diff options
| -rw-r--r-- | absl/synchronization/mutex.cc | 18 |
1 files changed, 0 insertions, 18 deletions
diff --git a/absl/synchronization/mutex.cc b/absl/synchronization/mutex.cc index 70a17371..27fd6a50 100644 --- a/absl/synchronization/mutex.cc +++ b/absl/synchronization/mutex.cc @@ -991,24 +991,6 @@ static PerThreadSynch* Enqueue(PerThreadSynch* head, SynchWaitParams* waitp, if (MuEquivalentWaiter(s, s->next)) { // s->may_skip is known to be true s->skip = s->next; // s may skip to its successor } - } else if ((flags & kMuHasBlocked) && - (s->priority >= head->next->priority) && - (!head->maybe_unlocking || - (waitp->how == kExclusive && - Condition::GuaranteedEqual(waitp->cond, nullptr)))) { - // This thread has already waited, then was woken, then failed to acquire - // the mutex and now tries to requeue. Try to requeue it at head, - // otherwise it can suffer bad latency (wait whole qeueue several times). - // However, we need to be conservative. First, we need to ensure that we - // respect priorities. Then, we need to be careful to not break wait - // queue invariants: we require either that unlocker is not scanning - // the queue or that the current thread is a writer with no condition - // (unlocker will recheck the queue for such waiters). - s->next = head->next; - head->next = s; - if (MuEquivalentWaiter(s, s->next)) { // s->may_skip is known to be true - s->skip = s->next; // s may skip to its successor - } } else { // enqueue not done any other way, so // we're inserting s at the back // s will become new head; copy data from head into it |