mustash: gpu: implement SignalQuery in CommandBufferLocal

components/mus/gles2/command_buffer_local.cc

Index: components/mus/gles2/command_buffer_local.cc
diff --git a/components/mus/gles2/command_buffer_local.cc b/components/mus/gles2/command_buffer_local.cc
index 834722ca5bc1b43181b5992ad96011df7181e4f9..a11ccc90bb5926cb140e41f998ab8f650ea12197 100644
--- a/components/mus/gles2/command_buffer_local.cc
+++ b/components/mus/gles2/command_buffer_local.cc
@@ -23,6 +23,7 @@
 #include "gpu/command_buffer/service/image_factory.h"
 #include "gpu/command_buffer/service/image_manager.h"
 #include "gpu/command_buffer/service/memory_tracking.h"
+#include "gpu/command_buffer/service/query_manager.h"
 #include "gpu/command_buffer/service/shader_translator_cache.h"
 #include "gpu/command_buffer/service/transfer_buffer_manager.h"
 #include "gpu/command_buffer/service/valuebuffer_manager.h"
@@ -326,11 +327,19 @@ void CommandBufferLocal::SignalSyncPoint(uint32_t sync_point,
       base::Bind(&PostTask, client_thread_task_runner_, callback));
 }
 
-void CommandBufferLocal::SignalQuery(uint32_t query,
+void CommandBufferLocal::SignalQuery(uint32_t query_id,
                                      const base::Closure& callback) {
   DCHECK(CalledOnValidThread());
-  // TODO(piman)
-  NOTIMPLEMENTED();
+
+  gpu::gles2::QueryManager* query_manager =
+      driver_->GetDecoder()->GetQueryManager();
+  DCHECK(query_manager);
+
+  gpu::gles2::QueryManager::Query* query = query_manager->GetQuery(query_id);

[Peng, 2016/01/20 19:57:13]

CommandBufferLocal::SignalQuery() is called on the client thread (the mus main
thread), the QueryManager is used on the GPU thread. Seems GetQuery() &
AddCallback() are not thread safe (see [1]). So I think you have to post a task
to client GPU thread, and then execute those code. And I believe the callback
passed to query->AddCallback() will be invoked on the GPU thread, but the
callback of SignalQuery() should be called on the client thread, so you have to
some extra work for it (Like the code at line 327).


BTW, you may consider adding a SignalQuery() in CommandBufferDriver instead of
exposing decoder to CommandBufferLocal. And call it from
CommandBufferLocal::SignalQueryOnGpuThread()



[1]
https://code.google.com/p/chromium/codesearch#chromium/src/gpu/command_buffer...

[Hadi, 2016/01/20 21:33:29]

Done. Used gpu_state_->command_buffer_task_runner()->PostTask() to send tasks to
GPU thread.

+  if (query)
+    query->AddCallback(callback);
+  else
+    callback.Run();
 }
 
 void CommandBufferLocal::SetLock(base::Lock* lock) {