std::bitset solution for GL Query cache.

gpu/command_buffer/client/query_tracker.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_CLIENT_QUERY_TRACKER_H_
 #define GPU_COMMAND_BUFFER_CLIENT_QUERY_TRACKER_H_
 
 #include <GLES2/gl2.h>
 
+#include <bitset>
 #include <deque>
 #include <list>
-#include <vector>
 
 #include "base/atomicops.h"
 #include "base/containers/hash_tables.h"
 #include "gles2_impl_export.h"
 #include "gpu/command_buffer/common/gles2_cmd_format.h"
 
 namespace gpu {
 
 class CommandBufferHelper;
 class MappedMemoryManager;
 
 namespace gles2 {
 
 class GLES2Implementation;
 
 // Manages buckets of QuerySync instances in mapped memory.
 class GLES2_IMPL_EXPORT QuerySyncManager {
  public:
   static const size_t kSyncsPerBucket = 1024;
 
   struct Bucket {
     Bucket(QuerySync* sync_mem, int32 shm_id, uint32 shm_offset);
     ~Bucket();
     QuerySync* syncs;
     int32 shm_id;
     uint32 base_shm_offset;
-    std::vector<unsigned short> free_queries;
+    std::bitset<kSyncsPerBucket> in_use_queries;
+    uint32 in_use_query_count;

[reveman, 2015/05/18 19:58:42]

Can we use in_use_queries.count() instead?

+    uint32 next_query_scan_pos;
   };
   struct QueryInfo {
     QueryInfo(Bucket* bucket, int32 id, uint32 offset, QuerySync* sync_mem)
         : bucket(bucket),
           shm_id(id),
           shm_offset(offset),
           sync(sync_mem) {
     }
 
     QueryInfo()
@@ skipping 118 matching lines @@
   QueryList removed_queries_;
   QuerySyncManager query_sync_manager_;
 
   DISALLOW_COPY_AND_ASSIGN(QueryTracker);
 };
 
 }  // namespace gles2
 }  // namespace gpu
 
 #endif  // GPU_COMMAND_BUFFER_CLIENT_QUERY_TRACKER_H_