Use FUTEX_WAIT_BITSET to avoid converting timeouts.
Add unittests for pthread APIs with timeout parameter.
Bug: 17569991
Change-Id: I6b3b9b2feae03680654cd64c3112ce7644632c87
diff --git a/libc/bionic/pthread_mutex.cpp b/libc/bionic/pthread_mutex.cpp
index 851fc3d..23dc3b0 100644
--- a/libc/bionic/pthread_mutex.cpp
+++ b/libc/bionic/pthread_mutex.cpp
@@ -296,11 +296,15 @@
*/
static inline __always_inline int __pthread_normal_mutex_lock(pthread_mutex_internal_t* mutex,
uint16_t shared,
- const timespec* abs_timeout_or_null,
- clockid_t clock) {
+ bool use_realtime_clock,
+ const timespec* abs_timeout_or_null) {
if (__predict_true(__pthread_normal_mutex_trylock(mutex, shared) == 0)) {
return 0;
}
+ int result = check_timespec(abs_timeout_or_null);
+ if (result != 0) {
+ return result;
+ }
ScopedTrace trace("Contending for pthread mutex");
@@ -317,15 +321,8 @@
// made by other threads visible to the current CPU.
while (atomic_exchange_explicit(&mutex->state, locked_contended,
memory_order_acquire) != unlocked) {
- timespec ts;
- timespec* rel_timeout = NULL;
- if (abs_timeout_or_null != NULL) {
- rel_timeout = &ts;
- if (!timespec_from_absolute_timespec(*rel_timeout, *abs_timeout_or_null, clock)) {
- return ETIMEDOUT;
- }
- }
- if (__futex_wait_ex(&mutex->state, shared, locked_contended, rel_timeout) == -ETIMEDOUT) {
+ if (__futex_wait_ex(&mutex->state, shared, locked_contended, use_realtime_clock,
+ abs_timeout_or_null) == -ETIMEDOUT) {
return ETIMEDOUT;
}
}
@@ -396,14 +393,15 @@
pthread_mutex_internal_t* mutex,
uint16_t shared,
uint16_t old_state,
- const timespec* rel_timeout) {
+ bool use_realtime_clock,
+ const timespec* abs_timeout) {
// __futex_wait always waits on a 32-bit value. But state is 16-bit. For a normal mutex, the owner_tid
// field in mutex is not used. On 64-bit devices, the __pad field in mutex is not used.
// But when a recursive or errorcheck mutex is used on 32-bit devices, we need to add the
// owner_tid value in the value argument for __futex_wait, otherwise we may always get EAGAIN error.
#if defined(__LP64__)
- return __futex_wait_ex(&mutex->state, shared, old_state, rel_timeout);
+ return __futex_wait_ex(&mutex->state, shared, old_state, use_realtime_clock, abs_timeout);
#else
// This implementation works only when the layout of pthread_mutex_internal_t matches below expectation.
@@ -412,19 +410,21 @@
static_assert(offsetof(pthread_mutex_internal_t, owner_tid) == 2, "");
uint32_t owner_tid = atomic_load_explicit(&mutex->owner_tid, memory_order_relaxed);
- return __futex_wait_ex(&mutex->state, shared, (owner_tid << 16) | old_state, rel_timeout);
+ return __futex_wait_ex(&mutex->state, shared, (owner_tid << 16) | old_state,
+ use_realtime_clock, abs_timeout);
#endif
}
static int __pthread_mutex_lock_with_timeout(pthread_mutex_internal_t* mutex,
- const timespec* abs_timeout_or_null, clockid_t clock) {
+ bool use_realtime_clock,
+ const timespec* abs_timeout_or_null) {
uint16_t old_state = atomic_load_explicit(&mutex->state, memory_order_relaxed);
uint16_t mtype = (old_state & MUTEX_TYPE_MASK);
uint16_t shared = (old_state & MUTEX_SHARED_MASK);
// Handle common case first.
if ( __predict_true(mtype == MUTEX_TYPE_BITS_NORMAL) ) {
- return __pthread_normal_mutex_lock(mutex, shared, abs_timeout_or_null, clock);
+ return __pthread_normal_mutex_lock(mutex, shared, use_realtime_clock, abs_timeout_or_null);
}
// Do we already own this recursive or error-check mutex?
@@ -484,16 +484,13 @@
old_state = new_state;
}
- // We are in locked_contended state, sleep until someone wakes us up.
- timespec ts;
- timespec* rel_timeout = NULL;
- if (abs_timeout_or_null != NULL) {
- rel_timeout = &ts;
- if (!timespec_from_absolute_timespec(*rel_timeout, *abs_timeout_or_null, clock)) {
- return ETIMEDOUT;
- }
+ int result = check_timespec(abs_timeout_or_null);
+ if (result != 0) {
+ return result;
}
- if (__recursive_or_errorcheck_mutex_wait(mutex, shared, old_state, rel_timeout) == -ETIMEDOUT) {
+ // We are in locked_contended state, sleep until someone wakes us up.
+ if (__recursive_or_errorcheck_mutex_wait(mutex, shared, old_state, use_realtime_clock,
+ abs_timeout_or_null) == -ETIMEDOUT) {
return ETIMEDOUT;
}
old_state = atomic_load_explicit(&mutex->state, memory_order_relaxed);
@@ -518,7 +515,7 @@
return 0;
}
}
- return __pthread_mutex_lock_with_timeout(mutex, NULL, 0);
+ return __pthread_mutex_lock_with_timeout(mutex, false, nullptr);
}
int pthread_mutex_unlock(pthread_mutex_t* mutex_interface) {
@@ -613,17 +610,12 @@
#if !defined(__LP64__)
extern "C" int pthread_mutex_lock_timeout_np(pthread_mutex_t* mutex_interface, unsigned ms) {
+ timespec ts;
+ timespec_from_ms(ts, ms);
timespec abs_timeout;
- clock_gettime(CLOCK_MONOTONIC, &abs_timeout);
- abs_timeout.tv_sec += ms / 1000;
- abs_timeout.tv_nsec += (ms % 1000) * 1000000;
- if (abs_timeout.tv_nsec >= NS_PER_S) {
- abs_timeout.tv_sec++;
- abs_timeout.tv_nsec -= NS_PER_S;
- }
-
+ absolute_timespec_from_timespec(abs_timeout, ts, CLOCK_MONOTONIC);
int error = __pthread_mutex_lock_with_timeout(__get_internal_mutex(mutex_interface),
- &abs_timeout, CLOCK_MONOTONIC);
+ false, &abs_timeout);
if (error == ETIMEDOUT) {
error = EBUSY;
}
@@ -633,7 +625,7 @@
int pthread_mutex_timedlock(pthread_mutex_t* mutex_interface, const timespec* abs_timeout) {
return __pthread_mutex_lock_with_timeout(__get_internal_mutex(mutex_interface),
- abs_timeout, CLOCK_REALTIME);
+ true, abs_timeout);
}
int pthread_mutex_destroy(pthread_mutex_t* mutex_interface) {