[obs] scheduler: serialize cadence controls

Track the LGMP serial for each accepted frame-schedule message and wait for its acknowledgement before sending another. Preserve pending RESET, IMMEDIATE, and feedback state after definite enqueue failures. Use bounded retry polling and request one fresh immediate frame after an ambiguous pointer-queue fault recovers.
2026-08-09 00:31:31 +00:00 · 2026-08-06 17:03:09 +10:00
parent 1040683a3a
commit 8a04037c9b
8 changed files with 345 additions and 43 deletions
--- a/client/src/app.c
+++ b/client/src/app.c
@@ -469,7 +469,8 @@ void app_handleButtonPress(int button)
    return;
  }

-  if (!core_inputEnabled() || !g_cursor.inView || !g_cursor.viewReq)
+  if (!core_inputEnabled() || g_cursor.exitWait ||
+      !g_cursor.inView || !g_cursor.viewReq)
    return;

  if (!purespice_mousePress(button))
@@ -492,7 +493,7 @@ void app_handleButtonRelease(int button)
    return;
  }

-  if (!core_inputEnabled())
+  if (!core_inputEnabled() || g_cursor.exitWait)
    return;

  if (!purespice_mouseRelease(button))
--- a/client/src/core.c
+++ b/client/src/core.c
@@ -62,18 +62,21 @@ static int exitPos(double pos, int edge)

 static void cancelExit(const char * why)
 {
-  if (!g_cursor.exit)
+  if (!g_cursor.exit && !g_cursor.exitWait)
    return;

  MTRACE("exit cancel=%s target=%.3f,%.3f", why,
      g_cursor.exitPos.x, g_cursor.exitPos.y);
-  g_cursor.exit = false;
+  g_cursor.exit      = false;
+  g_cursor.exitWait  = false;
+  g_cursor.exitRetry = false;
+  g_cursor.exitDelta = (struct DoublePoint) { 0 };
 }

-static void finishExit(void)
+static bool finishExit(void)
 {
  if (!g_cursor.exit || g_cursor.viewReq)
-    return;
+    return false;

  const int x = exitPos(g_cursor.exitPos.x, g_state.dstRect.x);
  const int y = exitPos(g_cursor.exitPos.y, g_state.dstRect.y);
@@ -82,21 +85,27 @@ static void finishExit(void)
  MTRACE("exit warp target=%d,%d projected=%.3f,%.3f inWin=%d",
      x, y, g_cursor.exitPos.x, g_cursor.exitPos.y, g_cursor.inWindow);

-  if (x < 0 || x >= g_state.windowW ||
-      y < 0 || y >= g_state.windowH)
+  if (g_cursor.exitWait)
+    g_cursor.viewReq = true;
+  else if (x < 0 || x >= g_state.windowW ||
+           y < 0 || y >= g_state.windowH)
    g_cursor.inWindow = false;

  core_warpPointer(x, y, true);
+  return g_cursor.exitWait;
 }

-static void startExit(double x, double y)
+static void startExit(double x, double y, bool wait)
 {
-  g_cursor.exit    = true;
-  g_cursor.exitPos = (struct DoublePoint) { x, y };
+  g_cursor.exit      = true;
+  g_cursor.exitWait  = wait;
+  g_cursor.exitRetry = false;
+  g_cursor.exitPos   = (struct DoublePoint) { x, y };
+  g_cursor.exitDelta = (struct DoublePoint) { 0 };
  core_setCursorInView(false);
 }

-static bool moveExit(double ex, double ey)
+static struct DoublePoint exitMove(double ex, double ey)
 {
  if (g_cursor.useScale && g_params.scaleMouseInput)
  {
@@ -106,18 +115,115 @@ static bool moveExit(double ex, double ey)

  struct DoublePoint move = {.x = ex, .y = ey};
  util_rotatePoint(&move);
-  g_cursor.exitPos.x += move.x;
-  g_cursor.exitPos.y += move.y;
+  return move;
+}

