bool * cursorWake)
{
  LG_LOCK(l_cursorRepaint.lock);
  const uint64_t serial = l_cursorRepaint.requestedSerial;
  l_cursorRepaint.rendering = true;

  *cursorWake = l_cursorRepaint.wakeArmed;
  if (l_cursorRepaint.wakeArmed)
    l_cursorRepaint.wakeArmed = false;

  LG_UNLOCK(l_cursorRepaint.lock);
  return serial;
}

static void cursorRepaintRenderEnd(
    uint64_t serial, uint64_t renderTime, bool success, bool cursorOnly)
{
  LG_LOCK(l_cursorRepaint.lock);
  if (success)
  {
    l_cursorRepaint.presentedSerial      = serial;
    l_cursorRepaint.lastRenderTime       = renderTime;
    l_cursorRepaint.lastRenderCursorOnly = cursorOnly;
  }
  l_cursorRepaint.rendering = false;

  const bool wake = success && !g_state.jitRender &&
    l_cursorRepaint.requestedSerial != l_cursorRepaint.presentedSerial;
  LG_UNLOCK(l_cursorRepaint.lock);

  if (wake)
    lgSignalEvent(e_cursorRepaint);
}

static int cursorRepaintThread(void * unused)
{
  while (app_getState() != APP_STATE_SHUTDOWN)
  {
    lgWaitEvent(e_cursorRepaint, TIMEOUT_INFINITE);

    while (app_getState() != APP_STATE_SHUTDOWN)
    {
      uint64_t waitTime = 0;

      LG_LOCK(l_cursorRepaint.lock);
      if (l_cursorRepaint.requestedSerial ==
            l_cursorRepaint.presentedSerial ||
          l_cursorRepaint.rendering || l_cursorRepaint.wakeArmed)
      {
        LG_UNLOCK(l_cursorRepaint.lock);
        break;
      }

      const uint64_t now    = nanotime();
      const uint64_t period = cursorRepaintPeriod();
      /* Give an on-rate source frame enough time to absorb this cursor update.
       * Cursor-only rendering retains the full output cadence once needed. */
      const uint64_t grace =
        l_cursorRepaint.lastRenderCursorOnly ? 0 : period / 4;
      const uint64_t deadline =
        l_cursorRepaint.lastRenderTime + period + grace;
      if (l_cursorRepaint.lastRenderTime && now < deadline)
        waitTime = deadline - now;
      else
      {
        l_cursorRepaint.wakeArmed = true;
        app_invalidateWindow(false);
      }
      LG_UNLOCK(l_cursorRepaint.lock);

      if (!waitTime)
        break;

      struct timespec deadlineTime;
      clock_gettime(CLOCK_MONOTONIC, &deadlineTime);
      tsAdd(&deadlineTime, waitTime);
      lgWaitEventAbs(e_cursorRepaint, &deadlineTime);
    }
  }

  return 0;
}

static int renderThread(void * unused)
{
  if (!RENDERER(renderStartup, g_state.useDMA))
  {
    DEBUG_ERROR("EGL render failed to start");
    app_setState(APP_STATE_SHUTDOWN);

    /* unblock threads waiting on the condition */
    lgSignalEvent(e_startup);
    return 1;
  }

  if (!g_state.lgr->ops.supports ||
      !RENDERER(supports, LG_SUPPORTS_DMABUF))
    g_state.useDMA = false;

  /* start up the fps timer */
  LGTimer * fpsTimer;
  if (!lgCreateTimer(500, fpsTimerFn, NULL, &fpsTimer))
  {
    DEBUG_ERROR("Failed to create the fps timer");
    return 1;
  }

  app_initOverlays();
  LGTimer * tickTimer;
  if (!lgCreateTimer(1000 / TICK_RATE, tickTimerFn, NULL, &tickTimer))
  {
    lgTimerDestroy(fpsTimer);
    DEBUG_ERROR("Failed to create the tick timer");
    return 1;
  }

  LG_LOCK_INIT(g_state.lgrLock);

  /* signal to other threads that the renderer is ready */
  lgSignalEvent(e_startup);

  struct timespec time;
  clock_gettime(CLOCK_MONOTONIC, &time);

  while(likely(app_getState() != APP_STATE_SHUTDOWN))
  {
    LG_RendererFrameToken cadenceToken = LG_RENDERER_FRAME_TOKEN_NONE;

    if (g_state.jitRender)
    {
      const LG_DSWaitFrameResult  waitResult = g_state.ds->waitFrame();
      if (waitResult & LG_DS_WAIT_FRAME_CADENCE)
        frameScheduler_observeCadence();

      const LG_RendererFrameToken queuedAtWake =
        waitResult == LG_DS_WAIT_FRAME_CADENCE ?
          frameTimingQueuedToken() : LG_RENDERER_FRAME_TOKEN_NONE;
      const bool                  forceRender =
        waitResult & LG_DS_WAIT_FRAME_FORCE_RENDER;
      app_handleRenderEvent(microtime());

      const uint64_t pending       =
        atomic_load_explicit(&g_state.pendingCount, memory_order_acquire);
      const bool     overlayNeeded = app_overlayNeedsRender();
      uint64_t       outputPeriod  = 0;
      const bool     periodKnown   = overlayNeeded &&
        g_state.ds->getFramePeriod &&
        g_state.ds->getFramePeriod(&outputPeriod);
      const uint64_t elapsed       = g_state.lastRenderTimeValid ?
        nanotime() - g_state.lastRenderTime : 0;
      const bool     overlayRender = overlayNeeded &&
        (!g_state.lastRenderTimeValid || !periodKnown ||
         elapsed + outputPeriod >= g_state.overlayFrameTime);
      const bool     clientWake    = lgResetEvent(g_state.frameEvent);
      const bool     cursorRender  = cursorRepaintNeeded();

      if (!clientWake && !forceRender && !pending && !overlayRender &&
          !cursorRender)
      {
        if (g_state.ds->skipFrame)
          g_state.ds->skipFrame();
        continue;
      }

      if (pending > 0)
      {
        atomic_fetch_sub(&g_state.pendingCount, 1);
        if (!clientWake)
          cadenceToken = queuedAtWake;
      }
    }
    else if (g_params.fpsMin != 0)
    {
      app_handleRenderEvent(microtime());
      lgWaitEventAbs(g_state.frameEvent, &time);
    }

    bool           cursorWake;
    const uint64_t cursorSerial = cursorRepaintRenderBegin(&cursorWake);
    const uint64_t renderStart  = nanotime();

    frameTimingPublishReady();

    int resize = atomic_load(&g_state.lgrResize);
    if (unlikely(resize))
    {
      g_state.io->DisplaySize = (ImVec2) {
        .x = g_state.windowW,
        .y = g_state.windowH,
      };
      g_state.io->DisplayFramebufferScale = (ImVec2) {
        .x = g_state.windowScale,
        .y = g_state.windowScale,
      };
      igGetStyle()->FontScaleMain = 1.0f / g_state.windowScale;
    }

    const bool fontDirty  = atomic_exchange(&g_state.fontDirty, false);
    const bool fontUpdate = fontDirty ||
      g_state.fontScale != g_state.windowScale;
    if (unlikely(fontUpdate))
    {
      if (!util_buildUIFontAtlas(g_state.io->Fonts,
            g_params.uiSize * g_state.windowScale, &g_state.fontLarge))
        DEBUG_FATAL("Failed to build font atlas: %s (%s)", g_params.uiFont, g_state.fontName);

      if (g_state.lgr && !RENDERER(onFontUpdate))
        DEBUG_FATAL("Failed to upload the ImGui font atlas");

      g_state.fontScale = g_state.windowScale;
    }

    if (unlikely(resize || fontUpdate))
      cadenceToken = LG_RENDERER_FRAME_TOKEN_NONE;

    if (unlikely(resize))
    {
      if (g_state.lgr)
        RENDERER(onResize, g_state.windowW, g_state.windowH,
            g_state.windowScale, g_state.dstRect, g_params.winRotate);
      atomic_compare_exchange_weak(&g_state.lgrResize, &resize, 0);
    }

    const uint64_t prepareStart = nanotime();

    queueCursorRedraw();

    LG_LOCK(g_state.lgrLock);

    const bool queueFull = renderQueue_process();

    if (g_state.videoGeometryDirty)
    {
      g_state.videoGeometryDirty = false;
      LG_UNLOCK(g_state.lgrLock);
      core_updatePositionInfo();
      LG_LOCK(g_state.lgrLock);
    }

    int sourceResize = atomic_load(&g_state.lgrResize);
    if (unlikely(sourceResize))
    {
      RENDERER(onResize, g_state.windowW, g_state.windowH,
          g_state.windowScale, g_state.dstRect, g_params.winRotate);
      atomic_compare_exchange_weak(
          &g_state.lgrResize, &sourceResize, 0);
    }

    const LG_RendererFrameToken frameTokenLimit = frameTimingQueuedToken();

    const bool     windowInvalid =
      atomic_exchange(&g_state.invalidateWindow, false);
    const bool     overlayFull   = app_overlayNeedsFullRender();
    const bool     invalidate    = queueFull || windowInvalid || overlayFull;
    const uint64_t prepareTime   = nanotime() - prepareStart;

    if (unlikely(invalidate))
      cadenceToken = LG_RENDERER_FRAME_TOKEN_NONE;

    LG_RendererFrameTiming rendererTiming = {};
    if (unlikely(!RENDERER(render, g_params.winRotate, frameTokenLimit,
          invalidate, preSwapCallback, NULL, &rendererTiming)))
    {
      LG_UNLOCK(g_state.lgrLock);
      cursorRepaintRenderEnd(cursorSerial, renderStart, false, false);
      break;
    }
    const uint64_t renderEnd = nanotime();
    LG_UNLOCK(g_state.lgrLock);
    renderQueue_presented();
    cursorRepaintRenderEnd(cursorSerial, renderStart, true,
        cursorWake &&
        rendererTiming.frameToken == LG_RENDERER_FRAME_TOKEN_NONE);

    if (!g_state.jitRender)
      frameScheduler_observeCadence();

    if (rendererTiming.frameToken != LG_RENDERER_FRAME_TOKEN_NONE)
      frameTimingFinishRender(
          &rendererTiming, prepareStart, prepareTime, renderEnd,
          cadenceToken);
    frameTimingPublishReady();

    const uint64_t t     = nanotime();
    const uint64_t delta = t - g_state.lastRenderTime;

    g_state.lastRenderTime = t;
    atomic_fetch_add_explicit(&g_state.renderCount, 1, memory_order_relaxed);

    if (!g_state.jitRender && g_params.fpsMin != 0)
    {
      /* A frame-driven swap also satisfies the minimum render rate. */
      clock_gettime(CLOCK_MONOTONIC, &time);
      tsAdd(&time, app_overlayNeedsRender() ?
          g_state.overlayFrameTime : g_state.frameTime);
    }

    if (likely(g_state.lastRenderTimeValid))
    {
      const float fdelta = (float)delta / 1e6f;
      ringbuffer_push(g_state.renderTimings, &fdelta);
    }
    g_state.lastRenderTimeValid = true;

    const uint64_t now = microtime();
    if (unlikely(
          !g_state.resizeDone &&
          g_state.resizeTimeout < now))
    {
      if (g_params.autoResize)
      {
        g_state.ds->setWindowSize(
          g_state.dstRect.w,
          g_state.dstRect.h
        );
      }
      g_state.resizeDone = true;
    }
  }

  app_setState(APP_STATE_SHUTDOWN);

  lgTimerDestroy(tickTimer);
  lgTimerDestroy(fpsTimer);

  if (g_state.transport.handle &&
      g_state.transport.ops->sessionValid(g_state.transport.handle))
  {
    lgInput_setTransport(NULL, NULL);
    lgAudio_setTransport(NULL, NULL);
    clipboard_setTransport(NULL, NULL);
  }
  else
  {
    lgInput_dropTransport();
    lgAudio_dropTransport();
    clipboard_dropTransport();
  }

  core_stopVideoThreads();

  if (g_state.videoOps && g_state.videoOps->type == LG_VIDEO_TYPE_FRAME &&
      g_state.videoOps->frame->detachRenderer)
    g_state.videoOps->frame->detachRenderer(g_state.transport.handle);
  else if (g_state.videoOps &&
      g_state.videoOps->type == LG_VIDEO_TYPE_SW_SURFACE)
  {
    lgSwSurface_setActive(g_state.videoOps->swSurface,
        g_state.transport.handle, false, NULL, NULL);
    g_state.videoOps->swSurface->detach(g_state.transport.handle);
  }

  RENDERER(deinitialize);
  g_state.lgr = NULL;
  LG_LOCK_FREE(g_state.lgrLock);

  return 0;
}


int main_cursorThread(void * unused)
{
  LG_RendererCursor        cursorType = LG_CURSOR_COLOR;
  struct VideoSourceState * source =
    &g_state.videoSource[LG_VIDEO_SOURCE_PRIMARY];

  lgWaitEvent(e_startup, TIMEOUT_INFINITE);

