[ltt-dev] [PATCH RFC urcu 2/2] Map symbols to allow multiple RCU flavors to be used in one binary

Paul E. McKenney paulmck at linux.vnet.ibm.com
Wed Mar 23 14:38:02 EDT 2011


Probably need similar mapping for rcu_defer().  Definitely need
backwards-compatibility mapping for programs compiled against
old versions of the library.

Signed-off-by: Paul E. McKenney <paulmck at linux.vnet.ibm.com>
---
 Makefile.am          |    3 +-
 tests/Makefile.am    |   33 ++--
 tests/rcutorture.h   |    1 -
 tests/urcutorture.c  |   13 +-
 urcu-bp.c            |    4 +
 urcu-bp.h            |    8 +-
 urcu-call-rcu-impl.h |  618 +++++++++++++++++++++++++++++++++++++++++++++++++
 urcu-call-rcu.c      |  620 --------------------------------------------------
 urcu-qsbr.c          |   36 ++--
 urcu-qsbr.h          |   18 +-
 urcu.c               |    5 +
 urcu.h               |   20 ++-
 12 files changed, 704 insertions(+), 675 deletions(-)
 create mode 100644 urcu-call-rcu-impl.h
 delete mode 100644 urcu-call-rcu.c

diff --git a/Makefile.am b/Makefile.am
index 7956e7e..ef3bfef 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -30,7 +30,7 @@ COMPAT+=compat_futex.c
 endif
 
 lib_LTLIBRARIES = liburcu.la liburcu-qsbr.la liburcu-mb.la liburcu-signal.la \
-		  liburcu-bp.la liburcu-defer.la liburcu-call.la \
+		  liburcu-bp.la liburcu-defer.la \
 		  libwfqueue.la libwfstack.la librculfqueue.la librculfstack.la
 
 liburcu_la_SOURCES = urcu.c urcu-pointer.c $(COMPAT)
@@ -45,7 +45,6 @@ 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 $(COMPAT)
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 3c025a4..8dacb11 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -28,21 +28,20 @@ if COMPAT_FUTEX
 COMPAT+=$(top_srcdir)/compat_futex.c
 endif
 
-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 $(COMPAT)
+URCU=$(top_srcdir)/urcu.c $(top_srcdir)/urcu-pointer.c $(top_srcdir)/wfqueue.c $(COMPAT)
+URCU_QSBR=$(top_srcdir)/urcu-qsbr.c $(top_srcdir)/urcu-pointer.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 $(top_srcdir)/urcu-call-rcu.c $(top_srcdir)/wfqueue.c $(COMPAT)
+URCU_MB=$(top_srcdir)/urcu.c $(top_srcdir)/urcu-pointer.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 $(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 $(COMPAT)
+URCU_SIGNAL=$(top_srcdir)/urcu.c $(top_srcdir)/urcu-pointer.c $(top_srcdir)/wfqueue.c $(COMPAT)
+URCU_BP=$(top_srcdir)/urcu-bp.c $(top_srcdir)/urcu-pointer.c $(top_srcdir)/wfqueue.c $(COMPAT)
+URCU_DEFER=$(top_srcdir)/urcu.c $(top_srcdir)/urcu-defer.c $(top_srcdir)/urcu-pointer.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
@@ -95,24 +94,24 @@ test_perthreadlock_SOURCES = test_perthreadlock.c $(URCU_SIGNAL)
 
 
 rcutorture_urcu_SOURCES = urcutorture.c
-rcutorture_urcu_CFLAGS = -DTORTURE_URCU $(AM_CFLAGS)
-rcutorture_urcu_LDADD = $(URCU) $(URCU_CALL_LIB) $(WFQUEUE_LIB)
+rcutorture_urcu_CFLAGS = -DRCU_MEMBARRIER $(AM_CFLAGS)
+rcutorture_urcu_LDADD = $(URCU) $(WFQUEUE_LIB)
 
 rcutorture_urcu_mb_SOURCES = urcutorture.c
-rcutorture_urcu_mb_CFLAGS = -DTORTURE_URCU_MB $(AM_CFLAGS)
-rcutorture_urcu_mb_LDADD = $(URCU_MB_LIB) $(URCU_CALL_LIB) $(WFQUEUE_LIB)
+rcutorture_urcu_mb_CFLAGS = -DRCU_MB $(AM_CFLAGS)
+rcutorture_urcu_mb_LDADD = $(URCU_MB_LIB) $(WFQUEUE_LIB)
 
 rcutorture_qsbr_SOURCES = urcutorture.c
-rcutorture_qsbr_CFLAGS = -DTORTURE_QSBR $(AM_CFLAGS)
-rcutorture_qsbr_LDADD = $(URCU_QSBR_LIB) $(URCU_CALL_LIB) $(WFQUEUE_LIB)
+rcutorture_qsbr_CFLAGS = -DRCU_QSBR $(AM_CFLAGS)
+rcutorture_qsbr_LDADD = $(URCU_QSBR_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) $(URCU_CALL_LIB) $(WFQUEUE_LIB)
+rcutorture_urcu_signal_CFLAGS = -DRCU_SIGNAL $(AM_CFLAGS)
+rcutorture_urcu_signal_LDADD = $(URCU_SIGNAL_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) $(URCU_CALL_LIB) $(WFQUEUE_LIB)
+rcutorture_urcu_bp_CFLAGS = -DRCU_BP $(AM_CFLAGS)
+rcutorture_urcu_bp_LDADD = $(URCU_BP_LIB) $(WFQUEUE_LIB)
 
 test_mutex_SOURCES = test_mutex.c $(URCU)
 
diff --git a/tests/rcutorture.h b/tests/rcutorture.h
index 66fdd7f..aba74b0 100644
--- a/tests/rcutorture.h
+++ b/tests/rcutorture.h
@@ -66,7 +66,6 @@
  */
 
