Eliminate atomic operations in thread cancellation functions, it should

reduce overheads of cancellation points.

12 files changed, 176 insertions, 213 deletions

diff --git a/lib/libthr/thread/thr_cancel.c b/lib/libthr/thread/thr_cancel.c
index 1047eb2..8df0304 100644
--- a/lib/libthr/thread/thr_cancel.c
+++ b/lib/libthr/thread/thr_cancel.c
@@ -38,126 +38,120 @@ __weak_reference(_pthread_setcancelstate, pthread_setcancelstate);
 __weak_reference(_pthread_setcanceltype, pthread_setcanceltype);
 __weak_reference(_pthread_testcancel, pthread_testcancel);
 
+static inline void
+testcancel(struct pthread *curthread)
+{
+	if (__predict_false(SHOULD_CANCEL(curthread) &&
+	    !THR_IN_CRITICAL(curthread)))
+		_pthread_exit(PTHREAD_CANCELED);
+}
+
+void
+_thr_testcancel(struct pthread *curthread)
+{
+	testcancel(curthread);
+}
+
 int
 _pthread_cancel(pthread_t pthread)
 {
 	struct pthread *curthread = _get_curthread();
-	int oldval, newval = 0;
-	int oldtype;
 	int ret;
 
 	/*
-	 * POSIX says _pthread_cancel should be async cancellation safe,
-	 * so we temporarily disable async cancellation.
+	 * POSIX says _pthread_cancel should be async cancellation safe.
+	 * _thr_ref_add and _thr_ref_delete will enter and leave critical
+	 * region automatically.
 	 */
-	_pthread_setcanceltype(PTHREAD_CANCEL_DEFERRED, &oldtype);
-	if ((ret = _thr_ref_add(curthread, pthread, 0)) != 0) {
-		_pthread_setcanceltype(oldtype, NULL);
-		return (ret);
+	if ((ret = _thr_ref_add(curthread, pthread, 0)) == 0) {
+		THR_THREAD_LOCK(curthread, pthread);
+		if (!pthread->cancel_pending) {
+			pthread->cancel_pending = 1;
+			if (pthread->cancel_enable)
+				_thr_send_sig(pthread, SIGCANCEL);
+		}
+		THR_THREAD_UNLOCK(curthread, pthread);
+		_thr_ref_delete(curthread, pthread);
 	}
-
-	do {
-		oldval = pthread->cancelflags;
-		if (oldval & THR_CANCEL_NEEDED)
-			break;
-		newval = oldval | THR_CANCEL_NEEDED;
-	} while (!atomic_cmpset_acq_int(&pthread->cancelflags, oldval, newval));
-
-	if (!(oldval & THR_CANCEL_NEEDED) && SHOULD_ASYNC_CANCEL(newval))
-		_thr_send_sig(pthread, SIGCANCEL);
-
-	_thr_ref_delete(curthread, pthread);
-	_pthread_setcanceltype(oldtype, NULL);
-	return (0);
-}
-
-static inline void
-testcancel(struct pthread *curthread)
-{
-	int newval;
-
-	newval = curthread->cancelflags;
-	if (SHOULD_CANCEL(newval) && !THR_IN_CRITICAL(curthread))
-		_pthread_exit(PTHREAD_CANCELED);
+	return (ret);
 }
 
 int
 _pthread_setcancelstate(int state, int *oldstate)
 {
 	struct pthread *curthread = _get_curthread();
-	int oldval, ret;
+	int oldval;
 
-	oldval = curthread->cancelflags;
-	if (oldstate != NULL)
-		*oldstate = ((oldval & THR_CANCEL_DISABLE) ?
-		    PTHREAD_CANCEL_DISABLE : PTHREAD_CANCEL_ENABLE);
+	oldval = curthread->cancel_enable;
 	switch (state) {
 	case PTHREAD_CANCEL_DISABLE:
-		atomic_set_int(&curthread->cancelflags, THR_CANCEL_DISABLE);
-		ret = 0;
+		THR_LOCK(curthread);
+		curthread->cancel_enable = 0;
+		THR_UNLOCK(curthread);
 		break;
 	case PTHREAD_CANCEL_ENABLE:
-		atomic_clear_int(&curthread->cancelflags, THR_CANCEL_DISABLE);
-		testcancel(curthread);
-		ret = 0;
+		THR_LOCK(curthread);
+		curthread->cancel_enable = 1;
+		THR_UNLOCK(curthread);
 		break;
 	default:
-		ret = EINVAL;
+		return (EINVAL);
 	}
 
-	return (ret);
+	if (oldstate) {
+		*oldstate = oldval ? PTHREAD_CANCEL_ENABLE :
+			PTHREAD_CANCEL_DISABLE;
+	}
+	return (0);
 }
 
 int
 _pthread_setcanceltype(int type, int *oldtype)
 {
 	struct pthread	*curthread = _get_curthread();
-	int oldval, ret;
+	int oldval;
 