  // subscribe to the pointer queue
  while(app_getState() == APP_STATE_RUNNING &&
      !atomic_load_explicit(
        &g_state.stopVideoThreads, memory_order_acquire))
  {
    LG_TransportPointer pointer;
    const LG_TransportStatus status = g_state.videoOps->frame->nextPointer(
        g_state.transport.handle, &pointer);
    if (status != LG_TRANSPORT_OK)
    {
      if (videoStatusRetry(status,
            g_state.videoOps->frame->setStatusListener,
            atomic_load_explicit(
              &g_state.videoPointerAvailable, memory_order_acquire)))
      {
        if (!atomic_load_explicit(
              &g_state.stopVideoThreads, memory_order_acquire) &&
            queueCursorRedraw())
          cursorRepaintRequest();
        continue;
      }

      if (status == LG_TRANSPORT_DISCONNECTED)
      {
        lgInput_dropTransport();
        lgAudio_dropTransport();
        clipboard_dropTransport();
        primaryLost();
      }
      else
      {
        DEBUG_ERROR("Pointer transport failed with status %d", status);
        primaryWorkerFailed();
      }
      break;
    }

    const bool inputAvailable = lgInput_available();
    if (!videoPayloadAccept(
          &g_state.videoPointerAvailable, &g_state.videoPointerEpoch,
          pointer.epoch,
          g_state.videoOps->frame->setStatusListener != NULL, 0))
    {
      g_state.videoOps->frame->releasePointer(
          g_state.transport.handle, &pointer);
      continue;
    }
    LG_LOCK(g_state.videoSourceLock);
    const uint64_t sourceGeneration = atomic_load_explicit(
        &source->generation, memory_order_acquire);
    if (!sourceGeneration)
    {
      LG_UNLOCK(g_state.videoSourceLock);
      videoPayloadRelease();
      g_state.videoOps->frame->releasePointer(
          g_state.transport.handle, &pointer);
      continue;
    }

    const bool wasRendered = source->cursorStateValid &&
      source->cursorVisible && (g_cursor.draw || !inputAvailable);
    bool hotspotChanged = false;

    if (pointer.flags & LG_TRANSPORT_POINTER_VISIBLE_VALID)
      source->cursorVisible =
        pointer.flags & LG_TRANSPORT_POINTER_VISIBLE;

    if (pointer.flags & LG_TRANSPORT_POINTER_SHAPE)
    {
      const int oldHX = source->cursorHX;
      const int oldHY = source->cursorHY;

      switch (pointer.type)
      {
        case CURSOR_TYPE_COLOR       : cursorType = LG_CURSOR_COLOR       ; break;
        case CURSOR_TYPE_MONOCHROME  : cursorType = LG_CURSOR_MONOCHROME  ; break;
        case CURSOR_TYPE_MASKED_COLOR: cursorType = LG_CURSOR_MASKED_COLOR; break;
        default:
          LG_UNLOCK(g_state.videoSourceLock);
          videoPayloadRelease();
          DEBUG_ERROR("Invalid cursor type");
          g_state.videoOps->frame->releasePointer(
              g_state.transport.handle, &pointer);
          continue;
      }

      hotspotChanged =
        source->cursorHX != pointer.hx || source->cursorHY != pointer.hy;
      source->cursorHX = pointer.hx;
      source->cursorHY = pointer.hy;

      if (hotspotChanged && source->cursorStateValid &&
          !(pointer.flags & LG_TRANSPORT_POINTER_POSITION))
      {
        source->cursorX += oldHX - pointer.hx;
        source->cursorY += oldHY - pointer.hy;
      }
    }

    const bool whiteLevelChanged =
      (pointer.flags & LG_TRANSPORT_POINTER_VISIBLE_VALID) &&
      pointer.sdrWhiteLevel &&
      pointer.sdrWhiteLevel != source->cursorWhiteLevel;
    if (whiteLevelChanged)
      source->cursorWhiteLevel = pointer.sdrWhiteLevel;

    if (pointer.flags & LG_TRANSPORT_POINTER_POSITION)
    {
      source->cursorX          = pointer.x;
      source->cursorY          = pointer.y;
      source->cursorStateValid = true;
    }

    const bool sourceApplied = atomic_load_explicit(
        &g_state.videoSourceApplied, memory_order_acquire) ==
      LG_VIDEO_SOURCE_PRIMARY && atomic_load_explicit(
        &g_state.videoSourceAppliedGeneration, memory_order_acquire) ==
      sourceGeneration;
    if (sourceApplied)
      atomic_exchange_explicit(
          &g_cursor.redraw, false, memory_order_acq_rel);

    const bool valid        = source->cursorStateValid;
    const bool guestVisible = source->cursorVisible;
    const bool visible      = guestVisible &&
      (g_cursor.draw || !inputAvailable);
    const int x  = source->cursorX;
    const int y  = source->cursorY;
    const int hx = source->cursorHX;
    const int hy = source->cursorHY;
    const bool isRendered = valid && visible;
    bool wasValid = false;
    if (sourceApplied)
    {
      wasValid               = g_cursor.guest.valid;
      g_cursor.guest.visible = guestVisible;
      g_cursor.guest.x       = x;
      g_cursor.guest.y       = y;
      g_cursor.guest.hx      = hx;
      g_cursor.guest.hy      = hy;
      g_cursor.guest.valid   = valid;
    }
    if (pointer.flags & LG_TRANSPORT_POINTER_SHAPE)
      renderQueue_sourceCursorImage(RENDER_QUEUE_SOURCE_PRIMARY,
          sourceGeneration, cursorType, pointer.width, pointer.height,
          pointer.pitch, pointer.shape);

    if (pointer.flags & LG_TRANSPORT_POINTER_COLOR_TRANSFORM)
      renderQueue_sourceCursorColorTransform(RENDER_QUEUE_SOURCE_PRIMARY,
          sourceGeneration, pointer.colorTransform);

    if (whiteLevelChanged)
      renderQueue_sourceCursorWhiteLevel(RENDER_QUEUE_SOURCE_PRIMARY,
          sourceGeneration, pointer.sdrWhiteLevel);

    if (valid)
      renderQueue_sourceCursorState(RENDER_QUEUE_SOURCE_PRIMARY,
          sourceGeneration, visible, x, y, hx, hy);
    LG_UNLOCK(g_state.videoSourceLock);

    if (sourceApplied)
    {
      if (!wasValid && valid && core_inputEnabled())
        core_alignToGuest();
      if ((pointer.flags & LG_TRANSPORT_POINTER_POSITION) || hotspotChanged)
        core_handleGuestMouseUpdate();
      app_updateMouseState();
    }

    const bool contentChanged =
      (pointer.flags & (LG_TRANSPORT_POINTER_SHAPE |
        LG_TRANSPORT_POINTER_COLOR_TRANSFORM)) || whiteLevelChanged;
    if (sourceApplied &&
        !atomic_load_explicit(&g_state.stopVideo, memory_order_acquire) &&
        (wasRendered != isRendered ||
         ((wasRendered || isRendered) &&
          (g_params.mouseRedraw || contentChanged))))
      cursorRepaintRequest();

    videoPayloadRelease();
    g_state.videoOps->frame->releasePointer(
        g_state.transport.handle, &pointer);
  }

  if (g_state.videoOps->frame->stopPointer)
    g_state.videoOps->frame->stopPointer(g_state.transport.handle);

  return 0;
}

int main_frameThread(void * unused)
{
  uint64_t          frameSerial   = 0;
  uint32_t          formatVersion = 0;
  LG_RendererFormat rendererFormat;
  uint64_t          sourceGeneration = 0;

  if (g_state.useDMA)
    DEBUG_INFO("Using DMA buffer support");

  lgWaitEvent(e_startup, TIMEOUT_INFINITE);
  if (app_getState() != APP_STATE_RUNNING)
  {
    if (g_state.videoOps->frame->stopFrame)
      g_state.videoOps->frame->stopFrame(g_state.transport.handle);
    return 0;
  }

  while(app_getState() == APP_STATE_RUNNING &&
      !atomic_load_explicit(
        &g_state.stopVideoThreads, memory_order_acquire))
  {
    LG_TransportFrame frame;
    const LG_TransportStatus status = g_state.videoOps->frame->nextFrame(
        g_state.transport.handle, g_state.useDMA, &frame);
    if (status != LG_TRANSPORT_OK)
    {
      if (videoStatusRetry(status,
            g_state.videoOps->frame->setStatusListener,
            atomic_load_explicit(
              &g_state.videoFrameAvailable, memory_order_acquire)))
      {
        if (g_state.lgr->ops.onFramePoll)
          RENDERER(onFramePoll);
        continue;
      }
      if (status == LG_TRANSPORT_DISCONNECTED)
      {
        lgInput_dropTransport();
        lgAudio_dropTransport();
        clipboard_dropTransport();
        primaryLost();
      }
      else if (status == LG_TRANSPORT_END)
        primaryWorkerFailed();
      else
      {
        DEBUG_ERROR("Frame transport failed with status %d", status);
        primaryWorkerFailed();
      }
      break;
    }

    const uint64_t currentGeneration = atomic_load_explicit(
        &g_state.videoSource[LG_VIDEO_SOURCE_PRIMARY].generation,
        memory_order_acquire);
    bool sourceChanged;
    if (!videoFramePayloadAccept(&frame, currentGeneration,
          g_state.videoOps->frame->setStatusListener != NULL,
          &sourceGeneration, &frameSerial, &formatVersion, &sourceChanged))
    {
      g_state.videoOps->frame->releaseFrame(
          g_state.transport.handle, &frame);
      continue;
    }
    const uint64_t dispatchStart = nanotime();

    const LG_TransportFrameFormat * format = frame.format;
    if (!format)
    {
      videoPayloadRelease();
      DEBUG_ERROR("Transport returned a frame without format metadata");
      g_state.videoOps->frame->releaseFrame(g_state.transport.handle, &frame);
      primaryWorkerFailed();
      break;
    }
    const bool formatChanged = sourceChanged ||
      !g_state.formatValid || format->version != formatVersion;
    bool rendererSupportsNativeHDR = false;
    if (formatChanged)
    {
      memset(&rendererFormat, 0, sizeof(rendererFormat));
      rendererFormat.type          = format->type;
      rendererFormat.screenWidth   = format->screenWidth;
      rendererFormat.screenHeight  = format->screenHeight;
      rendererFormat.dataWidth     = format->dataWidth;
      rendererFormat.dataHeight    = format->dataHeight;
      rendererFormat.frameWidth    = format->frameWidth;
      rendererFormat.frameHeight   = format->frameHeight;
      rendererFormat.stride        = format->stride;
      rendererFormat.pitch         = format->pitch;
      rendererFormat.hdr           = format->hdr;
      rendererFormat.hdrPQ         = format->hdrPQ;
      rendererFormat.hdrMetadata   = format->hdrMetadata;
      rendererFormat.sdrWhiteLevel = format->sdrWhiteLevel;

      if (rendererFormat.hdrMetadata)
      {
        memcpy(rendererFormat.hdrDisplayPrimary, format->hdrDisplayPrimary,
            sizeof(rendererFormat.hdrDisplayPrimary));
        memcpy(rendererFormat.hdrWhitePoint, format->hdrWhitePoint,
            sizeof(rendererFormat.hdrWhitePoint));
        rendererFormat.hdrMaxDisplayLuminance       =
          format->hdrMaxDisplayLuminance;
        rendererFormat.hdrMinDisplayLuminance       =
          format->hdrMinDisplayLuminance;
        rendererFormat.hdrMaxContentLightLevel      =
          format->hdrMaxContentLightLevel;
        rendererFormat.hdrMaxFrameAverageLightLevel =
          format->hdrMaxFrameAverageLightLevel;
      }

      if (frame.flags & LG_TRANSPORT_FRAME_TRUNCATED)
      {
        DEBUG_BREAK();
        DEBUG_WARN("Transport buffer too small, screen truncated");
        DEBUG_BREAK();
        app_msgBox("Transport buffer too small",
            "The transport buffer is too small for this frame.");
      }

      switch (format->rotation)
      {
        case FRAME_ROT_0  : rendererFormat.rotate = LG_ROTATE_0  ; break;
        case FRAME_ROT_90 : rendererFormat.rotate = LG_ROTATE_90 ; break;
        case FRAME_ROT_180: rendererFormat.rotate = LG_ROTATE_180; break;
        case FRAME_ROT_270: rendererFormat.rotate = LG_ROTATE_270; break;
        default:
          DEBUG_ERROR("Unsupported frame rotation");
          rendererFormat.rotate = LG_ROTATE_0;
          break;
      }
      bool invalid = false;
      switch (format->type)
      {
        case FRAME_TYPE_RGBA:
        case FRAME_TYPE_BGRA:
        case FRAME_TYPE_RGBA10:
          rendererFormat.bpp = 32;
          break;
        case FRAME_TYPE_RGBA16F:
          rendererFormat.bpp = 64;
          break;
        case FRAME_TYPE_BGR_32:
        case FRAME_TYPE_RGB_24:
          rendererFormat.bpp = 24;
          break;
        default:
          invalid = true;
          break;
      }

      if (invalid)
      {
        videoPayloadRelease();
        DEBUG_ERROR("Unsupported frame type");
        g_state.videoOps->frame->releaseFrame(
            g_state.transport.handle, &frame);
        primaryWorkerFailed();
        break;
      }

    }
    if (formatChanged)
    {
      DEBUG_INFO("Format: %s %ux%u (%ux%u) stride:%u pitch:%u rotation:%d hdr:%d pq:%d sdrWhite:%u nits",
          FrameTypeStr[format->type], format->frameWidth, format->frameHeight,
          format->dataWidth, format->dataHeight, format->stride, format->pitch,
          format->rotation, format->hdr ? 1 : 0, format->hdrPQ ? 1 : 0,
          rendererFormat.sdrWhiteLevel);

      LG_LOCK(g_state.lgrLock);
      if (!RENDERER(onFrameFormat, rendererFormat))
      {
        LG_UNLOCK(g_state.lgrLock);
        videoPayloadRelease();
        DEBUG_ERROR("Renderer failed to configure format");
        g_state.videoOps->frame->releaseFrame(
            g_state.transport.handle, &frame);
        primaryWorkerFailed();
        break;
      }
      rendererSupportsNativeHDR = !rendererFormat.hdr ||
        !g_state.lgr->ops.supports || RENDERER(supports,
          rendererFormat.hdrPQ ? LG_SUPPORTS_HDR_PQ : LG_SUPPORTS_HDR_SCRGB);

      struct VideoSourceState * source =
        &g_state.videoSource[LG_VIDEO_SOURCE_PRIMARY];
      atomic_store_explicit(
          &source->width, rendererFormat.screenWidth, memory_order_relaxed);
      atomic_store_explicit(
          &source->height, rendererFormat.screenHeight, memory_order_relaxed);
      atomic_store_explicit(
          &source->rotate, rendererFormat.rotate, memory_order_release);
    }

    uint32_t damageCount = frame.damageRectsCount <=
      LG_TRANSPORT_MAX_DAMAGE_RECTS ? frame.damageRectsCount : 0;
    bool invalidDamage = damageCount != frame.damageRectsCount ||
      (damageCount && !frame.damageRects);
    for (uint32_t i = 0; !invalidDamage && i < damageCount; ++i)
    {
      const FrameDamageRect * rect = &frame.damageRects[i];
      invalidDamage = rect->x > format->frameWidth ||
        rect->y > format->frameHeight ||
        rect->width > format->frameWidth - rect->x ||
        rect->height > format->frameHeight - rect->y;
    }
    if (invalidDamage)
    {
      DEBUG_WARN("Invalid damage rectangles, forcing a full update");
      damageCount = 0;
    }

    const LG_RendererFrameToken frameToken = frameTimingReserve();
    g_state.frameImportTime     = 0;
    g_state.frameImportWaitTime = 0;

    const bool rendererOwnsFrame = frame.dmaFD >= 0 && frame.releaseFn;
    if (!RENDERER(onFrame, frame.framebuffer, frame.dmaFD,
          frame.damageRects, damageCount, frameToken,
          rendererOwnsFrame ? frame.releaseFn     : NULL,
          rendererOwnsFrame ? frame.releaseOpaque : NULL,
          rendererOwnsFrame ? frame.releaseHandle : 0))
    {
      if (formatChanged)
        LG_UNLOCK(g_state.lgrLock);
      videoPayloadRelease();
      frameTimingCancel(frameToken);
      g_state.videoOps->frame->releaseFrame(g_state.transport.handle, &frame);
      DEBUG_ERROR("Renderer onFrame returned failure");
      primaryWorkerFailed();
      break;
    }
    /* A DMA snapshot can complete on the render thread immediately after it
     * is signalled below, so sample producer timing while this lease is still
     * unambiguously owned by the frame thread. */
    LG_TransportFrameTiming timing = {};
    if (g_state.videoOps->frame->getFrameTiming)
      g_state.videoOps->frame->getFrameTiming(
          g_state.transport.handle, &frame, &timing);

