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#include "pthread_impl.h"
void __lock_2(volatile int *l)
{
if (!__syscall(SYS_futex, l, FUTEX_LOCK_PI, 0, 0))
return;
int old, tid = __pthread_self()->tid;
while ((old = a_cas(l, 0, tid))) {
a_cas(l, old, old|INT_MIN);
__syscall(SYS_futex, l, FUTEX_WAIT, old|INT_MIN, 0);
}
}
void __lock(volatile int *l)
{
if (a_cas(l, 0, __pthread_self()->tid)) __lock_2(l);
}
void __unlock_2(volatile int *l)
{
if (__syscall(SYS_futex, l, FUTEX_UNLOCK_PI)) {
*l = 0;
__syscall(SYS_futex, l, FUTEX_WAKE, 1);
}
}
void __unlock(volatile int *l)
{
int old = *l;
if (!(old & INT_MIN) && a_cas(l, old, 0)==old) return;
__unlock_2(l);
}
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