[ltt-dev] [PATCH RFC] v2 call_rcu() interface for userspace-rcu
Paul E. McKenney
paulmck at linux.vnet.ibm.com
Mon Nov 1 16:18:18 EDT 2010
Updated based on review comments, added a couple of bug fixes.
Courtesy of LKS hacking session. ;-)
Adds call_rcu(), with RCU threads to invoke the callbacks. By default,
there will be one such RCU thread per process, created the first time
that call_rcu() is invoked. On systems supporting sched_getcpu(), it
is possible to create one RCU thread per CPU by calling
create_all_cpu_call_rcu_data().
Signed-off-by: Paul E. McKenney <paulmck at linux.vnet.ibm.com>
Makefile.am | 5
configure.ac | 2
tests/Makefile.am | 25 +--
tests/rcutorture.h | 41 ++++-
urcu-call-rcu.c | 405 ++++++++++++++++++++++++++++++++++++++++++++++++++
urcu-call-rcu.h | 80 +++++++++
urcu-defer.h | 8
urcu/wfqueue-static.h | 15 +
8 files changed, 557 insertions(+), 24 deletions(-)
diff --git a/Makefile.am b/Makefile.am
index 79a7152..64bb299 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -29,8 +29,8 @@ COMPAT+=compat_futex.c
endif
lib_LTLIBRARIES = liburcu.la liburcu-qsbr.la liburcu-mb.la liburcu-signal.la \
- liburcu-bp.la liburcu-defer.la libwfqueue.la libwfstack.la \
- librculfqueue.la librculfstack.la
+ liburcu-bp.la liburcu-defer.la liburcu-call.la \
+ libwfqueue.la libwfstack.la librculfqueue.la librculfstack.la
liburcu_la_SOURCES = urcu.c urcu-pointer.c $(COMPAT)
@@ -44,6 +44,7 @@ liburcu_signal_la_CFLAGS = -DRCU_SIGNAL
liburcu_bp_la_SOURCES = urcu-bp.c urcu-pointer.c $(COMPAT)
+liburcu_call_la_SOURCES = urcu-call-rcu.c $(COMPAT)
liburcu_defer_la_SOURCES = urcu-defer.c $(COMPAT)
libwfqueue_la_SOURCES = wfqueue.c $(COMPAT)
diff --git a/configure.ac b/configure.ac
index 89bdb6c..083ed95 100644
--- a/configure.ac
+++ b/configure.ac
@@ -34,7 +34,7 @@ AC_TYPE_SIZE_T
# Checks for library functions.
AC_FUNC_MALLOC
AC_FUNC_MMAP
-AC_CHECK_FUNCS([bzero gettimeofday munmap strtoul])
+AC_CHECK_FUNCS([bzero gettimeofday munmap sched_getcpu strtoul sysconf])
# Find arch type
case $host_cpu in
diff --git a/tests/Makefile.am b/tests/Makefile.am
index a43dd75..3c025a4 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -1,5 +1,5 @@
AM_LDFLAGS=-lpthread
-AM_CFLAGS=-I$(top_srcdir) -I$(top_builddir)
+AM_CFLAGS=-I$(top_srcdir) -I$(top_builddir) -g
noinst_PROGRAMS = test_urcu test_urcu_dynamic_link test_urcu_timing \
test_urcu_signal test_urcu_signal_dynamic_link test_urcu_signal_timing \
@@ -28,20 +28,21 @@ if COMPAT_FUTEX
COMPAT+=$(top_srcdir)/compat_futex.c
endif
-URCU=$(top_srcdir)/urcu.c $(top_srcdir)/urcu-pointer.c $(COMPAT)
-URCU_QSBR=$(top_srcdir)/urcu-qsbr.c $(top_srcdir)/urcu-pointer.c $(COMPAT)
+URCU=$(top_srcdir)/urcu.c $(top_srcdir)/urcu-pointer.c $(top_srcdir)/urcu-call-rcu.c $(top_srcdir)/wfqueue.c $(COMPAT)
