+// SPDX-FileCopyrightText: 2009 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+// SPDX-FileCopyrightText: 2009 Paul E. McKenney, IBM Corporation.
+//
+// SPDX-License-Identifier: LGPL-2.1-or-later
+
#ifndef _URCU_DEFER_IMPL_H
#define _URCU_DEFER_IMPL_H
/*
- * urcu-defer-impl.h
- *
* Userspace RCU header - memory reclamation.
*
* TO BE INCLUDED ONLY FROM URCU LIBRARY CODE. See urcu-defer.h for linking
* dynamically with the userspace rcu reclamation library.
*
- * Copyright (c) 2009 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- * Copyright (c) 2009 Paul E. McKenney, IBM Corporation.
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- *
* IBM's contributions to this file may be relicensed under LGPLv2 or later.
*/
#include <pthread.h>
#include <stdio.h>
#include <signal.h>
-#include <assert.h>
#include <string.h>
#include <errno.h>
#include <poll.h>
#include "urcu/futex.h"
+#include <urcu/assert.h>
#include <urcu/compiler.h>
#include <urcu/arch.h>
#include <urcu/uatomic.h>
uatomic_set(&defer_thread_futex, 0);
} else {
cmm_smp_rmb(); /* Read queue before read futex */
- if (uatomic_read(&defer_thread_futex) != -1)
- return;
- while (futex_noasync(&defer_thread_futex, FUTEX_WAIT, -1,
- NULL, NULL, 0)) {
+ while (uatomic_read(&defer_thread_futex) == -1) {
+ if (!futex_noasync(&defer_thread_futex, FUTEX_WAIT, -1, NULL, NULL, 0)) {
+ /*
+ * Prior queued wakeups queued by unrelated code
+ * using the same address can cause futex wait to
+ * return 0 even through the futex value is still
+ * -1 (spurious wakeups). Check the value again
+ * in user-space to validate whether it really
+ * differs from -1.
+ */
+ continue;
+ }
switch (errno) {
- case EWOULDBLOCK:
+ case EAGAIN:
/* Value already changed. */
return;
case EINTR:
/* Retry if interrupted by signal. */
- break; /* Get out of switch. */
+ break; /* Get out of switch. Check again. */
default:
/* Unexpected error. */
urcu_die(errno);
_rcu_defer_barrier_thread();
mutex_unlock(&rcu_defer_mutex);
}
-URCU_ATTR_ALIAS(urcu_stringify(rcu_defer_barrier_thread))
-void alias_rcu_defer_barrier_thread();
/*
* rcu_defer_barrier - Execute all queued rcu callbacks.
end:
mutex_unlock(&rcu_defer_mutex);
}
-URCU_ATTR_ALIAS(urcu_stringify(rcu_defer_barrier))
-void alias_rcu_defer_barrier();
/*
* _defer_rcu - Queue a RCU callback.
* Worse-case: must allow 2 supplementary entries for fct pointer.
*/
if (caa_unlikely(head - tail >= DEFER_QUEUE_SIZE - 2)) {
- assert(head - tail <= DEFER_QUEUE_SIZE);
+ urcu_posix_assert(head - tail <= DEFER_QUEUE_SIZE);
rcu_defer_barrier_thread();
- assert(head - CMM_LOAD_SHARED(URCU_TLS(defer_queue).tail) == 0);
+ urcu_posix_assert(head - CMM_LOAD_SHARED(URCU_TLS(defer_queue).tail) == 0);
}
/*
{
_defer_rcu(fct, p);
}
-URCU_ATTR_ALIAS(urcu_stringify(defer_rcu)) void alias_defer_rcu();
static void start_defer_thread(void)
{
int ret;
+ sigset_t newmask, oldmask;
+
+ ret = sigfillset(&newmask);
+ urcu_posix_assert(!ret);
+ ret = pthread_sigmask(SIG_BLOCK, &newmask, &oldmask);
+ urcu_posix_assert(!ret);
ret = pthread_create(&tid_defer, NULL, thr_defer, NULL);
- assert(!ret);
+ if (ret)
+ urcu_die(ret);
+
+ ret = pthread_sigmask(SIG_SETMASK, &oldmask, NULL);
+ urcu_posix_assert(!ret);
}
static void stop_defer_thread(void)
wake_up_defer();
ret = pthread_join(tid_defer, &tret);
- assert(!ret);
+ urcu_posix_assert(!ret);
CMM_STORE_SHARED(defer_thread_stop, 0);
/* defer thread should always exit when futex value is 0 */
- assert(uatomic_read(&defer_thread_futex) == 0);
+ urcu_posix_assert(uatomic_read(&defer_thread_futex) == 0);
}
int rcu_defer_register_thread(void)
{
int was_empty;
- assert(URCU_TLS(defer_queue).last_head == 0);
- assert(URCU_TLS(defer_queue).q == NULL);
+ urcu_posix_assert(URCU_TLS(defer_queue).last_head == 0);
+ urcu_posix_assert(URCU_TLS(defer_queue).q == NULL);
URCU_TLS(defer_queue).q = malloc(sizeof(void *) * DEFER_QUEUE_SIZE);
if (!URCU_TLS(defer_queue).q)
return -ENOMEM;
mutex_unlock(&defer_thread_mutex);
return 0;
}
-URCU_ATTR_ALIAS(urcu_stringify(rcu_defer_register_thread))
-int alias_rcu_defer_register_thread();
void rcu_defer_unregister_thread(void)
{
stop_defer_thread();
mutex_unlock(&defer_thread_mutex);
}
-URCU_ATTR_ALIAS(urcu_stringify(rcu_defer_unregister_thread))
-void alias_rcu_defer_unregister_thread();
void rcu_defer_exit(void)
{
- assert(cds_list_empty(®istry_defer));
+ urcu_posix_assert(cds_list_empty(®istry_defer));
}
-URCU_ATTR_ALIAS(urcu_stringify(rcu_defer_exit))
-void alias_rcu_defer_exit();
#endif /* _URCU_DEFER_IMPL_H */