Index: base/task_scheduler/scheduler_lock_impl.cc |
diff --git a/base/task_scheduler/scheduler_lock_impl.cc b/base/task_scheduler/scheduler_lock_impl.cc |
index 7480e18da164edea00b7cafaed5d6e32ac86d835..c1acccd4fb8117094747bd8a4f1bd5b56bcdf7f5 100644 |
--- a/base/task_scheduler/scheduler_lock_impl.cc |
+++ b/base/task_scheduler/scheduler_lock_impl.cc |
@@ -67,19 +67,24 @@ class SafeAcquisitionTracker { |
// Otherwise, make sure that the previous lock acquired is an allowed |
// predecessor. |
AutoLock auto_lock(allowed_predecessor_map_lock_); |
+ // Using at() is exception-safe here as |lock| was registered already. |
const SchedulerLockImpl* allowed_predecessor = |
allowed_predecessor_map_.at(lock); |
DCHECK_EQ(acquired_locks->back(), allowed_predecessor); |
} |
+ // This asserts that lock's registered predecessor is safe. Since registration |
robliao
2016/08/04 17:25:20
This change should be pulled out of this CL. Nice
gab
2016/08/04 17:43:05
Done: https://codereview.chromium.org/2218443002/
|
+ // only happens at construction time, the predecessor is safe (no cycle |
+ // possible) as long as it is either null or already registered. |
void AssertSafePredecessor(const SchedulerLockImpl* lock) const { |
allowed_predecessor_map_lock_.AssertAcquired(); |
- for (const SchedulerLockImpl* predecessor = |
- allowed_predecessor_map_.at(lock); |
- predecessor != nullptr; |
- predecessor = allowed_predecessor_map_.at(predecessor)) { |
- DCHECK_NE(predecessor, lock) << |
- "Scheduler lock predecessor cycle detected."; |
+ // Using at() is exception-safe here as |lock| was registered already. |
+ const SchedulerLockImpl* predecessor = allowed_predecessor_map_.at(lock); |
+ if (predecessor) { |
+ DCHECK(allowed_predecessor_map_.find(predecessor) != |
+ allowed_predecessor_map_.end()) |
+ << "SchedulerLock was registered before its predecessor. " |
+ << "Potential cycle detected"; |
} |
} |