X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=src%2Fstdio%2F__lockfile.c;h=0f60a14990943605b12038178c595c7210cc0f73;hb=8d404733e1314ef633aa09a90865e94fe711b4ca;hp=93c94867868801c4d4df7dd8d3e9fb0f90648b18;hpb=a37452430f93700aeb122d693959ad79d8e43ada;p=musl

diff --git a/src/stdio/__lockfile.c b/src/stdio/__lockfile.c
index 93c94867..0f60a149 100644
--- a/src/stdio/__lockfile.c
+++ b/src/stdio/__lockfile.c
@@ -1,20 +1,23 @@
 #include "stdio_impl.h"
 #include "pthread_impl.h"
 
-void __lockfile(FILE *f)
+int __lockfile(FILE *f)
 {
-	int spins=100000;
-	int tid;
-
-	if (f->lock < 0) return;
-	tid = __pthread_self()->tid;
-	if (f->lock == tid) {
-		while (f->lockcount == INT_MAX);
-		f->lockcount++;
-		return;
+	int owner = f->lock, tid = __pthread_self()->tid;
+	if ((owner & ~MAYBE_WAITERS) == tid)
+		return 0;
+	owner = a_cas(&f->lock, 0, tid);
+	if (!owner) return 1;
+	while ((owner = a_cas(&f->lock, 0, tid|MAYBE_WAITERS))) {
+		if ((owner & MAYBE_WAITERS) ||
+		    a_cas(&f->lock, owner, owner|MAYBE_WAITERS)==owner)
+			__futexwait(&f->lock, owner|MAYBE_WAITERS, 1);
 	}
-	while (f->lock || a_cas(&f->lock, 0, tid))
-		if (spins) spins--, a_spin();
-		else syscall(SYS_sched_yield);
-	f->lockcount = 1;
+	return 1;
+}
+
+void __unlockfile(FILE *f)
+{
+	if (a_swap(&f->lock, 0) & MAYBE_WAITERS)
+		__wake(&f->lock, 1, 1);
 }