+URCU_QSBR=$(top_srcdir)/urcu-qsbr.c $(top_srcdir)/urcu-pointer.c $(top_srcdir)/urcu-call-rcu.c $(top_srcdir)/wfqueue.c $(COMPAT)
# URCU_MB uses urcu.c but -DRCU_MB must be defined
-URCU_MB=$(top_srcdir)/urcu.c $(top_srcdir)/urcu-pointer.c $(COMPAT)
+URCU_MB=$(top_srcdir)/urcu.c $(top_srcdir)/urcu-pointer.c $(top_srcdir)/urcu-call-rcu.c $(top_srcdir)/wfqueue.c $(COMPAT)
# URCU_SIGNAL uses urcu.c but -DRCU_SIGNAL must be defined
-URCU_SIGNAL=$(top_srcdir)/urcu.c $(top_srcdir)/urcu-pointer.c $(COMPAT)
-URCU_BP=$(top_srcdir)/urcu-bp.c $(top_srcdir)/urcu-pointer.c $(COMPAT)
-URCU_DEFER=$(top_srcdir)/urcu.c $(top_srcdir)/urcu-defer.c $(top_srcdir)/urcu-pointer.c $(COMPAT)
+URCU_SIGNAL=$(top_srcdir)/urcu.c $(top_srcdir)/urcu-pointer.c $(top_srcdir)/urcu-call-rcu.c $(top_srcdir)/wfqueue.c $(COMPAT)
+URCU_BP=$(top_srcdir)/urcu-bp.c $(top_srcdir)/urcu-pointer.c $(top_srcdir)/urcu-call-rcu.c $(top_srcdir)/wfqueue.c $(COMPAT)
+URCU_DEFER=$(top_srcdir)/urcu.c $(top_srcdir)/urcu-defer.c $(top_srcdir)/urcu-pointer.c $(top_srcdir)/urcu-call-rcu.c $(top_srcdir)/wfqueue.c $(COMPAT)
URCU_LIB=$(top_builddir)/liburcu.la
URCU_QSBR_LIB=$(top_builddir)/liburcu-qsbr.la
URCU_MB_LIB=$(top_builddir)/liburcu-mb.la
URCU_SIGNAL_LIB=$(top_builddir)/liburcu-signal.la
URCU_BP_LIB=$(top_builddir)/liburcu-bp.la
+URCU_CALL_LIB=$(top_builddir)/liburcu-call.la
WFQUEUE_LIB=$(top_builddir)/libwfqueue.la
WFSTACK_LIB=$(top_builddir)/libwfstack.la
RCULFQUEUE_LIB=$(top_builddir)/librculfqueue.la
@@ -95,23 +96,23 @@ test_perthreadlock_SOURCES = test_perthreadlock.c $(URCU_SIGNAL)
rcutorture_urcu_SOURCES = urcutorture.c
rcutorture_urcu_CFLAGS = -DTORTURE_URCU $(AM_CFLAGS)
-rcutorture_urcu_LDADD = $(URCU)
+rcutorture_urcu_LDADD = $(URCU) $(URCU_CALL_LIB) $(WFQUEUE_LIB)
rcutorture_urcu_mb_SOURCES = urcutorture.c
rcutorture_urcu_mb_CFLAGS = -DTORTURE_URCU_MB $(AM_CFLAGS)
-rcutorture_urcu_mb_LDADD = $(URCU_MB_LIB)
+rcutorture_urcu_mb_LDADD = $(URCU_MB_LIB) $(URCU_CALL_LIB) $(WFQUEUE_LIB)
rcutorture_qsbr_SOURCES = urcutorture.c
rcutorture_qsbr_CFLAGS = -DTORTURE_QSBR $(AM_CFLAGS)
-rcutorture_qsbr_LDADD = $(URCU_QSBR_LIB)
+rcutorture_qsbr_LDADD = $(URCU_QSBR_LIB) $(URCU_CALL_LIB) $(WFQUEUE_LIB)
rcutorture_urcu_signal_SOURCES = urcutorture.c
rcutorture_urcu_signal_CFLAGS = -DTORTURE_URCU_SIGNAL $(AM_CFLAGS)
-rcutorture_urcu_signal_LDADD = $(URCU_SIGNAL_LIB)
+rcutorture_urcu_signal_LDADD = $(URCU_SIGNAL_LIB) $(URCU_CALL_LIB) $(WFQUEUE_LIB)
rcutorture_urcu_bp_SOURCES = urcutorture.c
rcutorture_urcu_bp_CFLAGS = -DTORTURE_URCU_BP $(AM_CFLAGS)
-rcutorture_urcu_bp_LDADD = $(URCU_BP_LIB)
+rcutorture_urcu_bp_LDADD = $(URCU_BP_LIB) $(URCU_CALL_LIB) $(WFQUEUE_LIB)
test_mutex_SOURCES = test_mutex.c $(URCU)
diff --git a/tests/rcutorture.h b/tests/rcutorture.h
index 181547a..1970d33 100644
--- a/tests/rcutorture.h
+++ b/tests/rcutorture.h
@@ -65,6 +65,8 @@
* Test variables.