    const uint64_t queueStart = nanotime();
    atomic_fetch_add_explicit(&g_state.frameCount, 1, memory_order_relaxed);
    frameTimingQueue(frameToken, frame.serial, &timing,
        g_state.frameImportTime, g_state.frameImportWaitTime,
        dispatchStart, queueStart);

    if (formatChanged)
    {
      g_state.formatValid = true;
      formatVersion       = format->version;
#ifdef ENABLE_TESTS
      atomic_store_explicit(&l_testFrameType, format->type,
          memory_order_release);
#endif
      /* Publish the format only after accepting and timing its first frame.
       * lgrLock prevents the render thread from consuming either update until
       * both are ready. */
      renderQueue_sourceSurfaceFormat(RENDER_QUEUE_SOURCE_PRIMARY,
          sourceGeneration, rendererFormat, rendererSupportsNativeHDR);
    }
#ifdef ENABLE_TESTS
    atomic_store_explicit(&l_testFrameSerial, frame.serial,
        memory_order_release);
#endif

    if (atomic_load_explicit(
          &g_state.videoSource[LG_VIDEO_SOURCE_PRIMARY].generation,
          memory_order_acquire) == sourceGeneration &&
        atomic_load_explicit(
          &g_state.videoFrameAvailable, memory_order_acquire))
    {
      atomic_store_explicit(
          &g_state.videoSource[LG_VIDEO_SOURCE_PRIMARY].ready, true,
          memory_order_release);
      app_useVideoSource(LG_VIDEO_SOURCE_PRIMARY);
    }

    if (formatChanged)
    {
      LG_UNLOCK(g_state.lgrLock);
      if (g_params.autoResize)
        g_state.ds->setWindowSize(rendererFormat.frameWidth,
            rendererFormat.frameHeight);
    }

    if (g_state.jitRender)
    {
      if (atomic_load_explicit(&g_state.pendingCount, memory_order_acquire) < 10)
        atomic_fetch_add_explicit(&g_state.pendingCount, 1,
            memory_order_release);
    }
    else
      lgSignalEvent(g_state.frameEvent);

    if ((frame.flags & LG_TRANSPORT_FRAME_REQUEST_ACTIVATION) &&
        g_params.requestActivation)
      g_state.ds->requestActivation();

    const bool blockScreensaver =
      frame.flags & LG_TRANSPORT_FRAME_BLOCK_SCREENSAVER;
    if (g_params.autoScreensaver &&
        g_state.autoIdleInhibitState != blockScreensaver)
    {
      if (blockScreensaver)
        g_state.ds->inhibitIdle();
      else
        g_state.ds->uninhibitIdle();
      g_state.autoIdleInhibitState = blockScreensaver;
    }

    frameTimingFinishFrame(frameToken, &timing);
    videoPayloadRelease();

    if (!rendererOwnsFrame)
      g_state.videoOps->frame->releaseFrame(g_state.transport.handle, &frame);
  }

  if (app_getState() != APP_STATE_SHUTDOWN)
  {
    if (app_getState() == APP_STATE_RESTART)
      videoSourceInvalidate(LG_VIDEO_SOURCE_PRIMARY);
    else
      atomic_store_explicit(
          &g_state.videoSource[LG_VIDEO_SOURCE_PRIMARY].ready, false,
          memory_order_release);

    if (!fallbackRequestVideo())
      videoSourceShowSplashIfNeeded();
  }

  /* Queue the replacement before releasing desktop snapshots. The existing
   * front buffer remains visible until the render thread draws it or the
   * splash requested above. */
  LG_LOCK(g_state.lgrLock);
  RENDERER(onRestart);
  LG_UNLOCK(g_state.lgrLock);

  /* Renderer reset requests release for every asynchronous DMA snapshot.
   * Drain those requests before the transport unsubscribes or reconnects. */
  if (g_state.videoOps->frame->stopFrame)
    g_state.videoOps->frame->stopFrame(g_state.transport.handle);

  return 0;
}

static RenderQueueSource renderQueueSource(LG_VideoSource source)
{
  switch(source)
  {
    case LG_VIDEO_SOURCE_PRIMARY:
      return RENDER_QUEUE_SOURCE_PRIMARY;

    case LG_VIDEO_SOURCE_FALLBACK:
      return RENDER_QUEUE_SOURCE_FALLBACK;

    case LG_VIDEO_SOURCE_NONE:
    case LG_VIDEO_SOURCE_COUNT:
      break;
  }

  return RENDER_QUEUE_SOURCE_NONE;
}

static void videoSourceBeginLocked(LG_VideoSource source)
{
  struct VideoSourceState * state = &g_state.videoSource[source];
  const uint64_t generation =
    renderQueue_sourceBegin(renderQueueSource(source));

  atomic_store_explicit(&state->ready, false, memory_order_release);
  atomic_store_explicit(
      &state->transitionSerial, 0, memory_order_relaxed);
  atomic_store_explicit(
      &state->transitionPending, false, memory_order_relaxed);
  atomic_store_explicit(&state->appliedWidth, 0, memory_order_relaxed);
  atomic_store_explicit(&state->appliedHeight, 0, memory_order_relaxed);
  atomic_store_explicit(
      &state->appliedRotate, LG_ROTATE_0, memory_order_relaxed);
  atomic_store_explicit(
      &state->generation, generation, memory_order_release);
  state->configurePending = false;
}

static void videoSourceBegin(LG_VideoSource source)
{
  LG_LOCK(g_state.videoSourceLock);
  videoSourceBeginLocked(source);
  LG_UNLOCK(g_state.videoSourceLock);
}

static bool videoSourceInvalidate(LG_VideoSource source)
{
  struct VideoSourceState * state = &g_state.videoSource[source];
  LG_LOCK(g_state.videoSourceLock);
  const uint64_t generation = atomic_exchange_explicit(
      &state->generation, 0, memory_order_acq_rel);
  atomic_store_explicit(&state->ready, false, memory_order_release);
  LG_UNLOCK(g_state.videoSourceLock);
  if (generation)
    renderQueue_sourceInvalidate(renderQueueSource(source), generation);
  return generation != 0;
}

static void videoSourceShowSplashIfNeeded(void)
{
  LG_LOCK(g_state.videoSplashLock);
  bool available;
  for (;;)
  {
    available = false;
    const LG_VideoSource source = atomic_load_explicit(
        &g_state.videoSourceRequested, memory_order_acquire);
    if (source <= LG_VIDEO_SOURCE_NONE || source >= LG_VIDEO_SOURCE_COUNT)
      break;

    const struct VideoSourceState * state = &g_state.videoSource[source];
    const uint64_t generation = atomic_load_explicit(
        &state->generation, memory_order_acquire);
    const bool transitionPending = atomic_load_explicit(
        &state->transitionPending, memory_order_acquire);
    const LG_VideoSource applied = atomic_load_explicit(
        &g_state.videoSourceApplied, memory_order_acquire);
    const uint64_t appliedGeneration = atomic_load_explicit(
        &g_state.videoSourceAppliedGeneration, memory_order_acquire);
    available = generation &&
      ((applied == source && appliedGeneration == generation) ||
       (atomic_load_explicit(&state->ready, memory_order_acquire) &&
        transitionPending));

    if (source == atomic_load_explicit(
          &g_state.videoSourceRequested, memory_order_acquire) &&
        generation == atomic_load_explicit(
          &state->generation, memory_order_acquire))
      break;
  }

  if (!available)
    overlaySplash_show(true);
  LG_UNLOCK(g_state.videoSplashLock);
}

static void videoSourceClearCursor(LG_VideoSource source)
{
  struct VideoSourceState * state = &g_state.videoSource[source];
  LG_LOCK(g_state.videoSourceLock);
  state->cursorStateValid = false;
  state->cursorVisible    = false;
  state->cursorWhiteLevel = 0;
  if (atomic_load_explicit(
        &g_state.videoSourceApplied, memory_order_acquire) == source)
    g_cursor.guest.valid = false;
  renderQueue_sourceClearCursor(renderQueueSource(source));
  LG_UNLOCK(g_state.videoSourceLock);
}

static bool videoComponentStatusChanged(atomic_bool * available,
    atomic_uint_least64_t * epoch, atomic_int * reason,
    const LG_VideoComponentStatus * status)
{
  /* Close the component before changing epochs so a consumer can never pair
   * a newly available state with a payload from the prior endpoint. */
  const bool oldAvailable = atomic_exchange_explicit(
      available, false, memory_order_acq_rel);
  const uint64_t oldEpoch = atomic_exchange_explicit(
      epoch, status->epoch, memory_order_acq_rel);
  atomic_store_explicit(reason, status->reason, memory_order_release);
  atomic_store_explicit(
      available, status->available, memory_order_release);
  return oldAvailable != status->available ||
    oldEpoch != status->epoch;
}

static bool videoComponentPayloadCurrent(const atomic_bool * available,
    const atomic_uint_least64_t * epoch, uint64_t payloadEpoch,
    bool trackEpoch)
{
  if (!atomic_load_explicit(available, memory_order_acquire))
    return false;
  return !trackEpoch || (payloadEpoch && atomic_load_explicit(
        epoch, memory_order_acquire) == payloadEpoch);
}

/* Success retains the payload gate. The caller must release it after every
 * externally visible effect derived from the accepted payload is complete. */
static bool videoPayloadAccept(const atomic_bool * available,
    const atomic_uint_least64_t * epoch, uint64_t payloadEpoch,
    bool trackEpoch, uint64_t sourceGeneration)
{
  LG_LOCK(g_state.videoPayloadLock);
  const bool current = videoComponentPayloadCurrent(
      available, epoch, payloadEpoch, trackEpoch) &&
    (!sourceGeneration || atomic_load_explicit(
      &g_state.videoSource[LG_VIDEO_SOURCE_PRIMARY].generation,
      memory_order_acquire) == sourceGeneration);
  if (!current)
    LG_UNLOCK(g_state.videoPayloadLock);
  return current;
}

static void videoPayloadRelease(void)
{
  LG_UNLOCK(g_state.videoPayloadLock);
}

static bool videoFramePayloadAccept(const LG_TransportFrame * frame,
    uint64_t currentGeneration, bool trackEpoch,
    uint64_t * sourceGeneration, uint64_t * frameSerial,
    uint32_t * formatVersion, bool * sourceChanged)
{
  if (!currentGeneration || !videoPayloadAccept(
        &g_state.videoFrameAvailable, &g_state.videoFrameEpoch,
        frame->epoch, trackEpoch, currentGeneration))
    return false;

  *sourceChanged = *sourceGeneration != currentGeneration;
  if (*sourceChanged)
  {
    *sourceGeneration = currentGeneration;
    *frameSerial       = 0;
    *formatVersion     = 0;
  }

  if (!*sourceChanged && frame->serial == *frameSerial &&
      g_state.formatValid && !frame->scheduleOwner)
  {
    videoPayloadRelease();
    return false;
  }

  *frameSerial = frame->serial;
  return true;
}

static void primaryVideoStatusChanged(void * opaque,
    const LG_VideoStatus * status)
{
  (void)opaque;
  if (!status || !atomic_load_explicit(
        &g_state.videoStatusActive, memory_order_acquire) ||
      app_getState() != APP_STATE_RUNNING)
    return;

  LG_LOCK(g_state.videoPayloadLock);
  if (!atomic_load_explicit(
        &g_state.videoStatusActive, memory_order_acquire) ||
      app_getState() != APP_STATE_RUNNING)
  {
    LG_UNLOCK(g_state.videoPayloadLock);
    return;
  }

  const bool frameWasAvailable = atomic_load_explicit(
      &g_state.videoFrameAvailable, memory_order_acquire);
  const bool first = !atomic_exchange_explicit(
      &g_state.videoStatusKnown, true, memory_order_acq_rel);
  const bool frameChanged = videoComponentStatusChanged(
      &g_state.videoFrameAvailable, &g_state.videoFrameEpoch,
      &g_state.videoFrameReason, &status->frame) || first;
  const bool pointerChanged = videoComponentStatusChanged(
      &g_state.videoPointerAvailable, &g_state.videoPointerEpoch,
      &g_state.videoPointerReason, &status->pointer) || first;

  if (pointerChanged)
    videoSourceClearCursor(LG_VIDEO_SOURCE_PRIMARY);

  if (frameChanged)
  {
    const uint64_t sourceGeneration = atomic_load_explicit(
        &g_state.videoSource[LG_VIDEO_SOURCE_PRIMARY].generation,
        memory_order_acquire);
    if (!status->frame.available || frameWasAvailable || !sourceGeneration)
    {
      videoSourceInvalidate(LG_VIDEO_SOURCE_PRIMARY);
      /* Keep an inactive generation while frames are unavailable so an
       * independent pointer component can continue updating its retained
       * state. */
      videoSourceBegin(LG_VIDEO_SOURCE_PRIMARY);
    }
  }
  LG_UNLOCK(g_state.videoPayloadLock);

  if (frameChanged)
    g_state.videoOps->frame->cancelFrameWait(g_state.transport.handle);
  if (pointerChanged && g_state.videoOps->frame->nextPointer)
    g_state.videoOps->frame->cancelPointerWait(g_state.transport.handle);

  if (!frameChanged)
    return;

  if (status->frame.available)
    return;

  if (atomic_load_explicit(&g_state.stopVideo, memory_order_acquire))
    return;

  const bool fallbackReady = fallbackRequestVideo();
  if (atomic_load_explicit(&g_state.stopVideo, memory_order_acquire))
  {
    if (g_state.fallback)
      lgTransportFallback_requestVideoActive(g_state.fallback, false);
    return;
  }

  if (!fallbackReady)
    videoSourceShowSplashIfNeeded();
}

static void primaryVideoStatusStart(void)
{
  if (!g_state.videoOps || g_state.videoOps->type != LG_VIDEO_TYPE_FRAME)
    return;

  atomic_store_explicit(
      &g_state.videoFrameAvailable, false, memory_order_relaxed);
  atomic_store_explicit(
      &g_state.videoPointerAvailable, false, memory_order_relaxed);
  atomic_store_explicit(
      &g_state.videoStatusKnown, false, memory_order_relaxed);
  atomic_store_explicit(
      &g_state.videoFrameEpoch, 0, memory_order_relaxed);
  atomic_store_explicit(
      &g_state.videoPointerEpoch, 0, memory_order_relaxed);
  atomic_store_explicit(
      &g_state.videoFrameReason, LG_TRANSPORT_UNAVAILABLE,
      memory_order_relaxed);
  atomic_store_explicit(
      &g_state.videoPointerReason, LG_TRANSPORT_UNAVAILABLE,
      memory_order_relaxed);
  atomic_store_explicit(
      &g_state.videoStatusActive, true, memory_order_release);

  if (g_state.videoOps->frame->setStatusListener)
  {
    g_state.videoOps->frame->setStatusListener(g_state.transport.handle,
        primaryVideoStatusChanged, NULL);
    return;
  }

  const LG_VideoStatus status =
  {
    .frame =
    {
      .available = true,
      .epoch     = 1,
      .reason    = LG_TRANSPORT_OK,
    },
    .pointer =
    {
      .available = g_state.videoOps->frame->nextPointer != NULL,
      .epoch     = g_state.videoOps->frame->nextPointer ? 1 : 0,
      .reason    = g_state.videoOps->frame->nextPointer ?
        LG_TRANSPORT_OK : LG_TRANSPORT_UNAVAILABLE,
    },
  };
  primaryVideoStatusChanged(NULL, &status);
}

static void primaryVideoStatusStop(void)
{
  if (!atomic_exchange_explicit(
        &g_state.videoStatusActive, false, memory_order_acq_rel))
    return;

  if (g_state.videoOps && g_state.videoOps->type == LG_VIDEO_TYPE_FRAME &&
      g_state.videoOps->frame->setStatusListener)
    g_state.videoOps->frame->setStatusListener(
        g_state.transport.handle, NULL, NULL);

