Add a reference counter for threads using urcu-bp, thus ensuring that
even if the urcu destructor is executed before each thread using RCU
read-side critical sections exit, those threads will not see a corrupted
thread list.
Also, don't use URCU_TLS() within urcu_bp_thread_exit_notifier(). It
appears that this is racy (although this was probably due to the issue
fixed by reference counting). Anyway, play safe, and pass the rcu_key
received as parameter instead.
Those issues only reproduce when threads are still active when the
urcu-bp destructor is called.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
*/
#define RCU_QS_ACTIVE_ATTEMPTS 100
*/
#define RCU_QS_ACTIVE_ATTEMPTS 100
+static
+int rcu_bp_refcount;
+
static
void __attribute__((constructor)) rcu_bp_init(void);
static
static
void __attribute__((constructor)) rcu_bp_init(void);
static
/* Called with signals off and mutex locked */
static
/* Called with signals off and mutex locked */
static
-void remove_thread(void)
+void remove_thread(struct rcu_reader *rcu_reader_reg)
- struct rcu_reader *rcu_reader_reg;
-
- rcu_reader_reg = URCU_TLS(rcu_reader);
cleanup_thread(find_chunk(rcu_reader_reg), rcu_reader_reg);
URCU_TLS(rcu_reader) = NULL;
}
cleanup_thread(find_chunk(rcu_reader_reg), rcu_reader_reg);
URCU_TLS(rcu_reader) = NULL;
}
/* Disable signals, take mutex, remove from registry */
static
/* Disable signals, take mutex, remove from registry */
static
-void rcu_bp_unregister(void)
+void rcu_bp_unregister(struct rcu_reader *rcu_reader_reg)
{
sigset_t newmask, oldmask;
int ret;
{
sigset_t newmask, oldmask;
int ret;
abort();
mutex_lock(&rcu_gp_lock);
abort();
mutex_lock(&rcu_gp_lock);
+ remove_thread(rcu_reader_reg);
mutex_unlock(&rcu_gp_lock);
ret = pthread_sigmask(SIG_SETMASK, &oldmask, NULL);
if (ret)
abort();
mutex_unlock(&rcu_gp_lock);
ret = pthread_sigmask(SIG_SETMASK, &oldmask, NULL);
if (ret)
abort();
static
void urcu_bp_thread_exit_notifier(void *rcu_key)
{
static
void urcu_bp_thread_exit_notifier(void *rcu_key)
{
- assert(rcu_key == URCU_TLS(rcu_reader));
- rcu_bp_unregister();
+ rcu_bp_unregister(rcu_key);
}
static
void rcu_bp_init(void)
{
mutex_lock(&init_lock);
}
static
void rcu_bp_init(void)
{
mutex_lock(&init_lock);
+ if (!rcu_bp_refcount++) {
int ret;
ret = pthread_key_create(&urcu_bp_key,
int ret;
ret = pthread_key_create(&urcu_bp_key,
static
void rcu_bp_exit(void)
{
static
void rcu_bp_exit(void)
{
- struct registry_chunk *chunk, *tmp;
- int ret;
+ mutex_lock(&init_lock);
+ if (!--rcu_bp_refcount) {
+ struct registry_chunk *chunk, *tmp;
+ int ret;
- cds_list_for_each_entry_safe(chunk, tmp,
- ®istry_arena.chunk_list, node) {
- munmap(chunk, chunk->data_len + sizeof(struct registry_chunk));
+ cds_list_for_each_entry_safe(chunk, tmp,
+ ®istry_arena.chunk_list, node) {
+ munmap(chunk, chunk->data_len
+ + sizeof(struct registry_chunk));
+ }
+ ret = pthread_key_delete(urcu_bp_key);
+ if (ret)
+ abort();
- ret = pthread_key_delete(urcu_bp_key);
- if (ret)
- abort();
+ mutex_unlock(&init_lock);