gpu: Use explicit atomics instead of assuming that 32bit read/writes are atomic.

gpu/command_buffer/service/query_manager.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_QUERY_MANAGER_H_
 #define GPU_COMMAND_BUFFER_SERVICE_QUERY_MANAGER_H_
 
 #include <deque>
 #include <vector>
+#include "base/atomicops.h"
 #include "base/basictypes.h"
 #include "base/containers/hash_tables.h"
 #include "base/logging.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "gpu/command_buffer/service/feature_info.h"
 #include "gpu/command_buffer/service/gl_utils.h"
 #include "gpu/gpu_export.h"
 
 namespace gpu {
@@ skipping 34 matching lines @@
     }
 
     uint32 shm_offset() const {
       return shm_offset_;
     }
 
     // Returns false if shared memory for sync is invalid.
     virtual bool Begin() = 0;
 
     // Returns false if shared memory for sync is invalid.
-    virtual bool End(uint32 submit_count) = 0;
+    virtual bool End(base::subtle::Atomic32 submit_count) = 0;
 
     // Returns false if shared memory for sync is invalid.
     virtual bool Process() = 0;
 
     virtual void Destroy(bool have_context) = 0;
 
     void AddCallback(base::Closure callback);
 
    protected:
     virtual ~Query();
 
     QueryManager* manager() const {
       return manager_;
     }
 
     void MarkAsDeleted() {
       deleted_ = true;
     }
 
     // Returns false if shared memory for sync is invalid.
     bool MarkAsCompleted(uint64 result);
 
-    void MarkAsPending(uint32 submit_count) {
+    void MarkAsPending(base::subtle::Atomic32 submit_count) {
       DCHECK(!pending_);
       pending_ = true;
       submit_count_ = submit_count;
     }
 
     void UnmarkAsPending() {
       DCHECK(pending_);
       pending_ = false;
     }
 
     // Returns false if shared memory for sync is invalid.
-    bool AddToPendingQueue(uint32 submit_count) {
+    bool AddToPendingQueue(base::subtle::Atomic32 submit_count) {
       return manager_->AddPendingQuery(this, submit_count);
     }
 
     // Returns false if shared memory for sync is invalid.
-    bool AddToPendingTransferQueue(uint32 submit_count) {
+    bool AddToPendingTransferQueue(base::subtle::Atomic32 submit_count) {
       return manager_->AddPendingTransferQuery(this, submit_count);
     }
 
     void BeginQueryHelper(GLenum target, GLuint id) {
       manager_->BeginQueryHelper(target, id);
     }
 
     void EndQueryHelper(GLenum target) {
       manager_->EndQueryHelper(target);
     }
 
-    uint32 submit_count() const {
-      return submit_count_;
-    }
+    base::subtle::Atomic32 submit_count() const { return submit_count_; }
 
    private:
     friend class QueryManager;
     friend class QueryManagerTest;
     friend class base::RefCounted<Query>;
 
     void RunCallbacks();
 
     // The manager that owns this Query.
     QueryManager* manager_;
 
     // The type of query.
     GLenum target_;
 
     // The shared memory used with this Query.
     int32 shm_id_;
     uint32 shm_offset_;
 
     // Count to set process count do when completed.
-    uint32 submit_count_;
+    base::subtle::Atomic32 submit_count_;
 
     // True if in the queue.
     bool pending_;
 
     // True if deleted.
     bool deleted_;
 
     // List of callbacks to run when result is available.
     std::vector<base::Closure> callbacks_;
   };
@@ skipping 13 matching lines @@
   // Gets the query info for the given query.
   Query* GetQuery(GLuint client_id);
 
   // Removes a query info for the given query.
   void RemoveQuery(GLuint client_id);
 
   // Returns false if any query is pointing to invalid shared memory.
   bool BeginQuery(Query* query);
 
   // Returns false if any query is pointing to invalid shared memory.
-  bool EndQuery(Query* query, uint32 submit_count);
+  bool EndQuery(Query* query, base::subtle::Atomic32 submit_count);
 
   // Processes pending queries. Returns false if any queries are pointing
   // to invalid shared memory.
   bool ProcessPendingQueries();
 
   // True if there are pending queries.
   bool HavePendingQueries();
 
   // Processes pending transfer queries. Returns false if any queries are
   // pointing to invalid shared memory.
@@ skipping 10 matching lines @@
   void StartTracking(Query* query);
   void StopTracking(Query* query);
 
   // Wrappers for BeginQueryARB and EndQueryARB to hide differences between
   // ARB_occlusion_query2 and EXT_occlusion_query_boolean.
   void BeginQueryHelper(GLenum target, GLuint id);
   void EndQueryHelper(GLenum target);
 
   // Adds to queue of queries waiting for completion.
   // Returns false if any query is pointing to invalid shared memory.
-  bool AddPendingQuery(Query* query, uint32 submit_count);
+  bool AddPendingQuery(Query* query, base::subtle::Atomic32 submit_count);
 
   // Adds to queue of transfer queries waiting for completion.
   // Returns false if any query is pointing to invalid shared memory.
-  bool AddPendingTransferQuery(Query* query, uint32 submit_count);
+  bool AddPendingTransferQuery(Query* query,
+                               base::subtle::Atomic32 submit_count);
 
   // Removes a query from the queue of pending queries.
   // Returns false if any query is pointing to invalid shared memory.
   bool RemovePendingQuery(Query* query);
 
   // Returns a target used for the underlying GL extension
   // used to emulate a query.
   GLenum AdjustTargetForEmulation(GLenum target);
 
   // Used to validate shared memory and get GL errors.
@@ skipping 17 matching lines @@
   // Async pixel transfer queries waiting for completion.
   QueryQueue pending_transfer_queries_;
 
   DISALLOW_COPY_AND_ASSIGN(QueryManager);
 };
 
 }  // namespace gles2
 }  // namespace gpu
 
 #endif  // GPU_COMMAND_BUFFER_SERVICE_QUERY_MANAGER_H_