-  const bool inside =
-    g_cursor.exitPos.x >= g_state.dstRect.x &&
-    g_cursor.exitPos.x <  g_state.dstRect.x + g_state.dstRect.w &&
-    g_cursor.exitPos.y >= g_state.dstRect.y &&
-    g_cursor.exitPos.y <  g_state.dstRect.y + g_state.dstRect.h;
+static struct Point exitDir(void)
+{
+  return (struct Point) {
+    .x = g_cursor.exitPos.x < g_state.dstRect.x ? -1 :
+      g_cursor.exitPos.x >= g_state.dstRect.x + g_state.dstRect.w ? 1 : 0,
+    .y = g_cursor.exitPos.y < g_state.dstRect.y ? -1 :
+      g_cursor.exitPos.y >= g_state.dstRect.y + g_state.dstRect.h ? 1 : 0,
+  };
+}

-  MTRACE("exit move=%.3f,%.3f target=%.3f,%.3f inside=%d",
-      move.x, move.y, g_cursor.exitPos.x, g_cursor.exitPos.y, inside);
-  return inside;
+static bool exitInward(struct DoublePoint move)
+{
+  const struct Point dir = exitDir();
+  return move.x * dir.x < 0 || move.y * dir.y < 0;
+}
+
+static struct DoublePoint exitInput(struct DoublePoint move)
+{
+  double temp;
+  switch((g_state.rotate + g_params.winRotate) % LG_ROTATE_MAX)
+  {
+    case LG_ROTATE_0:
+      break;
+
+    case LG_ROTATE_90:
+      temp   = move.x;
+      move.x = -move.y;
+      move.y = temp;
+      break;
+
+    case LG_ROTATE_180:
+      move.x = -move.x;
+      move.y = -move.y;
+      break;
+
+    case LG_ROTATE_270:
+      temp   = move.x;
+      move.x = move.y;
+      move.y = -temp;
+      break;
+  }
+
+  if (g_cursor.useScale && g_params.scaleMouseInput)
+  {
+    move.x /= g_cursor.scale.x;
+    move.y /= g_cursor.scale.y;
+  }
+
+  return move;
+}
+
+static struct DoublePoint clampExit(double ex, double ey)
+{
+  struct DoublePoint move = exitMove(ex, ey);
+  const struct Point dir = exitDir();
+  if (move.x * dir.x > 0)
+    move.x = 0;
+  if (move.y * dir.y > 0)
+    move.y = 0;
+
+  const struct DoublePoint input = exitInput(move);
+  MTRACE("exit clamp input=%.3f,%.3f move=%.3f,%.3f dir=%d,%d",
+      input.x, input.y, move.x, move.y, dir.x, dir.y);
+  return input;
+}
+
+static bool moveExit(double ex, double ey)
+{
+  const struct DoublePoint move = exitMove(ex, ey);
+  const bool inward = exitInward(move);
+
+  if (!inward)
+  {
+    g_cursor.exitPos.x += move.x;
+    g_cursor.exitPos.y += move.y;
+  }
+
+  MTRACE("exit move=%.3f,%.3f target=%.3f,%.3f inward=%d",
+      move.x, move.y, g_cursor.exitPos.x, g_cursor.exitPos.y, inward);
+  return inward;
+}
+
+static void startRetry(void)
+{
+  if (!g_cursor.exitWait || g_cursor.exit || g_cursor.exitRetry)
+    return;
+
+  MTRACE("exit retry target=%.3f,%.3f", g_cursor.exitPos.x,
+      g_cursor.exitPos.y);
+  g_cursor.pos.x     = util_clamp(g_cursor.exitPos.x, 0,
+      g_state.windowW - 1);
+  g_cursor.pos.y     = util_clamp(g_cursor.exitPos.y, 0,
+      g_state.windowH - 1);
+  g_cursor.exitRetry = true;
+  g_cursor.realign   = true;
+  g_state.ds->grabPointer();
+}
+
+static void retryExit(double ex, double ey)
+{
+  const struct DoublePoint input = clampExit(ex, ey);
+  g_cursor.exitDelta.x += input.x;
+  g_cursor.exitDelta.y += input.y;
+
+  if (input.x != 0 || input.y != 0)
+    startRetry();
 }

 bool core_inputEnabled(void)
@@ -193,9 +299,17 @@ void core_setCursorInView(bool enable)
      enable, g_cursor.viewReq, g_cursor.inView, g_state.focused,
      g_cursor.inWindow, g_cursor.grab);

