#ifndef _SIMPLE_MTX_H
#define _SIMPLE_MTX_H
+#include "util/futex.h"
+#include "util/macros.h"
+
#include "c11/threads.h"
-#if defined(__GNUC__) && defined(HAVE_LINUX_FUTEX_H)
+#if UTIL_FUTEX_SUPPORTED
/* mtx_t - Fast, simple mutex
*
#define _SIMPLE_MTX_INITIALIZER_NP { 0 }
-#include <stdint.h>
-#include <linux/futex.h>
-#include <sys/time.h>
-#include <sys/syscall.h>
-
-static inline long sys_futex(void *addr1, int op, int val1,
- struct timespec *timeout, void *addr2, int val3)
-{
- return syscall(SYS_futex, addr1, op, val1, timeout, addr2, val3);
-}
-
-static inline int futex_wake(uint32_t *addr, int count)
-{
- return sys_futex(addr, FUTEX_WAKE, count, NULL, NULL, 0);
-}
-
-static inline int futex_wait(uint32_t *addr, int32_t value)
-{
- return sys_futex(addr, FUTEX_WAIT, value, NULL, NULL, 0);
-}
+#define _SIMPLE_MTX_INVALID_VALUE 0xd0d0d0d0
static inline void
-simple_mtx_init(simple_mtx_t *mtx, int type)
+simple_mtx_init(simple_mtx_t *mtx, ASSERTED int type)
{
assert(type == mtx_plain);
}
static inline void
-simple_mtx_destroy(simple_mtx_t *mtx)
+simple_mtx_destroy(ASSERTED simple_mtx_t *mtx)
{
+#ifndef NDEBUG
+ mtx->val = _SIMPLE_MTX_INVALID_VALUE;
+#endif
}
static inline void
uint32_t c;
c = __sync_val_compare_and_swap(&mtx->val, 0, 1);
+
+ assert(c != _SIMPLE_MTX_INVALID_VALUE);
+
if (__builtin_expect(c != 0, 0)) {
if (c != 2)
c = __sync_lock_test_and_set(&mtx->val, 2);
while (c != 0) {
- futex_wait(&mtx->val, 2);
+ futex_wait(&mtx->val, 2, NULL);
c = __sync_lock_test_and_set(&mtx->val, 2);
}
}
uint32_t c;
c = __sync_fetch_and_sub(&mtx->val, 1);
+
+ assert(c != _SIMPLE_MTX_INVALID_VALUE);
+
if (__builtin_expect(c != 1, 0)) {
mtx->val = 0;
futex_wake(&mtx->val, 1);
}
}
+static inline void
+simple_mtx_assert_locked(simple_mtx_t *mtx)
+{
+ assert(mtx->val);
+}
+
#else
typedef mtx_t simple_mtx_t;
mtx_unlock(mtx);
}
+static inline void
+simple_mtx_assert_locked(simple_mtx_t *mtx)
+{
+#ifdef DEBUG
+ /* NOTE: this would not work for recursive mutexes, but
+ * mtx_t doesn't support those
+ */
+ int ret = mtx_trylock(mtx);
+ assert(ret == thrd_busy);
+ if (ret == thrd_success)
+ mtx_unlock(mtx);
+#else
+ (void)mtx;
+#endif
+}
+
#endif
#endif