-	oldval = curthread->cancelflags;
-	if (oldtype != NULL)
-		*oldtype = ((oldval & THR_CANCEL_AT_POINT) ?
-				 PTHREAD_CANCEL_ASYNCHRONOUS :
-				 PTHREAD_CANCEL_DEFERRED);
+	oldval = curthread->cancel_async;
 	switch (type) {
 	case PTHREAD_CANCEL_ASYNCHRONOUS:
-		atomic_set_int(&curthread->cancelflags, THR_CANCEL_AT_POINT);
+		curthread->cancel_async = 1;
 		testcancel(curthread);
-		ret = 0;
 		break;
 	case PTHREAD_CANCEL_DEFERRED:
-		atomic_clear_int(&curthread->cancelflags, THR_CANCEL_AT_POINT);
-		ret = 0;
+		curthread->cancel_async = 0;
 		break;
 	default:
-		ret = EINVAL;
+		return (EINVAL);
 	}
 
-	return (ret);
+	if (oldtype) {
+		*oldtype = oldval ? PTHREAD_CANCEL_ASYNCHRONOUS :
+		 	PTHREAD_CANCEL_DEFERRED;
+	}
+	return (0);
 }
 
 void
 _pthread_testcancel(void)
 {
-	testcancel(_get_curthread());
+	struct pthread *curthread = _get_curthread();
+
+	_thr_cancel_enter(curthread);
+	_thr_cancel_leave(curthread);
 }
 
-int
+void
 _thr_cancel_enter(struct pthread *curthread)
 {
-	int oldval;
-
-	oldval = curthread->cancelflags;
-	if (!(oldval & THR_CANCEL_AT_POINT)) {
-		atomic_set_int(&curthread->cancelflags, THR_CANCEL_AT_POINT);
+	if (curthread->cancel_enable) {
+		curthread->cancel_point++;
 		testcancel(curthread);
 	}
-	return (oldval);
 }
 
 void
-_thr_cancel_leave(struct pthread *curthread, int previous)
+_thr_cancel_leave(struct pthread *curthread)
 {
-	if (!(previous & THR_CANCEL_AT_POINT))
-		atomic_clear_int(&curthread->cancelflags, THR_CANCEL_AT_POINT);
+	if (curthread->cancel_enable)
+		curthread->cancel_point--;
 }
diff --git a/lib/libthr/thread/thr_cond.c b/lib/libthr/thread/thr_cond.c
index d0266d6..e587a6d 100644
--- a/lib/libthr/thread/thr_cond.c
+++ b/lib/libthr/thread/thr_cond.c
@@ -195,7 +195,6 @@ cond_wait_common(pthread_cond_t *cond, pthread_mutex_t *mutex,
 	struct cond_cancel_info info;
 	pthread_cond_t  cv;
 	long		seq, oldseq;
-	int		oldcancel;
 	int		ret = 0;
 
 	/*
@@ -231,9 +230,9 @@ cond_wait_common(pthread_cond_t *cond, pthread_mutex_t *mutex,
 
 		if (cancel) {
 			THR_CLEANUP_PUSH(curthread, cond_cancel_handler, &info);
-			oldcancel = _thr_cancel_enter(curthread);
+			_thr_cancel_enter(curthread);
 			ret = _thr_umtx_wait(&cv->c_seqno, seq, tsp);
-			_thr_cancel_leave(curthread, oldcancel);
+			_thr_cancel_leave(curthread);
 			THR_CLEANUP_POP(curthread, 0);
 		} else {
 			ret = _thr_umtx_wait(&cv->c_seqno, seq, tsp);
diff --git a/lib/libthr/thread/thr_create.c b/lib/libthr/thread/thr_create.c
index 99e3d0c..276e550 100644
--- a/lib/libthr/thread/thr_create.c
+++ b/lib/libthr/thread/thr_create.c
@@ -105,8 +105,8 @@ _pthread_create(pthread_t * thread, const pthread_attr_t * attr,
 	new_thread->magic = THR_MAGIC;
 	new_thread->start_routine = start_routine;
 	new_thread->arg = arg;
-	new_thread->cancelflags = PTHREAD_CANCEL_ENABLE |
-	    PTHREAD_CANCEL_DEFERRED;
+	new_thread->cancel_enable = 1;
+	new_thread->cancel_async = 0;
 	/* Initialize the mutex queue: */
 	TAILQ_INIT(&new_thread->mutexq);
 	TAILQ_INIT(&new_thread->pp_mutexq);
diff --git a/lib/libthr/thread/thr_exit.c b/lib/libthr/thread/thr_exit.c
index d438ac5..32ecc6b 100644
--- a/lib/libthr/thread/thr_exit.c
+++ b/lib/libthr/thread/thr_exit.c
@@ -87,7 +87,7 @@ _pthread_exit(void *status)
 	struct pthread *curthread = _get_curthread();
 
 	/* Check if this thread is already in the process of exiting: */
-	if ((curthread->cancelflags & THR_CANCEL_EXITING) != 0) {
+	if (curthread->cancelling) {
 		char msg[128];
 		snprintf(msg, sizeof(msg), "Thread %p has called "
 		    "pthread_exit() from a destructor. POSIX 1003.1 "
@@ -96,7 +96,7 @@ _pthread_exit(void *status)
 	}
 
