bool Mutex::AwaitImpl(const Condition &cond, int64 end_time) {
// end_time is milliseconds since the epoch. A value of zero indicates no
// timeout.
while (!cond.Eval() && (end_time == 0 || GetCurrentTimeMillis() < end_time)) {
Unlock();
// Yield the rest of our CPU timeslice before reacquiring the lock.
// Otherwise we'll spin pointlessly here, hurting performance.
// (The Condition cannot possibly change when no other thread runs.)
ThreadYield();
Lock();
}
return cond.Eval();
}