 #include <stdlib.h>
-#include "../urcu-call-rcu.h"
 
 DEFINE_PER_THREAD(long long, n_reads_pt);
 DEFINE_PER_THREAD(long long, n_updates_pt);
diff --git a/tests/urcutorture.c b/tests/urcutorture.c
index 63fa386..a098d87 100644
--- a/tests/urcutorture.c
+++ b/tests/urcutorture.c
@@ -8,22 +8,19 @@
 #include "api.h"
 #define _LGPL_SOURCE
 
-#ifdef TORTURE_RCU_MEMBARRIER
-#define RCU_MEMBARRIER
+#ifdef RCU_MEMBARRIER
 #include <urcu.h>
 #endif
-#ifdef TORTURE_URCU_SIGNAL
-#define RCU_SIGNAL
+#ifdef RCU_SIGNAL
 #include <urcu.h>
 #endif
-#ifdef TORTURE_URCU_MB
-#define RCU_MB
+#ifdef RCU_MB
 #include <urcu.h>
 #endif
-#ifdef TORTURE_QSBR
+#ifdef RCU_QSBR
 #include <urcu-qsbr.h>
 #endif
-#ifdef TORTURE_URCU_BP
+#ifdef RCU_BP
 #include <urcu-bp.h>
 #endif
 
diff --git a/urcu-bp.c b/urcu-bp.c
index 04bb675..5474f9f 100644
--- a/urcu-bp.c
+++ b/urcu-bp.c
@@ -35,6 +35,8 @@
 #include <unistd.h>
 #include <sys/mman.h>
 
+#include "urcu-bp-map.h"
+
 #include "urcu-bp-static.h"
 /* Do not #define _LGPL_SOURCE to ensure we can emit the wrapper symbols */
 #include "urcu-bp.h"
@@ -375,3 +377,5 @@ void rcu_bp_after_fork_child(void)
 	ret = pthread_sigmask(SIG_SETMASK, &oldmask, NULL);
 	assert(!ret);
 }
+
+#include "urcu-call-rcu-impl.h"
diff --git a/urcu-bp.h b/urcu-bp.h
index d92fbd1..fdf885c 100644
--- a/urcu-bp.h
+++ b/urcu-bp.h
@@ -46,6 +46,8 @@
 extern "C" {
 #endif
 
+#include "urcu-bp-map.h"
+
 /*
  * Important !
  *
@@ -69,8 +71,8 @@ extern "C" {
  *
  * Mark the beginning and end of a read-side critical section.
  */
-#define rcu_read_lock()		_rcu_read_lock()
-#define rcu_read_unlock()	_rcu_read_unlock()
+#define rcu_read_lock_bp()		_rcu_read_lock()
+#define rcu_read_unlock_bp()		_rcu_read_unlock()
 
