1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 #include "content/common/gpu/sync_point_manager.h"
9 #include "base/logging.h"
10 #include "base/rand_util.h"
14 static const int kMaxSyncBase = INT_MAX;
16 SyncPointManager::SyncPointManager()
17 : next_sync_point_(base::RandInt(1, kMaxSyncBase)) {
18 // To reduce the risk that a sync point created in a previous GPU process
19 // will be in flight in the next GPU process, randomize the starting sync
20 // point number. http://crbug.com/373452
23 SyncPointManager::~SyncPointManager() {
26 uint32 SyncPointManager::GenerateSyncPoint() {
27 base::AutoLock lock(lock_);
28 uint32 sync_point = next_sync_point_++;
29 // When an integer overflow occurs, don't return 0.
31 sync_point = next_sync_point_++;
33 // Note: wrapping would take days for a buggy/compromized renderer that would
34 // insert sync points in a loop, but if that were to happen, better explicitly
35 // crash the GPU process than risk worse.
36 // For normal operation (at most a few per frame), it would take ~a year to
38 CHECK(sync_point_map_.find(sync_point) == sync_point_map_.end());
39 sync_point_map_.insert(std::make_pair(sync_point, ClosureList()));
43 void SyncPointManager::RetireSyncPoint(uint32 sync_point) {
44 DCHECK(thread_checker_.CalledOnValidThread());
47 base::AutoLock lock(lock_);
48 SyncPointMap::iterator it = sync_point_map_.find(sync_point);
49 if (it == sync_point_map_.end()) {
50 LOG(ERROR) << "Attempted to retire sync point that"
51 " didn't exist or was already retired.";
54 list.swap(it->second);
55 sync_point_map_.erase(it);
57 for (ClosureList::iterator i = list.begin(); i != list.end(); ++i)
61 void SyncPointManager::AddSyncPointCallback(uint32 sync_point,
62 const base::Closure& callback) {
63 DCHECK(thread_checker_.CalledOnValidThread());
65 base::AutoLock lock(lock_);
66 SyncPointMap::iterator it = sync_point_map_.find(sync_point);
67 if (it != sync_point_map_.end()) {
68 it->second.push_back(callback);
75 bool SyncPointManager::IsSyncPointRetired(uint32 sync_point) {
76 DCHECK(thread_checker_.CalledOnValidThread());
78 base::AutoLock lock(lock_);
79 SyncPointMap::iterator it = sync_point_map_.find(sync_point);
80 return it == sync_point_map_.end();
84 } // namespace content