 @@ -1,450 +1,468 @@
-/*	$NetBSD: pthread_cond.c,v 1.66 2020/01/13 18:22:56 ad Exp $	*/
+/*	$NetBSD: pthread_cond.c,v 1.67 2020/01/29 15:07:46 kamil Exp $	*/
 /*-
  * Copyright (c) 2001, 2006, 2007, 2008 The NetBSD Foundation, Inc.
  * All rights reserved.
+ *
  * This code is derived from software contributed to The NetBSD Foundation
  * by Nathan J. Williams and Andrew Doran.
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
+ *
  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGE.
  */
 /*
  * We assume that there will be no contention on pthread_cond_t::ptc_lock
  * because functioning applications must call both the wait and wakeup
  * functions while holding the same application provided mutex.  The
  * spinlock is present only to prevent libpthread causing the application
  * to crash or malfunction as a result of corrupted data structures, in
  * the event that the application is buggy.
+ *
  * If there is contention on spinlock when real-time threads are in use,
  * it could cause a deadlock due to priority inversion: the thread holding
  * the spinlock may not get CPU time to make forward progress and release
  * the spinlock to a higher priority thread that is waiting for it.
  * Contention on the spinlock will only occur with buggy applications,
  * so at the time of writing it's not considered a major bug in libpthread.
  */
 #include <sys/cdefs.h>
-__RCSID("$NetBSD: pthread_cond.c,v 1.66 2020/01/13 18:22:56 ad Exp $");
+__RCSID("$NetBSD: pthread_cond.c,v 1.67 2020/01/29 15:07:46 kamil Exp $");
 #include <stdlib.h>
 #include <errno.h>
 #include <sys/time.h>
 #include <sys/types.h>
 #include "pthread.h"
 #include "pthread_int.h"
 #include "reentrant.h"
 int	_sys___nanosleep50(const struct timespec *, struct timespec *);
 extern int pthread__started;
 static int pthread_cond_wait_nothread(pthread_t, pthread_mutex_t *,
     pthread_cond_t *, const struct timespec *);
 int	_pthread_cond_has_waiters_np(pthread_cond_t *);
 __weak_alias(pthread_cond_has_waiters_np,_pthread_cond_has_waiters_np)
 __strong_alias(__libc_cond_init,pthread_cond_init)
 __strong_alias(__libc_cond_signal,pthread_cond_signal)
 __strong_alias(__libc_cond_broadcast,pthread_cond_broadcast)
 __strong_alias(__libc_cond_wait,pthread_cond_wait)
 __strong_alias(__libc_cond_timedwait,pthread_cond_timedwait)
 __strong_alias(__libc_cond_destroy,pthread_cond_destroy)
 static clockid_t
 pthread_cond_getclock(const pthread_cond_t *cond)
+{
 	pthread__error(EINVAL, "Invalid condition variable",
 	    cond->ptc_magic == _PT_COND_MAGIC);
 	return cond->ptc_private ?
