Use C11 atomics instead of atomic_and/or

Remove the 4 uses of atomic_and and atomic_or with atomic_fetch_and_acquire
and atomic_fetch_or_acquire. This is preserves existing implied semantics,
however relaxed MO on FUTEX_OWNER_DIED accesses may be correct.

Passes regress on AArch64.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

diff --git a/nptl/pthread_create.c b/nptl/pthread_create.c
index ee29cb3..59d8df8 100644 (file)
--- a/nptl/pthread_create.c
+++ b/nptl/pthread_create.c
@@ -539,7 +539,7 @@ start_thread (void *arg)
 # endif
          this->__list.__next = NULL;
 
-         atomic_or (&this->__lock, FUTEX_OWNER_DIED);
+         atomic_fetch_or_acquire (&this->__lock, FUTEX_OWNER_DIED);
          futex_wake ((unsigned int *) &this->__lock, 1,
                      /* XYZ */ FUTEX_SHARED);
        }

diff --git a/nptl/pthread_mutex_lock.c b/nptl/pthread_mutex_lock.c
index 6e767a8..439b1e6 100644 (file)
--- a/nptl/pthread_mutex_lock.c
+++ b/nptl/pthread_mutex_lock.c
@@ -462,7 +462,7 @@ __pthread_mutex_lock_full (pthread_mutex_t *mutex)
 
        if (__glibc_unlikely (oldval & FUTEX_OWNER_DIED))
          {
-           atomic_and (&mutex->__data.__lock, ~FUTEX_OWNER_DIED);
+           atomic_fetch_and_acquire (&mutex->__data.__lock, ~FUTEX_OWNER_DIED);
 
            /* We got the mutex.  */
            mutex->__data.__count = 1;

diff --git a/nptl/pthread_mutex_timedlock.c b/nptl/pthread_mutex_timedlock.c
index 0fcaabf..af70a60 100644 (file)
--- a/nptl/pthread_mutex_timedlock.c
+++ b/nptl/pthread_mutex_timedlock.c
@@ -392,7 +392,7 @@ __pthread_mutex_clocklock_common (pthread_mutex_t *mutex,
 
        if (__glibc_unlikely (oldval & FUTEX_OWNER_DIED))
          {
-           atomic_and (&mutex->__data.__lock, ~FUTEX_OWNER_DIED);
+           atomic_fetch_and_acquire (&mutex->__data.__lock, ~FUTEX_OWNER_DIED);
 
            /* We got the mutex.  */
            mutex->__data.__count = 1;

diff --git a/nptl/pthread_mutex_trylock.c b/nptl/pthread_mutex_trylock.c
index 8a7de8e..5052494 100644 (file)
--- a/nptl/pthread_mutex_trylock.c
+++ b/nptl/pthread_mutex_trylock.c
@@ -308,7 +308,7 @@ ___pthread_mutex_trylock (pthread_mutex_t *mutex)
 
        if (__glibc_unlikely (oldval & FUTEX_OWNER_DIED))
          {
-           atomic_and (&mutex->__data.__lock, ~FUTEX_OWNER_DIED);
+           atomic_fetch_and_acquire (&mutex->__data.__lock, ~FUTEX_OWNER_DIED);
 
            /* We got the mutex.  */
            mutex->__data.__count = 1;