# define membarrier(...) -ENOSYS
#endif
-#define MEMBARRIER_EXPEDITED (1 << 0)
-#define MEMBARRIER_DELAYED (1 << 1)
-#define MEMBARRIER_QUERY (1 << 16)
+enum membarrier_cmd {
+ MEMBARRIER_CMD_QUERY = 0,
+ MEMBARRIER_CMD_SHARED = (1 << 0),
+};
#ifdef RCU_MEMBARRIER
static int init_done;
_CMM_STORE_SHARED(URCU_TLS(rcu_reader).need_mb, 0);
cmm_smp_mb();
}
- poll(NULL,0,10);
+ (void) poll(NULL, 0, 10);
}
#endif /* #else #ifndef DISTRUST_SIGNALS_EXTREME */
}
static void smp_mb_master(int group)
{
if (caa_likely(rcu_has_sys_membarrier))
- (void) membarrier(MEMBARRIER_EXPEDITED);
+ (void) membarrier(MEMBARRIER_CMD_SHARED, 0);
else
cmm_smp_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);
+ (void) poll(NULL, 0, 1);
}
}
cmm_smp_mb(); /* read ->need_mb before ending the barrier */
{
/* Read reader_gp before read futex */
smp_mb_master(RCU_MB_GROUP);
- if (uatomic_read(&rcu_gp.futex) == -1)
- futex_async(&rcu_gp.futex, FUTEX_WAIT, -1,
- NULL, NULL, 0);
+ if (uatomic_read(&rcu_gp.futex) != -1)
+ return;
+ while (futex_async(&rcu_gp.futex, FUTEX_WAIT, -1,
+ NULL, NULL, 0)) {
+ switch (errno) {
+ case EWOULDBLOCK:
+ /* Value already changed. */
+ return;
+ case EINTR:
+ /* Retry if interrupted by signal. */
+ break; /* Get out of switch. */
+ default:
+ /* Unexpected error. */
+ urcu_die(errno);
+ }
+ }
}
/*
assert(!(URCU_TLS(rcu_reader).ctr & RCU_GP_CTR_NEST_MASK));
mutex_lock(&rcu_registry_lock);
+ assert(!URCU_TLS(rcu_reader).registered);
+ URCU_TLS(rcu_reader).registered = 1;
rcu_init(); /* In case gcc does not support constructor attribute */
cds_list_add(&URCU_TLS(rcu_reader).node, ®istry);
mutex_unlock(&rcu_registry_lock);
void rcu_unregister_thread(void)
{
mutex_lock(&rcu_registry_lock);
+ assert(URCU_TLS(rcu_reader).registered);
+ URCU_TLS(rcu_reader).registered = 0;
cds_list_del(&URCU_TLS(rcu_reader).node);
mutex_unlock(&rcu_registry_lock);
}
#ifdef RCU_MEMBARRIER
void rcu_init(void)
{
+ int ret;
+
if (init_done)
return;
init_done = 1;
- if (!membarrier(MEMBARRIER_EXPEDITED | MEMBARRIER_QUERY))
+ ret = membarrier(MEMBARRIER_CMD_QUERY, 0);
+ if (ret >= 0 && (ret & MEMBARRIER_CMD_SHARED)) {
rcu_has_sys_membarrier = 1;
+ }
}
#endif