 	    *(clockid_t *)cond->ptc_private : CLOCK_REALTIME;
+}
 int
 pthread_cond_init(pthread_cond_t *cond, const pthread_condattr_t *attr)
+{
 	if (__predict_false(__uselibcstub))
 		return __libc_cond_init_stub(cond, attr);
 	pthread__error(EINVAL, "Invalid condition variable attribute",
 	    (attr == NULL) || (attr->ptca_magic == _PT_CONDATTR_MAGIC));
 	cond->ptc_magic = _PT_COND_MAGIC;
 	pthread_lockinit(&cond->ptc_lock);
 	PTQ_INIT(&cond->ptc_waiters);
 	cond->ptc_mutex = NULL;
 	if (attr && attr->ptca_private) {
 		cond->ptc_private = malloc(sizeof(clockid_t));
 		if (cond->ptc_private == NULL)
 			return errno;
 		*(clockid_t *)cond->ptc_private =
 		    *(clockid_t *)attr->ptca_private;
 	} else
 		cond->ptc_private = NULL;
 	return 0;
+}
 int
 pthread_cond_destroy(pthread_cond_t *cond)
+{
 	if (__predict_false(__uselibcstub))
 		return __libc_cond_destroy_stub(cond);
 	pthread__error(EINVAL, "Invalid condition variable",
 	    cond->ptc_magic == _PT_COND_MAGIC);
 	pthread__error(EBUSY, "Destroying condition variable in use",
 	    cond->ptc_mutex == NULL);
 	cond->ptc_magic = _PT_COND_DEAD;
 	free(cond->ptc_private);
 	return 0;
+}
 int
 pthread_cond_timedwait(pthread_cond_t *cond, pthread_mutex_t *mutex,
 		       const struct timespec *abstime)
+{
 	pthread_t self;
 	int retval;
 	clockid_t clkid = pthread_cond_getclock(cond);
 	if (__predict_false(__uselibcstub))
 		return __libc_cond_timedwait_stub(cond, mutex, abstime);
 	pthread__error(EINVAL, "Invalid condition variable",
 	    cond->ptc_magic == _PT_COND_MAGIC);
 	pthread__error(EINVAL, "Invalid mutex",
 	    mutex->ptm_magic == _PT_MUTEX_MAGIC);
 	pthread__error(EPERM, "Mutex not locked in condition wait",
 	    mutex->ptm_owner != NULL);
 	self = pthread__self();
 	/* Just hang out for a while if threads aren't running yet. */
 	if (__predict_false(pthread__started == 0)) {
 		return pthread_cond_wait_nothread(self, mutex, cond, abstime);
+	}
 	if (__predict_false(self->pt_cancel)) {
 		pthread__cancelled();
+	}
 	/* Note this thread as waiting on the CV. */
 	pthread__spinlock(self, &cond->ptc_lock);
 	cond->ptc_mutex = mutex;
 	PTQ_INSERT_HEAD(&cond->ptc_waiters, self, pt_sleep);
 	self->pt_sleepobj = cond;
 	pthread__spinunlock(self, &cond->ptc_lock);
 	do {
 		self->pt_willpark = 1;
 		pthread_mutex_unlock(mutex);
 		self->pt_willpark = 0;
 		do {
 			retval = _lwp_park(clkid, TIMER_ABSTIME,
 			    __UNCONST(abstime), self->pt_unpark,
 			    __UNVOLATILE(&mutex->ptm_waiters),
 			    __UNVOLATILE(&mutex->ptm_waiters));
 			self->pt_unpark = 0;
 		} while (retval == -1 && errno == ESRCH);
 		pthread_mutex_lock(mutex);
 		/*
 		 * If we have cancelled then exit.  POSIX dictates that
 		 * the mutex must be held when we action the cancellation.
+		 *
 		 * If we absorbed a pthread_cond_signal() and cannot take
 		 * the wakeup, we must ensure that another thread does.
+		 *
 		 * If awoke early, we may still be on the sleep queue and
 		 * must remove ourself.
 		 */
 		if (__predict_false(retval != 0)) {
 			switch (errno) {
 			case EINTR:
 			case EALREADY:
 				retval = 0;
 				break;
 			default:
 				retval = errno;
 				break;
+			}
+		}
 		if (__predict_false(self->pt_cancel | retval)) {
 			pthread_cond_signal(cond);
 			if (self->pt_cancel) {
 				pthread__cancelled();
+			}
 			break;
+		}
 	} while (self->pt_sleepobj != NULL);
 	return retval;
+}
 int
 pthread_cond_wait(pthread_cond_t *cond, pthread_mutex_t *mutex)
+{
 	if (__predict_false(__uselibcstub))
 		return __libc_cond_wait_stub(cond, mutex);
 	return pthread_cond_timedwait(cond, mutex, NULL);
+}
 static int __noinline
 pthread__cond_wake_one(pthread_cond_t *cond)
+{
 	pthread_t self, signaled;
 	pthread_mutex_t *mutex;
 	lwpid_t lid;
 	pthread__error(EINVAL, "Invalid condition variable",
 	    cond->ptc_magic == _PT_COND_MAGIC);
 	/*
 	 * Pull the first thread off the queue.  If the current thread
 	 * is associated with the condition variable, remove it without
 	 * awakening (error case in pthread_cond_timedwait()).