 	/* Flag this thread as exiting. */
-	atomic_set_int(&curthread->cancelflags, THR_CANCEL_EXITING);
+	curthread->cancelling = 1;
 	
 	_thr_exit_cleanup();
 
diff --git a/lib/libthr/thread/thr_fork.c b/lib/libthr/thread/thr_fork.c
index cb487d4..3a99a4e 100644
--- a/lib/libthr/thread/thr_fork.c
+++ b/lib/libthr/thread/thr_fork.c
@@ -143,7 +143,7 @@ _fork(void)
 	if ((ret = __sys_fork()) == 0) {
 		/* Child process */
 		errsave = errno;
-		curthread->cancelflags &= ~THR_CANCEL_NEEDED;
+		curthread->cancel_pending = 0;
 		curthread->flags &= ~THR_FLAGS_NEED_SUSPEND;
 
 		/*
diff --git a/lib/libthr/thread/thr_init.c b/lib/libthr/thread/thr_init.c
index 3624cf8..ae4ea33 100644
--- a/lib/libthr/thread/thr_init.c
+++ b/lib/libthr/thread/thr_init.c
@@ -402,7 +402,8 @@ init_main_thread(struct pthread *thread)
 	 */
 	thread->magic = THR_MAGIC;
 
-	thread->cancelflags = PTHREAD_CANCEL_ENABLE | PTHREAD_CANCEL_DEFERRED;
+	thread->cancel_enable = 1;
+	thread->cancel_async = 0;
 	thr_set_name(thread->tid, "initial thread");
 
 	/* Initialize the mutex queue: */
diff --git a/lib/libthr/thread/thr_join.c b/lib/libthr/thread/thr_join.c
index de27074..92a3b62 100644
--- a/lib/libthr/thread/thr_join.c
+++ b/lib/libthr/thread/thr_join.c
@@ -76,7 +76,6 @@ join_common(pthread_t pthread, void **thread_return,
 	struct timespec ts, ts2, *tsp;
 	void *tmp;
 	long tid;
-	int oldcancel;
 	int ret = 0;
 
 	if (pthread == NULL)
@@ -104,7 +103,7 @@ join_common(pthread_t pthread, void **thread_return,
 	THREAD_LIST_UNLOCK(curthread);
 
 	THR_CLEANUP_PUSH(curthread, backout_join, pthread);
-	oldcancel = _thr_cancel_enter(curthread);
+	_thr_cancel_enter(curthread);
 
 	tid = pthread->tid;
 	while (pthread->tid != TID_TERMINATED) {
@@ -123,7 +122,7 @@ join_common(pthread_t pthread, void **thread_return,
 			break;
 	}
 
-	_thr_cancel_leave(curthread, oldcancel);
+	_thr_cancel_leave(curthread);
 	THR_CLEANUP_POP(curthread, 0);
 
 	if (ret == ETIMEDOUT) {
diff --git a/lib/libthr/thread/thr_list.c b/lib/libthr/thread/thr_list.c
index d85771d..e23e57d 100644
--- a/lib/libthr/thread/thr_list.c
+++ b/lib/libthr/thread/thr_list.c
@@ -293,6 +293,7 @@ _thr_ref_add(struct pthread *curthread, struct pthread *thread,
 	THREAD_LIST_LOCK(curthread);
 	if ((ret = _thr_find_thread(curthread, thread, include_dead)) == 0) {
 		thread->refcount++;
+		THR_CRITICAL_ENTER(curthread);
 	}
 	THREAD_LIST_UNLOCK(curthread);
 
@@ -309,7 +310,7 @@ _thr_ref_delete(struct pthread *curthread, struct pthread *thread)
 }
 
 void
-_thr_ref_delete_unlocked(struct pthread *curthread __unused,
+_thr_ref_delete_unlocked(struct pthread *curthread,
 	struct pthread *thread)
 {
 	if (thread != NULL) {
@@ -317,6 +318,7 @@ _thr_ref_delete_unlocked(struct pthread *curthread __unused,
 		if ((thread->refcount == 0) && thread->state == PS_DEAD &&
 		    (thread->tlflags & TLFLAGS_DETACHED) != 0)
 			THR_GCLIST_ADD(thread);
+		THR_CRITICAL_LEAVE(curthread);
 	}
 }
 
diff --git a/lib/libthr/thread/thr_private.h b/lib/libthr/thread/thr_private.h
index 2e370b9..4459a2a 100644
--- a/lib/libthr/thread/thr_private.h
+++ b/lib/libthr/thread/thr_private.h
@@ -350,22 +350,25 @@ struct pthread {
 	void			*arg;
 	struct pthread_attr	attr;
 
