[client] lgmp: fix timeout due to improper handling of pause/resume

client/include/interface/transport.h

@@ -201,11 +201,17 @@ typedef struct LG_TransportOps
   LG_TransportStatus (*nextFrame)(LG_Transport * transport, bool useDMA,
       LG_TransportFrame * frame);
   void (*releaseFrame)(LG_Transport * transport, LG_TransportFrame * frame);
+  /* Called by the frame consumer as it exits. A backend may release transient
+   * stream resources; nextFrame must reacquire them when the consumer restarts. */
+  void (*stopFrame)(LG_Transport * transport);
 
   LG_TransportStatus (*nextPointer)(LG_Transport * transport,
       LG_TransportPointer * pointer);
   void (*releasePointer)(LG_Transport * transport,
       LG_TransportPointer * pointer);
+  /* Called by the pointer consumer as it exits. A backend may release transient
+   * stream resources; nextPointer must reacquire them when the consumer restarts. */
+  void (*stopPointer)(LG_Transport * transport);
 
   LG_TransportStatus (*sendControl)(LG_Transport * transport,
       const LG_TransportControl * control, LG_TransportControlToken * token);

client/src/main.c

@@ -569,6 +569,9 @@ int main_cursorThread(void * unused)
     g_state.transportOps->releasePointer(g_state.transport, &pointer);
   }
 
+  if (g_state.transportOps->stopPointer)
+    g_state.transportOps->stopPointer(g_state.transport);
+
   return 0;
 }
 
@@ -583,7 +586,11 @@ int main_frameThread(void * unused)
 
   lgWaitEvent(e_startup, TIMEOUT_INFINITE);
   if (app_getState() != APP_STATE_RUNNING)
+  {
+    if (g_state.transportOps->stopFrame)
+      g_state.transportOps->stopFrame(g_state.transport);
     return 0;
+  }
 
   while(app_getState() == APP_STATE_RUNNING && !g_state.stopVideo)
   {
@@ -813,6 +820,9 @@ int main_frameThread(void * unused)
     app_useSpiceDisplay(false);
   }
 
+  if (g_state.transportOps->stopFrame)
+    g_state.transportOps->stopFrame(g_state.transport);
+
   RENDERER(onRestart);
 
   if (app_getState() != APP_STATE_SHUTDOWN)

client/transports/LGMP/lgmp.c

@@ -204,20 +204,47 @@ static bool lgmp_create(LG_Transport ** result)
   return true;
 }
 
-static void lgmp_closeQueues(struct LG_Transport * this)
+static void lgmp_stopFrame(struct LG_Transport * this)
 {
   if (this->framePending && this->frameQueue)
   {
-    lgmpClientMessageDone(this->frameQueue);
+    const LGMP_STATUS status = lgmpClientMessageDone(this->frameQueue);
-    this->framePending = false;
+    if (status != LGMP_OK)
+      DEBUG_WARN("Failed to release pending LGMP frame: %s",
+          lgmpStatusString(status));
+  }
+  this->framePending = false;
+  LGMP_STATUS status = lgmpClientUnsubscribe(&this->frameQueue);
+  if (status != LGMP_OK)
+  {
+    DEBUG_WARN("Failed to unsubscribe from the LGMP frame queue: %s",
+        lgmpStatusString(status));
+    this->frameQueue = NULL;
   }
-  lgmpClientUnsubscribe(&this->frameQueue);
 
+  this->frameSerial = 0;
+  this->formatValid = false;
+}
+
+static void lgmp_stopPointer(struct LG_Transport * this)
+{
   LG_LOCK(this->pointerLock);
-  lgmpClientUnsubscribe(&this->pointerQueue);
+  const LGMP_STATUS status = lgmpClientUnsubscribe(&this->pointerQueue);
+  if (status != LGMP_OK)
+  {
+    DEBUG_WARN("Failed to unsubscribe from the LGMP pointer queue: %s",
+        lgmpStatusString(status));
+    this->pointerQueue = NULL;
+  }
   LG_UNLOCK(this->pointerLock);
 }
 
+static void lgmp_closeQueues(struct LG_Transport * this)
+{
+  lgmp_stopFrame(this);
+  lgmp_stopPointer(this);
+}
+
 static void lgmp_closeDMA(struct LG_Transport * this)
 {
   for (unsigned i = 0; i < LGMP_Q_FRAME_LEN; ++i)
@@ -359,8 +386,6 @@ static void lgmp_disconnect(LG_Transport * this)
   lgmp_closeQueues(this);
   lgmp_closeDMA(this);
   this->connected = false;
-  this->frameSerial = 0;
-  this->formatValid = false;
 }
 
 static bool lgmp_sessionValid(LG_Transport * this)
@@ -389,10 +414,13 @@ static LG_TransportStatus lgmp_subscribe(PLGMPClient client, uint32_t id,
   if (*queue)
     return LG_TRANSPORT_OK;
 
-  LGMP_STATUS status = lgmpClientSubscribe(client, id, queue);
+  PLGMPClientQueue subscribed = NULL;
+  LGMP_STATUS status = lgmpClientSubscribe(client, id, &subscribed);
   switch (status)
   {
-    case LGMP_OK:                return LG_TRANSPORT_OK;
+    case LGMP_OK:
+      *queue = subscribed;
+      return LG_TRANSPORT_OK;
     case LGMP_ERR_NO_SUCH_QUEUE: return LG_TRANSPORT_TIMEOUT;
     case LGMP_ERR_INVALID_SESSION: return LG_TRANSPORT_DISCONNECTED;
     default:
@@ -594,10 +622,16 @@ static LG_TransportStatus lgmp_nextPointer(LG_Transport * this,
   uint32_t pointerFlags  = 0;
   size_t   shapeSize     = 0;
   size_t   transformSize = 0;
+  LG_TransportStatus status = LG_TRANSPORT_OK;
+  if (!this->pointerQueue)
+  {
     LG_LOCK(this->pointerLock);
-  LG_TransportStatus status = lgmp_subscribe(this->client, LGMP_Q_POINTER,
+    status = lgmp_subscribe(this->client, LGMP_Q_POINTER,
         &this->pointerQueue);
     LG_UNLOCK(this->pointerLock);
+    if (status == LG_TRANSPORT_TIMEOUT)
+      usleep(1000);
+  }
   if (status == LG_TRANSPORT_OK)
   {
     LGMPMessage message;
@@ -649,11 +683,7 @@ static LG_TransportStatus lgmp_nextPointer(LG_Transport * this,
     }
   }
   if (status != LG_TRANSPORT_OK)
-  {
-    if (status == LG_TRANSPORT_TIMEOUT)
-      usleep(1000);
     return status;
-  }
 
   const KVMFRCursor * cursor = (const KVMFRCursor *)this->pointerData;
   memset(result, 0, sizeof(*result));
@@ -771,8 +801,10 @@ const LG_TransportOps LGT_LGMP =
   .detachRenderer = lgmp_detachRenderer,
   .nextFrame      = lgmp_nextFrame,
   .releaseFrame   = lgmp_releaseFrame,
+  .stopFrame      = lgmp_stopFrame,
   .nextPointer    = lgmp_nextPointer,
   .releasePointer = lgmp_releasePointer,
+  .stopPointer    = lgmp_stopPointer,
   .sendControl    = lgmp_sendControl,
   .controlStatus  = lgmp_controlStatus,
 };