  LG_LOCK(g_state.videoPayloadLock);
  atomic_store_explicit(
      &g_state.videoFrameAvailable, false, memory_order_release);
  atomic_store_explicit(
      &g_state.videoPointerAvailable, false, memory_order_release);
  atomic_store_explicit(
      &g_state.videoFrameReason, LG_TRANSPORT_DISCONNECTED,
      memory_order_release);
  atomic_store_explicit(
      &g_state.videoPointerReason, LG_TRANSPORT_DISCONNECTED,
      memory_order_release);
  atomic_store_explicit(
      &g_state.videoStatusKnown, false, memory_order_release);
  LG_UNLOCK(g_state.videoPayloadLock);
}

void main_videoStreamEnabled(void)
{
  if (!g_state.videoOps || g_state.videoOps->type != LG_VIDEO_TYPE_FRAME ||
      !g_state.videoOps->frame->setStatusListener ||
      !atomic_load_explicit(
        &g_state.videoStatusKnown, memory_order_acquire) ||
      atomic_load_explicit(
        &g_state.videoFrameAvailable, memory_order_acquire))
    return;

  if (!fallbackRequestVideo())
    videoSourceShowSplashIfNeeded();
}

static void videoSourceReject(void * opaque, RenderQueueSource queueSource,
    uint64_t serial)
{
  (void)opaque;

  LG_VideoSource source = LG_VIDEO_SOURCE_NONE;
  if (queueSource == RENDER_QUEUE_SOURCE_PRIMARY)
    source = LG_VIDEO_SOURCE_PRIMARY;
  else if (queueSource == RENDER_QUEUE_SOURCE_FALLBACK)
    source = LG_VIDEO_SOURCE_FALLBACK;

  if (source == LG_VIDEO_SOURCE_NONE)
    return;

  struct VideoSourceState * state = &g_state.videoSource[source];
  if (atomic_compare_exchange_strong_explicit(&state->transitionSerial,
        &serial, 0, memory_order_acq_rel, memory_order_relaxed))
    atomic_store_explicit(
        &state->transitionPending, false, memory_order_release);
}

static bool videoSourcePrepare(void * opaque, RenderQueueSource queueSource,
    uint64_t generation, uint64_t serial)
{
  (void)opaque;

  LG_VideoSource source = LG_VIDEO_SOURCE_NONE;
  if (queueSource == RENDER_QUEUE_SOURCE_PRIMARY)
    source = LG_VIDEO_SOURCE_PRIMARY;
  else if (queueSource == RENDER_QUEUE_SOURCE_FALLBACK)
    source = LG_VIDEO_SOURCE_FALLBACK;

  if (source == LG_VIDEO_SOURCE_NONE)
    return true;

  struct VideoSourceState * state = &g_state.videoSource[source];
  if (atomic_load_explicit(&state->generation, memory_order_acquire) !=
        generation ||
      !atomic_load_explicit(&state->ready, memory_order_acquire) ||
      atomic_load_explicit(
        &g_state.videoSourceRequested, memory_order_acquire) != source)
    goto reject;

  const int width = atomic_load_explicit(
      &state->width, memory_order_relaxed);
  const int height = atomic_load_explicit(
      &state->height, memory_order_relaxed);
  const LG_RendererRotate rotate = atomic_load_explicit(
      &state->rotate, memory_order_relaxed);
  if (width <= 0 || height <= 0)
    goto reject;

  LG_LOCK(g_state.videoSplashLock);
  if (atomic_load_explicit(&state->generation, memory_order_acquire) !=
        generation ||
      !atomic_load_explicit(&state->ready, memory_order_acquire) ||
      atomic_load_explicit(
        &g_state.videoSourceRequested, memory_order_acquire) != source)
  {
    LG_UNLOCK(g_state.videoSplashLock);
    goto reject;
  }

  if (!g_state.haveSrcSize || g_state.srcSize.x != width ||
      g_state.srcSize.y != height || g_state.rotate != rotate)
  {
    g_state.srcSize.x   = width;
    g_state.srcSize.y   = height;
    g_state.rotate      = rotate;
    g_state.haveSrcSize        = true;
    g_state.videoGeometryDirty = true;
  }

  atomic_store_explicit(
      &g_state.videoSource[source].appliedWidth, width, memory_order_relaxed);
  atomic_store_explicit(
      &g_state.videoSource[source].appliedHeight, height,
      memory_order_relaxed);
  atomic_store_explicit(
      &g_state.videoSource[source].appliedRotate, rotate,
      memory_order_release);

  overlaySplash_show(false);
  LG_UNLOCK(g_state.videoSplashLock);

  return true;

reject:
  videoSourceReject(opaque, queueSource, serial);
  return false;
}

static void videoSourceApplied(void * opaque, RenderQueueSource queueSource,
    uint64_t generation, uint64_t serial, bool swSurface)
{
  (void)opaque;
  (void)swSurface;

  LG_VideoSource source = LG_VIDEO_SOURCE_NONE;
  if (queueSource == RENDER_QUEUE_SOURCE_PRIMARY)
    source = LG_VIDEO_SOURCE_PRIMARY;
  else if (queueSource == RENDER_QUEUE_SOURCE_FALLBACK)
    source = LG_VIDEO_SOURCE_FALLBACK;

  bool cursorStateValid = false;
  bool cursorVisible    = false;
  int  cursorX          = 0;
  int  cursorY          = 0;
  int  cursorHX         = 0;
  int  cursorHY         = 0;

  LG_LOCK(g_state.videoSourceLock);
  atomic_store_explicit(
      &g_state.videoSourceApplied, source, memory_order_release);
  atomic_store_explicit(
      &g_state.videoSourceAppliedGeneration, generation,
      memory_order_release);

  if (source != LG_VIDEO_SOURCE_NONE)
  {
    struct VideoSourceState * state = &g_state.videoSource[source];
    if (atomic_load_explicit(&state->generation, memory_order_acquire) ==
        generation)
    {
      cursorStateValid = state->cursorStateValid;
      cursorVisible    = state->cursorVisible;
      cursorX          = state->cursorX;
      cursorY          = state->cursorY;
      cursorHX         = state->cursorHX;
      cursorHY         = state->cursorHY;

      uint64_t pendingSerial = serial;
      if (atomic_compare_exchange_strong_explicit(&state->transitionSerial,
            &pendingSerial, 0, memory_order_acq_rel, memory_order_relaxed))
      {
        atomic_store_explicit(
            &state->transitionPending, false, memory_order_release);
        state->configurePending = false;
      }
    }
  }

  const LG_VideoSource requested = atomic_load_explicit(
      &g_state.videoSourceRequested, memory_order_acquire);
  if (source == LG_VIDEO_SOURCE_PRIMARY &&
      requested == LG_VIDEO_SOURCE_PRIMARY && g_state.fallback)
    lgTransportFallback_requestVideoActive(g_state.fallback, false);

  g_cursor.guest.valid = cursorStateValid;
  if (cursorStateValid)
  {
    g_cursor.guest.visible = cursorVisible;
    g_cursor.guest.x       = cursorX;
    g_cursor.guest.y       = cursorY;
    g_cursor.guest.hx      = cursorHX;
    g_cursor.guest.hy      = cursorHY;
  }
  LG_UNLOCK(g_state.videoSourceLock);

  const bool fallback = source == LG_VIDEO_SOURCE_FALLBACK;
  lgInput_useTransport(!fallback);
  overlayStatus_set(LG_USER_STATUS_SPICE, fallback);
  atomic_store_explicit(&g_cursor.redraw, true, memory_order_release);
  app_invalidateWindow(false);
  app_updateMouseState();
  app_refreshVideoSource();
}

static bool swSurfaceEventAccepted(LG_VideoSource source)
{
  return source != LG_VIDEO_SOURCE_FALLBACK ||
    lgTransportFallback_acceptsVideoEvents(g_state.fallback);
}

static void swSurfaceConfigure(LG_VideoSource source,
    unsigned int width, unsigned int height)
{
  struct VideoSourceState * state = &g_state.videoSource[source];
  uint64_t generation;
  LG_LOCK(g_state.videoSourceLock);
  if (!swSurfaceEventAccepted(source))
  {
    LG_UNLOCK(g_state.videoSourceLock);
    return;
  }

  videoSourceBeginLocked(source);
  generation = atomic_load_explicit(
      &state->generation, memory_order_acquire);
  atomic_store_explicit(&state->width, width, memory_order_relaxed);
  atomic_store_explicit(&state->height, height, memory_order_relaxed);
  atomic_store_explicit(&state->rotate, LG_ROTATE_0, memory_order_release);
  state->configurePending = true;
  LG_UNLOCK(g_state.videoSourceLock);

  if (!renderQueue_sourceSwSurfaceConfigure(renderQueueSource(source),
        generation, width, height))
    return;

  LG_LOCK(g_state.videoSourceLock);
  if (atomic_load_explicit(
        &state->generation, memory_order_acquire) != generation)
  {
    LG_UNLOCK(g_state.videoSourceLock);
    return;
  }
  atomic_store_explicit(&state->ready, true, memory_order_release);
  LG_UNLOCK(g_state.videoSourceLock);

  if (source == LG_VIDEO_SOURCE_PRIMARY && g_params.autoResize)
    g_state.ds->setWindowSize(width, height);

  app_refreshVideoSource();
}

static void swSurfaceDestroy(LG_VideoSource source)
{
  if (!videoSourceInvalidate(source))
    return;
  if (app_getState() == APP_STATE_SHUTDOWN)
    return;

  const LG_VideoSource applied = atomic_load_explicit(
      &g_state.videoSourceApplied, memory_order_acquire);
  const LG_VideoSource requested = atomic_load_explicit(
      &g_state.videoSourceRequested, memory_order_acquire);
  if (applied != source && requested != source)
    return;

  /* Retain the last presented surface until this source reconnects or a
   * replacement becomes ready. */
  videoSourceShowSplashIfNeeded();
}

static void swSurfaceDrawFill(LG_VideoSource source, int x, int y,
    int width, int height, uint32_t color)
{
  LG_LOCK(g_state.videoSourceLock);
  const bool     accepted = swSurfaceEventAccepted(source);
  const uint64_t generation = accepted ? atomic_load_explicit(
      &g_state.videoSource[source].generation, memory_order_acquire) : 0;
  LG_UNLOCK(g_state.videoSourceLock);

  if (!accepted)
    return;

  renderQueue_sourceSwSurfaceDrawFill(renderQueueSource(source), generation,
      x, y, width, height, color);
}

static void swSurfaceDrawBitmap(LG_VideoSource source, bool topDown,
    int x, int y, int width, int height, int stride, const void * data)
{
  LG_LOCK(g_state.videoSourceLock);
  const bool     accepted = swSurfaceEventAccepted(source);
  const uint64_t generation = accepted ? atomic_load_explicit(
      &g_state.videoSource[source].generation, memory_order_acquire) : 0;
  LG_UNLOCK(g_state.videoSourceLock);

  if (!accepted)
    return;

  renderQueue_sourceSwSurfaceDrawBitmap(renderQueueSource(source), generation,
      x, y, width, height, stride, data, topDown);
}

static void swSurfacePointer(LG_VideoSource source,
    const LG_TransportPointer * pointer)
{
  struct VideoSourceState * state = &g_state.videoSource[source];
  LG_RendererCursor type = LG_CURSOR_COLOR;
  if (pointer->flags & LG_TRANSPORT_POINTER_SHAPE)
    switch (pointer->type)
    {
      case CURSOR_TYPE_COLOR:
        type = LG_CURSOR_COLOR;
        break;

      case CURSOR_TYPE_MONOCHROME:
        type = LG_CURSOR_MONOCHROME;
        break;

      case CURSOR_TYPE_MASKED_COLOR:
        type = LG_CURSOR_MASKED_COLOR;
        break;

      default:
        return;
    }

  const bool drawCursor = source != LG_VIDEO_SOURCE_PRIMARY ||
    g_cursor.draw || !lgInput_available();
  LG_LOCK(g_state.videoSourceLock);
  if (!swSurfaceEventAccepted(source))
  {
    LG_UNLOCK(g_state.videoSourceLock);
    return;
  }

  const uint64_t generation = atomic_load_explicit(
      &state->generation, memory_order_acquire);
  if (!generation)
  {
    LG_UNLOCK(g_state.videoSourceLock);
    return;
  }

  const bool wasRendered = state->cursorStateValid &&
    state->cursorVisible && drawCursor;
  bool hotspotChanged = false;

  if (pointer->flags & LG_TRANSPORT_POINTER_SHAPE)
  {
    const int oldHX = state->cursorHX;
    const int oldHY = state->cursorHY;
    hotspotChanged =
      state->cursorHX != pointer->hx || state->cursorHY != pointer->hy;
    state->cursorHX = pointer->hx;
    state->cursorHY = pointer->hy;
    if (hotspotChanged && state->cursorStateValid &&
        !(pointer->flags & LG_TRANSPORT_POINTER_POSITION))
    {
      state->cursorX += oldHX - pointer->hx;
      state->cursorY += oldHY - pointer->hy;
    }
  }

  if (pointer->flags & LG_TRANSPORT_POINTER_POSITION)
  {
    state->cursorX          = pointer->x;
    state->cursorY          = pointer->y;
    state->cursorStateValid = true;
  }

  if (pointer->flags & LG_TRANSPORT_POINTER_VISIBLE_VALID)
    state->cursorVisible = pointer->flags & LG_TRANSPORT_POINTER_VISIBLE;

  const bool whiteLevelChanged = pointer->sdrWhiteLevel &&
    pointer->sdrWhiteLevel != state->cursorWhiteLevel;
  if (whiteLevelChanged)
    state->cursorWhiteLevel = pointer->sdrWhiteLevel;