- 	/*
-	 * Cancelability flags 
-	 */
-#define	THR_CANCEL_DISABLE		0x0001
-#define	THR_CANCEL_EXITING		0x0002
-#define THR_CANCEL_AT_POINT		0x0004
-#define THR_CANCEL_NEEDED		0x0008
-#define	SHOULD_CANCEL(val)					\
-	(((val) & (THR_CANCEL_DISABLE | THR_CANCEL_EXITING |	\
-		 THR_CANCEL_NEEDED)) == THR_CANCEL_NEEDED)
-
-#define	SHOULD_ASYNC_CANCEL(val)				\
-	(((val) & (THR_CANCEL_DISABLE | THR_CANCEL_EXITING |	\
-		 THR_CANCEL_NEEDED | THR_CANCEL_AT_POINT)) ==	\
-		 (THR_CANCEL_NEEDED | THR_CANCEL_AT_POINT))
-	int			cancelflags;
+#define	SHOULD_CANCEL(thr)					\
+	((thr)->cancel_pending &&				\
+	 ((thr)->cancel_point || (thr)->cancel_async) &&	\
+	 (thr)->cancel_enable && (thr)->cancelling == 0)
+
+	/* Cancellation is enabled */
+	int			cancel_enable;
+
+	/* Cancellation request is pending */
+	int			cancel_pending;
+
+	/* Thread is at cancellation point */
+	int			cancel_point;
+
+	/* Asynchronouse cancellation is enabled */
+	int			cancel_async;
+
+	/* Cancellation is in progress */
+	int			cancelling;
 
 	/* Thread temporary signal mask. */
 	sigset_t		sigmask;
@@ -620,8 +623,9 @@ void    _thread_cleanupspecific(void) __hidden;
 void    _thread_dump_info(void) __hidden;
 void	_thread_printf(int, const char *, ...) __hidden;
 void	_thr_spinlock_init(void) __hidden;
-int	_thr_cancel_enter(struct pthread *) __hidden;
-void	_thr_cancel_leave(struct pthread *, int) __hidden;
+void	_thr_cancel_enter(struct pthread *) __hidden;
+void	_thr_cancel_leave(struct pthread *) __hidden;
+void	_thr_testcancel(struct pthread *) __hidden;
 void	_thr_signal_block(struct pthread *) __hidden;
 void	_thr_signal_unblock(struct pthread *) __hidden;
 void	_thr_signal_init(void) __hidden;
diff --git a/lib/libthr/thread/thr_sem.c b/lib/libthr/thread/thr_sem.c
index ad10aaf..6dbf7f4 100644
--- a/lib/libthr/thread/thr_sem.c
+++ b/lib/libthr/thread/thr_sem.c
@@ -176,16 +176,16 @@ int
 _sem_wait(sem_t *sem)
 {
 	struct pthread *curthread;
-	int val, oldcancel, retval;
+	int val, retval;
 
 	if (sem_check_validity(sem) != 0)
 		return (-1);
 
 	curthread = _get_curthread();
 	if ((*sem)->syssem != 0) {
-		oldcancel = _thr_cancel_enter(curthread);
+		_thr_cancel_enter(curthread);
 		retval = ksem_wait((*sem)->semid);
-		_thr_cancel_leave(curthread, oldcancel);
+		_thr_cancel_leave(curthread);
 		return (retval);
 	}
 
@@ -195,9 +195,9 @@ _sem_wait(sem_t *sem)
 			if (atomic_cmpset_acq_int(&(*sem)->count, val, val - 1))
 				return (0);
 		}
-		oldcancel = _thr_cancel_enter(curthread);
+		_thr_cancel_enter(curthread);
 		retval = _thr_umtx_wait((umtx_t *)&(*sem)->count, 0, NULL);
-		_thr_cancel_leave(curthread, oldcancel);
+		_thr_cancel_leave(curthread);
 	} while (retval == 0);
 	errno = retval;
 	return (-1);
@@ -209,16 +209,16 @@ _sem_timedwait(sem_t * __restrict sem,
 {
 	struct timespec ts, ts2;
 	struct pthread *curthread;
-	int val, oldcancel, retval;
+	int val, retval;
 
 	if (sem_check_validity(sem) != 0)
 		return (-1);
 
 	curthread = _get_curthread();
 	if ((*sem)->syssem != 0) {
-		oldcancel = _thr_cancel_enter(curthread);
+		_thr_cancel_enter(curthread);
 		retval = ksem_timedwait((*sem)->semid, abstime);
-		_thr_cancel_leave(curthread, oldcancel);
+		_thr_cancel_leave(curthread);
 		return (retval);
 	}
 
