[Mesa-dev] [PATCH v2 04/26] util/u_queue: add util_queue_fence_wait_timeout
Nicolai Hähnle
nhaehnle at gmail.com
Mon Nov 6 10:23:35 UTC 2017
From: Nicolai Hähnle <nicolai.haehnle at amd.com>
v2:
- style fixes
- fix missing timeout handling in futex path
Reviewed-by: Marek Olšák <marek.olsak at amd.com> (v1)
---
src/util/futex.h | 9 ++++--
src/util/simple_mtx.h | 2 +-
src/util/u_queue.c | 82 ++++++++++++++++++++++++++++++++++++++++++++++++++-
src/util/u_queue.h | 54 ++++++++++++++++++++-------------
4 files changed, 121 insertions(+), 26 deletions(-)
diff --git a/src/util/futex.h b/src/util/futex.h
index fa42cf4cf59..330e18f03a2 100644
--- a/src/util/futex.h
+++ b/src/util/futex.h
@@ -26,33 +26,36 @@
#if defined(HAVE_FUTEX)
#include <limits.h>
#include <stdint.h>
#include <unistd.h>
#include <linux/futex.h>
#include <sys/syscall.h>
#include <sys/time.h>
-static inline long sys_futex(void *addr1, int op, int val1, struct timespec *timeout, void *addr2, int val3)
+static inline long sys_futex(void *addr1, int op, int val1, const 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)
{
return sys_futex(addr, FUTEX_WAKE, 1, NULL, NULL, 0);
}
static inline int futex_wake_all(uint32_t *addr)
{
return sys_futex(addr, FUTEX_WAKE, INT_MAX, NULL, NULL, 0);
}
-static inline int futex_wait(uint32_t *addr, int32_t value)
+static inline int futex_wait(uint32_t *addr, int32_t value, const struct timespec *timeout)
{
- return sys_futex(addr, FUTEX_WAIT, value, NULL, NULL, 0);
+ /* FUTEX_WAIT_BITSET with FUTEX_BITSET_MATCH_ANY is equivalent to
+ * FUTEX_WAIT, except that it treats the timeout as absolute. */
+ return sys_futex(addr, FUTEX_WAIT_BITSET, value, timeout, NULL,
+ FUTEX_BITSET_MATCH_ANY);
}
#endif
#endif /* UTIL_FUTEX_H */
diff --git a/src/util/simple_mtx.h b/src/util/simple_mtx.h
index 0c2602d03b6..4186a2d4d64 100644
--- a/src/util/simple_mtx.h
+++ b/src/util/simple_mtx.h
@@ -72,21 +72,21 @@ simple_mtx_destroy(simple_mtx_t *mtx)
static inline void
simple_mtx_lock(simple_mtx_t *mtx)
{
uint32_t c;
c = __sync_val_compare_and_swap(&mtx->val, 0, 1);
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);
}
}
}
static inline void
simple_mtx_unlock(simple_mtx_t *mtx)
{
uint32_t c;
diff --git a/src/util/u_queue.c b/src/util/u_queue.c
index 706ee8b04d9..43c28ac6ef8 100644
--- a/src/util/u_queue.c
+++ b/src/util/u_queue.c
@@ -19,20 +19,23 @@
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
* USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial portions
* of the Software.
*/
#include "u_queue.h"
+#include <time.h>
+
+#include "util/os_time.h"
#include "util/u_string.h"
#include "util/u_thread.h"
static void util_queue_killall_and_wait(struct util_queue *queue);
/****************************************************************************
* Wait for all queues to assert idle when exit() is called.
*
* Otherwise, C++ static variable destructors can be called while threads
* are using the static variables.
@@ -84,39 +87,116 @@ remove_from_atexit_list(struct util_queue *queue)
break;
}
}
mtx_unlock(&exit_mutex);
}
/****************************************************************************
* util_queue_fence
*/
+#ifdef UTIL_QUEUE_FENCE_FUTEX
+static bool
+do_futex_fence_wait(struct util_queue_fence *fence,
+ bool timeout, int64_t abs_timeout)
+{
+ uint32_t v = fence->val;
+ struct timespec ts;
+ ts.tv_sec = abs_timeout / (1000*1000*1000);
+ ts.tv_nsec = abs_timeout % (1000*1000*1000);
+
+ while (v != 0) {
+ if (v != 2) {
+ v = p_atomic_cmpxchg(&fence->val, 1, 2);
+ if (v == 0)
+ return true;
+ }
+
+ int r = futex_wait(&fence->val, 2, timeout ? &ts : NULL);
+ if (timeout && r < 0) {
+ if (errno == -ETIMEDOUT)
+ return false;
+ }
+
+ v = fence->val;
+ }
+
+ return true;
+}
+
+void
+_util_queue_fence_wait(struct util_queue_fence *fence)
+{
+ do_futex_fence_wait(fence, false, 0);
+}
+
+bool
+_util_queue_fence_wait_timeout(struct util_queue_fence *fence,
+ int64_t abs_timeout)
+{
+ return do_futex_fence_wait(fence, true, abs_timeout);
+}
+
+#endif
+
#ifdef UTIL_QUEUE_FENCE_STANDARD
void
util_queue_fence_signal(struct util_queue_fence *fence)
{
mtx_lock(&fence->mutex);
fence->signalled = true;
cnd_broadcast(&fence->cond);
mtx_unlock(&fence->mutex);
}
void
-util_queue_fence_wait(struct util_queue_fence *fence)
+_util_queue_fence_wait(struct util_queue_fence *fence)
{
mtx_lock(&fence->mutex);
while (!fence->signalled)
cnd_wait(&fence->cond, &fence->mutex);
mtx_unlock(&fence->mutex);
}
+bool
+_util_queue_fence_wait_timeout(struct util_queue_fence *fence,
+ int64_t abs_timeout)
+{
+ /* This terrible hack is made necessary by the fact that we really want an
+ * internal interface consistent with os_time_*, but cnd_timedwait is spec'd
+ * to be relative to the TIME_UTC clock.
