diff options
Diffstat (limited to 'nptl/cancellation.c')
| -rw-r--r-- | nptl/cancellation.c | 50 |
1 files changed, 38 insertions, 12 deletions
diff --git a/nptl/cancellation.c b/nptl/cancellation.c index 8d54a6add1..f4b08902b2 100644 --- a/nptl/cancellation.c +++ b/nptl/cancellation.c @@ -30,19 +30,26 @@ int __pthread_enable_asynccancel (void) { struct pthread *self = THREAD_SELF; + int oldval = atomic_load_relaxed (&self->cancelhandling); - int oldval = THREAD_GETMEM (self, canceltype); - THREAD_SETMEM (self, canceltype, PTHREAD_CANCEL_ASYNCHRONOUS); + while (1) + { + int newval = oldval | CANCELTYPE_BITMASK; - int ch = THREAD_GETMEM (self, cancelhandling); + if (newval == oldval) + break; - if (self->cancelstate == PTHREAD_CANCEL_ENABLE - && (ch & CANCELED_BITMASK) - && !(ch & EXITING_BITMASK) - && !(ch & TERMINATED_BITMASK)) - { - THREAD_SETMEM (self, result, PTHREAD_CANCELED); - __do_cancel (); + if (atomic_compare_exchange_weak_acquire (&self->cancelhandling, + &oldval, newval)) + { + if (cancel_enabled_and_canceled_and_async (newval)) + { + self->result = PTHREAD_CANCELED; + __do_cancel (); + } + + break; + } } return oldval; @@ -56,10 +63,29 @@ __pthread_disable_asynccancel (int oldtype) { /* If asynchronous cancellation was enabled before we do not have anything to do. */ - if (oldtype == PTHREAD_CANCEL_ASYNCHRONOUS) + if (oldtype & CANCELTYPE_BITMASK) return; struct pthread *self = THREAD_SELF; - self->canceltype = PTHREAD_CANCEL_DEFERRED; + int newval; + int oldval = atomic_load_relaxed (&self->cancelhandling); + do + { + newval = oldval & ~CANCELTYPE_BITMASK; + } + while (!atomic_compare_exchange_weak_acquire (&self->cancelhandling, + &oldval, newval)); + + /* We cannot return when we are being canceled. Upon return the + thread might be things which would have to be undone. The + following loop should loop until the cancellation signal is + delivered. */ + while (__glibc_unlikely ((newval & (CANCELING_BITMASK | CANCELED_BITMASK)) + == CANCELING_BITMASK)) + { + futex_wait_simple ((unsigned int *) &self->cancelhandling, newval, + FUTEX_PRIVATE); + newval = atomic_load_relaxed (&self->cancelhandling); + } } libc_hidden_def (__pthread_disable_asynccancel) |