-  if (g_cursor.exit &&
-      (enable || !g_state.focused || !g_cursor.inWindow ||
-       g_state.ignoreInput || !g_state.posInfoValid || app_isOverlayMode()))
+  if (enable && g_cursor.exitWait && !g_cursor.exit)
+  {
+    startRetry();
+    return;
+  }
+
+  if ((g_cursor.exit && enable) ||
+      ((g_cursor.exit || g_cursor.exitWait) &&
+       (!g_state.focused || !g_cursor.inWindow || g_state.ignoreInput ||
+        !g_state.posInfoValid || app_isOverlayMode())) ||
+      (g_cursor.exitWait && !g_cursor.exit && !enable))
    cancelExit(enable ? "view" : "state");

  if (enable && !g_state.focused)
@@ -253,10 +367,25 @@ void core_handleGrabEvent(bool active)
      warpSupport == LG_DS_WARP_NONE)
    return;

+  struct DoublePoint replay = { 0 };
  if (!active)
-    finishExit();
+  {
+    if (finishExit() || g_cursor.exitWait)
+      return;
+  }
+  else if (g_cursor.exitRetry)
+  {
+    replay             = g_cursor.exitDelta;
+    g_cursor.exitWait  = false;
+    g_cursor.exitRetry = false;
+    g_cursor.exitDelta = (struct DoublePoint) { 0 };
+    g_cursor.warpState = WARP_STATE_ON;
+  }

  applyView(active, false);
+
+  if (replay.x != 0 || replay.y != 0)
+    core_handleMouseNormal(replay.x, replay.y);
 }

 void core_setGrab(bool enable)
@@ -282,6 +411,7 @@ void core_setGrabQuiet(bool enable)
  if (g_cursor.grab == enable)
    return;

+  cancelExit("capture");
  g_cursor.grab = enable;
  g_cursor.acc.x = 0.0;
  g_cursor.acc.y = 0.0;
@@ -389,7 +519,10 @@ void core_onWindowSizeChanged(unsigned width, unsigned height)

 void core_updatePositionInfo(void)
 {
-  cancelExit("geometry");
+  if (g_cursor.exitWait && !g_cursor.exit)
+    startRetry();
+  else
+    cancelExit("geometry");

  if (g_params.setGuestRes &&
      g_state.transportFeatures & LG_TRANSPORT_FEATURE_WINDOW_SIZE)
@@ -630,7 +763,8 @@ void core_handleGuestMouseUpdate(void)
  }

  const bool overlay = app_isOverlayMode();
-  if (overlay || !g_cursor.inView || !g_cursor.viewReq)
+  if (overlay || g_cursor.exitWait ||
+      !g_cursor.inView || !g_cursor.viewReq)
  {
    MTRACE("guest drop=%s guest=%d,%d local=%.3f,%.3f inWin=%d "
        "inView=%d req=%d", overlay ? "overlay" : "view",
@@ -712,6 +846,12 @@ void core_handleMouseNormal(double ex, double ey)
  if (!core_inputEnabled())
    return;

