*/
#define _BSD_SOURCE
+#define _GNU_SOURCE
+#define _LGPL_SOURCE
#include <stdio.h>
#include <pthread.h>
#include <signal.h>
#include <assert.h>
#include <stdlib.h>
+#include <stdint.h>
#include <string.h>
#include <errno.h>
#include <poll.h>
-#include "urcu-static.h"
+#include "urcu/wfcqueue.h"
+#include "urcu/map/urcu.h"
+#include "urcu/static/urcu.h"
+#include "urcu-pointer.h"
+#include "urcu/tls-compat.h"
+
+#include "urcu-die.h"
+
/* Do not #define _LGPL_SOURCE to ensure we can emit the wrapper symbols */
+#undef _LGPL_SOURCE
#include "urcu.h"
+#define _LGPL_SOURCE
+
+/*
+ * If a reader is really non-cooperative and refuses to commit its
+ * rcu_active_readers count to memory (there is no barrier in the reader
+ * per-se), kick it after a few loops waiting for it.
+ */
+#define KICK_READER_LOOPS 10000
+
+/*
+ * Active attempts to check for reader Q.S. before calling futex().
+ */
+#define RCU_QS_ACTIVE_ATTEMPTS 100
#ifdef RCU_MEMBARRIER
static int init_done;
-int has_sys_membarrier;
+int rcu_has_sys_membarrier;
void __attribute__((constructor)) rcu_init(void);
#endif
static pthread_mutex_t rcu_gp_lock = PTHREAD_MUTEX_INITIALIZER;
-int gp_futex;
+int32_t rcu_gp_futex;
/*
* Global grace period counter.
* Written to only by each individual reader. Read by both the reader and the
* writers.
*/
-struct rcu_reader __thread rcu_reader;
+DEFINE_URCU_TLS(struct rcu_reader, rcu_reader);
#ifdef DEBUG_YIELD
-unsigned int yield_active;
-unsigned int __thread rand_yield;
+unsigned int rcu_yield_active;
+DEFINE_URCU_TLS(unsigned int, rcu_rand_yield);
#endif
-static LIST_HEAD(registry);
+static CDS_LIST_HEAD(registry);
static void mutex_lock(pthread_mutex_t *mutex)
{
#ifndef DISTRUST_SIGNALS_EXTREME
ret = pthread_mutex_lock(mutex);
- if (ret) {
- perror("Error in pthread mutex lock");
- exit(-1);
- }
+ if (ret)
+ urcu_die(ret);
#else /* #ifndef DISTRUST_SIGNALS_EXTREME */
while ((ret = pthread_mutex_trylock(mutex)) != 0) {
- if (ret != EBUSY && ret != EINTR) {
- printf("ret = %d, errno = %d\n", ret, errno);
- perror("Error in pthread mutex lock");
- exit(-1);
- }
- if (CAA_LOAD_SHARED(rcu_reader.need_mb)) {
+ if (ret != EBUSY && ret != EINTR)
+ urcu_die(ret);
+ if (CMM_LOAD_SHARED(URCU_TLS(rcu_reader).need_mb)) {
cmm_smp_mb();
- _CAA_STORE_SHARED(rcu_reader.need_mb, 0);
+ _CMM_STORE_SHARED(URCU_TLS(rcu_reader).need_mb, 0);
cmm_smp_mb();
}
poll(NULL,0,10);
int ret;
ret = pthread_mutex_unlock(mutex);
- if (ret) {
- perror("Error in pthread mutex unlock");
- exit(-1);
- }
+ if (ret)
+ urcu_die(ret);
}
#ifdef RCU_MEMBARRIER
static void smp_mb_master(int group)
{
- if (likely(has_sys_membarrier))
+ if (caa_likely(rcu_has_sys_membarrier))
membarrier(MEMBARRIER_EXPEDITED);
else
cmm_smp_mb();
* Ask for each threads to execute a cmm_smp_mb() so we can consider the
* compiler barriers around rcu read lock as real memory barriers.
*/
- if (list_empty(®istry))
+ if (cds_list_empty(®istry))
return;
/*
* pthread_kill has a cmm_smp_mb(). But beware, we assume it performs
* safe and don't assume anything : we use cmm_smp_mc() to make sure the
* cache flush is enforced.
