Shared Raster Worker Threads

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 <vector>
 
 #include "base/allocator/allocator_extension.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/memory/discardable_memory.h"
 #include "base/memory/shared_memory.h"
 #include "base/metrics/field_trial.h"
 #include "base/metrics/histogram.h"
 #include "base/metrics/stats_table.h"
 #include "base/path_service.h"
 #include "base/strings/string16.h"
 #include "base/strings/string_tokenizer.h"
+#include "base/strings/string_number_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/threading/thread_local.h"
 #include "base/threading/thread_restrictions.h"
 #include "base/values.h"
+#include "cc/base/switches.h"
+#include "cc/resources/raster_worker_pool.h"
 #include "content/child/appcache/appcache_dispatcher.h"
 #include "content/child/appcache/appcache_frontend_impl.h"
 #include "content/child/child_histogram_message_filter.h"
 #include "content/child/db_message_filter.h"
 #include "content/child/indexed_db/indexed_db_dispatcher.h"
 #include "content/child/indexed_db/indexed_db_message_filter.h"
 #include "content/child/npapi/npobject_util.h"
 #include "content/child/plugin_messages.h"
 #include "content/child/resource_dispatcher.h"
 #include "content/child/runtime_features.h"
@@ skipping 111 matching lines @@
 using blink::WebView;
 
 namespace content {
 
 namespace {
 
 const int64 kInitialIdleHandlerDelayMs = 1000;
 const int64 kShortIdleHandlerDelayMs = 1000;
 const int64 kLongIdleHandlerDelayMs = 30*1000;
 const int kIdleCPUUsageThresholdInPercents = 3;
+const int kMinRasterThreads = 1;
+const int kMaxRasterThreads = 64;
 
 // Keep the global RenderThreadImpl in a TLS slot so it is impossible to access
 // incorrectly from the wrong thread.
 base::LazyInstance<base::ThreadLocalPointer<RenderThreadImpl> >
     lazy_tls = LAZY_INSTANCE_INITIALIZER;
 
 class RenderViewZoomer : public RenderViewVisitor {
  public:
   RenderViewZoomer(const std::string& scheme,
                    const std::string& host,
@@ skipping 230 matching lines @@
 
   memory_pressure_listener_.reset(new base::MemoryPressureListener(
       base::Bind(&RenderThreadImpl::OnMemoryPressure, base::Unretained(this))));
 
   renderer_process_id_ = base::kNullProcessId;
 
   // AllocateGpuMemoryBuffer must be used exclusively on one thread but
   // it doesn't have to be the same thread RenderThreadImpl is created on.
   allocate_gpu_memory_buffer_thread_checker_.DetachFromThread();
 
+  if (command_line.HasSwitch(cc::switches::kNumRasterThreads)) {

[jamesr, 2014/01/15 19:17:33]

if this flag is only going to be used in content/ (as it appears to be the case)
then it should be defined in content's switches list, not cc::switches.  The
flag will have to be different for browser and renderer compositors anyway.

otherwise patch lgtm.  It'd be fine to move this switch to the right place in a
follow-up.

+    int num_raster_threads;
+    std::string string_value =
+        command_line.GetSwitchValueASCII(cc::switches::kNumRasterThreads);
+    if (base::StringToInt(string_value, &num_raster_threads) &&
+        num_raster_threads >= kMinRasterThreads &&
+        num_raster_threads <= kMaxRasterThreads) {
+      cc::RasterWorkerPool::SetNumRasterThreads(num_raster_threads);
+    } else {
+      LOG(WARNING) << "Failed to parse switch " <<
+                      cc::switches::kNumRasterThreads  << ": " << string_value;
+    }
+  }
+
   TRACE_EVENT_END_ETW("RenderThreadImpl::Init", 0, "");
 }
 
 RenderThreadImpl::~RenderThreadImpl() {
 }
 
 void RenderThreadImpl::Shutdown() {
   FOR_EACH_OBSERVER(
       RenderProcessObserver, observers_, OnRenderProcessShutdown());
 
@@ skipping 931 matching lines @@
   if (!gamepad_shared_memory_reader_)
     gamepad_shared_memory_reader_.reset(new GamepadSharedMemoryReader);
   gamepad_shared_memory_reader_->SampleGamepads(*data);
 }
 
 base::ProcessId RenderThreadImpl::renderer_process_id() const {
   return renderer_process_id_;
 }
 
 }  // namespace content