internal locks: new owner of contended lock must set waiters flag

[musl] / src / thread / __lock.c

diff --git a/src/thread/__lock.c b/src/thread/__lock.c
index d173409..5ba5dc5 100644 (file)
--- a/src/thread/__lock.c
+++ b/src/thread/__lock.c
@@ -4,7 +4,7 @@ void __lock_2(volatile int *l)
 {
        if (!__syscall(SYS_futex, l, FUTEX_LOCK_PI, 0, 0))
                return;
-       int old, tid = __pthread_self()->tid;
+       int old, tid = __pthread_self()->tid|INT_MIN;
        while ((old = a_cas(l, 0, tid))) {
                a_cas(l, old, old|INT_MIN);
                __syscall(SYS_futex, l, FUTEX_WAIT, old|INT_MIN, 0);