 	 */
 	self = pthread__self();
 	pthread__spinlock(self, &cond->ptc_lock);
 	if (self->pt_sleepobj == cond) {
 		PTQ_REMOVE(&cond->ptc_waiters, self, pt_sleep);
 		self->pt_sleepobj = NULL;
+	}
 	signaled = PTQ_FIRST(&cond->ptc_waiters);
 	if (__predict_false(signaled == NULL)) {
 		cond->ptc_mutex = NULL;
 		pthread__spinunlock(self, &cond->ptc_lock);
 		return 0;
+	}
 	mutex = cond->ptc_mutex;
 	if (PTQ_NEXT(signaled, pt_sleep) == NULL) {
 		cond->ptc_mutex = NULL;
 		PTQ_INIT(&cond->ptc_waiters);
 	} else {
 		PTQ_REMOVE(&cond->ptc_waiters, signaled, pt_sleep);
+	}
 	signaled->pt_sleepobj = NULL;
 	lid = signaled->pt_lid;
 	pthread__spinunlock(self, &cond->ptc_lock);
 	/*
 	 * For all valid uses of pthread_cond_signal(), the caller will
 	 * hold the mutex that the target is using to synchronize with.
 	 * To avoid the target awakening and immediately blocking on the
 	 * mutex, transfer the thread to be awoken to the current thread's
 	 * deferred wakeup list.  The waiter will be set running when the
 	 * caller (this thread) releases the mutex.
 	 */
 	if (__predict_false(self->pt_nwaiters == (size_t)pthread__unpark_max)) {
 		(void)_lwp_unpark_all(self->pt_waiters, self->pt_nwaiters,
 		    __UNVOLATILE(&mutex->ptm_waiters));
 		self->pt_nwaiters = 0;
+	}
 	self->pt_waiters[self->pt_nwaiters++] = lid;
 	pthread__mutex_deferwake(self, mutex);
 	return 0;
+}
 int
 pthread_cond_signal(pthread_cond_t *cond)
+{
 	if (__predict_false(__uselibcstub))
 		return __libc_cond_signal_stub(cond);
 	pthread__error(EINVAL, "Invalid condition variable",
 	    cond->ptc_magic == _PT_COND_MAGIC);
 	if (__predict_true(PTQ_EMPTY(&cond->ptc_waiters)))
 		return 0;
 	return pthread__cond_wake_one(cond);
+}
 static int __noinline
 pthread__cond_wake_all(pthread_cond_t *cond)
+{
 	pthread_t self, signaled;
 	pthread_mutex_t *mutex;
 	u_int max;
 	size_t nwaiters;
 	pthread__error(EINVAL, "Invalid condition variable",
 	    cond->ptc_magic == _PT_COND_MAGIC);
 	/*
 	 * Try to defer waking threads (see pthread_cond_signal()).
 	 * Only transfer waiters for which there is no pending wakeup.
 	 */
 	self = pthread__self();
 	pthread__spinlock(self, &cond->ptc_lock);
 	max = pthread__unpark_max;
 	mutex = cond->ptc_mutex;
 	nwaiters = self->pt_nwaiters;
 	PTQ_FOREACH(signaled, &cond->ptc_waiters, pt_sleep) {
 		if (__predict_false(nwaiters == max)) {
 			/* Overflow. */
 			(void)_lwp_unpark_all(self->pt_waiters,
 			    nwaiters, __UNVOLATILE(&mutex->ptm_waiters));
 			nwaiters = 0;
+		}
 		signaled->pt_sleepobj = NULL;
 		self->pt_waiters[nwaiters++] = signaled->pt_lid;
+	}
 	PTQ_INIT(&cond->ptc_waiters);
 	self->pt_nwaiters = nwaiters;
 	cond->ptc_mutex = NULL;
 	pthread__spinunlock(self, &cond->ptc_lock);
 	pthread__mutex_deferwake(self, mutex);
 	return 0;
+}
 int
 pthread_cond_broadcast(pthread_cond_t *cond)
+{
 	if (__predict_false(__uselibcstub))
 		return __libc_cond_broadcast_stub(cond);
 	pthread__error(EINVAL, "Invalid condition variable",
