Ping watchdog thread during GpuChannel destruction

gpu/ipc/service/gpu_command_buffer_stub.cc

Index: gpu/ipc/service/gpu_command_buffer_stub.cc
diff --git a/gpu/ipc/service/gpu_command_buffer_stub.cc b/gpu/ipc/service/gpu_command_buffer_stub.cc
index 412d9a97182600dd249a90304302123b615ba887..3e206101b2eceb4f4a93ec5eb13c2dc21543f088 100644
--- a/gpu/ipc/service/gpu_command_buffer_stub.cc
+++ b/gpu/ipc/service/gpu_command_buffer_stub.cc
@@ -26,6 +26,7 @@
 #include "gpu/command_buffer/service/logger.h"
 #include "gpu/command_buffer/service/mailbox_manager.h"
 #include "gpu/command_buffer/service/memory_tracking.h"
+#include "gpu/command_buffer/service/progress_reporter.h"
 #include "gpu/command_buffer/service/query_manager.h"
 #include "gpu/command_buffer/service/sync_point_manager.h"
 #include "gpu/command_buffer/service/transfer_buffer_manager.h"
@@ -105,6 +106,35 @@ class GpuCommandBufferMemoryTracker : public gles2::MemoryTracker {
   DISALLOW_COPY_AND_ASSIGN(GpuCommandBufferMemoryTracker);
 };
 
+// GpuCommandBufferProgressReporter is used as a bridge between the
+// ContextGroup and the GpuChannel's GpuWatchdogThread.
+class GpuCommandBufferProgressReporter : public gles2::ProgressReporter {
+ public:
+  GpuCommandBufferProgressReporter(GpuChannel* channel) : channel_(channel) {}
+
+  void ReportProgress() override {
+    if (auto* watchdog = channel_->watchdog()) {
+      // CheckArmed posts a task. Throttle this so we don't post more than

[vmiura, 2016/09/30 18:24:35]

Rather than adding throttling here, it seems we could make
GpuWatchdogThread::PostAcknowledge() keep track if it posted a task
(acknowledged_ flag) so that it doesn't post OnAcknowledge repeatedly.

The flag would be cleared when the check was re-armed.

OnAcknowledge() earlies out anyway if the check isn't armed so I don't know why
we didn't just do this.

[ericrk, 2016/10/01 06:19:27]

Good point - I don't want to overload this CL, so I've removed the throttling
here and am adding the GpuWatchdogThread tweaks in a new CL.

+      // one task per second.
+      base::TimeTicks now = base::TimeTicks::Now();
+      if (now < next_check_time_)
+        return;
+
+      next_check_time_ = now + base::TimeDelta::FromSeconds(kMaxCheckRateS);
+      watchdog->CheckArmed();
+    }
+  }
+
+ private:
+  // The max rate at which we will signal the watchdog thread.
+  static const int kMaxCheckRateS = 1;
+
+  // The GpuChannel always outlives the GpuCommandBufferStub and the
+  // ContextGroups it creates, so it's safe to hold by raw pointer here.
+  GpuChannel* channel_;
+  base::TimeTicks next_check_time_;
+};
+
 // FastSetActiveURL will shortcut the expensive call to SetActiveURL when the
 // url_hash matches.
 void FastSetActiveURL(const GURL& url, size_t url_hash, GpuChannel* channel) {
@@ -469,7 +499,8 @@ bool GpuCommandBufferStub::Initialize(
         manager->shader_translator_cache(),
         manager->framebuffer_completeness_cache(), feature_info,
         init_params.attribs.bind_generates_resource,
-        gmb_factory ? gmb_factory->AsImageFactory() : nullptr);
+        gmb_factory ? gmb_factory->AsImageFactory() : nullptr,
+        base::MakeUnique<GpuCommandBufferProgressReporter>(channel_));
   }
 
 #if defined(OS_MACOSX)