*/
+#include "../urcu-call-rcu.h"
+
DEFINE_PER_THREAD(long long, n_reads_pt);
DEFINE_PER_THREAD(long long, n_updates_pt);
@@ -296,10 +298,30 @@ void *rcu_read_stress_test(void *arg)
return (NULL);
}
+static pthread_mutex_t call_rcu_test_mutex = PTHREAD_MUTEX_INITIALIZER;
+static pthread_cond_t call_rcu_test_cond = PTHREAD_COND_INITIALIZER;
+
+void rcu_update_stress_test_rcu(struct rcu_head *head)
+{
+ if (pthread_mutex_lock(&call_rcu_test_mutex) != 0) {
+ perror("pthread_mutex_lock");
+ exit(-1);
+ }
+ if (pthread_cond_signal(&call_rcu_test_cond) != 0) {
+ perror("pthread_cond_signal");
+ exit(-1);
+ }
+ if (pthread_mutex_unlock(&call_rcu_test_mutex) != 0) {
+ perror("pthread_mutex_unlock");
+ exit(-1);
+ }
+}
+
void *rcu_update_stress_test(void *arg)
{
int i;
struct rcu_stress *p;
+ struct rcu_head rh;
while (goflag == GOFLAG_INIT)
poll(NULL, 0, 1);
@@ -317,7 +339,24 @@ void *rcu_update_stress_test(void *arg)
for (i = 0; i < RCU_STRESS_PIPE_LEN; i++)
if (i != rcu_stress_idx)
rcu_stress_array[i].pipe_count++;
- synchronize_rcu();
+ if (n_updates & 0x1)
+ synchronize_rcu();
+ else {
+ if (pthread_mutex_lock(&call_rcu_test_mutex) != 0) {
+ perror("pthread_mutex_lock");
+ exit(-1);
+ }
+ call_rcu(&rh, rcu_update_stress_test_rcu);
+ if (pthread_cond_wait(&call_rcu_test_cond,
+ &call_rcu_test_mutex) != 0) {
+ perror("pthread_cond_wait");
+ exit(-1);
+ }
+ if (pthread_mutex_unlock(&call_rcu_test_mutex) != 0) {
+ perror("pthread_mutex_unlock");
+ exit(-1);
+ }
+ }
n_updates++;
}
return NULL;
diff --git a/urcu-call-rcu.c b/urcu-call-rcu.c
new file mode 100644
index 0000000..a2497b6
--- /dev/null
+++ b/urcu-call-rcu.c
@@ -0,0 +1,405 @@
+/*
+ * urcu-call-rcu.c
+ *
+ * Userspace RCU library - batch memory reclamation with kernel API
+ *
+ * Copyright (c) 2010 Paul E. McKenney <paulmck at linux.vnet.ibm.com>
+ *
+ * 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
+ */
+
+#include <stdio.h>
+#include <pthread.h>
+#include <signal.h>
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <poll.h>
+#include <sys/time.h>
+#include <syscall.h>
+#include <unistd.h>
+
+#include "config.h"
+#include "urcu/wfqueue.h"
+#include "urcu-call-rcu.h"
+#include "urcu-pointer.h"
+
+/* Data structure that identifies a call_rcu thread. */
+
+struct call_rcu_data {
+ struct wfq_queue cbs;
+ unsigned long flags;
+ pthread_mutex_t mtx;
+ pthread_cond_t cond;
+ unsigned long qlen;
+ pthread_t tid;
+} __attribute__((aligned(CACHE_LINE_SIZE)));
+
+/* Link a thread using call_rcu() to its call_rcu thread. */
+
+static __thread struct call_rcu_data *thread_call_rcu_data;
+
+/* Guard call_rcu thread creation. */
+
+static pthread_mutex_t call_rcu_mutex = PTHREAD_MUTEX_INITIALIZER;
+
+/* If a given thread does not have its own call_rcu thread, this is default. */
+
+static struct call_rcu_data *default_call_rcu_data;
+
+extern void synchronize_rcu(void);
+
+/*
+ * If the sched_getcpu() and sysconf(_SC_NPROCESSORS_CONF) calls are
+ * available, then we can have call_rcu threads assigned to individual
+ * CPUs rather than only to specific threads.
