void
runtime·notewakeup(Note *n)
{
if(runtime·xchg(&n->key, 1))
runtime·throw("notewakeup - double wakeup");
runtime·futexwakeup(&n->key, 1);
}
static void
futexunlock(Lock *l)
{
uint32 v;
v = runtime·xchg(&l->key, MUTEX_UNLOCKED);
if(v == MUTEX_UNLOCKED)
runtime·throw("unlock of unlocked lock");
if(v == MUTEX_SLEEPING)
futexwakeup(&l->key, 1);
}
void
runtime·unlock(Lock *l)
{
uint32 v;
if(--m->locks < 0)
runtime·throw("runtime·unlock: lock count");
v = runtime·xchg(&l->key, MUTEX_UNLOCKED);
if(v == MUTEX_UNLOCKED)
runtime·throw("unlock of unlocked lock");
if(v == MUTEX_SLEEPING)
runtime·futexwakeup(&l->key, 1);
}
static void
futexunlock(Lock *l)
{
uint32 v;
// Atomically get value and clear lock bit.
again:
v = l->key;
if((v&1) == 0)
throw("unlock of unlocked lock");
if(!cas(&l->key, v, v&~1))
goto again;
// If there were waiters, wake one.
if(v & ~1)
futexwakeup(&l->key);
}
void
runtime·notewakeup(Note *n)
{
runtime·xchg(&n->key, 1);
runtime·futexwakeup(&n->key, 1);
}
void
runtime·notewakeup(Note *n)
{
runtime·xchg(&n->state, 1);
futexwakeup(&n->state, 1<<30);
}