  const bool valid        = state->cursorStateValid;
  const bool guestVisible = state->cursorVisible;
  const bool visible      = guestVisible && drawCursor;
  const int x  = state->cursorX;
  const int y  = state->cursorY;
  const int hx = state->cursorHX;
  const int hy = state->cursorHY;
  const bool isRendered = valid && visible;
  const bool sourceApplied = atomic_load_explicit(
      &g_state.videoSourceApplied, memory_order_acquire) == source &&
    atomic_load_explicit(&g_state.videoSourceAppliedGeneration,
        memory_order_acquire) == generation;
  bool wasValid = false;
  if (sourceApplied)
  {
    wasValid               = g_cursor.guest.valid;
    g_cursor.guest.visible = guestVisible;
    g_cursor.guest.x       = x;
    g_cursor.guest.y       = y;
    g_cursor.guest.hx      = hx;
    g_cursor.guest.hy      = hy;
    g_cursor.guest.valid   = valid;
  }

  if (pointer->flags & LG_TRANSPORT_POINTER_SHAPE)
    renderQueue_sourceCursorImage(renderQueueSource(source), generation,
        type, pointer->width, pointer->height, pointer->pitch,
        pointer->shape);

  if (pointer->flags & LG_TRANSPORT_POINTER_COLOR_TRANSFORM)
    renderQueue_sourceCursorColorTransform(renderQueueSource(source),
        generation, pointer->colorTransform);

  if (whiteLevelChanged)
    renderQueue_sourceCursorWhiteLevel(renderQueueSource(source),
        generation, pointer->sdrWhiteLevel);

  if (valid && (pointer->flags & (LG_TRANSPORT_POINTER_POSITION |
      LG_TRANSPORT_POINTER_VISIBLE_VALID | LG_TRANSPORT_POINTER_SHAPE)))
    renderQueue_sourceCursorState(renderQueueSource(source), generation,
        visible, x, y, hx, hy);
  LG_UNLOCK(g_state.videoSourceLock);

  if (sourceApplied)
  {
    if (!wasValid && valid && core_inputEnabled())
      core_alignToGuest();
    if (source == LG_VIDEO_SOURCE_PRIMARY &&
        ((pointer->flags & LG_TRANSPORT_POINTER_POSITION) || hotspotChanged))
      core_handleGuestMouseUpdate();
    app_updateMouseState();
  }

  const bool contentChanged =
    (pointer->flags & (LG_TRANSPORT_POINTER_SHAPE |
      LG_TRANSPORT_POINTER_COLOR_TRANSFORM)) || whiteLevelChanged;
  if (sourceApplied && (wasRendered != isRendered ||
       ((wasRendered || isRendered) &&
        (g_params.mouseRedraw || contentChanged))))
    cursorRepaintRequest();
}

static LG_VideoSource swSurfaceSource(void * opaque)
{
  return (LG_VideoSource)(uintptr_t)opaque;
}

static void swSurfaceEventConfigure(void * opaque,
    unsigned int width, unsigned int height)
{
  swSurfaceConfigure(swSurfaceSource(opaque), width, height);
}

static void swSurfaceEventDestroy(void * opaque)
{
  const LG_VideoSource source = swSurfaceSource(opaque);
  if (swSurfaceEventAccepted(source))
    swSurfaceDestroy(source);
}

static void swSurfaceEventDrawFill(void * opaque, int x, int y,
    int width, int height, uint32_t color)
{
  swSurfaceDrawFill(swSurfaceSource(opaque), x, y, width, height, color);
}

static void swSurfaceEventDrawBitmap(void * opaque, bool topDown,
    int x, int y, int width, int height, int stride, const void * data)
{
  swSurfaceDrawBitmap(swSurfaceSource(opaque), topDown,
      x, y, width, height, stride, data);
}

static void swSurfaceEventPointer(void * opaque,
    const LG_TransportPointer * pointer)
{
  swSurfacePointer(swSurfaceSource(opaque), pointer);
}

static const LG_SwSurfaceEventOps swSurfaceEvents =
{
  .configure  = swSurfaceEventConfigure,
  .destroy    = swSurfaceEventDestroy,
  .drawFill   = swSurfaceEventDrawFill,
  .drawBitmap = swSurfaceEventDrawBitmap,
  .pointer    = swSurfaceEventPointer,
};

static bool fallbackRequestVideo(void)
{
  if (!g_state.fallback || atomic_load_explicit(
        &g_state.stopVideo, memory_order_acquire))
    return false;

  lgTransportFallback_requestVideoActive(g_state.fallback, true);
  if (atomic_load_explicit(&g_state.stopVideo, memory_order_acquire))
  {
    lgTransportFallback_requestVideoActive(g_state.fallback, false);
    return false;
  }

  if (!lgTransportFallback_usable(g_state.fallback) ||
      !lgTransportFallback_ready(g_state.fallback))
    return false;

  const bool active = app_useVideoSource(LG_VIDEO_SOURCE_FALLBACK);
  if (atomic_load_explicit(&g_state.stopVideo, memory_order_acquire))
  {
    lgTransportFallback_requestVideoActive(g_state.fallback, false);
    return false;
  }

  return active;
}

static void fallbackConnected(void * opaque,
    const LG_TransportSession * session)
{
  (void)opaque;
  atomic_fetch_and_explicit(&g_state.transportLost,
      ~TRANSPORT_LOST_FALLBACK, memory_order_acq_rel);
  if (app_getState() == APP_STATE_SHUTDOWN)
    return;

  if (session->name[0] && !atomic_load_explicit(
        &g_state.lgHostConnected, memory_order_acquire))
    core_setTitle(session->name);

  if (lgTransportFallback_videoRequested(g_state.fallback))
    fallbackRequestVideo();
  else
    app_refreshVideoSource();
}

static void fallbackDisconnected(void * opaque)
{
  (void)opaque;
  swSurfaceDestroy(LG_VIDEO_SOURCE_FALLBACK);
  videoSourceClearCursor(LG_VIDEO_SOURCE_FALLBACK);
  if (app_getState() != APP_STATE_SHUTDOWN && !atomic_load_explicit(
        &g_state.lgHostConnected, memory_order_acquire))
    videoSourceShowSplashIfNeeded();
}

static void fallbackVideoStateChanged(void * opaque, bool ready)
{
  (void)opaque;
  if (app_getState() == APP_STATE_SHUTDOWN)
    return;

  if (ready && lgTransportFallback_videoRequested(g_state.fallback))
  {
    fallbackRequestVideo();
    return;
  }

  swSurfaceDestroy(LG_VIDEO_SOURCE_FALLBACK);
  videoSourceClearCursor(LG_VIDEO_SOURCE_FALLBACK);
  app_refreshVideoSource();
}

static void fallbackLost(void * opaque)
{
  (void)opaque;
  const unsigned int lost = atomic_fetch_or_explicit(&g_state.transportLost,
      TRANSPORT_LOST_FALLBACK, memory_order_acq_rel) |
    TRANSPORT_LOST_FALLBACK;
  if ((lost & TRANSPORT_LOST_ALL) == TRANSPORT_LOST_ALL)
  {
    DEBUG_INFO("Primary and fallback transport sessions disconnected");
    app_setState(APP_STATE_SHUTDOWN);
  }
}

static void fallbackEndpointMismatch(void * opaque, const uint8_t primary[16],
    const uint8_t fallback[16])
{
  (void)opaque;
  (void)primary;
  (void)fallback;
  atomic_store_explicit(
      &g_state.fallbackEndpointMismatch, true, memory_order_release);
  app_invalidateWindow(false);
}

static const LG_TransportFallbackEventOps fallbackEvents =
{
  .connected    = fallbackConnected,
  .lost         = fallbackLost,
  .disconnected = fallbackDisconnected,
  .videoStateChanged = fallbackVideoStateChanged,
  .endpointMismatch = fallbackEndpointMismatch,
};

static void primaryLost(void)
{
  /* Establish restart before updating the transport bookkeeping. Primary
   * workers may still be unwinding abandoned payloads in parallel and must
   * observe that their failures no longer warrant a terminal shutdown. */
  app_setState(APP_STATE_RESTART);
  atomic_store_explicit(
      &g_state.lgHostConnected, false, memory_order_release);
  unsigned int lost = atomic_load_explicit(
      &g_state.transportLost, memory_order_acquire);
  for (;;)
  {
    unsigned int next = lost | TRANSPORT_LOST_PRIMARY;
    if (lgTransportFallback_usable(g_state.fallback))
      next &= ~TRANSPORT_LOST_FALLBACK;
    if (atomic_compare_exchange_weak_explicit(&g_state.transportLost,
          &lost, next, memory_order_acq_rel, memory_order_acquire))
    {
      lost = next;
      break;
    }
  }
  if ((lost & TRANSPORT_LOST_ALL) == TRANSPORT_LOST_ALL)
  {
    DEBUG_INFO("Primary and fallback transport sessions disconnected");
    app_setState(APP_STATE_SHUTDOWN);
    return;
  }

  DEBUG_INFO("Waiting for the host to restart...");
}

static bool fallbackStart(const uint8_t primaryUUID[16])
{
  if (!option_get_bool("spice", "enable") ||
      strcmp(g_params.transport, "spice") == 0)
    return true;

  if (lgTransportFallback_start("spice", &swSurfaceEvents,
        (void *)(uintptr_t)LG_VIDEO_SOURCE_FALLBACK,
        &fallbackEvents, NULL, primaryUUID, &g_state.fallback))
    return true;

  DEBUG_ERROR("Failed to start the SPICE fallback transport");
  return false;
}

static void fallbackStop(void)
{
  lgTransportFallback_stop(&g_state.fallback);
}

static void fallbackHandleEvents(void)
{
  if (!atomic_exchange_explicit(
        &g_state.fallbackEndpointMismatch, false, memory_order_acq_rel))
    return;

  app_msgBox(
      "SPICE Configuration Error",
      "You have connected SPICE to the wrong guest.\n"
      "SPICE fallback services will not function until this is corrected.");
}

void intHandler(int sig)
{
  switch(sig)
  {
    case SIGINT:
    case SIGTERM:
      if (app_getState() != APP_STATE_SHUTDOWN)
      {
        DEBUG_INFO("Caught signal, shutting down...");
        app_setState(APP_STATE_SHUTDOWN);
      }
      else
      {
        DEBUG_INFO("Caught second signal, force quitting...");
        printAllThreadBacktraces();
        signal(sig, SIG_DFL);
        raise(sig);
      }
      break;
  }
}

static bool tryRenderer(const int index, const LG_RendererParams lgrParams,
    bool * needsOpenGL)
{
  const LG_RendererOps *r = LG_Renderers[index];

  if (!IS_LG_RENDERER_VALID(r))
  {
    DEBUG_ERROR("FIXME: Renderer %d is invalid, skipping", index);
    return false;
  }

  // create the renderer
  g_state.lgr  = NULL;
  *needsOpenGL = false;
  if (!r->create(&g_state.lgr, lgrParams, needsOpenGL))
  {
    g_state.lgr = NULL;
    return false;
  }

  // init the ops member
  memcpy(&g_state.lgr->ops, r, sizeof(*r));

  // initialize the renderer
  if (!r->initialize(g_state.lgr))
  {
    r->deinitialize(g_state.lgr);
    g_state.lgr = NULL;
    return false;
  }

  DEBUG_INFO("Using Renderer: %s", r->getName());
  return true;
}

static void reportBadVersion(const LG_VersionMismatch * mismatch)
{
  DEBUG_BREAK();
  if (mismatch->valid)
  {
    DEBUG_ERROR("Incompatible %s version", mismatch->component);
    DEBUG_ERROR("Expected version: %u", mismatch->expectedVersion);
    DEBUG_ERROR("Current version : %u", mismatch->currentVersion);
  }
  else
    DEBUG_ERROR("The transport is not compatible with this client");
  DEBUG_ERROR("Please install matching Looking Glass components");
}

static const int RECOVERY_PENDING = -1;
static const int RECOVERY_NO      = 0;
static const int RECOVERY_YES     = 1;

struct RecoveryPrompt
{
  atomic_int       choice;
  atomic_uintptr_t handle;
  atomic_uintptr_t message;
  atomic_bool      messageClosed;
  uint64_t         instance;
  uint32_t         serial;
  uint32_t         failedSerial;
  LG_RecoveryState reportedState;
  bool             shown;
  bool             requested;
  bool             owned;
  bool             retryPrompt;
  bool             retryDeclined;
};

static bool recoveryGetInfo(LG_RecoveryInfo * info)
{
  if (!g_state.transport.ops->getRecoveryInfo)
    return false;

  return g_state.transport.ops->getRecoveryInfo(
      g_state.transport.handle, info) == LG_TRANSPORT_OK;
}

static void recoveryConfirm(bool yes, void * opaque)
{
  struct RecoveryPrompt * prompt = opaque;
  atomic_store_explicit(&prompt->choice,
      yes ? RECOVERY_YES : RECOVERY_NO, memory_order_release);
}

static void recoveryClosePrompt(struct RecoveryPrompt * prompt)
{
  if (atomic_load_explicit(
        &prompt->choice, memory_order_acquire) != RECOVERY_PENDING)
  {
    atomic_store_explicit(&prompt->handle, 0, memory_order_relaxed);
    return;
  }

