Validate all flush IDs if the unvalidated list gets too long.

The browser process normally never needs to validate sync tokens unless
it's returning resources to a renderer, so it's possible the highest
verified flush ID will almost never be updated and the list of
unvalidated flush IDs will grow indefinitely. Force a validation if that
happens to avoid wasting memory.

BUG=635051
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel

Review-Url: https://codereview.chromium.org/2318933005
Cr-Commit-Position: refs/heads/master@{#417168}

gpu/ipc/client/command_buffer_proxy_impl.cc

@@ -266,7 +266,6 @@ void CommandBufferProxyImpl::Flush(int32_t put_offset) {
     const uint32_t flush_id = channel_->OrderingBarrier(
         route_id_, stream_id_, put_offset, ++flush_count_, latency_info_,
         put_offset_changed, true, &highest_verified_flush_id);
-    UpdateVerifiedReleases(highest_verified_flush_id);
     if (put_offset_changed) {
       DCHECK(flush_id);
       const uint64_t fence_sync_release = next_fence_sync_release_ - 1;
@@ -276,6 +275,7 @@ void CommandBufferProxyImpl::Flush(int32_t put_offset) {
             std::make_pair(fence_sync_release, flush_id));
       }
     }
+    CleanupFlushedReleases(highest_verified_flush_id);
   }
 
   if (put_offset_changed)
@@ -298,7 +298,6 @@ void CommandBufferProxyImpl::OrderingBarrier(int32_t put_offset) {
     const uint32_t flush_id = channel_->OrderingBarrier(
         route_id_, stream_id_, put_offset, ++flush_count_, latency_info_,
         put_offset_changed, false, &highest_verified_flush_id);
-    UpdateVerifiedReleases(highest_verified_flush_id);
 
     if (put_offset_changed) {
       DCHECK(flush_id);
@@ -309,6 +308,7 @@ void CommandBufferProxyImpl::OrderingBarrier(int32_t put_offset) {
             std::make_pair(fence_sync_release, flush_id));
       }
     }
+    CleanupFlushedReleases(highest_verified_flush_id);
   }
 
   if (put_offset_changed)
@@ -746,6 +746,18 @@ void CommandBufferProxyImpl::UpdateVerifiedReleases(uint32_t verified_flush) {
   }
 }
 
+void CommandBufferProxyImpl::CleanupFlushedReleases(
+    uint32_t highest_verified_flush_id) {
+  DCHECK(channel_);
+  static const uint32_t kMaxUnverifiedFlushes = 1000;
+  if (flushed_release_flush_id_.size() > kMaxUnverifiedFlushes) {
+    // Prevent list of unverified flushes from growing indefinitely.
+    highest_verified_flush_id =
+        channel_->ValidateFlushIDReachedServer(stream_id_, false);
+  }
+  UpdateVerifiedReleases(highest_verified_flush_id);
+}
+
 gpu::CommandBufferSharedState* CommandBufferProxyImpl::shared_state() const {
   return reinterpret_cast<gpu::CommandBufferSharedState*>(
       shared_state_shm_->memory());

gpu/ipc/client/command_buffer_proxy_impl.h

@@ -209,6 +209,7 @@ class GPU_EXPORT CommandBufferProxyImpl
 
   // Updates the highest verified release fence sync.
   void UpdateVerifiedReleases(uint32_t verified_flush);
+  void CleanupFlushedReleases(uint32_t highest_verified_flush_id);
 
   // Try to read an updated copy of the state from shared memory, and calls
   // OnGpuStateError() if the new state has an error.