+  if (g_cursor.exitWait && !g_cursor.exit)
+  {
+    retryExit(ex, ey);
+    return;
+  }
+
  if (g_cursor.viewReq != g_cursor.inView)
  {
    if (g_cursor.viewReq)
@@ -885,7 +1025,9 @@ fallback:
          break;

        case LG_DS_WARP_SURFACE:
-          startExit(local.x, local.y);
+          startExit(local.x, local.y,
+              tx < 0 || tx >= g_state.windowW ||
+              ty < 0 || ty >= g_state.windowH);
          return;

        case LG_DS_WARP_SCREEN:
@@ -893,7 +1035,7 @@ fallback:
                g_state.windowPos.x + g_state.border.left + tx,
                g_state.windowPos.y + g_state.border.top  + ty))
          {
-            startExit(local.x, local.y);
+            startExit(local.x, local.y, false);
            return;
          }
      }
--- a/client/src/main.c
+++ b/client/src/main.c
@@ -133,6 +133,9 @@ static void lgInit(void)
  g_cursor.inView        = false;
  g_cursor.viewReq       = false;
  g_cursor.exit          = false;
+  g_cursor.exitWait      = false;
+  g_cursor.exitRetry     = false;
+  g_cursor.exitDelta     = (struct DoublePoint) { 0 };
  g_cursor.guest.valid   = false;

  // if spice is not in use, hide the local cursor
--- a/client/src/main.h
+++ b/client/src/main.h
@@ -301,9 +301,18 @@ struct CursorState
  /* true if a pointer exit is waiting for confinement to release */
  bool exit;

+  /* true if a surface exit is waiting for a pointer leave */
+  bool exitWait;
+
+  /* true if confinement is being restored after a failed exit */
+  bool exitRetry;
+
  /* the local pointer exit target */
  struct DoublePoint exitPos;

+  /* input retained while confinement is restored */
+  struct DoublePoint exitDelta;
+
  /* true if the guest should be realigned to the host when next drawn */
  bool realign;

--- a/client/tests/CMakeLists.txt
+++ b/client/tests/CMakeLists.txt
@@ -66,6 +66,7 @@ target_link_libraries(mouse-tests
 )
 set(MOUSE_CASES
  inset-exit
+  surface-edge
  exit-delay
  exit-guest
  exit-cancel
--- a/client/tests/mouse_test.c
+++ b/client/tests/mouse_test.c
@@ -329,6 +329,76 @@ static void setConf(bool active)
  core_handleGrabEvent(active);
 }

+static void setEdge(enum LG_DSWarpSupport support)
+{
+  reset();
+  m.support       = support;
+  g_state.windowW = 100;
+  g_state.windowH = 80;
+  g_state.dstRect = (LG_RendererRect) {
+    .valid = true,
+    .x     = 0,
+    .y     = 0,
+    .w     = 100,
+    .h     = 80,
+  };
+  setLocal(99, 40);
+}
+
+static void testSurfaceEdge(void)
+{
+  setEdge(LG_DS_WARP_SURFACE);
+
+  core_handleMouseNormal(1, 0);
+
+  const int move = first(EV_WARP);
+  CHECK(move >= 0);
+  CHECK(m.ev[move].x == 100);
+  CHECK(m.ev[move].y == 40);
+  CHECK(g_cursor.inWindow);
+  CHECK(g_cursor.inView);
+  CHECK(g_cursor.viewReq);
+  CHECK(g_cursor.exitWait);
+  CHECK(!m.conf.req);
+
+  core_handleGuestMouseUpdate();
+  CHECK(count(EV_GUEST) == 0);
+
+  core_handleMouseNormal(1, 0);
+  CHECK(!m.conf.req);
+  CHECK(!g_cursor.exitRetry);
+
+  g_cursor.pos.x = 104;
+  core_handleMouseNormal(1, 2);
+  CHECK(m.conf.req);
+  CHECK(g_cursor.pos.x == 99);
+  CHECK(g_cursor.inView);
+  CHECK(g_cursor.exitWait);
+  CHECK(g_cursor.exitRetry);
+  CHECK(count(EV_MOTION) == 0);
+
+  setConf(true);
+  CHECK(g_cursor.inView);
+  CHECK(!g_cursor.exitWait);
+  CHECK(!g_cursor.exitRetry);
+  CHECK(count(EV_MOTION) == 1);
+  CHECK(m.ev[first(EV_MOTION)].x == 0);
+  CHECK(m.ev[first(EV_MOTION)].y == 2);
+
+  setEdge(LG_DS_WARP_SURFACE);
+  core_handleMouseNormal(1, 0);
+  g_cursor.inWindow = false;
+  core_setCursorInView(false);
+  CHECK(!g_cursor.inWindow);
+  CHECK(!g_cursor.inView);
+  CHECK(!g_cursor.viewReq);
+  CHECK(!g_cursor.exitWait);
+
+  setEdge(LG_DS_WARP_SCREEN);
+  core_handleMouseNormal(1, 0);
+  CHECK(!g_cursor.inWindow);
+}
+
 static void startExit(void)
 {
  reset();
@@ -382,7 +452,7 @@ static void testExitCancel(void)
  CHECK(g_cursor.exit);
  CHECK(!g_cursor.viewReq);