+ */
+
+#if defined(HAVE_SCHED_GETCPU) && defined(HAVE_SYSCONF)
+
+/*
+ * Pointer to array of pointers to per-CPU call_rcu_data structures
+ * and # CPUs.
+ */
+
+static struct call_rcu_data **per_cpu_call_rcu_data;
+static long maxcpus;
+
+/* Allocate the array if it has not already been allocated. */
+
+static void alloc_cpu_call_rcu_data(void)
+{
+ struct call_rcu_data **p;
+
+ if (maxcpus != 0)
+ return;
+ maxcpus = sysconf(_SC_NPROCESSORS_CONF);
+ if (maxcpus == -1)
+ return;
+ p = malloc(maxcpus * sizeof(*per_cpu_call_rcu_data));
+ if (p != NULL)
+ memset(p, '\0', maxcpus * sizeof(*per_cpu_call_rcu_data));
+}
+
+#else /* #if defined(HAVE_SCHED_GETCPU) && defined(HAVE_SYSCONF) */
+
+static const struct call_rcu_data **per_cpu_call_rcu_data = NULL;
+static const long maxcpus = -1;
+
+static void alloc_cpu_call_rcu_data(void)
+{
+}
+
+static int sched_getcpu(void)
+{
+ return -1;
+}
+
+#endif /* #else #if defined(HAVE_SCHED_GETCPU) && defined(HAVE_SYSCONF) */
+
+/* Acquire the specified pthread mutex. */
+
+static void call_rcu_lock(pthread_mutex_t *pmp)
+{
+ if (pthread_mutex_lock(pmp) != 0) {
+ perror("pthread_mutex_lock");
+ exit(-1);
+ }
+}
+
+/* Release the specified pthread mutex. */
+
+static void call_rcu_unlock(pthread_mutex_t *pmp)
+{
+ if (pthread_mutex_unlock(pmp) != 0) {
+ perror("pthread_mutex_unlock");
+ exit(-1);
+ }
+}
+
+/* This is the code run by each call_rcu thread. */
+
+static void *call_rcu_thread(void *arg)
+{
+ unsigned long cbcount;
+ struct wfq_node *cbs;
+ struct wfq_node **cbs_tail;
+ struct call_rcu_data *crdp = (struct call_rcu_data *)arg;
+ struct rcu_head *rhp;
+
+ thread_call_rcu_data = crdp;
+ for (;;) {
+ if (&crdp->cbs.head != LOAD_SHARED(crdp->cbs.tail)) {
+ while ((cbs = LOAD_SHARED(crdp->cbs.head)) == NULL)
+ poll(NULL, 0, 1);
+ STORE_SHARED(crdp->cbs.head, NULL);
+ cbs_tail = (struct wfq_node **)
+ uatomic_xchg(&crdp->cbs.tail, &crdp->cbs.head);
+ synchronize_rcu();
+ cbcount = 0;
+ do {
+ while (cbs->next == NULL &&
+ &cbs->next != cbs_tail)
+ poll(NULL, 0, 1);
+ if (cbs == &crdp->cbs.dummy) {
+ cbs = cbs->next;
+ continue;
+ }
+ rhp = (struct rcu_head *)cbs;
+ cbs = cbs->next;
+ rhp->func(rhp);
+ cbcount++;
+ } while (cbs != NULL);
+ uatomic_sub(&crdp->qlen, cbcount);
+ }
+ if (crdp->flags & URCU_CALL_RCU_RT)
+ poll(NULL, 0, 10);
+ else {
+ call_rcu_lock(&crdp->mtx);
+ STORE_SHARED(crdp->flags,
+ crdp->flags & ~URCU_CALL_RCU_RUNNING);
+ if (&cbs->next != crdp->cbs.tail &&
+ pthread_cond_wait(&crdp->cond, &crdp->mtx) != 0) {
+ perror("pthread_cond_wait");
+ exit(-1);
+ }
+ STORE_SHARED(crdp->flags,
+ crdp->flags | URCU_CALL_RCU_RUNNING);
+ poll(NULL, 0, 10);
+ call_rcu_unlock(&crdp->mtx);
+ }
+ }
+ return NULL; /* NOTREACHED */
+}
+
+/*
+ * Create both a call_rcu thread and the corresponding call_rcu_data
+ * structure, linking the structure in as specified.