 #else /* !_LGPL_SOURCE */
 
@@ -115,4 +117,6 @@ static inline void rcu_init(void)
 }
 #endif
 
+#include "urcu-call-rcu.h"
+
 #endif /* _URCU_BP_H */
diff --git a/urcu-call-rcu-impl.h b/urcu-call-rcu-impl.h
new file mode 100644
index 0000000..68dbbdd
--- /dev/null
+++ b/urcu-call-rcu-impl.h
@@ -0,0 +1,618 @@
+/*
+ * 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"
+#include "urcu/list.h"
+
+/* Data structure that identifies a call_rcu thread. */
+
+struct call_rcu_data {
+	struct cds_wfq_queue cbs;
+	unsigned long flags;
+	pthread_mutex_t mtx;
+	pthread_cond_t cond;
+	unsigned long qlen;
+	pthread_t tid;
+	struct cds_list_head list;
+} __attribute__((aligned(CAA_CACHE_LINE_SIZE)));
+
+/*
+ * List of all call_rcu_data structures to keep valgrind happy.
+ * Protected by call_rcu_mutex.
+ */
+
+CDS_LIST_HEAD(call_rcu_data_list);
+
+/* 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;
+
+/*
+ * 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;
+	static int warned = 0;
+
+	if (maxcpus != 0)
+		return;
+	maxcpus = sysconf(_SC_NPROCESSORS_CONF);
+	if (maxcpus <= 0) {
+		return;
+	}
+	p = malloc(maxcpus * sizeof(*per_cpu_call_rcu_data));
+	if (p != NULL) {
+		memset(p, '\0', maxcpus * sizeof(*per_cpu_call_rcu_data));
+		per_cpu_call_rcu_data = p;
+	} else {
+		if (!warned) {
+			fprintf(stderr, "[error] liburcu: unable to allocate per-CPU pointer array\n");
+		}
+		warned = 1;
+	}
+}
+
+#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 cds_wfq_node *cbs;
+	struct cds_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 != _CMM_LOAD_SHARED(crdp->cbs.tail)) {
+			while ((cbs = _CMM_LOAD_SHARED(crdp->cbs.head)) == NULL)
+				poll(NULL, 0, 1);
+			_CMM_STORE_SHARED(crdp->cbs.head, NULL);
+			cbs_tail = (struct cds_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_STOP)
+			break;
+		if (crdp->flags & URCU_CALL_RCU_RT)
+			poll(NULL, 0, 10);
+		else {
+			call_rcu_lock(&crdp->mtx);
+			_CMM_STORE_SHARED(crdp->flags,
+				     crdp->flags & ~URCU_CALL_RCU_RUNNING);
+			if (&crdp->cbs.head ==
+			    _CMM_LOAD_SHARED(crdp->cbs.tail) &&
+			    pthread_cond_wait(&crdp->cond, &crdp->mtx) != 0) {
+				perror("pthread_cond_wait");
+				exit(-1);
+			}
+			_CMM_STORE_SHARED(crdp->flags,
+				     crdp->flags | URCU_CALL_RCU_RUNNING);
+			poll(NULL, 0, 10);
+			call_rcu_unlock(&crdp->mtx);
+		}
+	}
+	call_rcu_lock(&crdp->mtx);
+	crdp->flags |= URCU_CALL_RCU_STOPPED;
+	call_rcu_unlock(&crdp->mtx);
+	return NULL;
+}
+
+/*
+ * Create both a call_rcu thread and the corresponding call_rcu_data
+ * structure, linking the structure in as specified.  Caller must hold
+ * call_rcu_mutex.
+ */
+
+static 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));
+	cds_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;
+	cds_list_add(&crdp->list, &call_rcu_data_list);
+	cmm_smp_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 automatically
+ * 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)
+{
+	static int warned = 0;
+
+	if (per_cpu_call_rcu_data == NULL)
+		return NULL;
+	if (!warned && maxcpus > 0 && (cpu < 0 || maxcpus <= cpu)) {
+		fprintf(stderr, "[error] liburcu: get CPU # out of range\n");
+		warned = 1;
+	}
+	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.
+ */
+
+static struct call_rcu_data *__create_call_rcu_data(unsigned long flags)
+{
+	struct call_rcu_data *crdp;
+
+	call_rcu_data_init(&crdp, flags);
+	return crdp;
+}
+
+struct call_rcu_data *create_call_rcu_data(unsigned long flags)
+{
+	struct call_rcu_data *crdp;
+
+	call_rcu_lock(&call_rcu_mutex);
+	crdp = __create_call_rcu_data(flags);
+	call_rcu_unlock(&call_rcu_mutex);
+	return crdp;
+}
+
+/*
+ * Set the specified CPU to use the specified call_rcu_data structure.
+ *
+ * Use NULL to remove a CPU's call_rcu_data structure, but it is
+ * the caller's responsibility to dispose of the removed structure.
+ * Use get_cpu_call_rcu_data() to obtain a pointer to the old structure
+ * (prior to NULLing it out, of course).
+ */
+
+int set_cpu_call_rcu_data(int cpu, struct call_rcu_data *crdp)
+{
+	int warned = 0;
+
+	call_rcu_lock(&call_rcu_mutex);
+	if (cpu < 0 || maxcpus <= cpu) {
+		if (!warned) {
+			fprintf(stderr, "[error] liburcu: set CPU # out of range\n");
+			warned = 1;
+		}
+		call_rcu_unlock(&call_rcu_mutex);
+		errno = EINVAL;
+		return -EINVAL;
+	}
+	alloc_cpu_call_rcu_data();
+	call_rcu_unlock(&call_rcu_mutex);
+	if (per_cpu_call_rcu_data == NULL) {
+		errno = ENOMEM;
+		return -ENOMEM;
+	}
+	per_cpu_call_rcu_data[cpu] = crdp;
+	return 0;
+}
+
+/*
+ * 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;
+	static int warned = 0;
+
+	if (thread_call_rcu_data != NULL)
+		return thread_call_rcu_data;
+	if (maxcpus <= 0)
+		return get_default_call_rcu_data();
+	curcpu = sched_getcpu();
+	if (!warned && (curcpu < 0 || maxcpus <= curcpu)) {
+		fprintf(stderr, "[error] liburcu: gcrd CPU # out of range\n");
+		warned = 1;
+	}
+	if (curcpu >= 0 && maxcpus > curcpu &&
+	    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.)
+ *
+ * Use NULL to remove a thread's call_rcu_data structure, but it is
+ * the caller's responsibility to dispose of the removed structure.
