x86: allocate membarrier system call number

[urcu.git] / urcu / futex.h

diff --git a/urcu/futex.h b/urcu/futex.h
index cdaa430003ad6dfca0f5d7537ff4a1d021889a7e..4beb54a3d206f2d68e905dd25233f7e6819a529f 100644 (file)
--- a/urcu/futex.h
+++ b/urcu/futex.h
@@ -42,24 +42,71 @@ extern "C" {
  *
  * futex_async is signal-handler safe for the wakeup. It uses polling
  * on the wait-side in compatibility mode.
+ *
+ * BEWARE: sys_futex() FUTEX_WAIT may return early if interrupted
+ * (returns EINTR).
  */
 
-#ifdef CONFIG_RCU_HAVE_FUTEX
-#include <syscall.h>
-#define futex(...)     syscall(__NR_futex, __VA_ARGS__)
-#define futex_noasync(uaddr, op, val, timeout, uaddr2, val3)   \
-               futex(uaddr, op, val, timeout, uaddr2, val3)
-#define futex_async(uaddr, op, val, timeout, uaddr2, val3)     \
-               futex(uaddr, op, val, timeout, uaddr2, val3)
-#else
 extern int compat_futex_noasync(int32_t *uaddr, int op, int32_t val,
-       const struct timespec *timeout, int32_t *uaddr2, int32_t val3);
-#define futex_noasync(uaddr, op, val, timeout, uaddr2, val3)   \
-               compat_futex_noasync(uaddr, op, val, timeout, uaddr2, val3)
+               const struct timespec *timeout, int32_t *uaddr2, int32_t val3);
 extern int compat_futex_async(int32_t *uaddr, int op, int32_t val,
-       const struct timespec *timeout, int32_t *uaddr2, int32_t val3);
-#define futex_async(uaddr, op, val, timeout, uaddr2, val3)     \
-               compat_futex_async(uaddr, op, val, timeout, uaddr2, val3)
+               const struct timespec *timeout, int32_t *uaddr2, int32_t val3);
+
+#ifdef CONFIG_RCU_HAVE_FUTEX
+
+#include <unistd.h>
+#include <errno.h>
+#include <urcu/compiler.h>
+#include <urcu/arch.h>
+
+static inline int futex(int32_t *uaddr, int op, int32_t val,
+               const struct timespec *timeout, int32_t *uaddr2, int32_t val3)
+{
+       return syscall(__NR_futex, uaddr, op, val, timeout,
+                       uaddr2, val3);
+}
+
+static inline int futex_noasync(int32_t *uaddr, int op, int32_t val,
+               const struct timespec *timeout, int32_t *uaddr2, int32_t val3)
+{
+       int ret;
+
+       ret = futex(uaddr, op, val, timeout, uaddr2, val3);
+       if (caa_unlikely(ret < 0 && errno == ENOSYS)) {
+               return compat_futex_noasync(uaddr, op, val, timeout,
+                               uaddr2, val3);
+       }
+       return ret;
+
+}
+
+static inline int futex_async(int32_t *uaddr, int op, int32_t val,
+               const struct timespec *timeout, int32_t *uaddr2, int32_t val3)
+{
+       int ret;
+
+       ret = futex(uaddr, op, val, timeout, uaddr2, val3);
+       if (caa_unlikely(ret < 0 && errno == ENOSYS)) {
+               return compat_futex_async(uaddr, op, val, timeout,
+                               uaddr2, val3);
+       }
+       return ret;
+}
+
+#else
+
+static inline int futex_noasync(int32_t *uaddr, int op, int32_t val,
+               const struct timespec *timeout, int32_t *uaddr2, int32_t val3)
+{
+       return compat_futex_noasync(uaddr, op, val, timeout, uaddr2, val3);
+}
+
+static inline int futex_async(int32_t *uaddr, int op, int32_t val,
+               const struct timespec *timeout, int32_t *uaddr2, int32_t val3)
+{
+       return compat_futex_async(uaddr, op, val, timeout, uaddr2, val3);
+}
+
 #endif
 
 #ifdef __cplusplus