content/gpu: Simplify stub scheduling.

content/common/gpu/gpu_command_buffer_stub.cc

Index: content/common/gpu/gpu_command_buffer_stub.cc
diff --git a/content/common/gpu/gpu_command_buffer_stub.cc b/content/common/gpu/gpu_command_buffer_stub.cc
index 4de06dbfc8381f52a62cc7c8664246ec37644cce..da483626660ede099486e718828e6f83b1ed87cd 100644
--- a/content/common/gpu/gpu_command_buffer_stub.cc
+++ b/content/common/gpu/gpu_command_buffer_stub.cc
@@ -198,7 +198,7 @@ GpuCommandBufferStub::GpuCommandBufferStub(
       last_flush_count_(0),
       last_memory_allocation_valid_(false),
       watchdog_(watchdog),
-      sync_point_wait_count_(0),
+      waiting_for_sync_point_(false),
       delayed_work_scheduled_(false),
       previous_processed_num_(0),
       active_url_(active_url),
@@ -620,9 +620,8 @@ void GpuCommandBufferStub::OnInitialize(
                  base::Unretained(scheduler_.get())));
   command_buffer_->SetParseErrorCallback(
       base::Bind(&GpuCommandBufferStub::OnParseError, base::Unretained(this)));
-  scheduler_->SetSchedulingChangedCallback(
-      base::Bind(&GpuChannel::StubSchedulingChanged,
-                 base::Unretained(channel_)));
+  scheduler_->SetSchedulingChangedCallback(base::Bind(
+      &GpuCommandBufferStub::OnSchedulingChanged, base::Unretained(this)));
 
   if (watchdog_) {
     scheduler_->SetCommandProcessedCallback(
@@ -718,6 +717,12 @@ void GpuCommandBufferStub::OnParseError() {
   CheckContextLost();
 }
 
+void GpuCommandBufferStub::OnSchedulingChanged(bool scheduled) {
+  TRACE_EVENT1("gpu", "GpuCommandBufferStub::OnSchedulingChanged", "scheduled",
+               scheduled);
+  channel_->OnStubSchedulingChanged(this, scheduled);
+}
+
 void GpuCommandBufferStub::OnWaitForTokenInRange(int32 start,
                                                  int32 end,
                                                  IPC::Message* reply_message) {
@@ -908,27 +913,25 @@ bool GpuCommandBufferStub::OnWaitSyncPoint(uint32 sync_point) {
     return true;
   }
 
-  if (sync_point_wait_count_ == 0) {
-    TRACE_EVENT_ASYNC_BEGIN1("gpu", "WaitSyncPoint", this,
-                             "GpuCommandBufferStub", this);
-  }
+  TRACE_EVENT_ASYNC_BEGIN1("gpu", "WaitSyncPoint", this, "GpuCommandBufferStub",
+                           this);
+
   scheduler_->SetScheduled(false);

[jbauman, 2015/09/16 21:31:26]

DCHECK(!waiting_for_sync_point_);

[sunnyps, 2015/09/16 23:08:31]

Done.

-  ++sync_point_wait_count_;
+  waiting_for_sync_point_ = true;
   manager->sync_point_manager()->AddSyncPointCallback(
       sync_point,
       base::Bind(&RunOnThread, task_runner_,
                  base::Bind(&GpuCommandBufferStub::OnWaitSyncPointCompleted,
                             this->AsWeakPtr(), sync_point)));
-  return scheduler_->IsScheduled();
+  return false;

[piman, 2015/09/16 21:46:29]

AddSyncPointCallback may call the callback synchronously, if the sync point was
already retired. While there is the IsSyncPointRetired test above, you can't
rely on its result if the sync point is retired on another thread.

[sunnyps, 2015/09/16 23:08:31]

Done.

 }
 
 void GpuCommandBufferStub::OnWaitSyncPointCompleted(uint32 sync_point) {
+  DCHECK(waiting_for_sync_point_);
+  TRACE_EVENT_ASYNC_END1("gpu", "WaitSyncPoint", this, "GpuCommandBufferStub",
+                         this);
   PullTextureUpdates(sync_point);
-  --sync_point_wait_count_;
-  if (sync_point_wait_count_ == 0) {
-    TRACE_EVENT_ASYNC_END1("gpu", "WaitSyncPoint", this,
-                           "GpuCommandBufferStub", this);
-  }
+  waiting_for_sync_point_ = false;
   scheduler_->SetScheduled(true);
 }