+ * Use get_thread_call_rcu_data() to obtain a pointer to the old structure
+ * (prior to NULLing it out, of course).
+ */
+
+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;
+	int ret;
+
+	call_rcu_lock(&call_rcu_mutex);
+	alloc_cpu_call_rcu_data();
+	call_rcu_unlock(&call_rcu_mutex);
+	if (maxcpus <= 0) {
+		errno = EINVAL;
+		return -EINVAL;
+	}
+	if (per_cpu_call_rcu_data == NULL) {
+		errno = ENOMEM;
+		return -ENOMEM;
+	}
+	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);
+			errno = ENOMEM;
+			return -ENOMEM;
+		}
+		call_rcu_unlock(&call_rcu_mutex);
+		if ((ret = set_cpu_call_rcu_data(i, crdp)) != 0) {
+			/* FIXME: Leaks crdp for now. */
+			return ret; /* Can happen on race. */
+		}
+	}
+	return 0;
+}
+
+/*
+ * Wake up the call_rcu thread corresponding to the specified
+ * call_rcu_data structure.
+ */
+static void wake_call_rcu_thread(struct call_rcu_data *crdp)
+{
+	if (!(_CMM_LOAD_SHARED(crdp->flags) & URCU_CALL_RCU_RT)) {
+		call_rcu_lock(&crdp->mtx);
+		if (!(_CMM_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);
+	}
+}
+
+/*
+ * 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;
+
+	cds_wfq_node_init(&head->next);
+	head->func = func;
+	crdp = get_call_rcu_data();
+	cds_wfq_enqueue(&crdp->cbs, &head->next);
+	uatomic_inc(&crdp->qlen);
+	wake_call_rcu_thread(crdp);
+}
+
+/*
+ * Free up the specified call_rcu_data structure, terminating the
+ * associated call_rcu thread.  The caller must have previously
+ * removed the call_rcu_data structure from per-thread or per-CPU
+ * usage.  For example, set_cpu_call_rcu_data(cpu, NULL) for per-CPU
+ * call_rcu_data structures or set_thread_call_rcu_data(NULL) for
+ * per-thread call_rcu_data structures.
+ *
+ * We silently refuse to free up the default call_rcu_data structure
+ * because that is where we put any leftover callbacks.  Note that
+ * the possibility of self-spawning callbacks makes it impossible
+ * to execute all the callbacks in finite time without putting any
+ * newly spawned callbacks somewhere else.  The "somewhere else" of
+ * last resort is the default call_rcu_data structure.
+ *
+ * We also silently refuse to free NULL pointers.  This simplifies
+ * the calling code.
+ */
+void call_rcu_data_free(struct call_rcu_data *crdp)
+{
+	struct cds_wfq_node *cbs;
+	struct cds_wfq_node **cbs_tail;
+	struct cds_wfq_node **cbs_endprev;
+
+	if (crdp == NULL || crdp == default_call_rcu_data) {
+		return;
+	}
+	if ((crdp->flags & URCU_CALL_RCU_STOPPED) == 0) {
+		call_rcu_lock(&crdp->mtx);
+		crdp->flags |= URCU_CALL_RCU_STOP;
+		call_rcu_unlock(&crdp->mtx);
+		wake_call_rcu_thread(crdp);
+		while ((crdp->flags & URCU_CALL_RCU_STOPPED) == 0)
+			poll(NULL, 0, 1);
+	}
+	if (&crdp->cbs.head != _CMM_LOAD_SHARED(crdp->cbs.tail)) {
+		while ((cbs = _CMM_LOAD_SHARED(crdp->cbs.head)) == NULL)
+			poll(NULL, 0, 1);
+		_CMM_STORE_SHARED(crdp->cbs.head, NULL);
+		cbs_tail = (struct cds_wfq_node **)
+			uatomic_xchg(&crdp->cbs.tail, &crdp->cbs.head);
+		cbs_endprev = (struct cds_wfq_node **)
+			uatomic_xchg(&default_call_rcu_data, cbs_tail);
+		*cbs_endprev = cbs;
+		uatomic_add(&default_call_rcu_data->qlen,
+			    uatomic_read(&crdp->qlen));
+		cds_list_del(&crdp->list);
+		free(crdp);
+	}
+}
+
+/*
+ * Clean up all the per-CPU call_rcu threads.
+ */
+void free_all_cpu_call_rcu_data(void)
+{
+	int cpu;
+	struct call_rcu_data *crdp;
+
+	if (maxcpus <= 0)
+		return;
+	for (cpu = 0; cpu < maxcpus; cpu++) {
+		crdp = get_cpu_call_rcu_data(cpu);
+		if (crdp == NULL)
+			continue;
+		set_cpu_call_rcu_data(cpu, NULL);
+		call_rcu_data_free(crdp);
+	}
+}
+
+/*
+ * Acquire the call_rcu_mutex in order to ensure that the child sees
+ * all of the call_rcu() data structures in a consistent state.
+ * Suitable for pthread_atfork() and friends.
+ */
+void call_rcu_before_fork(void)
+{
+	call_rcu_lock(&call_rcu_mutex);
+}
+
+/*
+ * Clean up call_rcu data structures in the parent of a successful fork()
+ * that is not followed by exec() in the child.  Suitable for
+ * pthread_atfork() and friends.
+ */
+void call_rcu_after_fork_parent(void)
+{
+	call_rcu_unlock(&call_rcu_mutex);
+}
+
+/*
+ * Clean up call_rcu data structures in the child of a successful fork()
+ * that is not followed by exec().  Suitable for pthread_atfork() and
+ * friends.
+ */
+void call_rcu_after_fork_child(void)
+{
+	struct call_rcu_data *crdp;
+
+	/* Re-initialize the mutex. */
+	if (pthread_mutex_init(&call_rcu_mutex, NULL) != 0) {
+		perror("pthread_mutex_init");
+		exit(-1);
+	}
+
+	/*
+	 * Allocate a new default call_rcu_data structure in order
+	 * to get a working call_rcu thread to go with it.
+	 */
+	default_call_rcu_data = NULL;
+	(void)get_default_call_rcu_data();
+
+	/* Dispose of all of the rest of the call_rcu_data structures. */
+	while (call_rcu_data_list.next != call_rcu_data_list.prev) {
+		crdp = cds_list_entry(call_rcu_data_list.prev,
+				      struct call_rcu_data, list);
+		if (crdp == default_call_rcu_data)
+			crdp = cds_list_entry(crdp->list.prev,
+					      struct call_rcu_data, list);
+		crdp->flags = URCU_CALL_RCU_STOPPED;
