Fix vsync issue (flutter#204)

* Fix vsync issue

After the engine is shutdown, OnVsync no longer be called.

* Add lock when call OnVsync

1.Remove lock when create TdmClient.
2.Add lock when call OnVsync.
3.Change tdmClient to tdm_client.

Author: xiaowei-guan

shell/platform/tizen/flutter_tizen_engine.cc

@@ -286,6 +286,9 @@ bool FlutterTizenEngine::StopEngine() {
     if (plugin_registrar_destruction_callback_) {
       plugin_registrar_destruction_callback_(plugin_registrar_.get());
     }
+#ifndef TIZEN_RENDERER_EVAS_GL
+    tizen_vsync_waiter_.reset();
+#endif
     FlutterEngineResult result = embedder_api_.Shutdown(engine_);
     engine_ = nullptr;
     return (result == kSuccess);

shell/platform/tizen/tizen_vsync_waiter.cc

@@ -27,13 +27,20 @@ TizenVsyncWaiter::TizenVsyncWaiter(FlutterTizenEngine* engine)
 }
 
 TizenVsyncWaiter::~TizenVsyncWaiter() {
+  if (tdm_client_) {
+    tdm_client_->OnEngineStop();
+  }
   Send(kMessageQuit, 0);
   if (vblank_thread_) {
     ecore_thread_cancel(vblank_thread_);
     vblank_thread_ = nullptr;
   }
 }
 
+void TizenVsyncWaiter::SetTdmClient(TdmClient* tdm_client) {
+  tdm_client_ = tdm_client;
+}
+
 void TizenVsyncWaiter::AsyncWaitForVsync(intptr_t baton) {
   Send(kMessageRequestVblank, baton);
 }
@@ -62,6 +69,7 @@ void TizenVsyncWaiter::RequestVblankLoop(void* data, Ecore_Thread* thread) {
   TizenVsyncWaiter* tizen_vsync_waiter =
       reinterpret_cast<TizenVsyncWaiter*>(data);
   TdmClient tdm_client(tizen_vsync_waiter->engine_);
+  tizen_vsync_waiter->SetTdmClient(&tdm_client);
   if (!tdm_client.IsValid()) {
     FT_LOG(Error) << "Invalid tdm_client.";
     ecore_thread_cancel(thread);
@@ -106,6 +114,11 @@ TdmClient::~TdmClient() {
   DestroyTdm();
 }
 
+void TdmClient::OnEngineStop() {
+  std::lock_guard<std::mutex> lock(engine_mutex_);
+  engine_ = nullptr;
+}
+
 void TdmClient::WaitVblank(intptr_t baton) {
   baton_ = baton;
   tdm_error error = tdm_client_vblank_wait(vblank_, 1, VblankCallback, this);
@@ -164,12 +177,13 @@ void TdmClient::VblankCallback(tdm_client_vblank* vblank,
                                void* user_data) {
   TdmClient* client = reinterpret_cast<TdmClient*>(user_data);
   FT_ASSERT(client != nullptr);
-  FT_ASSERT(client->engine_ != nullptr);
-
-  uint64_t frame_start_time_nanos = tv_sec * 1e9 + tv_usec * 1e3;
-  uint64_t frame_target_time_nanos = 16.6 * 1e6 + frame_start_time_nanos;
-  client->engine_->OnVsync(client->baton_, frame_start_time_nanos,
-                           frame_target_time_nanos);
+  std::lock_guard<std::mutex> lock(client->engine_mutex_);
+  if (client->engine_) {
+    uint64_t frame_start_time_nanos = tv_sec * 1e9 + tv_usec * 1e3;
+    uint64_t frame_target_time_nanos = 16.6 * 1e6 + frame_start_time_nanos;
+    client->engine_->OnVsync(client->baton_, frame_start_time_nanos,
+                             frame_target_time_nanos);
+  }
 }
 
 }  // namespace flutter

shell/platform/tizen/tizen_vsync_waiter.h

@@ -7,6 +7,7 @@
 
 #include <Ecore.h>
 #include <tdm_client.h>
+#include <mutex>
 
 #include "flutter/shell/platform/embedder/embedder.h"
 
@@ -22,6 +23,7 @@ class TdmClient {
   void DestroyTdm();
   bool IsValid();
   void WaitVblank(intptr_t baton);
+  void OnEngineStop();
   static void VblankCallback(tdm_client_vblank* vblank,
                              tdm_error error,
                              unsigned int sequence,
@@ -30,6 +32,7 @@ class TdmClient {
                              void* user_data);
 
  private:
+  std::mutex engine_mutex_;
   tdm_client* client_{nullptr};
   tdm_client_output* output_{nullptr};
   tdm_client_vblank* vblank_{nullptr};
@@ -42,13 +45,15 @@ class TizenVsyncWaiter {
   TizenVsyncWaiter(FlutterTizenEngine* engine);
   virtual ~TizenVsyncWaiter();
   void AsyncWaitForVsync(intptr_t baton);
+  void SetTdmClient(TdmClient* tdm_client);
 
  private:
   void Send(int event, intptr_t baton);
   static void RequestVblankLoop(void* data, Ecore_Thread* thread);
   Ecore_Thread* vblank_thread_{nullptr};
   Eina_Thread_Queue* vblank_thread_queue_{nullptr};
   FlutterTizenEngine* engine_{nullptr};
+  TdmClient* tdm_client_{nullptr};
 };
 
 }  // namespace flutter