diff options
Diffstat (limited to 'nptl/libc-cancellation.c')
| -rw-r--r-- | nptl/libc-cancellation.c | 48 |
1 files changed, 30 insertions, 18 deletions
diff --git a/nptl/libc-cancellation.c b/nptl/libc-cancellation.c index 344a2181c8..72a6d108fd 100644 --- a/nptl/libc-cancellation.c +++ b/nptl/libc-cancellation.c @@ -33,13 +33,11 @@ attribute_hidden __libc_enable_asynccancel (void) { struct pthread *self = THREAD_SELF; - int oldval; - int newval; + int oldval = THREAD_GETMEM (self, cancelhandling); - do + while (1) { - oldval = THREAD_GETMEM (self, cancelhandling); - newval = oldval | CANCELTYPE_BITMASK; + int newval = oldval | CANCELTYPE_BITMASK; if (__builtin_expect ((oldval & CANCELED_BITMASK) != 0, 0)) { @@ -47,10 +45,14 @@ __libc_enable_asynccancel (void) if ((oldval & EXITING_BITMASK) != 0) break; - if (atomic_compare_and_exchange_bool_acq (&self->cancelhandling, - newval, oldval)) - /* Somebody else modified the word, try again. */ - continue; + int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling, + newval, oldval); + if (__builtin_expect (curval != oldval, 0)) + { + /* Somebody else modified the word, try again. */ + oldval = curval; + continue; + } THREAD_SETMEM (self, result, PTHREAD_CANCELED); @@ -58,9 +60,15 @@ __libc_enable_asynccancel (void) /* NOTREACHED */ } + + int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling, newval, + oldval); + if (__builtin_expect (curval == oldval, 1)) + break; + + /* Prepare the next round. */ + oldval = curval; } - while (atomic_compare_and_exchange_bool_acq (&self->cancelhandling, - newval, oldval)); return oldval; } @@ -76,19 +84,23 @@ __libc_disable_asynccancel (int oldtype) return; struct pthread *self = THREAD_SELF; - int oldval; - int newval; + int oldval = THREAD_GETMEM (self, cancelhandling); - do + while (1) { - oldval = THREAD_GETMEM (self, cancelhandling); - newval = oldval & ~CANCELTYPE_BITMASK; + int newval = oldval & ~CANCELTYPE_BITMASK; if (newval == oldval) break; + + int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling, newval, + oldval); + if (__builtin_expect (curval == oldval, 1)) + break; + + /* Prepare the next round. */ + oldval = curval; } - while (atomic_compare_and_exchange_bool_acq (&self->cancelhandling, newval, - oldval)); } #endif |