use a timer for the LGMP host instead of a thread

VERSION

@@ -1 +1 @@
-B1-180-ge3cbdd18a0+1
+B1-181-g243efcd51a+1

c-host/platform/Windows/src/platform.c

@@ -48,6 +48,7 @@ struct AppState
 };
 
 static struct AppState app = {0};
+HWND MessageHWND;
 
 // undocumented API to adjust the system timer resolution (yes, its a nasty hack)
 typedef NTSTATUS (__stdcall *ZwSetTimerResolution_t)(ULONG RequestedResolution, BOOLEAN Set, PULONG ActualResolution);
@@ -216,6 +217,9 @@ int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine
   }
   app.messageWnd = CreateWindowEx(0, "DUMMY_CLASS", "DUMMY_NAME", 0, 0, 0, 0, 0, HWND_MESSAGE, NULL, NULL, NULL);
 
+  // set the global
+  MessageHWND = app.messageWnd;
+
   app.trayMenu = CreatePopupMenu();
   AppendMenu(app.trayMenu, MF_STRING   , ID_MENU_OPEN_LOG, "Open Log File");
   AppendMenu(app.trayMenu, MF_SEPARATOR, 0               , NULL           );
@@ -298,3 +302,8 @@ const char * os_getExecutable()
 {
   return app.executable;
 }
+
+HWND os_getMessageWnd()
+{
+  return app.messageWnd;
+}

c-host/src/app.c

@@ -28,6 +28,7 @@ Place, Suite 330, Boston, MA 02111-1307 USA
 #include "common/thread.h"
 #include "common/ivshmem.h"
 #include "common/sysinfo.h"
+#include "common/time.h"
 
 #include <lgmp/host.h>
 
@@ -47,14 +48,14 @@ static const struct LGMPQueueConfig FRAME_QUEUE_CONFIG =
 {
   .queueID     = LGMP_Q_FRAME,
   .numMessages = LGMP_Q_FRAME_LEN,
-  .subTimeout  = 10000
+  .subTimeout  = 1000
 };
 
 static const struct LGMPQueueConfig POINTER_QUEUE_CONFIG =
 {
   .queueID     = LGMP_Q_POINTER,
   .numMessages = LGMP_Q_POINTER_LEN,
-  .subTimeout  = 10000
+  .subTimeout  = 1000
 };
 
 #define MAX_POINTER_SIZE (sizeof(KVMFRCursor) + (128 * 128 * 4))
@@ -78,32 +79,23 @@ struct app
 
   bool       running;
   bool       reinit;
-  LGThread * lgmpThread;
+  LGTimer  * lgmpTimer;
   LGThread * frameThread;
 };
 
 static struct app app;
 
-static int lgmpThread(void * opaque)
+static bool lgmpTimer(void * opaque)
 {
   LGMP_STATUS status;
-  while(app.running)
+  if ((status = lgmpHostProcess(app.lgmp)) != LGMP_OK)
   {
-    if ((status = lgmpHostProcess(app.lgmp)) != LGMP_OK)
-    {
-      DEBUG_ERROR("lgmpHostProcess Failed: %s", lgmpStatusString(status));
-      break;
-    }
-
-    /*
-     * do not decrease this value too far, see:
-     * https://lists.gnu.org/archive/html/qemu-devel/2020-01/msg06331.html
-     */
-    usleep(100 * 1000);
+    DEBUG_ERROR("lgmpHostProcess Failed: %s", lgmpStatusString(status));
+    app.running = false;
+    return false;
   }
 
-  app.running = false;
-  return 0;
+  return true;
 }
 
 static int frameThread(void * opaque)
@@ -210,9 +202,9 @@ static int frameThread(void * opaque)
 bool startThreads()
 {
   app.running = true;
-  if (!lgCreateThread("LGMPThread", lgmpThread, NULL, &app.lgmpThread))
+  if (!lgCreateTimer(100, lgmpTimer, NULL, &app.lgmpTimer))
   {
-    DEBUG_ERROR("Failed to create the LGMP thread");
+    DEBUG_ERROR("Failed to create the LGMP timer");
     return false;
   }
 
@@ -239,12 +231,11 @@ bool stopThreads()
   }
   app.frameThread = NULL;
 
-  if (app.lgmpThread && !lgJoinThread(app.lgmpThread, NULL))
+  if (app.lgmpTimer)
   {
-    DEBUG_WARN("Failed to join the LGMP thread");
-    ok = false;
+    lgTimerDestroy(app.lgmpTimer);
+    app.lgmpTimer = NULL;
   }
-  app.lgmpThread = NULL;
 
   return ok;
 }

common/include/common/time.h

@@ -20,6 +20,7 @@ Place, Suite 330, Boston, MA 02111-1307 USA
 #pragma once
 
 #include <stdint.h>
+#include <stdbool.h>
 
 #if defined(_WIN32)
 #include <windows.h>
@@ -28,6 +29,8 @@ Place, Suite 330, Boston, MA 02111-1307 USA
 #include <stdint.h>
 #endif
 
+typedef struct LGTimer LGTimer;
+
 static inline uint64_t microtime()
 {
 #if defined(_WIN32)
@@ -64,3 +67,10 @@ static inline void nsleep(uint64_t ns)
   nanosleep(&ts, NULL);
 }
 #endif
+
+typedef bool (*LGTimerFn)(void * udata);
+
+bool lgCreateTimer(const unsigned int intervalMS, LGTimerFn fn,
+    void * udata, LGTimer ** result);
+
+void lgTimerDestroy(LGTimer * timer);

common/src/platform/windows/CMakeLists.txt

@@ -12,6 +12,7 @@ add_library(lg_common_platform_code STATIC
     event.c
     windebug.c
     ivshmem.c
+    time.c
 )
 
 target_link_libraries(lg_common_platform_code

common/src/platform/windows/time.c

@@ -0,0 +1,72 @@
+/*
+Looking Glass - KVM FrameRelay (KVMFR) Client
+Copyright (C) 2017-2020 Geoffrey McRae <geoff@hostfission.com>
+https://looking-glass.hostfission.com
+
+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 "common/time.h"
+#include "common/debug.h"
+
+// decared by the platform
+extern HWND MessageHWND;
+
+struct LGTimer
+{
+  LGTimerFn   fn;
+  void      * udata;
+  UINT_PTR    handle;
+  bool        running;
+};
+
+static void TimerProc(HWND Arg1, UINT Arg2, UINT_PTR Arg3, DWORD Arg4)
+{
+  LGTimer * timer = (LGTimer *)Arg3;
+  if (!timer->fn(timer->udata))
+  {
+    KillTimer(Arg1, timer->handle);
+    timer->running = false;
+  }
+}
+
+bool lgCreateTimer(const unsigned int intervalMS, LGTimerFn fn,
+    void * udata, LGTimer ** result)
+{
+  LGTimer * ret = malloc(sizeof(LGTimer));
+  if (!ret)
+  {
+    DEBUG_ERROR("failed to malloc LGTimer struct");
+    return false;
+  }
+
+  ret->fn      = fn;
+  ret->udata   = udata;
+  ret->running = true;
+  ret->handle  = SetTimer(MessageHWND, (UINT_PTR)ret, intervalMS, TimerProc);
+
+  *result = ret;
+  return true;
+}
+
+void lgTimerDestroy(LGTimer * timer)
+{
+  if (timer->running)
+  {
+    if (!KillTimer(MessageHWND, timer->handle))
+      DEBUG_ERROR("failed to destroy the timer");
+  }
+
+  free(timer);
+}