+ */
+
+void call_rcu_data_init(struct call_rcu_data **crdpp, unsigned long flags)
+{
+ struct call_rcu_data *crdp;
+
+ crdp = malloc(sizeof(*crdp));
+ if (crdp == NULL) {
+ fprintf(stderr, "Out of memory.\n");
+ exit(-1);
+ }
+ memset(crdp, '\0', sizeof(*crdp));
+ wfq_init(&crdp->cbs);
+ crdp->qlen = 0;
+ if (pthread_mutex_init(&crdp->mtx, NULL) != 0) {
+ perror("pthread_mutex_init");
+ exit(-1);
+ }
+ if (pthread_cond_init(&crdp->cond, NULL) != 0) {
+ perror("pthread_cond_init");
+ exit(-1);
+ }
+ crdp->flags = flags | URCU_CALL_RCU_RUNNING;
+ mb(); /* Structure initialized before pointer is planted. */
+ *crdpp = crdp;
+ if (pthread_create(&crdp->tid, NULL, call_rcu_thread, crdp) != 0) {
+ perror("pthread_create");
+ exit(-1);
+ }
+}
+
+/*
+ * Return a pointer to the call_rcu_data structure for the specified
+ * CPU, returning NULL if there is none. We cannot automnatically
+ * created it because the platform we are running on might not define
+ * sched_getcpu().
+ */
+
+struct call_rcu_data *get_cpu_call_rcu_data(int cpu)
+{
+ if (per_cpu_call_rcu_data == NULL)
+ return NULL;
+ if (cpu < 0 || maxcpus <= cpu)
+ return NULL;
+ return per_cpu_call_rcu_data[cpu];
+}
+
+/*
+ * Return the tid corresponding to the call_rcu thread whose
+ * call_rcu_data structure is specified.
+ */
+
+pthread_t get_call_rcu_thread(struct call_rcu_data *crdp)
+{
+ return crdp->tid;
+}
+
+/*
+ * Create a call_rcu_data structure (with thread) and return a pointer.
+ */
+
+struct call_rcu_data *create_call_rcu_data(unsigned long flags)
+{
+ struct call_rcu_data *crdp;
+
+ call_rcu_data_init(&crdp, flags);
+ return crdp;
+}
+
+/*
+ * Set the specified CPU to use the specified call_rcu_data structure.
+ */
+
+int set_cpu_call_rcu_data(int cpu, struct call_rcu_data *crdp)
+{
+ call_rcu_lock(&call_rcu_mutex);
+ alloc_cpu_call_rcu_data();
+ call_rcu_unlock(&call_rcu_mutex);
+ if (cpu < 0 || maxcpus <= cpu || per_cpu_call_rcu_data == NULL)
+ return 0;
+ per_cpu_call_rcu_data[cpu] = crdp;
+ return 1;
+}
+
+/*
+ * Return a pointer to the default call_rcu_data structure, creating
+ * one if need be. Because we never free call_rcu_data structures,
+ * we don't need to be in an RCU read-side critical section.
+ */
+
+struct call_rcu_data *get_default_call_rcu_data(void)
+{
+ if (default_call_rcu_data != NULL)
+ return rcu_dereference(default_call_rcu_data);
+ call_rcu_lock(&call_rcu_mutex);
+ if (default_call_rcu_data != NULL) {
+ call_rcu_unlock(&call_rcu_mutex);
+ return default_call_rcu_data;
+ }
+ call_rcu_data_init(&default_call_rcu_data, 0);
+ call_rcu_unlock(&call_rcu_mutex);
+ return default_call_rcu_data;
+}
+
+/*
+ * Return the call_rcu_data structure that applies to the currently
+ * running thread. Any call_rcu_data structure assigned specifically
+ * to this thread has first priority, followed by any call_rcu_data
+ * structure assigned to the CPU on which the thread is running,
+ * followed by the default call_rcu_data structure. If there is not
+ * yet a default call_rcu_data structure, one will be created.
