Reduce the number of flushes while using glQueries.

gpu/command_buffer/client/query_tracker_unittest.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.
 
 // Tests for the QueryTracker.
 
 #include "gpu/command_buffer/client/query_tracker.h"
 
 #include <GLES2/gl2ext.h>
 #include "base/memory/scoped_ptr.h"
@@ skipping 89 matching lines @@
   }
 
   QuerySync* GetSync(QueryTracker::Query* query) {
     return query->info_.sync;
   }
 
   QuerySyncManager::Bucket* GetBucket(QueryTracker::Query* query) {
     return query->info_.bucket;
   }
 
+  uint32 GetFlushGeneration() { return helper_->flush_generation(); }
+
   scoped_ptr<CommandBuffer> command_buffer_;
   scoped_ptr<GLES2CmdHelper> helper_;
   scoped_ptr<MappedMemoryManager> mapped_memory_;
   scoped_ptr<QueryTracker> query_tracker_;
 };
 
 TEST_F(QueryTrackerTest, Basic) {
   const GLuint kId1 = 123;
   const GLuint kId2 = 124;
 
@@ skipping 37 matching lines @@
   EXPECT_FALSE(query->NeverUsed());
   EXPECT_TRUE(query->Pending());
   EXPECT_EQ(kToken, query->token());
   EXPECT_EQ(1, query->submit_count());
 
   // Check CheckResultsAvailable.
   EXPECT_FALSE(query->CheckResultsAvailable(helper_.get()));
   EXPECT_FALSE(query->NeverUsed());
   EXPECT_TRUE(query->Pending());
 
+  // Flush only once if no more flushes happened between a call to
+  // EndQuery command and CheckResultsAvailable
+  // Advance put_ so flush calls in CheckResultsAvailable go through
+  // and updates flush_generation count
+  helper_->Noop(1);
+  // Set Query in pending state_ to simulate EndQuery command is called
+  query->MarkAsPending(kToken);
+  EXPECT_TRUE(query->Pending());
+  // Store FlushGeneration count after EndQuery is called
+  uint32 gen1 = GetFlushGeneration();
+  EXPECT_FALSE(query->CheckResultsAvailable(helper_.get()));
+  uint32 gen2 = GetFlushGeneration();
+  EXPECT_NE(gen1, gen2);
+  // Repeated calls to CheckResultsAvailable should not flush unnecessarily
+  EXPECT_FALSE(query->CheckResultsAvailable(helper_.get()));
+  gen1 = GetFlushGeneration();
+  EXPECT_EQ(gen1, gen2);
+  EXPECT_FALSE(query->CheckResultsAvailable(helper_.get()));
+  gen1 = GetFlushGeneration();
+  EXPECT_EQ(gen1, gen2);
+
   // Simulate GPU process marking it as available.
   QuerySync* sync = GetSync(query);
   sync->process_count = query->submit_count();
   sync->result = kResult;
 
   // Check CheckResultsAvailable.
   EXPECT_TRUE(query->CheckResultsAvailable(helper_.get()));
   EXPECT_EQ(kResult, query->GetResult());
   EXPECT_FALSE(query->NeverUsed());
   EXPECT_FALSE(query->Pending());
@@ skipping 29 matching lines @@
 
   // Check FreeCompletedQueries.
   query_tracker_->FreeCompletedQueries();
   EXPECT_EQ(0u, bucket->used_query_count);
 }
 
 }  // namespace gles2
 }  // namespace gpu