-  core_handleMouseNormal(-3, 0);
+  core_handleMouseNormal(-0.25, 0);
  CHECK(!g_cursor.exit);
  CHECK(g_cursor.viewReq);
  CHECK(m.conf.req);
@@ -742,6 +812,7 @@ struct Test

 static const struct Test tests[] = {
  { "inset-exit"      , testInsetExit    },
+  { "surface-edge"    , testSurfaceEdge  },
  { "exit-delay"      , testExitWait     },
  { "exit-guest"      , testExitGuest    },
  { "exit-cancel"     , testExitCancel   },
--- a/obs/frame_scheduler.c
+++ b/obs/frame_scheduler.c
@@ -24,13 +24,79 @@

 #include <string.h>

-#define FRAME_SCHEDULER_LEASE_MS        1000U
-#define FRAME_SCHEDULER_RENEW_NS        250000000ULL
-#define FRAME_SCHEDULER_FEEDBACK_NS     50000000ULL
-#define FRAME_SCHEDULER_TICK_GRACE_NS   500000000ULL
-#define FRAME_SCHEDULER_TARGET_SLACK_NS 1000000ULL
-#define FRAME_SCHEDULER_MIN_PERIOD_NS   2000000ULL
-#define FRAME_SCHEDULER_MAX_PERIOD_NS   1000000000ULL
+#define FRAME_SCHEDULER_LEASE_MS          1000U
+#define FRAME_SCHEDULER_RENEW_NS          250000000ULL
+#define FRAME_SCHEDULER_FEEDBACK_NS       50000000ULL
+#define FRAME_SCHEDULER_TICK_GRACE_NS     500000000ULL
+#define FRAME_SCHEDULER_TARGET_SLACK_NS   1000000ULL
+#define FRAME_SCHEDULER_MIN_PERIOD_NS     2000000ULL
+#define FRAME_SCHEDULER_MAX_PERIOD_NS     1000000000ULL
+#define FRAME_SCHEDULER_CONTROL_RETRY_NS  10000000ULL
+#define FRAME_SCHEDULER_CONTROL_RETRY_MAX 250000000ULL
+
+static void lgFrameSchedulerControlBackoff(
+    LGFrameScheduler * scheduler, uint64_t now)
+{
+  uint64_t delay = scheduler->controlRetryDelay;
+  if (!delay)
+    delay = FRAME_SCHEDULER_CONTROL_RETRY_NS;
+
+  scheduler->nextControlCheck = now + delay;
+  scheduler->controlRetryDelay =
+    delay < FRAME_SCHEDULER_CONTROL_RETRY_MAX / 2 ?
+      delay * 2 : FRAME_SCHEDULER_CONTROL_RETRY_MAX;
+}
+
+static bool lgFrameSchedulerControlReady(LGFrameScheduler * scheduler,
+    PLGMPClientQueue queue, uint64_t now)
+{
+  if (!scheduler->controlPending)
+    return now >= scheduler->nextControlCheck;
+
+  if (now < scheduler->nextControlCheck)
+    return false;
+
+  uint32_t serial;
+  const LGMP_STATUS status = lgmpClientGetSerial(queue, &serial);
+  if (status != LGMP_OK ||
+      (int32_t)(serial - scheduler->controlSerial) < 0)
+  {
+    if (status != LGMP_OK)
+      scheduler->controlFaulted = true;
+    lgFrameSchedulerControlBackoff(scheduler, now);
+    return false;
+  }
+
+  scheduler->controlPending    = false;
+  scheduler->nextControlCheck  = 0;
+  scheduler->controlRetryDelay = FRAME_SCHEDULER_CONTROL_RETRY_NS;
+  if (scheduler->controlFaulted)
+  {
+    scheduler->controlFaulted   = false;
+    scheduler->immediatePending = true;
+  }
+  return true;
+}
+
+static bool lgFrameSchedulerSend(LGFrameScheduler * scheduler,
+    PLGMPClientQueue queue, const KVMFRFrameSchedule * message,
+    uint64_t now)
+{
+  uint32_t serial;
+  if (lgmpClientSendData(
+        queue, message, sizeof(*message), &serial) != LGMP_OK)
+  {
+    lgFrameSchedulerControlBackoff(scheduler, now);
+    return false;
+  }
+
+  scheduler->controlPending    = true;
+  scheduler->controlSerial     = serial;
+  scheduler->nextControlCheck  =
+    now + FRAME_SCHEDULER_CONTROL_RETRY_NS;
+  scheduler->controlRetryDelay = FRAME_SCHEDULER_CONTROL_RETRY_NS;
+  return true;
+}

