Purge memory via MemoryCoordinatorClientRegistry when a backgrounded renderer is suspended.

content/renderer/render_thread_impl.cc

 // Copyright (c) 2012 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 "content/renderer/render_thread_impl.h"
 
 #include <algorithm>
 #include <limits>
 #include <map>
 #include <utility>
@@ skipping 829 matching lines @@
     media::EnablePlatformDecoderSupport();
   }
 #endif
 
   memory_pressure_listener_.reset(new base::MemoryPressureListener(
       base::Bind(&RenderThreadImpl::OnMemoryPressure, base::Unretained(this)),
       base::Bind(&RenderThreadImpl::OnSyncMemoryPressure,
                  base::Unretained(this))));
 
   if (base::FeatureList::IsEnabled(features::kMemoryCoordinator)) {
+    // Currently it is not possible to enable both PurgeAndSuspend and
+    // MemoryCoordinator at the same time.
+    DCHECK(!base::FeatureList::IsEnabled(features::kPurgeAndSuspend));
+
     // Disable MemoryPressureListener when memory coordinator is enabled.
     base::MemoryPressureListener::SetNotificationsSuppressed(true);
 
     // TODO(bashi): Revisit how to manage the lifetime of
     // ChildMemoryCoordinatorImpl.
     // https://codereview.chromium.org/2094583002/#msg52
     mojom::MemoryCoordinatorHandlePtr parent_coordinator;
     GetRemoteInterfaces()->GetInterface(mojo::GetProxy(&parent_coordinator));
     memory_coordinator_ = CreateChildMemoryCoordinator(
         std::move(parent_coordinator), this);
@@ skipping 889 matching lines @@
   return handled;
 }
 
 void RenderThreadImpl::OnProcessBackgrounded(bool backgrounded) {
   ChildThreadImpl::OnProcessBackgrounded(backgrounded);
 
   if (backgrounded) {
     renderer_scheduler_->OnRendererBackgrounded();
   } else {
     renderer_scheduler_->OnRendererForegrounded();
+    // TODO(tasak): after enabling MemoryCoordinator, remove this Notify
+    // and follow MemoryCoordinator's request.
+    if (base::FeatureList::IsEnabled(features::kPurgeAndSuspend))
+      base::MemoryCoordinatorClientRegistry::GetInstance()->Notify(
+          base::MemoryState::NORMAL);
+
     record_purge_suspend_metric_closure_.Cancel();
     record_purge_suspend_metric_closure_.Reset(
         base::Bind(&RenderThreadImpl::RecordPurgeAndSuspendMetrics,
                    base::Unretained(this)));
     is_renderer_suspended_ = false;
   }
 }
 
 void RenderThreadImpl::OnProcessPurgeAndSuspend() {
   ChildThreadImpl::OnProcessPurgeAndSuspend();
-  if (is_renderer_suspended_ || !RendererIsHidden())
+  DCHECK(!is_renderer_suspended_);

[tasak, 2016/10/28 06:31:33]

This needs https://codereview.chromium.org/2462513002/ 's patch.

+  if (!RendererIsHidden())
     return;
-  // TODO(hajimehoshi): Implement purging e.g. cache (crbug/607077)
   is_renderer_suspended_ = true;
-  renderer_scheduler_->SuspendRenderer();
+  if (base::FeatureList::IsEnabled(features::kPurgeAndSuspend)) {
+    // TODO(tasak): After enabling MemoryCoordinator, remove this Notify
+    // and follow MemoryCoordinator's request.
+    base::MemoryCoordinatorClientRegistry::GetInstance()->Notify(
+        base::MemoryState::SUSPENDED);
+    renderer_scheduler_->SuspendRenderer();
+  }
 
   // Since purging is not a synchronous task (e.g. v8 GC, oilpan GC, ...),
   // we need to wait until the task is finished. So wait 15 seconds and
   // update purge+suspend UMA histogram.
   // TODO(tasak): use MemoryCoordinator's callback to report purge+suspend
   // UMA when MemoryCoordinator is available.
   GetRendererScheduler()->DefaultTaskRunner()->PostDelayedTask(
       FROM_HERE, record_purge_suspend_metric_closure_.callback(),
       base::TimeDelta::FromSeconds(15));
 }
@@ skipping 91 matching lines @@
                            blink_stats.blinkGCTotalAllocatedBytes +
                            malloc_usage + v8_usage + discardable_usage) /
                               1024 / 1024);
 }
 
 void RenderThreadImpl::OnProcessResume() {
   ChildThreadImpl::OnProcessResume();
 
   DCHECK(is_renderer_suspended_);
   is_renderer_suspended_ = false;
-  renderer_scheduler_->ResumeRenderer();
+  if (base::FeatureList::IsEnabled(features::kPurgeAndSuspend)) {
+    // TODO(tasak): after enabling MemoryCoordinator, remove this Notify
+    // and follow MemoryCoordinator's request.
+    base::MemoryCoordinatorClientRegistry::GetInstance()->Notify(
+        base::MemoryState::NORMAL);

[haraken, 2016/10/28 07:49:41]

I'm not sure if this should be NORMAL. It could be THROTTLE but we can adjust
the heuristics in a follow-up.

[chrisha, 2016/11/01 21:24:38]

Ditto. This seems fine for now.

+    renderer_scheduler_->ResumeRenderer();
+  }
 }
 
 scoped_refptr<gpu::GpuChannelHost> RenderThreadImpl::EstablishGpuChannelSync() {
   TRACE_EVENT0("gpu", "RenderThreadImpl::EstablishGpuChannelSync");
 
   if (gpu_channel_) {
     // Do nothing if we already have a GPU channel or are already
     // establishing one.
     if (!gpu_channel_->IsLost())
       return gpu_channel_;
@@ skipping 583 matching lines @@
   }
 }
 
 void RenderThreadImpl::OnRendererInterfaceRequest(
     mojom::RendererAssociatedRequest request) {
   DCHECK(!renderer_binding_.is_bound());
   renderer_binding_.Bind(std::move(request));
 }
 
 }  // namespace content