Reland 179911 and 179910

gpu/command_buffer/service/gpu_scheduler.h

 // 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.
 
 #ifndef GPU_COMMAND_BUFFER_SERVICE_GPU_SCHEDULER_H_
 #define GPU_COMMAND_BUFFER_SERVICE_GPU_SCHEDULER_H_
 
 #include <queue>
 
 #include "base/atomicops.h"
 #include "base/atomic_ref_count.h"
 #include "base/callback.h"
 #include "base/memory/linked_ptr.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/shared_memory.h"
 #include "gpu/command_buffer/common/command_buffer.h"
 #include "gpu/command_buffer/service/cmd_buffer_engine.h"
 #include "gpu/command_buffer/service/cmd_parser.h"
 #include "gpu/command_buffer/service/gles2_cmd_decoder.h"
 #include "gpu/gpu_export.h"
 
 namespace gfx {
 class GLFence;
 }
 
 namespace gpu {
 
-struct RefCountedCounter
-    : public base::RefCountedThreadSafe<RefCountedCounter> {
-  base::AtomicRefCount count;
-  RefCountedCounter() : count(0) {}
+class PreemptionFlag
+    : public base::RefCountedThreadSafe<PreemptionFlag> {
+ public:
+  PreemptionFlag() : flag_(0) {}
 
-  bool IsZero() { return base::AtomicRefCountIsZero(&count); }
-  void IncCount() { base::AtomicRefCountInc(&count); }
-  void DecCount() { base::AtomicRefCountDec(&count); }
-  void Reset() { base::subtle::NoBarrier_Store(&count, 0); }
+  bool IsSet() { return base::AtomicRefCountIsZero(&flag_); }
+  void Set() { base::AtomicRefCountInc(&flag_); }
+  void Reset() { base::subtle::NoBarrier_Store(&flag_, 0); }
+
  private:
-  ~RefCountedCounter() {}
+  base::AtomicRefCount flag_;
 
-  friend class base::RefCountedThreadSafe<RefCountedCounter>;
+  ~PreemptionFlag() {}
+
+  friend class base::RefCountedThreadSafe<PreemptionFlag>;
 };
 
 // This class schedules commands that have been flushed. They are received via
 // a command buffer and forwarded to a command parser. TODO(apatrick): This
 // class should not know about the decoder. Do not add additional dependencies
 // on it.
 class GPU_EXPORT GpuScheduler
     : NON_EXPORTED_BASE(public CommandBufferEngine),
       public base::SupportsWeakPtr<GpuScheduler> {
  public:
   GpuScheduler(CommandBuffer* command_buffer,
                AsyncAPIInterface* handler,
                gles2::GLES2Decoder* decoder);
 
   virtual ~GpuScheduler();
 
   void PutChanged();
 
-  void SetPreemptByCounter(scoped_refptr<RefCountedCounter> counter) {
-    preempt_by_counter_ = counter;
+  void SetPreemptByFlag(scoped_refptr<PreemptionFlag> flag) {
+    preemption_flag_ = flag;
   }
 
   // Sets whether commands should be processed by this scheduler. Setting to
   // false unschedules. Setting to true reschedules. Whether or not the
   // scheduler is currently scheduled is "reference counted". Every call with
   // false must eventually be paired by a call with true.
   void SetScheduled(bool is_scheduled);
 
   // Returns whether the scheduler is currently able to process more commands.
   bool IsScheduled();
@@ skipping 17 matching lines @@
   void DeferToFence(base::Closure task);
 
   // Polls the fences, invoking callbacks that were waiting to be triggered
   // by them and returns whether all fences were complete.
   bool PollUnscheduleFences();
 
   CommandParser* parser() const {
     return parser_.get();
   }
 
+  bool IsPreempted();
+
  private:
   // Artificially reschedule if the scheduler is still unscheduled after a
   // timeout.
   void RescheduleTimeOut();
 
   // The GpuScheduler holds a weak reference to the CommandBuffer. The
   // CommandBuffer owns the GpuScheduler and holds a strong reference to it
   // through the ProcessCommands callback.
   CommandBuffer* command_buffer_;
 
@@ skipping 28 matching lines @@
     ~UnscheduleFence();
 
     scoped_ptr<gfx::GLFence> fence;
     base::Closure task;
   };
   std::queue<linked_ptr<UnscheduleFence> > unschedule_fences_;
 
   base::Closure scheduled_callback_;
   base::Closure command_processed_callback_;
 
-  // If non-NULL and preempt_by_counter_->count is non-zero,
-  // exit PutChanged early.
-  scoped_refptr<RefCountedCounter> preempt_by_counter_;
+  // If non-NULL and |preemption_flag_->IsSet()|, exit PutChanged early.
+  scoped_refptr<PreemptionFlag> preemption_flag_;
   bool was_preempted_;
 
   DISALLOW_COPY_AND_ASSIGN(GpuScheduler);
 };
 
 }  // namespace gpu
 
 #endif  // GPU_COMMAND_BUFFER_SERVICE_GPU_SCHEDULER_H_