X-Git-Url: http://nsz.repo.hu/git/?p=musl;a=blobdiff_plain;f=src%2Fthread%2F__lock.c;h=d1734096b1ab81d024372d234f4d1e50eda7dad2;hp=d1717956a6f96f3ec1b0bb490350aab0dad4cf13;hb=f34d0ea511e552851c8c6148fb113816f41e6759;hpb=1b0ce9af6d2aa7b92edaf3e9c631cb635bae22bd

diff --git a/src/thread/__lock.c b/src/thread/__lock.c
index d1717956..d1734096 100644
--- a/src/thread/__lock.c
+++ b/src/thread/__lock.c
@@ -1,11 +1,32 @@
 #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)
 {
-	int spins=10000;
-	/* Do not use futexes because we insist that unlocking is a simple
-	 * assignment to optimize non-pathological code with no contention. */
-	while (a_swap(l, 1))
-		if (spins) spins--, a_spin();
-		else __syscall(SYS_sched_yield);
+	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);
 }