+ */
+struct call_rcu_data *get_call_rcu_data(void)
+{
+ int curcpu;
+
+ if (thread_call_rcu_data != NULL)
+ return thread_call_rcu_data;
+ curcpu = sched_getcpu();
+ if (per_cpu_call_rcu_data != NULL &&
+ per_cpu_call_rcu_data[curcpu] != NULL)
+ return per_cpu_call_rcu_data[curcpu];
+ return get_default_call_rcu_data();
+}
+
+/*
+ * Return a pointer to this task's call_rcu_data if there is one.
+ */
+
+struct call_rcu_data *get_thread_call_rcu_data(void)
+{
+ return thread_call_rcu_data;
+}
+
+/*
+ * Set this task's call_rcu_data structure as specified, regardless
+ * of whether or not this task already had one. (This allows switching
+ * to and from real-time call_rcu threads, for example.)
+ */
+
+void set_thread_call_rcu_data(struct call_rcu_data *crdp)
+{
+ thread_call_rcu_data = crdp;
+}
+
+/*
+ * Create a separate call_rcu thread for each CPU. This does not
+ * replace a pre-existing call_rcu thread -- use the set_cpu_call_rcu_data()
+ * function if you want that behavior.
+ */
+
+int create_all_cpu_call_rcu_data(unsigned long flags)
+{
+ int i;
+ struct call_rcu_data *crdp;
+
+ call_rcu_lock(&call_rcu_mutex);
+ alloc_cpu_call_rcu_data();
+ call_rcu_unlock(&call_rcu_mutex);
+ if (maxcpus == -1 || per_cpu_call_rcu_data == NULL)
+ return 0;
+ for (i = 0; i < maxcpus; i++) {
+ call_rcu_lock(&call_rcu_mutex);
+ if (get_cpu_call_rcu_data(i)) {
+ call_rcu_unlock(&call_rcu_mutex);
+ continue;
+ }
+ crdp = create_call_rcu_data(flags);
+ if (crdp == NULL) {
+ call_rcu_unlock(&call_rcu_mutex);
+ return 0;
+ }
+ if (!set_cpu_call_rcu_data(i, crdp)) {
+ call_rcu_unlock(&call_rcu_mutex);
+ return 0; /* should not happen, but... */
+ }
+ call_rcu_unlock(&call_rcu_mutex);
+ }
+ return 1;
+}
+
+/*
+ * Schedule a function to be invoked after a following grace period.
+ * This is the only function that must be called -- the others are
+ * only present to allow applications to tune their use of RCU for
+ * maximum performance.
+ *
+ * Note that unless a call_rcu thread has not already been created,
+ * the first invocation of call_rcu() will create one. So, if you
+ * need the first invocation of call_rcu() to be fast, make sure
+ * to create a call_rcu thread first. One way to accomplish this is
+ * "get_call_rcu_data();", and another is create_all_cpu_call_rcu_data().
+ */
+
+void call_rcu(struct rcu_head *head,
+ void (*func)(struct rcu_head *head))
+{
+ struct call_rcu_data *crdp;
+
+ wfq_node_init(&head->next);
+ head->func = func;
+ crdp = get_call_rcu_data();
+ wfq_enqueue(&crdp->cbs, &head->next);
+ uatomic_inc(&crdp->qlen);
+ if (!(LOAD_SHARED(crdp->flags) & URCU_CALL_RCU_RT)) {
+ call_rcu_lock(&crdp->mtx);
+ if (!(LOAD_SHARED(crdp->flags) & URCU_CALL_RCU_RUNNING)) {
+ if (pthread_cond_signal(&crdp->cond) != 0) {
+ perror("pthread_cond_signal");
+ exit(-1);
+ }
+ }
+ call_rcu_unlock(&crdp->mtx);
+ }
+}
diff --git a/urcu-call-rcu.h b/urcu-call-rcu.h
new file mode 100644
index 0000000..56e2ee5
--- /dev/null
+++ b/urcu-call-rcu.h
@@ -0,0 +1,80 @@
+#ifndef _URCU_CALL_RCU_H
+#define _URCU_CALL_RCU_H
+
+/*
+ * urcu-defer.h
+ *
+ * Userspace RCU header - deferred execution
+ *
+ * Copyright (c) 2009 Mathieu Desnoyers <mathieu.desnoyers at efficios.com>
+ * Copyright (c) 2009 Paul E. McKenney, IBM Corporation.