@@ -238,9 +238,9 @@ _sem_timedwait(sem_t * __restrict sem,
 		}
 		clock_gettime(CLOCK_REALTIME, &ts);
 		TIMESPEC_SUB(&ts2, abstime, &ts);
-		oldcancel = _thr_cancel_enter(curthread);
+		_thr_cancel_enter(curthread);
 		retval = _thr_umtx_wait((umtx_t *)&(*sem)->count, 0, &ts2);
-		_thr_cancel_leave(curthread, oldcancel);
+		_thr_cancel_leave(curthread);
 	} while (retval == 0);
 	errno = retval;
 	return (-1);
diff --git a/lib/libthr/thread/thr_sig.c b/lib/libthr/thread/thr_sig.c
index 495c153..14da797 100644
--- a/lib/libthr/thread/thr_sig.c
+++ b/lib/libthr/thread/thr_sig.c
@@ -68,9 +68,7 @@ void
 _thr_ast(struct pthread *curthread)
 {
 	if (!THR_IN_CRITICAL(curthread)) {
-		if (__predict_false(
-		    SHOULD_ASYNC_CANCEL(curthread->cancelflags)))
-			_pthread_testcancel();
+		_thr_testcancel(curthread);
 		if (__predict_false((curthread->flags &
 		    (THR_FLAGS_NEED_SUSPEND | THR_FLAGS_SUSPENDED))
 			== THR_FLAGS_NEED_SUSPEND))
@@ -154,12 +152,11 @@ int
 ___pause(void)
 {
 	struct pthread *curthread = _get_curthread();
-	int	oldcancel;
 	int	ret;
 
-	oldcancel = _thr_cancel_enter(curthread);
+	_thr_cancel_enter(curthread);
 	ret = __pause();
-	_thr_cancel_leave(curthread, oldcancel);
+	_thr_cancel_leave(curthread);
 	
 	return ret;
 }
@@ -248,7 +245,6 @@ __sigsuspend(const sigset_t * set)
 	struct pthread *curthread = _get_curthread();
 	sigset_t newset;
 	const sigset_t *pset;
-	int oldcancel;
 	int ret;
 
 	if (SIGISMEMBER(*set, SIGCANCEL)) {
@@ -258,9 +254,9 @@ __sigsuspend(const sigset_t * set)
 	} else
 		pset = set;
 
-	oldcancel = _thr_cancel_enter(curthread);
+	_thr_cancel_enter(curthread);
 	ret = __sys_sigsuspend(pset);
-	_thr_cancel_leave(curthread, oldcancel);
+	_thr_cancel_leave(curthread);
 
 	return (ret);
 }
@@ -294,7 +290,6 @@ __sigtimedwait(const sigset_t *set, siginfo_t *info,
 	struct pthread	*curthread = _get_curthread();
 	sigset_t newset;
 	const sigset_t *pset;
-	int oldcancel;
 	int ret;
 
 	if (SIGISMEMBER(*set, SIGCANCEL)) {
@@ -303,9 +298,9 @@ __sigtimedwait(const sigset_t *set, siginfo_t *info,
 		pset = &newset;
 	} else
 		pset = set;
-	oldcancel = _thr_cancel_enter(curthread);
+	_thr_cancel_enter(curthread);
 	ret = __sys_sigtimedwait(pset, info, timeout);
-	_thr_cancel_leave(curthread, oldcancel);
+	_thr_cancel_leave(curthread);
 	return (ret);
 }
 
@@ -333,7 +328,6 @@ __sigwaitinfo(const sigset_t *set, siginfo_t *info)
 	struct pthread	*curthread = _get_curthread();
 	sigset_t newset;
 	const sigset_t *pset;
-	int oldcancel;
 	int ret;
 
 	if (SIGISMEMBER(*set, SIGCANCEL)) {
@@ -343,9 +337,9 @@ __sigwaitinfo(const sigset_t *set, siginfo_t *info)
 	} else
 		pset = set;
 
-	oldcancel = _thr_cancel_enter(curthread);
+	_thr_cancel_enter(curthread);
 	ret = __sys_sigwaitinfo(pset, info);
-	_thr_cancel_leave(curthread, oldcancel);
+	_thr_cancel_leave(curthread);
 	return (ret);
 }
 
@@ -373,7 +367,6 @@ __sigwait(const sigset_t *set, int *sig)
 	struct pthread	*curthread = _get_curthread();
 	sigset_t newset;
 	const sigset_t *pset;
-	int oldcancel;
 	int ret;
 
 	if (SIGISMEMBER(*set, SIGCANCEL)) {
@@ -383,8 +376,8 @@ __sigwait(const sigset_t *set, int *sig)
 	} else 
 		pset = set;
 
-	oldcancel = _thr_cancel_enter(curthread);
+	_thr_cancel_enter(curthread);
 	ret = __sys_sigwait(pset, sig);
-	_thr_cancel_leave(curthread, oldcancel);
+	_thr_cancel_leave(curthread);
 	return (ret);
 }
diff --git a/lib/libthr/thread/thr_syscalls.c b/lib/libthr/thread/thr_syscalls.c
index f994288..7a07cca 100644
--- a/lib/libthr/thread/thr_syscalls.c
+++ b/lib/libthr/thread/thr_syscalls.c
@@ -160,13 +160,12 @@ int
 __accept(int s, struct sockaddr *addr, socklen_t *addrlen)
 {
 	struct pthread *curthread;
-	int oldcancel;
 	int ret;
 
 	curthread = _get_curthread();
-	oldcancel = _thr_cancel_enter(curthread);
+	_thr_cancel_enter(curthread);
 	ret = __sys_accept(s, addr, addrlen);
-	_thr_cancel_leave(curthread, oldcancel);
+	_thr_cancel_leave(curthread);
 
  	return (ret);
 }
@@ -178,12 +177,11 @@ __aio_suspend(const struct aiocb * const iocbs[], int niocb, const struct
     timespec *timeout)
 {
 	struct pthread *curthread = _get_curthread();
-	int oldcancel;
 	int ret;
 