 	    cond->ptc_magic == _PT_COND_MAGIC);
 	if (__predict_true(PTQ_EMPTY(&cond->ptc_waiters)))
 		return 0;
 	return pthread__cond_wake_all(cond);
+}
 int
 _pthread_cond_has_waiters_np(pthread_cond_t *cond)
+{
 	return !PTQ_EMPTY(&cond->ptc_waiters);
+}
 int
 pthread_condattr_init(pthread_condattr_t *attr)
+{
 	attr->ptca_magic = _PT_CONDATTR_MAGIC;
 	attr->ptca_private = NULL;
 	return 0;
+}
 int
 pthread_condattr_setclock(pthread_condattr_t *attr, clockid_t clck)
+{
 	pthread__error(EINVAL, "Invalid condition variable attribute",
 	    attr->ptca_magic == _PT_CONDATTR_MAGIC);
 	switch (clck) {
 	case CLOCK_MONOTONIC:
 	case CLOCK_REALTIME:
 		if (attr->ptca_private == NULL)
 			attr->ptca_private = malloc(sizeof(clockid_t));
 		if (attr->ptca_private == NULL)
 			return errno;
 		*(clockid_t *)attr->ptca_private = clck;
 		return 0;
 	default:
 		return EINVAL;
+	}
+}
 int
 pthread_condattr_getclock(const pthread_condattr_t *__restrict attr,
     clockid_t *__restrict clock_id)
+{
 	pthread__error(EINVAL, "Invalid condition variable attribute",
 	    attr->ptca_magic == _PT_CONDATTR_MAGIC);
 	if (attr == NULL || attr->ptca_private == NULL)
 		return EINVAL;
 	*clock_id = *(clockid_t *)attr->ptca_private;
 	return 0;
+}
 int
 pthread_condattr_destroy(pthread_condattr_t *attr)
+{
 	pthread__error(EINVAL, "Invalid condition variable attribute",
 	    attr->ptca_magic == _PT_CONDATTR_MAGIC);
 	attr->ptca_magic = _PT_CONDATTR_DEAD;
 	free(attr->ptca_private);
 	return 0;
+}
 #ifdef _PTHREAD_PSHARED
 int
 pthread_condattr_getpshared(const pthread_condattr_t * __restrict attr,
     int * __restrict pshared)
+{
 	pthread__error(EINVAL, "Invalid condition variable attribute",
 	    attr->ptca_magic == _PT_CONDATTR_MAGIC);
 	*pshared = PTHREAD_PROCESS_PRIVATE;
 	return 0;
+}
 int
 pthread_condattr_setpshared(pthread_condattr_t *attr, int pshared)
+{
 	pthread__error(EINVAL, "Invalid condition variable attribute",
 	    attr->ptca_magic == _PT_CONDATTR_MAGIC);
 	switch(pshared) {
 	case PTHREAD_PROCESS_PRIVATE:
 		return 0;
 	case PTHREAD_PROCESS_SHARED:
 		return ENOSYS;
+	}
 	return EINVAL;
+}
 #endif
 /* Utility routine to hang out for a while if threads haven't started yet. */
 static int
 pthread_cond_wait_nothread(pthread_t self, pthread_mutex_t *mutex,
     pthread_cond_t *cond, const struct timespec *abstime)
+{
 	struct timespec now, diff;
 	int retval;
 	if (abstime == NULL) {
 		diff.tv_sec = 99999999;
 		diff.tv_nsec = 0;
 	} else {
 		clockid_t clck = pthread_cond_getclock(cond);
 		clock_gettime(clck, &now);
 		if  (timespeccmp(abstime, &now, <))
 			timespecclear(&diff);
 		else
 			timespecsub(abstime, &now, &diff);
+	}
 	do {
 		pthread__testcancel(self);
 		pthread_mutex_unlock(mutex);
 		retval = _sys___nanosleep50(&diff, NULL);
 		pthread_mutex_lock(mutex);
 	} while (abstime == NULL && retval == 0);
 	pthread__testcancel(self);
 	if (retval == 0)
 		return ETIMEDOUT;
 	else
 		/* spurious wakeup */
 		return 0;
+}