In RingBuffer::GetLargestFreeSizeNoWaiting, release until current token.

 RingBuffer::GetLargestFreeSizeNoWaiting can release any block for which
tokens have already been seen.

R=gman@chromium.org

Review URL: https://codereview.chromium.org/16226019

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@205224 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 38 insertions, 3 deletions

diff --git a/gpu/command_buffer/client/ring_buffer.cc b/gpu/command_buffer/client/ring_buffer.cc
index 46a86a2..42e09bd 100644
--- a/gpu/command_buffer/client/ring_buffer.cc
+++ b/gpu/command_buffer/client/ring_buffer.cc
@@ -94,8 +94,12 @@ void RingBuffer::FreePendingToken(RingBuffer::Offset offset,
 }
 
 unsigned int RingBuffer::GetLargestFreeSizeNoWaiting() {
-  // TODO(gman): Should check what the current token is and free up to that
-  //    point.
+  unsigned int last_token_read = helper_->last_token_read();
+  while (!blocks_.empty()) {
+    Block& block = blocks_.front();
+    if (block.token > last_token_read || block.state == IN_USE) break;
+    FreeOldestBlock();
+  }
   if (free_offset_ == in_use_offset_) {
     if (blocks_.empty()) {
       // The entire buffer is free.
diff --git a/gpu/command_buffer/client/ring_buffer_test.cc b/gpu/command_buffer/client/ring_buffer_test.cc
index ceeb2ed..921cf39 100644
--- a/gpu/command_buffer/client/ring_buffer_test.cc
+++ b/gpu/command_buffer/client/ring_buffer_test.cc
@@ -35,7 +35,29 @@ class BaseRingBufferTest : public testing::Test {
   static const unsigned int kBaseOffset = 128;
   static const unsigned int kBufferSize = 1024;
 
+  void RunPendingSetToken() {
+    for (std::vector<const void*>::iterator it = set_token_arguments_.begin();
+         it != set_token_arguments_.end();
+         ++it) {
+      api_mock_->SetToken(cmd::kSetToken, 1, *it);
+    }
+    set_token_arguments_.clear();
+    delay_set_token_ = false;
+  }
+
+  void SetToken(unsigned int command,
+                unsigned int arg_count,
+                const void* _args) {
+    EXPECT_EQ(cmd::kSetToken, command);
+    EXPECT_EQ(1u, arg_count);
+    if (delay_set_token_)
+      set_token_arguments_.push_back(_args);
+    else
+      api_mock_->SetToken(cmd::kSetToken, 1, _args);
+  }
+
   virtual void SetUp() {
+    delay_set_token_ = false;
     api_mock_.reset(new AsyncAPIMock);
     // ignore noops in the mock - we don't want to inspect the internals of the
     // helper.
@@ -43,7 +65,7 @@ class BaseRingBufferTest : public testing::Test {
         .WillRepeatedly(Return(error::kNoError));
     // Forward the SetToken calls to the engine
     EXPECT_CALL(*api_mock_.get(), DoCommand(cmd::kSetToken, 1, _))
-        .WillRepeatedly(DoAll(Invoke(api_mock_.get(), &AsyncAPIMock::SetToken),
+        .WillRepeatedly(DoAll(Invoke(this, &BaseRingBufferTest::SetToken),
                               Return(error::kNoError)));
 
     {
@@ -81,6 +103,9 @@ class BaseRingBufferTest : public testing::Test {
   scoped_ptr<CommandBufferService> command_buffer_;
   scoped_ptr<GpuScheduler> gpu_scheduler_;
   scoped_ptr<CommandBufferHelper> helper_;
+  std::vector<const void*> set_token_arguments_;
+  bool delay_set_token_;
+
 };
 
 #ifndef _MSC_VER
@@ -128,6 +153,7 @@ TEST_F(RingBufferTest, TestFreePendingToken) {
   const unsigned int kAllocCount = kBufferSize / kSize;
   CHECK(kAllocCount * kSize == kBufferSize);
 
+  delay_set_token_ = true;
   // Allocate several buffers to fill in the memory.
   int32 tokens[kAllocCount];
   for (unsigned int ii = 0; ii < kAllocCount; ++ii) {
@@ -140,6 +166,8 @@ TEST_F(RingBufferTest, TestFreePendingToken) {
   EXPECT_EQ(kBufferSize - (kSize * kAllocCount),
             allocator_->GetLargestFreeSizeNoWaiting());
 
+  RunPendingSetToken();
+
   // This allocation will need to reclaim the space freed above, so that should
   // process the commands until a token is passed.
   RingBuffer::Offset offset1 = allocator_->Alloc(kSize);
@@ -242,6 +270,7 @@ TEST_F(RingBufferWrapperTest, TestFreePendingToken) {
   const unsigned int kAllocCount = kBufferSize / kSize;
   CHECK(kAllocCount * kSize == kBufferSize);
 
+  delay_set_token_ = true;
   // Allocate several buffers to fill in the memory.
   int32 tokens[kAllocCount];
   for (unsigned int ii = 0; ii < kAllocCount; ++ii) {
@@ -254,6 +283,8 @@ TEST_F(RingBufferWrapperTest, TestFreePendingToken) {
   EXPECT_EQ(kBufferSize - (kSize * kAllocCount),
             allocator_->GetLargestFreeSizeNoWaiting());
 
+  RunPendingSetToken();
+
   // This allocation will need to reclaim the space freed above, so that should
   // process the commands until the token is passed.
   void* pointer1 = allocator_->Alloc(kSize);