 static void lgFrameSchedulerResetFeedback(LGFrameScheduler * scheduler)
 {
@@ -51,9 +117,10 @@ void lgFrameSchedulerInit(LGFrameScheduler * scheduler, bool supported,
    uint32_t clientID)
 {
  memset(scheduler, 0, sizeof(*scheduler));
-  scheduler->supported        = supported;
-  scheduler->immediatePending = supported;
-  scheduler->clientID         = clientID;
+  scheduler->supported         = supported;
+  scheduler->immediatePending  = supported;
+  scheduler->clientID          = clientID;
+  scheduler->controlRetryDelay = FRAME_SCHEDULER_CONTROL_RETRY_NS;
 }

 void lgFrameSchedulerSetActive(LGFrameScheduler * scheduler, bool active)
@@ -175,6 +242,9 @@ void lgFrameSchedulerUpdate(LGFrameScheduler * scheduler,
  if (!scheduler->supported || !queue)
    return;

+  if (!lgFrameSchedulerControlReady(scheduler, queue, now))
+    return;
+
  const bool tickStale = !scheduler->lastTick ||
    now - scheduler->lastTick > FRAME_SCHEDULER_TICK_GRACE_NS;
  if (!scheduler->sourceActive || tickStale || !scheduler->period)
@@ -189,7 +259,7 @@ void lgFrameSchedulerUpdate(LGFrameScheduler * scheduler,
      .flags      = KVMFR_FRAME_SCHEDULE_RELEASE,
    };

-    if (lgmpClientSendData(queue, &message, sizeof(message), NULL) != LGMP_OK)
+    if (!lgFrameSchedulerSend(scheduler, queue, &message, now))
      return;

    scheduler->active           = false;
@@ -234,7 +304,7 @@ void lgFrameSchedulerUpdate(LGFrameScheduler * scheduler,
    .lease                  = FRAME_SCHEDULER_LEASE_MS,
  };

-  if (lgmpClientSendData(queue, &message, sizeof(message), NULL) != LGMP_OK)
+  if (!lgFrameSchedulerSend(scheduler, queue, &message, now))
    return;

  scheduler->active           = true;
--- a/obs/frame_scheduler.h
+++ b/obs/frame_scheduler.h
@@ -34,11 +34,16 @@ typedef struct LGFrameScheduler
  bool     resetPending;
  bool     immediatePending;
  bool     feedbackDirty;
+  bool     controlPending;
+  bool     controlFaulted;
  uint32_t clientID;
  uint32_t generation;
+  uint32_t controlSerial;
  uint64_t period;
  uint64_t lastSend;
  uint64_t lastTick;
+  uint64_t nextControlCheck;
+  uint64_t controlRetryDelay;

  int64_t  phaseError;
  uint32_t feedbackFrameSerial;