diff options
Diffstat (limited to 'usr/src/lib/libc/port/threads/synch.c')
| -rw-r--r-- | usr/src/lib/libc/port/threads/synch.c | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/usr/src/lib/libc/port/threads/synch.c b/usr/src/lib/libc/port/threads/synch.c index 6856ebcc6b..9c6e918620 100644 --- a/usr/src/lib/libc/port/threads/synch.c +++ b/usr/src/lib/libc/port/threads/synch.c @@ -2184,6 +2184,77 @@ lmutex_unlock(mutex_t *mp) exit_critical(self); } +/* + * For specialized code in libc, like the asynchronous i/o code, + * the following sig_*() locking primitives are used in order + * to make the code asynchronous signal safe. Signals are + * deferred while locks acquired by these functions are held. + */ +void +sig_mutex_lock(mutex_t *mp) +{ + sigoff(curthread); + (void) _private_mutex_lock(mp); +} + +void +sig_mutex_unlock(mutex_t *mp) +{ + (void) _private_mutex_unlock(mp); + sigon(curthread); +} + +int +sig_mutex_trylock(mutex_t *mp) +{ + int error; + + sigoff(curthread); + if ((error = _private_mutex_trylock(mp)) != 0) + sigon(curthread); + return (error); +} + +/* + * sig_cond_wait() is a cancellation point. + */ +int +sig_cond_wait(cond_t *cv, mutex_t *mp) +{ + int error; + + ASSERT(curthread->ul_sigdefer != 0); + _private_testcancel(); + error = _cond_wait(cv, mp); + if (error == EINTR && curthread->ul_cursig) { + sig_mutex_unlock(mp); + /* take the deferred signal here */ + sig_mutex_lock(mp); + } + _private_testcancel(); + return (error); +} + +/* + * sig_cond_reltimedwait() is a cancellation point. + */ +int +sig_cond_reltimedwait(cond_t *cv, mutex_t *mp, const timespec_t *ts) +{ + int error; + + ASSERT(curthread->ul_sigdefer != 0); + _private_testcancel(); + error = _cond_reltimedwait(cv, mp, ts); + if (error == EINTR && curthread->ul_cursig) { + sig_mutex_unlock(mp); + /* take the deferred signal here */ + sig_mutex_lock(mp); + } + _private_testcancel(); + return (error); +} + static int shared_mutex_held(mutex_t *mparg) { |