+		call_rcu_data_free(crdp);
+	}
+}
diff --git a/urcu-call-rcu.c b/urcu-call-rcu.c
deleted file mode 100644
index 665f20c..0000000
--- a/urcu-call-rcu.c
+++ /dev/null
@@ -1,620 +0,0 @@
-/*
- * 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"
-#include "urcu/list.h"
-
-/* Data structure that identifies a call_rcu thread. */
-
-struct call_rcu_data {
-	struct cds_wfq_queue cbs;
-	unsigned long flags;
-	pthread_mutex_t mtx;
-	pthread_cond_t cond;
-	unsigned long qlen;
-	pthread_t tid;
-	struct cds_list_head list;
-} __attribute__((aligned(CAA_CACHE_LINE_SIZE)));
-
-/*
- * List of all call_rcu_data structures to keep valgrind happy.
- * Protected by call_rcu_mutex.
- */
-
-CDS_LIST_HEAD(call_rcu_data_list);
-
-/* 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;
-	static int warned = 0;
-
-	if (maxcpus != 0)
-		return;
-	maxcpus = sysconf(_SC_NPROCESSORS_CONF);
-	if (maxcpus <= 0) {
-		return;
-	}
-	p = malloc(maxcpus * sizeof(*per_cpu_call_rcu_data));
-	if (p != NULL) {
-		memset(p, '\0', maxcpus * sizeof(*per_cpu_call_rcu_data));
-		per_cpu_call_rcu_data = p;
-	} else {
-		if (!warned) {
-			fprintf(stderr, "[error] liburcu: unable to allocate per-CPU pointer array\n");
-		}
-		warned = 1;
-	}
-}
-
-#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 cds_wfq_node *cbs;
-	struct cds_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 != _CMM_LOAD_SHARED(crdp->cbs.tail)) {
-			while ((cbs = _CMM_LOAD_SHARED(crdp->cbs.head)) == NULL)
-				poll(NULL, 0, 1);
-			_CMM_STORE_SHARED(crdp->cbs.head, NULL);
-			cbs_tail = (struct cds_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_STOP)
-			break;
-		if (crdp->flags & URCU_CALL_RCU_RT)
-			poll(NULL, 0, 10);
-		else {
-			call_rcu_lock(&crdp->mtx);
-			_CMM_STORE_SHARED(crdp->flags,
-				     crdp->flags & ~URCU_CALL_RCU_RUNNING);
-			if (&crdp->cbs.head ==
-			    _CMM_LOAD_SHARED(crdp->cbs.tail) &&
-			    pthread_cond_wait(&crdp->cond, &crdp->mtx) != 0) {
-				perror("pthread_cond_wait");
-				exit(-1);
-			}
-			_CMM_STORE_SHARED(crdp->flags,
-				     crdp->flags | URCU_CALL_RCU_RUNNING);
-			poll(NULL, 0, 10);
-			call_rcu_unlock(&crdp->mtx);
-		}
-	}
-	call_rcu_lock(&crdp->mtx);
-	crdp->flags |= URCU_CALL_RCU_STOPPED;
-	call_rcu_unlock(&crdp->mtx);
-	return NULL;
-}
-
-/*
- * Create both a call_rcu thread and the corresponding call_rcu_data
- * structure, linking the structure in as specified.  Caller must hold
- * call_rcu_mutex.
- */
-
-static 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));
-	cds_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;
-	cds_list_add(&crdp->list, &call_rcu_data_list);
-	cmm_smp_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 automatically
- * 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)
-{
-	static int warned = 0;
-
-	if (per_cpu_call_rcu_data == NULL)
-		return NULL;
-	if (!warned && maxcpus > 0 && (cpu < 0 || maxcpus <= cpu)) {
-		fprintf(stderr, "[error] liburcu: get CPU # out of range\n");
-		warned = 1;
-	}
-	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.
- */
-
-static struct call_rcu_data *__create_call_rcu_data(unsigned long flags)
-{
-	struct call_rcu_data *crdp;
-
-	call_rcu_data_init(&crdp, flags);
-	return crdp;
-}
-
-struct call_rcu_data *create_call_rcu_data(unsigned long flags)
-{
-	struct call_rcu_data *crdp;
-
-	call_rcu_lock(&call_rcu_mutex);
-	crdp = __create_call_rcu_data(flags);
-	call_rcu_unlock(&call_rcu_mutex);
-	return crdp;
-}
-
-/*
- * Set the specified CPU to use the specified call_rcu_data structure.
- *
- * Use NULL to remove a CPU's call_rcu_data structure, but it is
- * the caller's responsibility to dispose of the removed structure.
- * Use get_cpu_call_rcu_data() to obtain a pointer to the old structure
- * (prior to NULLing it out, of course).
- */
-
-int set_cpu_call_rcu_data(int cpu, struct call_rcu_data *crdp)
-{
-	int warned = 0;
-
-	call_rcu_lock(&call_rcu_mutex);
-	if (cpu < 0 || maxcpus <= cpu) {
-		if (!warned) {
-			fprintf(stderr, "[error] liburcu: set CPU # out of range\n");
-			warned = 1;
-		}
-		call_rcu_unlock(&call_rcu_mutex);
-		errno = EINVAL;
-		return -EINVAL;
-	}
-	alloc_cpu_call_rcu_data();
-	call_rcu_unlock(&call_rcu_mutex);
-	if (per_cpu_call_rcu_data == NULL) {
-		errno = ENOMEM;
-		return -ENOMEM;
-	}
-	per_cpu_call_rcu_data[cpu] = crdp;
-	return 0;
-}
-
-/*
- * 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;
-	static int warned = 0;
-
-	if (thread_call_rcu_data != NULL)
-		return thread_call_rcu_data;
-	if (maxcpus <= 0)
-		return get_default_call_rcu_data();
-	curcpu = sched_getcpu();
-	if (!warned && (curcpu < 0 || maxcpus <= curcpu)) {
-		fprintf(stderr, "[error] liburcu: gcrd CPU # out of range\n");
-		warned = 1;
-	}
-	if (curcpu >= 0 && maxcpus > curcpu &&
-	    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.)
- *
- * Use NULL to remove a thread's call_rcu_data structure, but it is
- * the caller's responsibility to dispose of the removed structure.
- * Use get_thread_call_rcu_data() to obtain a pointer to the old structure
- * (prior to NULLing it out, of course).
- */
-
-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;