-	oldcancel = _thr_cancel_enter(curthread);
+	_thr_cancel_enter(curthread);
 	ret = __sys_aio_suspend(iocbs, niocb, timeout);
-	_thr_cancel_leave(curthread, oldcancel);
+	_thr_cancel_leave(curthread);
 
 	return (ret);
 }
@@ -194,12 +192,11 @@ int
 __close(int fd)
 {
 	struct pthread	*curthread = _get_curthread();
-	int	oldcancel;
 	int	ret;
 
-	oldcancel = _thr_cancel_enter(curthread);
+	_thr_cancel_enter(curthread);
 	ret = __sys_close(fd);
-	_thr_cancel_leave(curthread, oldcancel);
+	_thr_cancel_leave(curthread);
 	
 	return (ret);
 }
@@ -210,12 +207,11 @@ int
 __connect(int fd, const struct sockaddr *name, socklen_t namelen)
 {
 	struct pthread *curthread = _get_curthread();
-	int oldcancel;
 	int ret;
 
-	oldcancel = _thr_cancel_enter(curthread);
+	_thr_cancel_enter(curthread);
 	ret = __sys_connect(fd, name, namelen);
-	_thr_cancel_leave(curthread, oldcancel);
+	_thr_cancel_leave(curthread);
 
  	return (ret);
 }
@@ -226,12 +222,11 @@ int
 ___creat(const char *path, mode_t mode)
 {
 	struct pthread *curthread = _get_curthread();
-	int oldcancel;
 	int ret;
 
-	oldcancel = _thr_cancel_enter(curthread);
+	_thr_cancel_enter(curthread);
 	ret = __creat(path, mode);
-	_thr_cancel_leave(curthread, oldcancel);
+	_thr_cancel_leave(curthread);
 	
 	return ret;
 }
@@ -242,11 +237,10 @@ int
 __fcntl(int fd, int cmd,...)
 {
 	struct pthread *curthread = _get_curthread();
-	int	oldcancel;
 	int	ret;
 	va_list	ap;
 	
-	oldcancel = _thr_cancel_enter(curthread);
+	_thr_cancel_enter(curthread);
 
 	va_start(ap, cmd);
 	switch (cmd) {
@@ -266,7 +260,7 @@ __fcntl(int fd, int cmd,...)
 	}
 	va_end(ap);
 
-	_thr_cancel_leave(curthread, oldcancel);
+	_thr_cancel_leave(curthread);
 
 	return (ret);
 }
@@ -277,12 +271,11 @@ int
 __fsync(int fd)
 {
 	struct pthread *curthread = _get_curthread();
-	int	oldcancel;
 	int	ret;
 
-	oldcancel = _thr_cancel_enter(curthread);
+	_thr_cancel_enter(curthread);
 	ret = __sys_fsync(fd);
-	_thr_cancel_leave(curthread, oldcancel);
+	_thr_cancel_leave(curthread);
 
 	return (ret);
 }
@@ -293,12 +286,11 @@ int
 __msync(void *addr, size_t len, int flags)
 {
 	struct pthread *curthread = _get_curthread();
-	int	oldcancel;
 	int	ret;
 
-	oldcancel = _thr_cancel_enter(curthread);
+	_thr_cancel_enter(curthread);
 	ret = __sys_msync(addr, len, flags);
-	_thr_cancel_leave(curthread, oldcancel);
+	_thr_cancel_leave(curthread);
 
 	return ret;
 }
@@ -310,12 +302,11 @@ __nanosleep(const struct timespec *time_to_sleep,
     struct timespec *time_remaining)
 {
 	struct pthread *curthread = _get_curthread();
-	int		oldcancel;
 	int		ret;
 
-	oldcancel = _thr_cancel_enter(curthread);
+	_thr_cancel_enter(curthread);
 	ret = __sys_nanosleep(time_to_sleep, time_remaining);
-	_thr_cancel_leave(curthread, oldcancel);
+	_thr_cancel_leave(curthread);
 
 	return (ret);
 }
@@ -326,12 +317,11 @@ int
 __open(const char *path, int flags,...)
 {
 	struct pthread *curthread = _get_curthread();
-	int	oldcancel;
 	int	ret;
 	int	mode = 0;
 	va_list	ap;
 
-	oldcancel = _thr_cancel_enter(curthread);
+	_thr_cancel_enter(curthread);
 	
 	/* Check if the file is being created: */
 	if (flags & O_CREAT) {
@@ -343,7 +333,7 @@ __open(const char *path, int flags,...)
 	
 	ret = __sys_open(path, flags, mode);
 