  MsgBoxHandle handle = (MsgBoxHandle)atomic_exchange_explicit(
      &prompt->handle, 0, memory_order_acq_rel);
  app_msgBoxClose(handle);
}

static void recoveryCloseMessage(struct RecoveryPrompt * prompt)
{
  MsgBoxHandle handle = (MsgBoxHandle)atomic_exchange_explicit(
      &prompt->message, 0, memory_order_acq_rel);
  app_msgBoxClose(handle);
}

static void recoveryMessageClosed(MsgBoxHandle handle, void * opaque)
{
  struct RecoveryPrompt * prompt = opaque;
  atomic_store_explicit(
      &prompt->messageClosed, true, memory_order_release);

  uintptr_t expected = (uintptr_t)handle;
  atomic_compare_exchange_strong_explicit(&prompt->message,
      &expected, 0, memory_order_acq_rel, memory_order_acquire);
}

static void recoveryBeginMessage(struct RecoveryPrompt * prompt)
{
  recoveryCloseMessage(prompt);
  atomic_store_explicit(
      &prompt->messageClosed, false, memory_order_relaxed);
}

static void recoveryStoreMessage(struct RecoveryPrompt * prompt,
    MsgBoxHandle handle)
{
  atomic_store_explicit(
      &prompt->message, (uintptr_t)handle, memory_order_release);
  if (!atomic_load_explicit(
        &prompt->messageClosed, memory_order_acquire))
    return;

  uintptr_t expected = (uintptr_t)handle;
  atomic_compare_exchange_strong_explicit(&prompt->message,
      &expected, 0, memory_order_acq_rel, memory_order_acquire);
}

static void recoveryClose(struct RecoveryPrompt * prompt)
{
  recoveryClosePrompt(prompt);
  recoveryCloseMessage(prompt);
}

static int recoveryExit(struct RecoveryPrompt * prompt, int result)
{
  recoveryClose(prompt);
  return result;
}

static void retainMessage(MsgBoxHandle * messages, size_t capacity,
    int * count, MsgBoxHandle message)
{
  if (!message)
    return;

  if ((size_t)*count >= capacity)
  {
    app_msgBoxClose(message);
    return;
  }

  messages[(*count)++] = message;
}

static void recoveryShowPrompt(struct RecoveryPrompt * prompt,
    const LG_VersionMismatch * mismatch, bool hasFallback)
{
  const char * fallback = hasFallback ?
    "The client will then switch to its SPICE fallback." :
    "SPICE is disabled in this client, so use another SPICE viewer.";

  recoveryCloseMessage(prompt);
  prompt->shown       = true;
  prompt->retryPrompt = false;
  atomic_store_explicit(
      &prompt->choice, RECOVERY_PENDING, memory_order_relaxed);
  MsgBoxHandle handle;
  if (mismatch->valid)
  {
    const char * component = mismatch->component[0] ?
      mismatch->component : "transport";
    handle = app_confirmMsgBox(
        "Incompatible Transport Version", recoveryConfirm, prompt,
        "Expected %s version: %u\n"
        "Current %s version: %u\n"
        "\n"
        "Enable recovery mode to restore the guest display topology?\n"
        "%s",
        component, mismatch->expectedVersion,
        component, mismatch->currentVersion, fallback);
  }
  else
  {
    handle = app_confirmMsgBox(
        "Incompatible Transport Version", recoveryConfirm, prompt,
        "The transport is not compatible with this client.\n"
        "\n"
        "Enable recovery mode to restore the guest display topology?\n"
        "%s", fallback);
  }
  atomic_store_explicit(
      &prompt->handle, (uintptr_t)handle, memory_order_release);
  if (atomic_load_explicit(
        &prompt->choice, memory_order_acquire) != RECOVERY_PENDING)
    atomic_store_explicit(&prompt->handle, 0, memory_order_relaxed);
}

static const char * recoveryErrorText(LG_RecoveryError error)
{
  switch (error)
  {
    case LG_RECOVERY_ERR_HELPER_UNAVAILABLE:
      return "The IDD helper is unavailable";

    case LG_RECOVERY_ERR_TOPOLOGY_FAILED:
      return "Windows could not restore the saved display topology";

    case LG_RECOVERY_ERR_NO_FALLBACK_DISPLAY:
      return "No fallback display became active";

    case LG_RECOVERY_ERR_BUSY:
      return "A conflicting recovery request is already in progress";

    case LG_RECOVERY_ERR_CAPACITY:
      return "Too many recovery requests are pending";

    case LG_RECOVERY_ERR_UNSUPPORTED:
      return "Recovery is not supported by the guest driver";

    case LG_RECOVERY_ERR_NONE:
      break;
  }

  return "The guest could not enter recovery mode";
}

static int recoveryTakeChoice(struct RecoveryPrompt * prompt)
{
  const int choice = atomic_exchange_explicit(
      &prompt->choice, RECOVERY_PENDING, memory_order_acq_rel);
  if (choice != RECOVERY_PENDING)
    atomic_store_explicit(&prompt->handle, 0, memory_order_relaxed);
  return choice;
}

static void recoveryShowRetry(struct RecoveryPrompt * prompt,
    const char * reason, uint32_t failedSerial)
{
  recoveryClose(prompt);
  if (failedSerial)
    prompt->failedSerial = failedSerial;
  prompt->serial        = 0;
  prompt->reportedState = LG_RECOVERY_STATE_FAILED;
  prompt->shown         = true;
  prompt->requested     = false;
  prompt->owned         = false;
  prompt->retryPrompt   = true;
  atomic_store_explicit(
      &prompt->choice, RECOVERY_PENDING, memory_order_relaxed);
  MsgBoxHandle handle = app_confirmMsgBox(
      "Recovery Failed", recoveryConfirm, prompt,
      "%s.\n\nRetry guest display recovery?", reason);
  atomic_store_explicit(
      &prompt->handle, (uintptr_t)handle, memory_order_release);
  if (atomic_load_explicit(
        &prompt->choice, memory_order_acquire) != RECOVERY_PENDING)
    atomic_store_explicit(&prompt->handle, 0, memory_order_relaxed);
}

static void recoveryShowPending(struct RecoveryPrompt * prompt,
    const LG_VersionMismatch * mismatch)
{
  prompt->shown         = true;
  prompt->reportedState = LG_RECOVERY_STATE_SWITCHING;
  prompt->retryPrompt   = false;
  if (mismatch->valid)
  {
    const char * component = mismatch->component[0] ?
      mismatch->component : "transport";
    recoveryBeginMessage(prompt);
    recoveryStoreMessage(prompt, app_msgBoxWithClose(
          "Incompatible Transport Version",
          recoveryMessageClosed, prompt,
          "Expected %s version: %u\n"
          "Current %s version: %u\n"
          "\n"
          "Recovery mode is pending. Waiting for the guest driver.",
          component, mismatch->expectedVersion,
          component, mismatch->currentVersion));
  }
  else
  {
    recoveryBeginMessage(prompt);
    recoveryStoreMessage(prompt, app_msgBoxWithClose(
          "Incompatible Transport Version",
          recoveryMessageClosed, prompt,
          "The transport is not compatible with this client.\n"
          "\n"
          "Recovery mode is pending. Waiting for the guest driver."));
  }
}

static bool recoverySerialNewer(uint32_t serial, uint32_t reference)
{
  const uint32_t difference = serial - reference;
  return difference && difference < 0x80000000U;
}

static void recoveryHandleMismatch(struct RecoveryPrompt * prompt,
    const LG_VersionMismatch * mismatch)
{
  LG_RecoveryInfo info = { 0 };
  const bool available = recoveryGetInfo(&info) &&
    (info.capabilities & LG_RECOVERY_CAP_DISPLAY);
  if (!available)
  {
    if (prompt->requested && !prompt->retryPrompt &&
        !prompt->retryDeclined)
    {
      recoveryShowRetry(prompt,
          "The guest recovery channel is unavailable", 0);
      return;
    }

    if (prompt->shown)
      return;

    prompt->shown = true;
    if (mismatch->valid)
    {
      const char * component = mismatch->component[0] ?
        mismatch->component : "transport";
      recoveryBeginMessage(prompt);
      recoveryStoreMessage(prompt, app_msgBoxWithClose(
            "Incompatible Transport Version",
            recoveryMessageClosed, prompt,
            "Expected %s version: %u\n"
            "Current %s version: %u\n"
            "\n"
            "This guest driver does not support remote recovery.\n"
            "Use a guest console to install matching components.",
            component, mismatch->expectedVersion,
            component, mismatch->currentVersion));
    }
    else
    {
      recoveryBeginMessage(prompt);
      recoveryStoreMessage(prompt, app_msgBoxWithClose(
            "Incompatible Transport Version",
            recoveryMessageClosed, prompt,
            "The transport is not compatible with this client.\n"
            "\n"
            "This guest driver does not support remote recovery.\n"
            "Use a guest console to install matching components."));
    }
    return;
  }

  if (prompt->instance != info.instance)
  {
    recoveryClose(prompt);
    prompt->instance      = info.instance;
    prompt->serial        = 0;
    prompt->failedSerial  = 0;
    prompt->reportedState = LG_RECOVERY_STATE_UNKNOWN;
    prompt->shown         = false;
    prompt->requested     = false;
    prompt->owned         = false;
    prompt->retryPrompt   = false;
    prompt->retryDeclined = false;
    atomic_store_explicit(
        &prompt->choice, RECOVERY_PENDING, memory_order_relaxed);
  }

  if (info.uuidValid)
    lgTransportFallback_setPrimaryUUID(g_state.fallback, info.uuid);
  else
    lgTransportFallback_clearPrimaryUUID(g_state.fallback);

  const bool requestNewer = info.requestSerial != 0 &&
    (info.ackSerial == 0 ||
     recoverySerialNewer(info.requestSerial, info.ackSerial));
  const LG_RecoveryRequest globalRequest = requestNewer ?
    info.request : info.ackRequest;
  const uint32_t globalSerial = requestNewer ?
    info.requestSerial : info.ackSerial;
  if (prompt->requested && globalSerial &&
      globalRequest == LG_RECOVERY_REQ_NORMAL &&
      (globalSerial == prompt->serial ||
       recoverySerialNewer(globalSerial, prompt->serial)))
  {
    recoveryClose(prompt);
    prompt->serial        = 0;
    prompt->reportedState = LG_RECOVERY_STATE_UNKNOWN;
    prompt->shown         = prompt->retryDeclined;
    prompt->requested     = false;
    prompt->owned         = false;
    prompt->retryPrompt   = false;
    atomic_store_explicit(
        &prompt->choice, RECOVERY_PENDING, memory_order_relaxed);
  }

  const bool pendingRecovery = requestNewer &&
    info.request == LG_RECOVERY_REQ_RECOVERY;
  const bool failedRecovery = !requestNewer && info.ackSerial != 0 &&
    info.ackRequest == LG_RECOVERY_REQ_RECOVERY &&
    info.state == LG_RECOVERY_STATE_FAILED;
  const bool statusRecovery = !requestNewer && info.ackSerial != 0 &&
    info.ackRequest == LG_RECOVERY_REQ_RECOVERY &&
    (info.state == LG_RECOVERY_STATE_SWITCHING ||
     info.state == LG_RECOVERY_STATE_ACTIVE);
  if (failedRecovery && prompt->requested &&
      prompt->failedSerial != info.ackSerial &&
      (info.ackSerial == prompt->serial ||
       recoverySerialNewer(info.ackSerial, prompt->serial)))
  {
    if (prompt->owned && info.ackSerial == prompt->serial)
    {
      recoveryShowRetry(prompt, recoveryErrorText(info.error),
          info.ackSerial);
      return;
    }

    recoveryClose(prompt);
    prompt->serial        = 0;
    prompt->failedSerial  = info.ackSerial;
    prompt->reportedState = LG_RECOVERY_STATE_UNKNOWN;
    prompt->shown         = prompt->retryDeclined;
    prompt->requested     = false;
    prompt->owned         = false;
    prompt->retryPrompt   = false;
    atomic_store_explicit(
        &prompt->choice, RECOVERY_PENDING, memory_order_relaxed);
  }

  if (pendingRecovery)
  {
    if (!prompt->requested || prompt->serial != info.requestSerial)
    {
      recoveryClose(prompt);
      prompt->requested     = true;
      prompt->serial        = info.requestSerial;
      prompt->failedSerial  = 0;
      prompt->reportedState = LG_RECOVERY_STATE_UNKNOWN;
      prompt->shown         = false;
      prompt->owned         = false;
      prompt->retryPrompt   = false;
      atomic_store_explicit(
          &prompt->choice, RECOVERY_PENDING, memory_order_relaxed);
    }
  }
  else if (statusRecovery &&
      (!prompt->requested || prompt->serial != info.ackSerial))
  {
    recoveryClose(prompt);
    prompt->requested     = true;
    prompt->serial        = info.ackSerial;
    prompt->failedSerial  = 0;
    prompt->reportedState = LG_RECOVERY_STATE_UNKNOWN;
    prompt->shown         = false;
    prompt->owned         = false;
    prompt->retryPrompt   = false;
    atomic_store_explicit(
        &prompt->choice, RECOVERY_PENDING, memory_order_relaxed);
  }

  const bool retryChoice = prompt->retryPrompt;
  const int choice = recoveryTakeChoice(prompt);
  if (choice == RECOVERY_NO)
  {
    prompt->retryPrompt = false;
    if (retryChoice)
      prompt->retryDeclined = true;
    return;
  }

  if (choice == RECOVERY_YES)
  {
    prompt->retryPrompt   = false;
    prompt->retryDeclined = false;
    const LG_TransportStatus status =
      g_state.transport.ops->requestRecovery ?
        g_state.transport.ops->requestRecovery(g_state.transport.handle,
            LG_RECOVERY_REQ_RECOVERY, &prompt->serial) :
        LG_TRANSPORT_UNAVAILABLE;
    prompt->requested     = status == LG_TRANSPORT_OK;
    prompt->owned         = prompt->requested;
    prompt->reportedState = LG_RECOVERY_STATE_UNKNOWN;
    if (!prompt->requested)
    {
      recoveryShowRetry(prompt,
          "The recovery request could not be sent to the guest driver", 0);
      return;
    }

    prompt->failedSerial = 0;
    fallbackRequestVideo();
    recoveryShowPending(prompt, mismatch);
    app_alert(LG_ALERT_INFO, "Guest display recovery requested");
    return;
  }

  const bool matchingAck = prompt->requested && statusRecovery &&
    info.ackSerial == prompt->serial;
  if (matchingAck && info.state == LG_RECOVERY_STATE_ACTIVE)
  {
    fallbackRequestVideo();
    if (prompt->reportedState != LG_RECOVERY_STATE_ACTIVE)
    {
      prompt->shown         = true;
      prompt->reportedState = LG_RECOVERY_STATE_ACTIVE;
      if (mismatch->valid)
      {
        const char * component = mismatch->component[0] ?
          mismatch->component : "transport";
        recoveryBeginMessage(prompt);
        recoveryStoreMessage(prompt, app_msgBoxWithClose(
              "Incompatible Transport Version",
              recoveryMessageClosed, prompt,
              "Expected %s version: %u\n"
              "Current %s version: %u\n"
              "\n"
              "Recovery mode is active. SPICE video is available.",
              component, mismatch->expectedVersion,
              component, mismatch->currentVersion));
      }
      else
      {
        recoveryBeginMessage(prompt);
        recoveryStoreMessage(prompt, app_msgBoxWithClose(
              "Incompatible Transport Version",
              recoveryMessageClosed, prompt,
              "The transport is not compatible with this client.\n"
              "\n"
              "Recovery mode is active. SPICE video is available."));
      }
      app_alert(LG_ALERT_SUCCESS, "Guest display recovery is active");
    }
    return;
  }

  const bool pending = prompt->requested &&
    ((pendingRecovery &&
      info.requestSerial == prompt->serial) ||
     (matchingAck && info.state == LG_RECOVERY_STATE_SWITCHING));
  if (pending)
  {
    fallbackRequestVideo();
    if (prompt->reportedState != LG_RECOVERY_STATE_SWITCHING)
      recoveryShowPending(prompt, mismatch);
    return;
  }

  if (!prompt->shown)
    recoveryShowPrompt(prompt, mismatch, g_state.fallback != NULL);
}

static MsgBoxHandle showSpiceInputHelp(void)
{
  static bool done = false;
  if (!option_get_bool("spice", "enable") ||
      !option_get_bool("spice", "input") || done)
    return NULL;

  done = true;
  return app_msgBox(
    "Information",
    "Please note you can still control your guest\n"
    "through SPICE if you press the capture key.");
}

struct TransportSessionProbe
{
  LG_Transport *          transport;
  const LG_TransportOps * ops;
  LG_TransportCancelledFn cancelled;
  void *                  cancelOpaque;
  LG_TransportSession     session;
  LG_TransportStatus      status;
  atomic_bool             done;
};

static bool transportSessionCancelled(void * opaque)
{
  (void)opaque;
  return app_getState() != APP_STATE_RUNNING;
}

static bool primarySurfaceActivationCancelled(void * opaque)
{
  (void)opaque;
  return app_getState() != APP_STATE_RUNNING ||
    atomic_load_explicit(&g_state.stopVideo, memory_order_acquire);
}

static int transportSessionProbe(void * opaque)
{
  struct TransportSessionProbe * probe = opaque;
  probe->status = probe->ops->connectCancellable(
      probe->transport, &probe->session,
      probe->cancelled, probe->cancelOpaque);
  atomic_store_explicit(&probe->done, true, memory_order_release);
  return 0;
}

static int lg_run(void)
{
  LG_LOCK_INIT(l_cursorRepaint.lock);
  frameTimingInit();
  lgInput_init();
  lgAudio_init();
  if (!clipboard_init())
    return -1;