-	int ret;
-
-	call_rcu_lock(&call_rcu_mutex);
-	alloc_cpu_call_rcu_data();
-	call_rcu_unlock(&call_rcu_mutex);
-	if (maxcpus <= 0) {
-		errno = EINVAL;
-		return -EINVAL;
-	}
-	if (per_cpu_call_rcu_data == NULL) {
-		errno = ENOMEM;
-		return -ENOMEM;
-	}
-	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);
-			errno = ENOMEM;
-			return -ENOMEM;
-		}
-		call_rcu_unlock(&call_rcu_mutex);
-		if ((ret = set_cpu_call_rcu_data(i, crdp)) != 0) {
-			/* FIXME: Leaks crdp for now. */
-			return ret; /* Can happen on race. */
-		}
-	}
-	return 0;
-}
-
-/*
- * Wake up the call_rcu thread corresponding to the specified
- * call_rcu_data structure.
- */
-static void wake_call_rcu_thread(struct call_rcu_data *crdp)
-{
-	if (!(_CMM_LOAD_SHARED(crdp->flags) & URCU_CALL_RCU_RT)) {
-		call_rcu_lock(&crdp->mtx);
-		if (!(_CMM_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);
-	}
-}
-
-/*
- * 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;
-
-	cds_wfq_node_init(&head->next);
-	head->func = func;
-	crdp = get_call_rcu_data();
-	cds_wfq_enqueue(&crdp->cbs, &head->next);
-	uatomic_inc(&crdp->qlen);
-	wake_call_rcu_thread(crdp);
-}
-
-/*
- * Free up the specified call_rcu_data structure, terminating the
- * associated call_rcu thread.  The caller must have previously
- * removed the call_rcu_data structure from per-thread or per-CPU
- * usage.  For example, set_cpu_call_rcu_data(cpu, NULL) for per-CPU
- * call_rcu_data structures or set_thread_call_rcu_data(NULL) for
- * per-thread call_rcu_data structures.
- *
- * We silently refuse to free up the default call_rcu_data structure
- * because that is where we put any leftover callbacks.  Note that
- * the possibility of self-spawning callbacks makes it impossible
- * to execute all the callbacks in finite time without putting any
- * newly spawned callbacks somewhere else.  The "somewhere else" of
- * last resort is the default call_rcu_data structure.
- *
- * We also silently refuse to free NULL pointers.  This simplifies
- * the calling code.
- */
-void call_rcu_data_free(struct call_rcu_data *crdp)
-{
-	struct cds_wfq_node *cbs;
-	struct cds_wfq_node **cbs_tail;
-	struct cds_wfq_node **cbs_endprev;
-
-	if (crdp == NULL || crdp == default_call_rcu_data) {
-		return;
-	}
-	if ((crdp->flags & URCU_CALL_RCU_STOPPED) == 0) {
-		call_rcu_lock(&crdp->mtx);
-		crdp->flags |= URCU_CALL_RCU_STOP;
-		call_rcu_unlock(&crdp->mtx);
-		wake_call_rcu_thread(crdp);
-		while ((crdp->flags & URCU_CALL_RCU_STOPPED) == 0)
-			poll(NULL, 0, 1);
-	}
-	if (&crdp->cbs.head != _CMM_LOAD_SHARED(crdp->cbs.tail)) {
-		while ((cbs = _CMM_LOAD_SHARED(crdp->cbs.head)) == NULL)
-			poll(NULL, 0, 1);
-		_CMM_STORE_SHARED(crdp->cbs.head, NULL);
-		cbs_tail = (struct cds_wfq_node **)
-			uatomic_xchg(&crdp->cbs.tail, &crdp->cbs.head);
-		cbs_endprev = (struct cds_wfq_node **)
-			uatomic_xchg(&default_call_rcu_data, cbs_tail);
-		*cbs_endprev = cbs;
-		uatomic_add(&default_call_rcu_data->qlen,
-			    uatomic_read(&crdp->qlen));
-		cds_list_del(&crdp->list);
-		free(crdp);
-	}
-}
-
-/*
- * Clean up all the per-CPU call_rcu threads.
- */
-void free_all_cpu_call_rcu_data(void)
-{
-	int cpu;
-	struct call_rcu_data *crdp;
-
-	if (maxcpus <= 0)
-		return;
-	for (cpu = 0; cpu < maxcpus; cpu++) {
-		crdp = get_cpu_call_rcu_data(cpu);
-		if (crdp == NULL)
-			continue;
-		set_cpu_call_rcu_data(cpu, NULL);
-		call_rcu_data_free(crdp);
-	}
-}
-
-/*
- * Acquire the call_rcu_mutex in order to ensure that the child sees
- * all of the call_rcu() data structures in a consistent state.
- * Suitable for pthread_atfork() and friends.
- */
-void call_rcu_before_fork(void)
-{
-	call_rcu_lock(&call_rcu_mutex);
-}
-
-/*
- * Clean up call_rcu data structures in the parent of a successful fork()
- * that is not followed by exec() in the child.  Suitable for
- * pthread_atfork() and friends.
- */
-void call_rcu_after_fork_parent(void)
-{
-	call_rcu_unlock(&call_rcu_mutex);
-}
-
-/*
- * Clean up call_rcu data structures in the child of a successful fork()
- * that is not followed by exec().  Suitable for pthread_atfork() and
- * friends.
- */
-void call_rcu_after_fork_child(void)
-{
-	struct call_rcu_data *crdp;
-
-	/* Re-initialize the mutex. */
-	if (pthread_mutex_init(&call_rcu_mutex, NULL) != 0) {
-		perror("pthread_mutex_init");
-		exit(-1);
-	}
-
-	/*
-	 * Allocate a new default call_rcu_data structure in order
-	 * to get a working call_rcu thread to go with it.
-	 */
-	default_call_rcu_data = NULL;
-	(void)get_default_call_rcu_data();
-
-	/* Dispose of all of the rest of the call_rcu_data structures. */
-	while (call_rcu_data_list.next != call_rcu_data_list.prev) {
-		crdp = cds_list_entry(call_rcu_data_list.prev,
-				      struct call_rcu_data, list);
-		if (crdp == default_call_rcu_data)
-			crdp = cds_list_entry(crdp->list.prev,
-					      struct call_rcu_data, list);
-		crdp->flags = URCU_CALL_RCU_STOPPED;
-		call_rcu_data_free(crdp);
-	}
-}
diff --git a/urcu-qsbr.c b/urcu-qsbr.c
index 69effd5..8dcad33 100644
--- a/urcu-qsbr.c
+++ b/urcu-qsbr.c
@@ -32,6 +32,8 @@
 #include <errno.h>
 #include <poll.h>
 
