WebGraphicsContext3DCommandBufferImpl cleanup, Canvas2D thottling fix, GpuScheduler fix.

gpu/command_buffer/service/gpu_scheduler.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "gpu/command_buffer/service/gpu_scheduler.h"
 
 #include "base/callback.h"
 #include "base/command_line.h"
 #include "base/compiler_specific.h"
 #include "base/debug/trace_event.h"
 #include "base/message_loop.h"
+#include "base/time.h"
 #include "ui/gfx/gl/gl_context.h"
 #include "ui/gfx/gl/gl_bindings.h"
 #include "ui/gfx/gl/gl_surface.h"
 #include "ui/gfx/gl/gl_switches.h"
 
 using ::base::SharedMemory;
 
 namespace gpu {
 
 GpuScheduler::GpuScheduler(CommandBuffer* command_buffer,
@@ skipping 107 matching lines @@
   parser_.reset();
 }
 
 #if defined(OS_MACOSX)
 namespace {
 const unsigned int kMaxOutstandingSwapBuffersCallsPerOnscreenContext = 1;
 }
 #endif
 
 void GpuScheduler::PutChanged(bool sync) {
+  TRACE_EVENT0("gpu", "GpuScheduler:PutChanged");
   CommandBuffer::State state = command_buffer_->GetState();
   parser_->set_put(state.put_offset);
 
   if (sync)
     ProcessCommands();
   else
     ScheduleProcessCommands();
 }
 
 void GpuScheduler::ProcessCommands() {
   TRACE_EVENT0("gpu", "GpuScheduler:ProcessCommands");
   CommandBuffer::State state = command_buffer_->GetState();
   if (state.error != error::kNoError)
     return;
 
-  if (unscheduled_count_ > 0)
+  if (unscheduled_count_ > 0) {
+    TRACE_EVENT1("gpu", "EarlyOut_Unscheduled",
+                 "unscheduled_count_", unscheduled_count_);
     return;
+  }
 
   if (decoder_.get()) {
     if (!decoder_->MakeCurrent()) {
       LOG(ERROR) << "Context lost because MakeCurrent failed.";
       command_buffer_->SetParseError(error::kLostContext);
       return;
     }
   }
 
 #if defined(OS_MACOSX)
   bool do_rate_limiting = surface_.get() != NULL;
   // Don't swamp the browser process with SwapBuffers calls it can't handle.
   if (do_rate_limiting &&
       swap_buffers_count_ - acknowledged_swap_buffers_count_ >=
       kMaxOutstandingSwapBuffersCallsPerOnscreenContext) {
     // Stop doing work on this command buffer. In the GPU process,
     // receipt of the GpuMsg_AcceleratedSurfaceBuffersSwappedACK
     // message causes ProcessCommands to be scheduled again.
     return;
   }
 #endif
 
+  base::TimeTicks start_time = base::TimeTicks::Now();

[apatrick_chromium, 2011/06/02 22:07:43]

Does this have sufficient precision to measure 2ms on all platforms?

[jbates, 2011/06/03 00:05:55]

Not guaranteed according to the TimeTicks::Now() documentation, but even in the
worst case where some platform has 15ms resolution, we have latches and other
yielding means to make sure we switch contexts when necessary.

Any worse than 1ms granularity should be rare though, since we haven't seen
anything like that in our development environment.

+  base::TimeDelta elapsed;
+  bool is_break = false;
   error::Error error = error::kNoError;
-  int commands_processed = 0;
-  while (commands_processed < commands_per_update_ &&
-         !parser_->IsEmpty()) {
-    error = parser_->ProcessCommand();
+  do {
+    int commands_processed = 0;
+    while (commands_processed < commands_per_update_ &&
+           !parser_->IsEmpty()) {
+      error = parser_->ProcessCommand();
 
-    // TODO(piman): various classes duplicate various pieces of state, leading
-    // to needlessly complex update logic. It should be possible to simply share
-    // the state across all of them.
-    command_buffer_->SetGetOffset(static_cast<int32>(parser_->get()));
+      // TODO(piman): various classes duplicate various pieces of state, leading
+      // to needlessly complex update logic. It should be possible to simply
+      // share the state across all of them.
+      command_buffer_->SetGetOffset(static_cast<int32>(parser_->get()));
 
-    if (error == error::kWaiting || error == error::kYield) {
-      break;
-    } else if (error::IsError(error)) {
-      command_buffer_->SetParseError(error);
-      return;
+      if (error == error::kWaiting || error == error::kYield) {
+        is_break = true;
+        break;
+      } else if (error::IsError(error)) {
+        command_buffer_->SetParseError(error);
+        return;
+      }
+
+      if (unscheduled_count_ > 0) {
+        is_break = true;
+        break;
+      }
+
+      ++commands_processed;
+      if (command_processed_callback_.get()) {
+        command_processed_callback_->Run();
+      }
     }
-
-    if (unscheduled_count_ > 0)
-      break;
-
-    ++commands_processed;
-    if (command_processed_callback_.get()) {
-      command_processed_callback_->Run();
-    }
-  }
+    elapsed = base::TimeTicks::Now() - start_time;
+  } while(!is_break &&
+          !parser_->IsEmpty() &&
+          elapsed.InMicroseconds() < 2000);

[apatrick_chromium, 2011/06/02 22:07:43]

Could be a constant.

[jbates, 2011/06/03 00:05:55]

Done.

 
   if (unscheduled_count_ == 0 &&
       error != error::kWaiting &&
       !parser_->IsEmpty()) {
     ScheduleProcessCommands();
   }
 }
 
 void GpuScheduler::SetScheduled(bool scheduled) {
+  TRACE_EVENT2("gpu", "GpuScheduler:SetScheduled", "scheduled", scheduled,
+               "unscheduled_count_", unscheduled_count_);
   if (scheduled) {
     --unscheduled_count_;
     DCHECK_GE(unscheduled_count_, 0);
 
     if (unscheduled_count_ == 0) {
       if (scheduled_callback_.get())
         scheduled_callback_->Run();
 
       ScheduleProcessCommands();
     }
@@ skipping 51 matching lines @@
   command_processed_callback_.reset(callback);
 }
 
 void GpuScheduler::ScheduleProcessCommands() {
   MessageLoop::current()->PostTask(
       FROM_HERE,
       method_factory_.NewRunnableMethod(&GpuScheduler::ProcessCommands));
 }
 
 }  // namespace gpu