-	_thr_cancel_leave(curthread, oldcancel);
+	_thr_cancel_leave(curthread);
 
 	return ret;
 }
@@ -354,12 +344,11 @@ int
 __poll(struct pollfd *fds, unsigned int nfds, int timeout)
 {
 	struct pthread *curthread = _get_curthread();
-	int oldcancel;
 	int ret;
 
-	oldcancel = _thr_cancel_enter(curthread);
+	_thr_cancel_enter(curthread);
 	ret = __sys_poll(fds, nfds, timeout);
-	_thr_cancel_leave(curthread, oldcancel);
+	_thr_cancel_leave(curthread);
 
 	return ret;
 }
@@ -371,12 +360,11 @@ ___pselect(int count, fd_set *rfds, fd_set *wfds, fd_set *efds,
 	const struct timespec *timo, const sigset_t *mask)
 {
 	struct pthread *curthread = _get_curthread();
-	int oldcancel;
 	int ret;
 
-	oldcancel = _thr_cancel_enter(curthread);
+	_thr_cancel_enter(curthread);
 	ret = __pselect(count, rfds, wfds, efds, timo, mask);
-	_thr_cancel_leave(curthread, oldcancel);
+	_thr_cancel_leave(curthread);
 
 	return (ret);
 }
@@ -387,12 +375,11 @@ ssize_t
 __read(int fd, void *buf, size_t nbytes)
 {
 	struct pthread *curthread = _get_curthread();
-	int oldcancel;
 	ssize_t	ret;
 
-	oldcancel = _thr_cancel_enter(curthread);
+	_thr_cancel_enter(curthread);
 	ret = __sys_read(fd, buf, nbytes);
-	_thr_cancel_leave(curthread, oldcancel);
+	_thr_cancel_leave(curthread);
 
 	return ret;
 }
@@ -403,12 +390,11 @@ ssize_t
 __readv(int fd, const struct iovec *iov, int iovcnt)
 {
 	struct pthread *curthread = _get_curthread();
-	int oldcancel;
 	ssize_t ret;
 
-	oldcancel = _thr_cancel_enter(curthread);
+	_thr_cancel_enter(curthread);
 	ret = __sys_readv(fd, iov, iovcnt);
-	_thr_cancel_leave(curthread, oldcancel);
+	_thr_cancel_leave(curthread);
 
 	return ret;
 }
@@ -420,12 +406,11 @@ __recvfrom(int s, void *b, size_t l, int f, struct sockaddr *from,
     socklen_t *fl)
 {
 	struct pthread *curthread = _get_curthread();
-	int oldcancel;
 	ssize_t ret;
 
-	oldcancel = _thr_cancel_enter(curthread);
+	_thr_cancel_enter(curthread);
 	ret = __sys_recvfrom(s, b, l, f, from, fl);
-	_thr_cancel_leave(curthread, oldcancel);
+	_thr_cancel_leave(curthread);
 	return (ret);
 }
 
@@ -436,11 +421,10 @@ __recvmsg(int s, struct msghdr *m, int f)
 {
 	struct pthread *curthread = _get_curthread();
 	ssize_t ret;
-	int oldcancel;
 
-	oldcancel = _thr_cancel_enter(curthread);
+	_thr_cancel_enter(curthread);
 	ret = __sys_recvmsg(s, m, f);
-	_thr_cancel_leave(curthread, oldcancel);
+	_thr_cancel_leave(curthread);
 	return (ret);
 }
 
@@ -451,12 +435,11 @@ __select(int numfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
 	struct timeval *timeout)
 {
 	struct pthread *curthread = _get_curthread();
-	int oldcancel;
 	int ret;
 
-	oldcancel = _thr_cancel_enter(curthread);
+	_thr_cancel_enter(curthread);
 	ret = __sys_select(numfds, readfds, writefds, exceptfds, timeout);
-	_thr_cancel_leave(curthread, oldcancel);
+	_thr_cancel_leave(curthread);
 	return ret;
 }
 
@@ -467,11 +450,10 @@ __sendmsg(int s, const struct msghdr *m, int f)
 {
 	struct pthread *curthread = _get_curthread();
 	ssize_t ret;
-	int oldcancel;
 
-	oldcancel = _thr_cancel_enter(curthread);
+	_thr_cancel_enter(curthread);
 	ret = __sys_sendmsg(s, m, f);
-	_thr_cancel_leave(curthread, oldcancel);
+	_thr_cancel_leave(curthread);
 	return (ret);
 }
 
@@ -483,11 +465,10 @@ __sendto(int s, const void *m, size_t l, int f, const struct sockaddr *t,
 {
 	struct pthread *curthread = _get_curthread();
 	ssize_t ret;
-	int oldcancel;
 
-	oldcancel = _thr_cancel_enter(curthread);
+	_thr_cancel_enter(curthread);
 	ret = __sys_sendto(s, m, l, f, t, tl);
-	_thr_cancel_leave(curthread, oldcancel);
+	_thr_cancel_leave(curthread);
 	return (ret);
 }
 