+#include "urcu-qsbr-map.h"
+
 #define BUILD_QSBR_LIB
 #include "urcu-qsbr-static.h"
 /* Do not #define _LGPL_SOURCE to ensure we can emit the wrapper symbols */
@@ -121,10 +123,11 @@ static void update_counter_and_wait(void)
 #endif	/* !(CAA_BITS_PER_LONG < 64) */
 
 	/*
-	 * Must commit rcu_gp_ctr update to memory before waiting for quiescent
-	 * state. Failure to do so could result in the writer waiting forever
-	 * while new readers are always accessing data (no progress). Enforce
-	 * compiler-order of store to rcu_gp_ctr before load rcu_reader ctr.
+	 * Must commit rcu_gp_ctr update to memory before waiting for
+	 * quiescent state. Failure to do so could result in the writer
+	 * waiting forever while new readers are always accessing data
+	 * (no progress). Enforce compiler-order of store to rcu_gp_ctr
+	 * before load rcu_reader ctr.
 	 */
 	cmm_barrier();
 
@@ -194,8 +197,8 @@ void synchronize_rcu(void)
 
 	/*
 	 * Mark the writer thread offline to make sure we don't wait for
-	 * our own quiescent state. This allows using synchronize_rcu() in
-	 * threads registered as readers.
+	 * our own quiescent state. This allows using synchronize_rcu()
+	 * in threads registered as readers.
 	 */
 	if (was_online)
 		CMM_STORE_SHARED(rcu_reader.ctr, 0);
@@ -212,10 +215,11 @@ void synchronize_rcu(void)
 
 	/*
 	 * Must finish waiting for quiescent state for parity 0 before
-	 * committing next rcu_gp_ctr update to memory. Failure to do so could
-	 * result in the writer waiting forever while new readers are always
-	 * accessing data (no progress).  Enforce compiler-order of load
-	 * rcu_reader ctr before store to rcu_gp_ctr.
+	 * committing next rcu_gp_ctr update to memory. Failure to
+	 * do so could result in the writer waiting forever while new
+	 * readers are always accessing data (no progress).  Enforce
+	 * compiler-order of load rcu_reader ctr before store to
+	 * rcu_gp_ctr.
 	 */
 	cmm_barrier();
 
@@ -238,7 +242,8 @@ out:
 	 * freed.
 	 */
 	if (was_online)
-		_CMM_STORE_SHARED(rcu_reader.ctr, CMM_LOAD_SHARED(rcu_gp_ctr));
+		_CMM_STORE_SHARED(rcu_reader.ctr,
+				  CMM_LOAD_SHARED(rcu_gp_ctr));
 	cmm_smp_mb();
 }
 #else /* !(CAA_BITS_PER_LONG < 64) */
@@ -250,8 +255,8 @@ void synchronize_rcu(void)
 