+ *
+ * LGPL-compatible code should include this header with :
+ *
+ * #define _LGPL_SOURCE
+ * #include <urcu-defer.h>
+ *
+ * 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
+ */
+
+#include <stdlib.h>
+#include <pthread.h>
+
+#include "urcu/wfqueue.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Note that struct call_rcu_data is opaque to callers. */
+
+struct call_rcu_data;
+
+/* Flag values. */
+
+#define URCU_CALL_RCU_RT 0x1
+#define URCU_CALL_RCU_RUNNING 0x2
+
+/*
+ * The rcu_head data structure is placed in the structure to be freed
+ * via call_rcu().
+ */
+
+struct rcu_head {
+ struct wfq_node next;
+ void (*func)(struct rcu_head *head);
+};
+
+/*
+ * Exported functions
+ */
+void call_rcu_data_init(struct call_rcu_data **crdpp, unsigned long flags);
+struct call_rcu_data *get_cpu_call_rcu_data(int cpu);
+pthread_t get_call_rcu_thread(struct call_rcu_data *crdp);
+struct call_rcu_data *create_call_rcu_data(unsigned long flags);
+int set_cpu_call_rcu_data(int cpu, struct call_rcu_data *crdp);
+struct call_rcu_data *get_default_call_rcu_data(void);
+struct call_rcu_data *get_call_rcu_data(void);
+struct call_rcu_data *get_thread_call_rcu_data(void);
+void set_thread_call_rcu_data(struct call_rcu_data *crdp);
+int create_all_cpu_call_rcu_data(unsigned long flags);
+void call_rcu(struct rcu_head *head,
+ void (*func)(struct rcu_head *head));
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _URCU_CALL_RCU_H */
diff --git a/urcu-defer.h b/urcu-defer.h
index e161616..a64c75c 100644
--- a/urcu-defer.h
+++ b/urcu-defer.h
@@ -53,14 +53,6 @@ extern "C" {
extern void defer_rcu(void (*fct)(void *p), void *p);
/*
- * call_rcu will eventually be implemented with an API similar to the Linux
- * kernel call_rcu(), which will allow its use within RCU read-side C.S.
- * Generate an error if used for now.
- */
-
-#define call_rcu __error_call_rcu_not_implemented_please_use_defer_rcu
-
-/*
* Thread registration for reclamation.
*/
extern void rcu_defer_register_thread(void);
diff --git a/urcu/wfqueue-static.h b/urcu/wfqueue-static.h
index 0f7e68f..eba8cc2 100644
--- a/urcu/wfqueue-static.h
+++ b/urcu/wfqueue-static.h
@@ -47,11 +47,17 @@ extern "C" {
#define WFQ_ADAPT_ATTEMPTS 10 /* Retry if being set */
#define WFQ_WAIT 10 /* Wait 10 ms if being set */
+#ifdef _LGPL_SOURCE
+static inline
+#endif /* #ifdef _LGPL_SOURCE */
void _wfq_node_init(struct wfq_node *node)
{
node->next = NULL;
}
+#ifdef _LGPL_SOURCE
+static inline
+#endif /* #ifdef _LGPL_SOURCE */
void _wfq_init(struct wfq_queue *q)
{
int ret;
@@ -64,6 +70,9 @@ void _wfq_init(struct wfq_queue *q)
assert(!ret);
}
+#ifdef _LGPL_SOURCE
+static inline
+#endif /* #ifdef _LGPL_SOURCE */
void _wfq_enqueue(struct wfq_queue *q, struct wfq_node *node)
{
struct wfq_node **old_tail;
@@ -90,6 +99,9 @@ void _wfq_enqueue(struct wfq_queue *q, struct wfq_node *node)
* thread to be scheduled. The queue appears empty until tail->next is set by
* enqueue.
*/
+#ifdef _LGPL_SOURCE
+static inline
+#endif /* #ifdef _LGPL_SOURCE */
struct wfq_node *
___wfq_dequeue_blocking(struct wfq_queue *q)
{
@@ -128,6 +140,9 @@ ___wfq_dequeue_blocking(struct wfq_queue *q)
return node;
}
+#ifdef _LGPL_SOURCE
+static inline
+#endif /* #ifdef _LGPL_SOURCE */
struct wfq_node *
_wfq_dequeue_blocking(struct wfq_queue *q)
{
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