@@ -497,12 +478,11 @@ unsigned int
 ___sleep(unsigned int seconds)
 {
 	struct pthread *curthread = _get_curthread();
-	int		oldcancel;
 	unsigned int	ret;
 
-	oldcancel = _thr_cancel_enter(curthread);
+	_thr_cancel_enter(curthread);
 	ret = __sleep(seconds);
-	_thr_cancel_leave(curthread, oldcancel);
+	_thr_cancel_leave(curthread);
 	
 	return (ret);
 }
@@ -513,12 +493,11 @@ int
 ___system(const char *string)
 {
 	struct pthread *curthread = _get_curthread();
-	int	oldcancel;
 	int	ret;
 
-	oldcancel = _thr_cancel_enter(curthread);
+	_thr_cancel_enter(curthread);
 	ret = __system(string);
-	_thr_cancel_leave(curthread, oldcancel);
+	_thr_cancel_leave(curthread);
 	
 	return ret;
 }
@@ -529,12 +508,11 @@ int
 ___tcdrain(int fd)
 {
 	struct pthread *curthread = _get_curthread();
-	int	oldcancel;
 	int	ret;
 	
-	oldcancel = _thr_cancel_enter(curthread);
+	_thr_cancel_enter(curthread);
 	ret = __tcdrain(fd);
-	_thr_cancel_leave(curthread, oldcancel);
+	_thr_cancel_leave(curthread);
 
 	return (ret);
 }
@@ -545,12 +523,11 @@ int
 ___usleep(useconds_t useconds)
 {
 	struct pthread *curthread = _get_curthread();
-	int		oldcancel;
 	int		ret;
 
-	oldcancel = _thr_cancel_enter(curthread);
+	_thr_cancel_enter(curthread);
 	ret = __usleep(useconds);
-	_thr_cancel_leave(curthread, oldcancel);
+	_thr_cancel_leave(curthread);
 	
 	return (ret);
 }
@@ -569,12 +546,11 @@ pid_t
 ___wait(int *istat)
 {
 	struct pthread *curthread = _get_curthread();
-	int	oldcancel;
 	pid_t	ret;
 
-	oldcancel = _thr_cancel_enter(curthread);
+	_thr_cancel_enter(curthread);
 	ret = __wait(istat);
-	_thr_cancel_leave(curthread, oldcancel);
+	_thr_cancel_leave(curthread);
 
 	return ret;
 }
@@ -585,12 +561,11 @@ pid_t
 __wait3(int *status, int options, struct rusage *rusage)
 {
 	struct pthread *curthread = _get_curthread();
-	int oldcancel;
 	pid_t ret;
 
-	oldcancel = _thr_cancel_enter(curthread);
+	_thr_cancel_enter(curthread);
 	ret = _wait4(WAIT_ANY, status, options, rusage);
-	_thr_cancel_leave(curthread, oldcancel);
+	_thr_cancel_leave(curthread);
 
 	return (ret);
 }
@@ -601,12 +576,11 @@ pid_t
 __wait4(pid_t pid, int *status, int options, struct rusage *rusage)
 {
 	struct pthread *curthread = _get_curthread();
-	int oldcancel;
 	pid_t ret;
 
-	oldcancel = _thr_cancel_enter(curthread);
+	_thr_cancel_enter(curthread);
 	ret = __sys_wait4(pid, status, options, rusage);
-	_thr_cancel_leave(curthread, oldcancel);
+	_thr_cancel_leave(curthread);
 
 	return ret;
 }
@@ -617,12 +591,11 @@ pid_t
 ___waitpid(pid_t wpid, int *status, int options)
 {
 	struct pthread *curthread = _get_curthread();
-	int	oldcancel;
 	pid_t	ret;
 
-	oldcancel = _thr_cancel_enter(curthread);
+	_thr_cancel_enter(curthread);
 	ret = __waitpid(wpid, status, options);
-	_thr_cancel_leave(curthread, oldcancel);
+	_thr_cancel_leave(curthread);
 	
 	return ret;
 }
@@ -633,12 +606,11 @@ ssize_t
 __write(int fd, const void *buf, size_t nbytes)
 {
 	struct pthread *curthread = _get_curthread();
-	int	oldcancel;
 	ssize_t	ret;
 
-	oldcancel = _thr_cancel_enter(curthread);
+	_thr_cancel_enter(curthread);
 	ret = __sys_write(fd, buf, nbytes);
-	_thr_cancel_leave(curthread, oldcancel);
+	_thr_cancel_leave(curthread);
 
 	return ret;
 }
@@ -649,12 +621,11 @@ ssize_t
 __writev(int fd, const struct iovec *iov, int iovcnt)
 {
 	struct pthread *curthread = _get_curthread();
-	int	oldcancel;
 	ssize_t ret;
 
-	oldcancel = _thr_cancel_enter(curthread);
+	_thr_cancel_enter(curthread);
 	ret = __sys_writev(fd, iov, iovcnt);
-	_thr_cancel_leave(curthread, oldcancel);
+	_thr_cancel_leave(curthread);
 
 	return ret;
 }