 	/*
 	 * Mark the writer thread offline to make sure we don't wait for
-	 * our own quiescent state. This allows using synchronize_rcu() in
-	 * threads registered as readers.
+	 * our own quiescent state. This allows using synchronize_rcu()
+	 * in threads registered as readers.
 	 */
 	cmm_smp_mb();
 	if (was_online)
@@ -265,7 +270,8 @@ out:
 	mutex_unlock(&rcu_gp_lock);
 
 	if (was_online)
-		_CMM_STORE_SHARED(rcu_reader.ctr, CMM_LOAD_SHARED(rcu_gp_ctr));
+		_CMM_STORE_SHARED(rcu_reader.ctr,
+				  CMM_LOAD_SHARED(rcu_gp_ctr));
 	cmm_smp_mb();
 }
 #endif  /* !(CAA_BITS_PER_LONG < 64) */
@@ -326,3 +332,5 @@ void rcu_exit(void)
 {
 	assert(cds_list_empty(&registry));
 }
+
+#include "urcu-call-rcu-impl.h"
diff --git a/urcu-qsbr.h b/urcu-qsbr.h
index 116fd77..984d70c 100644
--- a/urcu-qsbr.h
+++ b/urcu-qsbr.h
@@ -40,6 +40,8 @@
 extern "C" {
 #endif 
 
+#include "urcu-qsbr-map.h"
+
 /*
  * Important !
  *
@@ -62,15 +64,15 @@ extern "C" {
  * rcu_read_unlock()
  *
  * Mark the beginning and end of a read-side critical section.
- * DON'T FORGET TO USE rcu_register_thread/rcu_unregister_thread() FOR EACH
- * THREAD WITH READ-SIDE CRITICAL SECTION.
+ * DON'T FORGET TO USE rcu_register_thread/rcu_unregister_thread()
+ * FOR EACH THREAD WITH READ-SIDE CRITICAL SECTION.
  */
-#define rcu_read_lock()		_rcu_read_lock()
-#define rcu_read_unlock()	_rcu_read_unlock()
+#define rcu_read_lock_qsbr()		_rcu_read_lock()
+#define rcu_read_unlock_qsbr()		_rcu_read_unlock()
 
-#define rcu_quiescent_state()	_rcu_quiescent_state()
-#define rcu_thread_offline()	_rcu_thread_offline()
-#define rcu_thread_online()	_rcu_thread_online()
+#define rcu_quiescent_state_qsbr()	_rcu_quiescent_state()
+#define rcu_thread_offline_qsbr()	_rcu_thread_offline()
+#define rcu_thread_online_qsbr()	_rcu_thread_online()
 
 #else /* !_LGPL_SOURCE */
 
@@ -122,4 +124,6 @@ extern void rcu_unregister_thread(void);
 }
 #endif
 
+#include "urcu-call-rcu.h"
+
 #endif /* _URCU_QSBR_H */
diff --git a/urcu.c b/urcu.c
index e529ac0..4ee9e3b 100644
--- a/urcu.c
+++ b/urcu.c
@@ -33,6 +33,8 @@
 #include <errno.h>
 #include <poll.h>
 
+#include "urcu-map.h"
+
 #include "urcu-static.h"
 /* Do not #define _LGPL_SOURCE to ensure we can emit the wrapper symbols */
 #include "urcu.h"
@@ -428,4 +430,7 @@ void rcu_exit(void)
 	assert(act.sa_sigaction == sigrcu_handler);
 	assert(cds_list_empty(&registry));
 }
+
 #endif /* #ifdef RCU_SIGNAL */
+
+#include "urcu-call-rcu-impl.h"
diff --git a/urcu.h b/urcu.h
index c6c54e7..00d9b75 100644
--- a/urcu.h
+++ b/urcu.h
@@ -43,12 +43,14 @@
 extern "C" {
 #endif 
 
+#include "urcu-map.h"
+
 /*
  * Important !
  *
  * Each thread containing read-side critical sections must be registered
- * with rcu_register_thread() before calling rcu_read_lock().
- * rcu_unregister_thread() should be called before the thread exits.
+ * with rcu_register_thread_mb() before calling rcu_read_lock_mb().
+ * rcu_unregister_thread_mb() should be called before the thread exits.
  */
 
 #ifdef _LGPL_SOURCE
@@ -68,8 +70,16 @@ extern "C" {
  * DON'T FORGET TO USE RCU_REGISTER/UNREGISTER_THREAD() FOR EACH THREAD WITH
  * READ-SIDE CRITICAL SECTION.
  */
-#define rcu_read_lock()		_rcu_read_lock()
-#define rcu_read_unlock()	_rcu_read_unlock()
+#ifdef RCU_MEMBARRIER
+#define rcu_read_lock_memb()		_rcu_read_lock()
+#define rcu_read_unlock_memb()		_rcu_read_unlock()
+#elif defined(RCU_SIGNAL)
+#define rcu_read_lock_sig()		_rcu_read_lock()
+#define rcu_read_unlock_sig()		_rcu_read_unlock()
+#elif defined(RCU_MB)
+#define rcu_read_lock_mb()		_rcu_read_lock()
+#define rcu_read_unlock_mb()		_rcu_read_unlock()
+#endif
 
 #else /* !_LGPL_SOURCE */
 
@@ -100,4 +110,6 @@ extern void rcu_init(void);
 }
 #endif
 
+#include "urcu-call-rcu.h"
+
 #endif /* _URCU_H */
-- 
1.7.3.2





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