*/
- list_for_each_entry(index, ®istry, node) {
- CAA_STORE_SHARED(index->need_mb, 1);
+ cds_list_for_each_entry(index, ®istry, node) {
+ CMM_STORE_SHARED(index->need_mb, 1);
pthread_kill(index->tid, SIGRCU);
}
/*
* relevant bug report. For Linux kernels, we recommend getting
* the Linux Test Project (LTP).
*/
- list_for_each_entry(index, ®istry, node) {
- while (CAA_LOAD_SHARED(index->need_mb)) {
+ cds_list_for_each_entry(index, ®istry, node) {
+ while (CMM_LOAD_SHARED(index->need_mb)) {
pthread_kill(index->tid, SIGRCU);
poll(NULL, 0, 1);
}
{
/* Read reader_gp before read futex */
smp_mb_master(RCU_MB_GROUP);
- if (uatomic_read(&gp_futex) == -1)
- futex_async(&gp_futex, FUTEX_WAIT, -1,
+ if (uatomic_read(&rcu_gp_futex) == -1)
+ futex_async(&rcu_gp_futex, FUTEX_WAIT, -1,
NULL, NULL, 0);
}
-void update_counter_and_wait(void)
+static void wait_for_readers(void)
{
- LIST_HEAD(qsreaders);
+ CDS_LIST_HEAD(qsreaders);
int wait_loops = 0;
struct rcu_reader *index, *tmp;
- /* Switch parity: 0 -> 1, 1 -> 0 */
- CAA_STORE_SHARED(rcu_gp_ctr, rcu_gp_ctr ^ RCU_GP_CTR_PHASE);
-
- /*
- * 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();
-
- /*
- *
- * Adding a cmm_smp_mb() which is _not_ formally required, but makes the
- * model easier to understand. It does not have a big performance impact
- * anyway, given this is the write-side.
- */
- cmm_smp_mb();
-
/*
- * Wait for each thread rcu_reader.ctr count to become 0.
+ * Wait for each thread URCU_TLS(rcu_reader).ctr to either
+ * indicate quiescence (not nested), or observe the current
+ * rcu_gp_ctr value.
*/
for (;;) {
wait_loops++;
if (wait_loops == RCU_QS_ACTIVE_ATTEMPTS) {
- uatomic_dec(&gp_futex);
+ uatomic_dec(&rcu_gp_futex);
/* Write futex before read reader_gp */
smp_mb_master(RCU_MB_GROUP);
}
- list_for_each_entry_safe(index, tmp, ®istry, node) {
+ cds_list_for_each_entry_safe(index, tmp, ®istry, node) {
if (!rcu_gp_ongoing(&index->ctr))
- list_move(&index->node, &qsreaders);
+ cds_list_move(&index->node, &qsreaders);
}
#ifndef HAS_INCOHERENT_CACHES
- if (list_empty(®istry)) {
+ if (cds_list_empty(®istry)) {
if (wait_loops == RCU_QS_ACTIVE_ATTEMPTS) {
/* Read reader_gp before write futex */
smp_mb_master(RCU_MB_GROUP);
- uatomic_set(&gp_futex, 0);
+ uatomic_set(&rcu_gp_futex, 0);
}
break;
} else {
#else /* #ifndef HAS_INCOHERENT_CACHES */
/*
* BUSY-LOOP. Force the reader thread to commit its
- * rcu_reader.ctr update to memory if we wait for too long.
+ * URCU_TLS(rcu_reader).ctr update to memory if we wait
+ * for too long.
*/
- if (list_empty(®istry)) {
+ if (cds_list_empty(®istry)) {
if (wait_loops == RCU_QS_ACTIVE_ATTEMPTS) {
/* Read reader_gp before write futex */
smp_mb_master(RCU_MB_GROUP);
- uatomic_set(&gp_futex, 0);
+ uatomic_set(&rcu_gp_futex, 0);
}
break;
} else {
#endif /* #else #ifndef HAS_INCOHERENT_CACHES */
}
/* put back the reader list in the registry */
- list_splice(&qsreaders, ®istry);
+ cds_list_splice(&qsreaders, ®istry);
}
void synchronize_rcu(void)
{
mutex_lock(&rcu_gp_lock);
- if (list_empty(®istry))
+ if (cds_list_empty(®istry))
goto out;
/* All threads should read qparity before accessing data structure
smp_mb_master(RCU_MB_GROUP);
/*
- * Wait for previous parity to be empty of readers.