#ifdef ENABLE_TESTS
  memset(&l_testCapture, 0, sizeof(l_testCapture));
  atomic_store_explicit(&l_testFrameSerial, 0, memory_order_relaxed);
  atomic_store_explicit(&l_testFrameType, FRAME_TYPE_INVALID,
      memory_order_relaxed);
  if (strcmp(g_params.transport, "test") == 0)
  {
    const char * capturePath = option_get_string("test", "captureFile");
    const int captureFrame   = option_get_int("test", "captureFrame");
    const int captureDelay   = option_get_int("test", "captureDelay");
    if (capturePath)
    {
      if (captureFrame < 1 || captureDelay < 0)
      {
        DEBUG_ERROR("test capture requires captureFrame >= 1 and "
            "captureDelay >= 0");
        return -1;
      }
      l_testCapture.path         = capturePath;
      l_testCapture.targetSerial = captureFrame;
      l_testCapture.delay        = captureDelay;
      l_testCapture.enabled      = true;
    }
  }
#endif

  g_cursor.sens = g_params.mouseSens;
       if (g_cursor.sens < -9) g_cursor.sens = -9;
  else if (g_cursor.sens >  9) g_cursor.sens =  9;

  /* setup imgui */
  igCreateContext(NULL);
  g_state.io    = igGetIO_Nil();
  g_state.style = igGetStyle();

  g_state.style->Colors[ImGuiCol_ModalWindowDimBg] = (ImVec4) { 0.0f, 0.0f, 0.0f, 0.4f };

  alloc_sprintf(&g_state.imGuiIni, "%s/imgui.ini", lgConfigDir());
  g_state.io->IniFilename   = g_state.imGuiIni;
  g_state.io->BackendFlags |= ImGuiBackendFlags_HasMouseCursors;

  g_state.windowScale = 1.0;
  if (!util_initUIFonts())
  {
    DEBUG_ERROR("Failed to initialize UI fonts");
    return -1;
  }

  g_state.fontName = util_getUIFont(g_params.uiFont);
  if (!g_state.fontName)
  {
    DEBUG_ERROR("Failed to load UI font: %s", g_params.uiFont);
    return -1;
  }
  DEBUG_INFO("Using font: %s", g_state.fontName);

  // initialize metrics ringbuffers
  g_state.renderTimings = ringbuffer_new(256, sizeof(float));
  g_state.frameLatency  = ringbuffer_new(4096, sizeof(OverlayFrameTiming));
  overlayGraph_setCompact(overlayGraph_register(
        "FRAME", g_state.renderTimings, 0.0f, 50.0f, NULL), true);
  overlayGraph_registerFrameTiming("FRAME LATENCY", g_state.frameLatency);

  // unknown guest OS at this time
  g_state.guestOS = LG_TRANSPORT_OS_OTHER;

  // search for the best displayserver ops to use
  for(int i = 0; i < LG_DISPLAYSERVER_COUNT; ++i)
    if (LG_DisplayServers[i]->probe())
    {
      g_state.ds = LG_DisplayServers[i];
      break;
    }

  if (!g_state.ds)
  {
    DEBUG_ERROR("No display servers available, tried:");
    for (int i = 0; i < LG_DISPLAYSERVER_COUNT; ++i)
      DEBUG_ERROR("* %s", LG_DisplayServers[i]->name);
    return -1;
  }

  ASSERT_LG_DS_VALID(g_state.ds);

  if (g_params.jitRender)
  {
    if (g_state.ds->waitFrame)
      g_state.jitRender = true;
    else
      DEBUG_WARN("JIT render not supported on display server backend, disabled");
  }

  // init the subsystem
  if (!g_state.ds->earlyInit())
  {
    DEBUG_ERROR("Subsystem early init failed");
    return -1;
  }

  if (evdev_start())
    DEBUG_INFO("Using evdev for keyboard capture");

  // override the SIGINIT handler so that we can tell the difference between
  // SIGINT and the user sending a close event, such as ALT+F4
  signal(SIGINT , intHandler);
  signal(SIGTERM, intHandler);

  if (!lgTransport_create(g_params.transport, &g_state.transport))
  {
    DEBUG_ERROR("Failed to create transport: %s", g_params.transport);
    return -1;
  }
  DEBUG_INFO("Using Transport: %s", g_state.transport.ops->name);

  LG_RecoveryInfo initialRecovery = { 0 };
  const bool initialRecoveryValid = recoveryGetInfo(&initialRecovery);

  g_state.videoOps = g_state.transport.ops->getVideoOps ?
    g_state.transport.ops->getVideoOps(g_state.transport.handle) : NULL;
  if (!g_state.videoOps ||
      (g_state.videoOps->type != LG_VIDEO_TYPE_FRAME &&
       g_state.videoOps->type != LG_VIDEO_TYPE_SW_SURFACE) ||
      (g_state.videoOps->type == LG_VIDEO_TYPE_FRAME &&
       (!g_state.videoOps->frame ||
        !g_state.videoOps->frame->nextFrame ||
        !g_state.videoOps->frame->releaseFrame ||
        !g_state.videoOps->frame->cancelFrameWait ||
        ((g_state.videoOps->frame->nextPointer != NULL) !=
         (g_state.videoOps->frame->releasePointer != NULL)) ||
        (g_state.videoOps->frame->nextPointer &&
         !g_state.videoOps->frame->cancelPointerWait))) ||
      (g_state.videoOps->type == LG_VIDEO_TYPE_SW_SURFACE &&
       (!g_state.videoOps->swSurface ||
        !g_state.videoOps->swSurface->attach ||
        !g_state.videoOps->swSurface->detach ||
        !g_state.videoOps->swSurface->setActive ||
        !g_state.videoOps->swSurface->cancelPending)))
  {
    DEBUG_ERROR("Transport does not provide a usable video source");
    return -1;
  }
  DEBUG_INFO("Using Video: %s", g_state.videoOps->name);

  // setup the startup condition
  if (!(e_startup = lgCreateEvent(false, 0)))
  {
    DEBUG_ERROR("failed to create the startup event");
    return -1;
  }

  // setup the new frame event
  if (!(g_state.frameEvent = lgCreateEvent(!g_state.jitRender, 0)))
  {
    DEBUG_ERROR("failed to create the frame event");
    return -1;
  }

  //setup the render command queue
  LG_LOCK_INIT(g_state.videoPayloadLock);
  LG_LOCK_INIT(g_state.videoSourceLock);
  LG_LOCK_INIT(g_state.videoSplashLock);
  renderQueue_init();
  renderQueue_setSourceFns(
      videoSourcePrepare, videoSourceReject, videoSourceApplied, NULL);
  atomic_store_explicit(&g_state.videoSourceRequested,
      LG_VIDEO_SOURCE_PRIMARY, memory_order_relaxed);
  atomic_store_explicit(&g_state.videoSourceApplied,
      LG_VIDEO_SOURCE_NONE, memory_order_relaxed);
  g_state.videoSource[LG_VIDEO_SOURCE_PRIMARY].swSurface =
    g_state.videoOps->type == LG_VIDEO_TYPE_SW_SURFACE;
  g_state.videoSource[LG_VIDEO_SOURCE_FALLBACK].swSurface = true;
  frameScheduler_init();

  g_state.micDefaultState = g_params.micDefaultState;

  const uint8_t * fallbackUUID = initialRecoveryValid &&
    initialRecovery.uuidValid ? initialRecovery.uuid : NULL;
  if (!fallbackStart(fallbackUUID))
    return -1;

  // select and init a renderer
  bool needsOpenGL = false;
  LG_RendererParams lgrParams;
  lgrParams.quickSplash = g_params.quickSplash;

  if (g_params.forceRenderer)
  {
    DEBUG_INFO("Trying forced renderer");
    if (!tryRenderer(g_params.forceRendererIndex, lgrParams, &needsOpenGL))
    {
      DEBUG_ERROR("Forced renderer failed to iniailize");
      return -1;
    }
  }
  else
  {
    // probe for a a suitable renderer
    for(unsigned int i = 0; i < LG_RENDERER_COUNT; ++i)
    {
      if (tryRenderer(i, lgrParams, &needsOpenGL))
        break;
    }
  }

  if (!g_state.lgr)
  {
    DEBUG_ERROR("Unable to find a suitable renderer");
    return -1;
  }

  g_state.useDMA = g_state.videoOps->type == LG_VIDEO_TYPE_FRAME &&
    g_state.videoOps->frame->supportsDMA(g_state.transport.handle);

  // initialize the window dimensions at init for renderers
  g_state.windowW  = g_params.w;
  g_state.windowH  = g_params.h;
  g_state.windowCX = g_params.w / 2;
  g_state.windowCY = g_params.h / 2;
  core_updatePositionInfo();

  const LG_DSInitParams params =
  {
    .title               = g_params.windowTitle,
    .appId               = g_params.appId,
    .x                   = g_params.x,
    .y                   = g_params.y,
    .w                   = g_params.w,
    .h                   = g_params.h,
    .center              = g_params.center,
    .fullscreen          = g_params.fullscreen,
    .resizable           = g_params.allowResize,
    .borderless          = g_params.borderless,
    .maximize            = g_params.maximize,
    .largeCursorDot      = g_params.largeCursorDot,
    .allowNoInput        = strcmp(g_params.transport, "test") == 0,
    .opengl              = needsOpenGL,
    .jitRender           = g_params.jitRender
  };

  g_state.dsInitialized = g_state.ds->init(params);
  if (!g_state.dsInitialized)
  {
    DEBUG_ERROR("Failed to initialize the displayserver backend");
    return -1;
  }

  if (g_params.noScreensaver)
    g_state.ds->inhibitIdle();

  // ensure renderer viewport is aware of the current window size
  core_updatePositionInfo();

  if (g_params.fpsMin <= 0)
  {
    // default 30 fps
    g_state.frameTime = 1000000000ULL / 30ULL;
  }
  else
  {
    DEBUG_INFO("Using the FPS minimum from args: %d", g_params.fpsMin);
    g_state.frameTime = 1000000000ULL / (unsigned long long)g_params.fpsMin;
  }

  // when the overlay is shown we should run at a minimum of 60 fps for
  // interactivity.
  g_state.overlayFrameTime = min(g_state.frameTime, 1000000000ULL / 60ULL);

  if (!g_state.jitRender)
  {
    if (!(e_cursorRepaint = lgCreateEvent(true, 0)))
    {
      DEBUG_ERROR("failed to create the cursor repaint event");
      return -1;
    }

    if (!lgCreateThread("cursorRepaint", cursorRepaintThread, NULL,
          &t_cursorRepaint))
    {
      DEBUG_ERROR("cursor repaint thread creation failed");
      return -1;
    }
  }

  keybind_commonRegister();
  keybind_inputRegister();

  if (g_state.jitRender)
    DEBUG_INFO("Using JIT render mode");

  lgInit();

  // start the renderThread so we don't just display junk
  if (!lgCreateThread("renderThread", renderThread, NULL, &t_render))
  {
    DEBUG_ERROR("render create thread failed");
    return -1;
  }

  // wait for startup to complete so that any error messages below are output at
  // the end of the output
  lgWaitEvent(e_startup, TIMEOUT_INFINITE);

  LG_RendererInterop interop = {
    .version = LG_RENDERER_INTEROP_VERSION,
    .size    = sizeof(interop),
  };
  const LG_RendererInterop * interopPtr = NULL;
  if (g_state.lgr->ops.getInterop &&
      g_state.lgr->ops.getInterop(g_state.lgr, &interop))
    interopPtr = &interop;
  bool videoAttached;
  if (g_state.videoOps->type == LG_VIDEO_TYPE_FRAME)
    videoAttached = !g_state.videoOps->frame->attachRenderer ||
      g_state.videoOps->frame->attachRenderer(
          g_state.transport.handle, interopPtr);
  else
    videoAttached = g_state.videoOps->swSurface->attach(
        g_state.transport.handle, &swSurfaceEvents,
        (void *)(uintptr_t)LG_VIDEO_SOURCE_PRIMARY);

  if (!videoAttached)
  {
    DEBUG_ERROR("Failed to attach the video source");
    return -1;
  }

  g_state.ds->startup();
  const bool clipboardAvailable =
    g_state.ds->cbInit && g_state.ds->cbInit();
  clipboard_setLocalAvailable(clipboardAvailable);

  if (g_params.captureOnStart)
    core_setGrab(true);

  int waitCount = 0;
  LG_TransportSession session;
  MsgBoxHandle msgs[10];
  int msgsCount;
  struct RecoveryPrompt recoveryPrompt = { 0 };
  atomic_init(&recoveryPrompt.choice, RECOVERY_PENDING);
  atomic_init(&recoveryPrompt.handle, 0);
  atomic_init(&recoveryPrompt.message, 0);
  atomic_init(&recoveryPrompt.messageClosed, false);

restart:
  frameTimingReset();
  msgsCount = 0;
  memset(msgs, 0, sizeof(msgs));

  uint64_t initialFallbackEnable = g_state.fallback ?
    microtime() + 1000 * 1000 : 0;

  while(app_getState() == APP_STATE_RUNNING)
  {
    fallbackHandleEvents();

    if (initialFallbackEnable && microtime() > initialFallbackEnable)
    {
      if (fallbackRequestVideo())
        initialFallbackEnable = 0;
    }

    struct TransportSessionProbe probe = {
      .transport    = g_state.transport.handle,
      .ops          = g_state.transport.ops,
      .cancelled    = transportSessionCancelled,
      .cancelOpaque = NULL,
      .done         = false,
    };
    LGThread * probeThread;
    if (!lgCreateThread("transportSession", transportSessionProbe, &probe,
          &probeThread))
    {
      DEBUG_ERROR("Failed to create transport session probe thread");
      return recoveryExit(&recoveryPrompt, -1);
    }

    while (app_getState() == APP_STATE_RUNNING &&
        !atomic_load_explicit(&probe.done, memory_order_acquire))
    {
      g_state.ds->wait(100);
      fallbackHandleEvents();
    }

    if (!lgJoinThread(probeThread, NULL))
    {
      DEBUG_ERROR("Failed to join transport session probe thread");
      return recoveryExit(&recoveryPrompt, -1);
    }

    if (app_getState() != APP_STATE_RUNNING)
      return recoveryExit(&recoveryPrompt, -1);

    if (probe.status == LG_TRANSPORT_OK)
    {
      session = probe.session;
      atomic_fetch_and_explicit(&g_state.transportLost,
          ~TRANSPORT_LOST_PRIMARY, memory_order_acq_rel);
      initialFallbackEnable = 0;
      break;
    }

    if (probe.status == LG_TRANSPORT_INVALID_VERSION)
    {
      if (waitCount++ == 0)
        reportBadVersion(&probe.session.versionMismatch);

      recoveryHandleMismatch(
          &recoveryPrompt, &probe.session.versionMismatch);

      g_state.ds->wait(1000);
      continue;
    }

    if (probe.status == LG_TRANSPORT_UNAVAILABLE ||
        probe.status == LG_TRANSPORT_DISCONNECTED)
    {
      if (waitCount++ == 0)
      {
        DEBUG_BREAK();
        DEBUG_INFO("The transport source is not available");
        DEBUG_INFO("Waiting for the source to start...");
      }
      if (waitCount == 30 && !g_params.disableWaitingMessage)
      {
        const size_t msgCapacity = sizeof(msgs) / sizeof(*msgs);
        retainMessage(msgs, msgCapacity, &msgsCount,
            app_msgBox("Transport Source Not Available",
              "The selected transport source is not available.\n"
              "Continuing to wait..."));
        retainMessage(msgs, msgCapacity, &msgsCount,
            showSpiceInputHelp());
      }
      g_state.ds->wait(1000);
      continue;
    }