+ */
+ int64_t rel = abs_timeout - os_time_get_nano();
+
+ if (rel > 0) {
+ struct timespec ts;
+
+ timespec_get(&ts, TIME_UTC);
+
+ ts.tv_sec += abs_timeout / (1000*1000*1000);
+ ts.tv_nsec += abs_timeout % (1000*1000*1000);
+ if (ts.tv_nsec >= (1000*1000*1000)) {
+ ts.tv_sec++;
+ ts.tv_nsec -= (1000*1000*1000);
+ }
+
+ mtx_lock(&fence->mutex);
+ while (!fence->signalled) {
+ if (cnd_timedwait(&fence->cond, &fence->mutex, &ts) != thrd_success)
+ break;
+ }
+ mtx_unlock(&fence->mutex);
+ }
+
+ return fence->signalled;
+}
+
void
util_queue_fence_init(struct util_queue_fence *fence)
{
memset(fence, 0, sizeof(*fence));
(void) mtx_init(&fence->mutex, mtx_plain);
cnd_init(&fence->cond);
fence->signalled = true;
}
void
diff --git a/src/util/u_queue.h b/src/util/u_queue.h
index 9c911fe6b4d..7f9b43d72ff 100644
--- a/src/util/u_queue.h
+++ b/src/util/u_queue.h
@@ -74,40 +74,20 @@ util_queue_fence_init(struct util_queue_fence *fence)
}
static inline void
util_queue_fence_destroy(struct util_queue_fence *fence)
{
assert(fence->val == 0);
/* no-op */
}
static inline void
-util_queue_fence_wait(struct util_queue_fence *fence)
-{
- uint32_t v = fence->val;
-
- if (likely(v == 0))
- return;
-
- do {
- if (v != 2) {
- v = p_atomic_cmpxchg(&fence->val, 1, 2);
- if (v == 0)
- return;
- }
-
- futex_wait(&fence->val, 2);
- v = fence->val;
- } while(v != 0);
-}
-
-static inline void
util_queue_fence_signal(struct util_queue_fence *fence)
{
uint32_t val = p_atomic_xchg(&fence->val, 0);
assert(val != 0);
if (val == 2)
futex_wake_all(&fence->val);
}
@@ -140,21 +120,20 @@ util_queue_fence_is_signalled(struct util_queue_fence *fence)
* Put this into your job structure.
*/
struct util_queue_fence {
mtx_t mutex;
cnd_t cond;
int signalled;
};
void util_queue_fence_init(struct util_queue_fence *fence);
void util_queue_fence_destroy(struct util_queue_fence *fence);
-void util_queue_fence_wait(struct util_queue_fence *fence);
void util_queue_fence_signal(struct util_queue_fence *fence);
/**
* Move \p fence back into unsignalled state.
*
* \warning The caller must ensure that no other thread may currently be
* waiting (or about to wait) on the fence.
*/
static inline void
util_queue_fence_reset(struct util_queue_fence *fence)
@@ -163,20 +142,53 @@ util_queue_fence_reset(struct util_queue_fence *fence)
fence->signalled = 0;
}
static inline bool
util_queue_fence_is_signalled(struct util_queue_fence *fence)
{
return fence->signalled != 0;
}
#endif
+void
+_util_queue_fence_wait(struct util_queue_fence *fence);
+
+static inline void
+util_queue_fence_wait(struct util_queue_fence *fence)
+{
+ if (unlikely(!util_queue_fence_is_signalled(fence)))
+ _util_queue_fence_wait(fence);
+}
+
+bool
+_util_queue_fence_wait_timeout(struct util_queue_fence *fence,
+ int64_t abs_timeout);
+
+/**
+ * Wait for the fence to be signaled with a timeout.
+ *
+ * \param fence the fence
+ * \param abs_timeout the absolute timeout in nanoseconds, relative to the
+ * clock provided by os_time_get_nano.
+ *
+ * \return true if the fence was signaled, false if the timeout occurred.
+ */
+static inline bool
+util_queue_fence_wait_timeout(struct util_queue_fence *fence,
+ int64_t abs_timeout)
+{
+ if (util_queue_fence_is_signalled(fence))
+ return true;
+
+ return _util_queue_fence_wait_timeout(fence, abs_timeout);
+}
+
typedef void (*util_queue_execute_func)(void *job, int thread_index);
struct util_queue_job {
void *job;
struct util_queue_fence *fence;
util_queue_execute_func execute;
util_queue_execute_func cleanup;
};
/* Put this into your context. */
--
2.11.0
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