+ * Wait for readers to observe original parity or be quiescent.
*/
- update_counter_and_wait(); /* 0 -> 1, wait readers in parity 0 */
+ wait_for_readers();
/*
- * Must finish waiting for quiescent state for parity 0 before
+ * Must finish waiting for quiescent state for original parity 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.
+ * URCU_TLS(rcu_reader).ctr before store to rcu_gp_ctr.
+ */
+ cmm_barrier();
+
+ /*
+ * Adding a cmm_smp_mb() which is _not_ formally required, but makes the
+ * model easier to understand. It does not have a big performance impact
+ * anyway, given this is the write-side.
+ */
+ cmm_smp_mb();
+
+ /* Switch parity: 0 -> 1, 1 -> 0 */
+ CMM_STORE_SHARED(rcu_gp_ctr, rcu_gp_ctr ^ RCU_GP_CTR_PHASE);
+
+ /*
+ * 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();
/*
+ *
* Adding a cmm_smp_mb() which is _not_ formally required, but makes the
* model easier to understand. It does not have a big performance impact
* anyway, given this is the write-side.
cmm_smp_mb();
/*
- * Wait for previous parity to be empty of readers.
+ * Wait for readers to observe new parity or be quiescent.
*/
- update_counter_and_wait(); /* 1 -> 0, wait readers in parity 1 */
+ wait_for_readers();
/* Finish waiting for reader threads before letting the old ptr being
* freed. Must be done within rcu_gp_lock because it iterates on reader
void rcu_register_thread(void)
{
- rcu_reader.tid = pthread_self();
- assert(rcu_reader.need_mb == 0);
- assert(!(rcu_reader.ctr & RCU_GP_CTR_NEST_MASK));
+ URCU_TLS(rcu_reader).tid = pthread_self();
+ assert(URCU_TLS(rcu_reader).need_mb == 0);
+ assert(!(URCU_TLS(rcu_reader).ctr & RCU_GP_CTR_NEST_MASK));
mutex_lock(&rcu_gp_lock);
rcu_init(); /* In case gcc does not support constructor attribute */
- list_add(&rcu_reader.node, ®istry);
+ cds_list_add(&URCU_TLS(rcu_reader).node, ®istry);
mutex_unlock(&rcu_gp_lock);
}
void rcu_unregister_thread(void)
{
mutex_lock(&rcu_gp_lock);
- list_del(&rcu_reader.node);
+ cds_list_del(&URCU_TLS(rcu_reader).node);
mutex_unlock(&rcu_gp_lock);
}
return;
init_done = 1;
if (!membarrier(MEMBARRIER_EXPEDITED | MEMBARRIER_QUERY))
- has_sys_membarrier = 1;
+ rcu_has_sys_membarrier = 1;
}
#endif
* executed on.
*/
cmm_smp_mb();
- _CAA_STORE_SHARED(rcu_reader.need_mb, 0);
+ _CMM_STORE_SHARED(URCU_TLS(rcu_reader).need_mb, 0);
cmm_smp_mb();
}
act.sa_flags = SA_SIGINFO | SA_RESTART;
sigemptyset(&act.sa_mask);
ret = sigaction(SIGRCU, &act, NULL);
- if (ret) {
- perror("Error in sigaction");
- exit(-1);
- }
+ if (ret)
+ urcu_die(errno);
}
void rcu_exit(void)
int ret;
ret = sigaction(SIGRCU, NULL, &act);
- if (ret) {
- perror("Error in sigaction");
- exit(-1);
- }
+ if (ret)
+ urcu_die(errno);
assert(act.sa_sigaction == sigrcu_handler);
- assert(list_empty(®istry));
+ assert(cds_list_empty(®istry));
}
+
#endif /* #ifdef RCU_SIGNAL */
+
+DEFINE_RCU_FLAVOR(rcu_flavor);
+
+#include "urcu-call-rcu-impl.h"
+#include "urcu-defer-impl.h"
projects / urcu.git / blobdiff