    DEBUG_ERROR("Transport connection failed with status %d", probe.status);
    return recoveryExit(&recoveryPrompt, -1);
  }

  if (app_getState() != APP_STATE_RUNNING)
    return recoveryExit(&recoveryPrompt, -1);

  recoveryClose(&recoveryPrompt);
  LG_RecoveryInfo recoveryInfo = { 0 };
  if (recoveryGetInfo(&recoveryInfo) &&
      (recoveryInfo.state == LG_RECOVERY_STATE_ACTIVE ||
       recoveryInfo.state == LG_RECOVERY_STATE_SWITCHING ||
       recoveryInfo.request == LG_RECOVERY_REQ_RECOVERY ||
       recoveryInfo.ackRequest == LG_RECOVERY_REQ_RECOVERY) &&
      g_state.transport.ops->requestRecovery)
  {
    const LG_TransportStatus status =
      g_state.transport.ops->requestRecovery(g_state.transport.handle,
          LG_RECOVERY_REQ_NORMAL, NULL);
    if (status != LG_TRANSPORT_OK)
      DEBUG_WARN("Failed to leave recovery mode: %d", status);
  }
  recoveryPrompt.serial        = 0;
  recoveryPrompt.failedSerial  = 0;
  recoveryPrompt.reportedState = LG_RECOVERY_STATE_UNKNOWN;
  recoveryPrompt.shown         = false;
  recoveryPrompt.requested     = false;
  recoveryPrompt.owned         = false;
  recoveryPrompt.retryPrompt   = false;
  recoveryPrompt.retryDeclined = false;
  atomic_store_explicit(
      &recoveryPrompt.choice, RECOVERY_PENDING, memory_order_relaxed);

  waitCount = 100;
  for (int i = 0; i < msgsCount; ++i)
    if (msgs[i])
      app_msgBoxClose(msgs[i]);

  DEBUG_INFO("Guest Information:");
  DEBUG_INFO("Version  : %s", session.version[0] ? session.version : "unknown");
  if (session.cpuModel[0])
    DEBUG_INFO("CPU Model: %s", session.cpuModel);
  if (session.cpus)
    DEBUG_INFO("CPU      : %u sockets, %u cores, %u threads",
        session.sockets, session.cores, session.cpus);
  if (session.capture[0])
    DEBUG_INFO("Using    : %s", session.capture);

  if (session.cpuModel[0] && session.cpus && session.cores)
  {
    char hostModel[1024] = {};
    int hostProcs   = 0;
    int hostCores   = 0;
    int hostSockets = 0;
    if (cpuInfo_get(hostModel, sizeof(hostModel), &hostProcs, &hostCores,
        &hostSockets))
    {
      if (hostProcs > hostCores && session.cpus <= session.cores)
      {
        DEBUG_BREAK();
        DEBUG_WARN("The host CPU has hardware threads but the guest is not aware of them");
        DEBUG_WARN("This can degrade latency-sensitive tasks including Looking Glass");
        if (strncmp(hostModel, "AMD ", 4) == 0)
          DEBUG_WARN("For AMD CPUs, enable the `topoext` CPU feature for the virtual machine");
        DEBUG_BREAK();
      }

      if (strcmp(session.cpuModel, hostModel) != 0)
      {
        DEBUG_BREAK();
        DEBUG_WARN("The guest is unaware of the acceleration features of the host CPU");
        DEBUG_WARN("Set the virtual machine CPU type to `host-passthrough`");
        DEBUG_BREAK();
      }
    }
  }

  static const char * osNames[] = { "Linux", "BSD", "OSX", "Windows", "Other" };
  const char * os = session.os < LG_TRANSPORT_OS_OTHER + 1 ?
    osNames[session.os] : "Unknown";
  DEBUG_INFO("OS       : %s", os);
  if (session.osName[0])
    DEBUG_INFO("OS Name  : %s", session.osName);

  g_state.guestOS        = session.os;
  g_state.guestUUIDValid = session.uuidValid;
  if (session.uuidValid)
  {
    memcpy(g_state.guestUUID, session.uuid, sizeof(g_state.guestUUID));
    lgTransportFallback_setPrimaryUUID(
        g_state.fallback, g_state.guestUUID);
  }
  else
    lgTransportFallback_clearPrimaryUUID(g_state.fallback);
  g_state.transportFeatures = session.features;
  frameScheduler_start(session.features);

  void              * inputOpaque = NULL;
  const LG_InputOps * inputOps    = g_state.transport.ops->getInputOps ?
    g_state.transport.ops->getInputOps(
        g_state.transport.handle, &inputOpaque) : NULL;
  lgInput_setTransport(inputOps, inputOpaque);

  void              * audioOpaque = NULL;
  const LG_AudioOps * audioOps    = g_state.transport.ops->getAudioOps ?
    g_state.transport.ops->getAudioOps(
        g_state.transport.handle, &audioOpaque) : NULL;
  lgAudio_setTransport(audioOps, audioOpaque);

  void * clipboardOpaque = NULL;
  const LG_ClipboardOps * clipboardOps =
    g_state.transport.ops->getClipboardOps ?
      g_state.transport.ops->getClipboardOps(
          g_state.transport.handle, &clipboardOpaque) : NULL;
  clipboard_setTransport(clipboardOps, clipboardOpaque);

  DEBUG_INFO("Starting session");
  atomic_store_explicit(
      &g_state.lgHostConnected, true, memory_order_release);

  if (g_state.videoOps->type == LG_VIDEO_TYPE_FRAME)
  {
    primaryVideoStatusStart();
    if (!atomic_load_explicit(&g_state.stopVideo, memory_order_acquire) &&
        !core_startVideoThreads())
    {
      primaryVideoStatusStop();
      return recoveryExit(&recoveryPrompt, -1);
    }
  }
  else
  {
    if (!lgSwSurface_setActive(g_state.videoOps->swSurface,
          g_state.transport.handle, true,
          primarySurfaceActivationCancelled, NULL))
    {
      DEBUG_ERROR("Failed to activate the primary software surface");
      return recoveryExit(&recoveryPrompt, -1);
    }
    app_useVideoSource(LG_VIDEO_SOURCE_PRIMARY);
  }

  while(likely(app_getState() == APP_STATE_RUNNING))
  {
    fallbackHandleEvents();
    if (unlikely(!g_state.transport.ops->sessionValid(
          g_state.transport.handle)))
    {
      lgInput_dropTransport();
      lgAudio_dropTransport();
      clipboard_dropTransport();
      primaryLost();
      break;
    }
    lgMessage_process();
    frameScheduler_update();
    g_state.ds->wait(100);
  }

  frameScheduler_stop();
  primaryVideoStatusStop();

  if (app_getState() == APP_STATE_RESTART)
  {
    atomic_store_explicit(
        &g_state.lgHostConnected, false, memory_order_release);
    g_state.guestUUIDValid = false;

    lgSignalEvent(e_startup);
    lgSignalEvent(g_state.frameEvent);

    if (g_state.videoOps->type == LG_VIDEO_TYPE_FRAME)
      core_stopVideoThreads();
    else
      lgSwSurface_setActive(g_state.videoOps->swSurface,
          g_state.transport.handle, false, NULL, NULL);
    videoSourceInvalidate(LG_VIDEO_SOURCE_PRIMARY);
    videoSourceClearCursor(LG_VIDEO_SOURCE_PRIMARY);
    lgInput_dropTransport();
    lgAudio_dropTransport();
    clipboard_dropTransport();
    g_state.transport.ops->disconnect(g_state.transport.handle);

    if (app_transitionState(APP_STATE_RESTART, APP_STATE_RUNNING))
    {
      lgInit();
      goto restart;
    }
  }

  return recoveryExit(&recoveryPrompt, 0);
}

static void lg_shutdown(void)
{
  app_setState(APP_STATE_SHUTDOWN);
  frameScheduler_stop();

  if (e_cursorRepaint)
    lgSignalEvent(e_cursorRepaint);

  if (t_render)
  {
    if (g_state.jitRender && g_state.ds->stopWaitFrame)
      g_state.ds->stopWaitFrame();
    lgSignalEvent(e_startup);
    lgSignalEvent(g_state.frameEvent);
    lgJoinThread(t_render, NULL);
  }

  // Stop external input callbacks before tearing down shared client state
  evdev_stop();
  if (g_state.ds && g_state.dsInitialized)
    g_state.ds->shutdown();

  fallbackStop();

  if (t_cursorRepaint)
  {
    lgJoinThread(t_cursorRepaint, NULL);
    t_cursorRepaint = NULL;
  }

  if (e_cursorRepaint)
  {
    lgFreeEvent(e_cursorRepaint);
    e_cursorRepaint = NULL;
  }
  LG_LOCK_FREE(l_cursorRepaint.lock);

  if (g_state.transport.ops)
  {
    lgInput_dropTransport();
    if (g_state.transport.handle &&
        g_state.transport.ops->sessionValid(g_state.transport.handle))
    {
      lgAudio_setTransport(NULL, NULL);
      clipboard_setTransport(NULL, NULL);
    }
    else
    {
      lgAudio_dropTransport();
      clipboard_dropTransport();
    }
    lgTransport_destroy(&g_state.transport);
  }

  lgInput_free();
  lgAudio_free();
  clipboard_setLocalAvailable(false);

  if (e_startup)
  {
    lgFreeEvent(e_startup);
    e_startup = NULL;
  }

  app_releaseAllKeybinds();
  ll_free(g_state.bindings);

  if (g_state.ds && g_state.dsInitialized)
  {
    g_state.dsInitialized = false;
    g_state.ds->free();
  }

  /* Clipboard sources own FUSE dataset references and are released by the
   * display server before the filesystem is unmounted. */
  clipboard_free();

  // Input callbacks have stopped; the evdev state and overlays can go
  evdev_free();

  if (g_state.overlays)
  {
    app_freeOverlays();
    ll_free(g_state.overlays);
    g_state.overlays = NULL;
  }

  // app_invalidateWindow runs during display server and overlay teardown
  if (g_state.frameEvent)
  {
    lgFreeEvent(g_state.frameEvent);
    g_state.frameEvent = NULL;
  }

  renderQueue_setSourceFns(NULL, NULL, NULL, NULL);
  renderQueue_free();
  LG_LOCK_FREE(g_state.videoPayloadLock);
  LG_LOCK_FREE(g_state.videoSourceLock);
  LG_LOCK_FREE(g_state.videoSplashLock);
  frameScheduler_free();

  // free metrics ringbuffers
  ringbuffer_free(&g_state.renderTimings);
  ringbuffer_free(&g_state.frameLatency);
  LG_LOCK_FREE(l_frameTiming.lock);

  free(g_state.fontName);
  igDestroyContext(NULL);
  free(g_state.imGuiIni);
}

int main(int argc, char * argv[])
{
  // initialize for DEBUG_* macros
  debug_init();

  if (getuid() == 0)
  {
    DEBUG_ERROR("Do not run looking glass as root!");
    return -1;
  }

  if (getuid() != geteuid())
  {
    DEBUG_ERROR("Do not run looking glass as setuid!");
    return -1;
  }

  lgInitProcessTitle(argc, &argv);
  core_setTitle(NULL);

  DEBUG_INFO("Looking Glass (%s)", BUILD_VERSION);
  DEBUG_INFO("Locking Method: " LG_LOCK_MODE);
  cpuInfo_log();

  if (!installCrashHandler("/proc/self/exe", argv[0]))
    DEBUG_WARN("Failed to install the crash handler");

  lgPathsInit("looking-glass");
  config_init();
  lgTransport_setup();
  egl_dynProcsInit();
  gl_dynProcsInit();

  if (!lgMessage_init())
    return -1;

  g_state.bindings = ll_new();

  g_state.overlays = ll_new();
  app_registerOverlay(&LGOverlaySplash, NULL);
  app_registerOverlay(&LGOverlayConfig, NULL);
  app_registerOverlay(&LGOverlayAlert , NULL);
  app_registerOverlay(&LGOverlayFPS   , NULL);
  app_registerOverlay(&LGOverlayGraphs, NULL);
  app_registerOverlay(&LGOverlayHelp  , NULL);
  app_registerOverlay(&LGOverlayMsg   , NULL);
  app_registerOverlay(&LGOverlayStatus, NULL);

  // early renderer setup for option registration
  for(unsigned int i = 0; i < LG_RENDERER_COUNT; ++i)
    LG_Renderers[i]->setup();

  for(unsigned int i = 0; i < LG_DISPLAYSERVER_COUNT; ++i)
    LG_DisplayServers[i]->setup();

  for(unsigned int i = 0; LG_AudioDevs[i]; ++i)
    if (LG_AudioDevs[i]->earlyInit)
      LG_AudioDevs[i]->earlyInit();

  evdev_earlyInit();

  if (!config_load(argc, argv))
    return -1;

  const int ret = lg_run();
  lg_shutdown();
  lgMessage_deinit();

  config_free();

  util_freeUIFonts();
  cleanupCrashHandler();
  return ret;
}