1 files changed, 71 insertions, 0 deletions
diff --git a/src/thread/__timedwait.c b/src/thread/__timedwait.c
new file mode 100644
index 0000000..666093b
--- /dev/null
+++ b/src/thread/__timedwait.c
@@ -0,0 +1,71 @@
+#include <pthread.h>
+#include <time.h>
+#include <errno.h>
+#include "futex.h"
+#include "syscall.h"
+#include "pthread_impl.h"
+
+#define IS32BIT(x) !((x)+0x80000000ULL>>32)
+#define CLAMP(x) (int)(IS32BIT(x) ? (x) : 0x7fffffffU+((0ULL+(x))>>63))
+
+static int __futex4_cp(volatile void *addr, int op, int val, const struct timespec *to)
+{
+	int r;
+#ifdef SYS_futex_time64
+	time_t s = to ? to->tv_sec : 0;
+	long ns = to ? to->tv_nsec : 0;
+	r = -ENOSYS;
+	if (SYS_futex == SYS_futex_time64 || !IS32BIT(s))
+		r = __syscall_cp(SYS_futex_time64, addr, op, val,
+			to ? ((long long[]){s, ns}) : 0);
+	if (SYS_futex == SYS_futex_time64 || r!=-ENOSYS) return r;
+	to = to ? (void *)(long[]){CLAMP(s), ns} : 0;
+#endif
+	r = __syscall_cp(SYS_futex, addr, op, val, to);
+	if (r != -ENOSYS) return r;
+	return __syscall_cp(SYS_futex, addr, op & ~FUTEX_PRIVATE, val, to);
+}
+
+static volatile int dummy = 0;
+weak_alias(dummy, __eintr_valid_flag);
+
+int __timedwait_cp(volatile int *addr, int val,
+	clockid_t clk, const struct timespec *at, int priv)
+{
+	int r;
+	struct timespec to, *top=0;
+
+	if (priv) priv = FUTEX_PRIVATE;
+
+	if (at) {
+		if (at->tv_nsec >= 1000000000UL) return EINVAL;
+		if (__clock_gettime(clk, &to)) return EINVAL;
+		to.tv_sec = at->tv_sec - to.tv_sec;
+		if ((to.tv_nsec = at->tv_nsec - to.tv_nsec) < 0) {
+			to.tv_sec--;
+			to.tv_nsec += 1000000000;
+		}
+		if (to.tv_sec < 0) return ETIMEDOUT;
+		top = &to;
+	}
+
+	r = -__futex4_cp(addr, FUTEX_WAIT|priv, val, top);
+	if (r != EINTR && r != ETIMEDOUT && r != ECANCELED) r = 0;
+	/* Mitigate bug in old kernels wrongly reporting EINTR for non-
+	 * interrupting (SA_RESTART) signal handlers. This is only practical
+	 * when NO interrupting signal handlers have been installed, and
+	 * works by sigaction tracking whether that's the case. */
+	if (r == EINTR && !__eintr_valid_flag) r = 0;
+
+	return r;
+}
+
+int __timedwait(volatile int *addr, int val,
+	clockid_t clk, const struct timespec *at, int priv)
+{
+	int cs, r;
+	__pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
+	r = __timedwait_cp(addr, val, clk, at, priv);
+	__pthread_setcancelstate(cs, 0);
+	return r;
+}