lttng_ust_init_thread: call urcu_register_thread

[lttng-ust.git] / src / lib / lttng-ust / lttng-ust-comm.c

diff --git a/src/lib/lttng-ust/lttng-ust-comm.c b/src/lib/lttng-ust/lttng-ust-comm.c
index 10883e9675b6374f42bfa38d0b7529eb8cbc05e1..0fe2da466ad1cce241b0b82efd864e651223341e 100644 (file)
--- a/src/lib/lttng-ust/lttng-ust-comm.c
+++ b/src/lib/lttng-ust/lttng-ust-comm.c
@@ -387,7 +387,7 @@ const char *get_lttng_home_dir(void)
  * Force a read (imply TLS allocation for dlopen) of TLS variables.
  */
 static
-void lttng_nest_count_alloc_tls(void)
+void lttng_ust_nest_count_alloc_tls(void)
 {
        asm volatile ("" : : "m" (URCU_TLS(lttng_ust_nest_count)));
 }
@@ -402,26 +402,26 @@ void lttng_ust_mutex_nest_alloc_tls(void)
  * Allocate lttng-ust urcu TLS.
  */
 static
-void lttng_lttng_ust_urcu_alloc_tls(void)
+void lttng_ust_urcu_alloc_tls(void)
 {
        (void) lttng_ust_urcu_read_ongoing();
 }
 
-void lttng_ust_alloc_tls(void)
+void lttng_ust_common_init_thread(int flags)
 {
-       lttng_lttng_ust_urcu_alloc_tls();
+       lttng_ust_urcu_alloc_tls();
        lttng_ringbuffer_alloc_tls();
-       lttng_vtid_alloc_tls();
-       lttng_nest_count_alloc_tls();
-       lttng_procname_alloc_tls();
+       lttng_ust_vtid_init_thread(flags);
+       lttng_ust_nest_count_alloc_tls();
+       lttng_ust_procname_init_thread(flags);
        lttng_ust_mutex_nest_alloc_tls();
-       lttng_ust_perf_counter_alloc_tls();
+       lttng_ust_perf_counter_init_thread(flags);
        lttng_ust_common_alloc_tls();
-       lttng_cgroup_ns_alloc_tls();
-       lttng_ipc_ns_alloc_tls();
-       lttng_net_ns_alloc_tls();
-       lttng_time_ns_alloc_tls();
-       lttng_uts_ns_alloc_tls();
+       lttng_ust_cgroup_ns_init_thread(flags);
+       lttng_ust_ipc_ns_init_thread(flags);
+       lttng_ust_net_ns_init_thread(flags);
+       lttng_ust_time_ns_init_thread(flags);
+       lttng_ust_uts_ns_init_thread(flags);
        lttng_ust_ring_buffer_client_discard_alloc_tls();
        lttng_ust_ring_buffer_client_discard_rt_alloc_tls();
        lttng_ust_ring_buffer_client_overwrite_alloc_tls();
@@ -446,7 +446,9 @@ void lttng_ust_init_thread(void)
         * ensure those are initialized before a signal handler nesting over
         * this thread attempts to use them.
         */
-       lttng_ust_alloc_tls();
+       lttng_ust_common_init_thread(LTTNG_UST_INIT_THREAD_MASK);
+
+       lttng_ust_urcu_register_thread();
 }
 
 int lttng_get_notify_socket(void *owner)
@@ -1757,18 +1759,25 @@ void wait_for_sessiond(struct sock_info *sock_info)
 
        DBG("Waiting for %s apps sessiond", sock_info->name);
        /* Wait for futex wakeup */
-       if (uatomic_read((int32_t *) sock_info->wait_shm_mmap))
-               goto end_wait;
-
-       while (lttng_ust_futex_async((int32_t *) sock_info->wait_shm_mmap,
-                       FUTEX_WAIT, 0, NULL, NULL, 0)) {
+       while (!uatomic_read((int32_t *) sock_info->wait_shm_mmap)) {
+               if (!lttng_ust_futex_async((int32_t *) sock_info->wait_shm_mmap, FUTEX_WAIT, 0, NULL, NULL, 0)) {
+                       /*
+                        * Prior queued wakeups queued by unrelated code
+                        * using the same address can cause futex wait to
+                        * return 0 even through the futex value is still
+                        * 0 (spurious wakeups). Check the value again
+                        * in user-space to validate whether it really
+                        * differs from 0.
+                        */
+                       continue;
+               }
                switch (errno) {
-               case EWOULDBLOCK:
+               case EAGAIN:
                        /* Value already changed. */
                        goto end_wait;
                case EINTR:
                        /* Retry if interrupted by signal. */
-                       break;  /* Get out of switch. */
+                       break;  /* Get out of switch. Check again. */
                case EFAULT:
                        wait_poll_fallback = 1;
                        DBG(
@@ -1808,7 +1817,7 @@ void *ust_listener_thread(void *arg)
        int sock, ret, prev_connect_failed = 0, has_waited = 0, fd;
        long timeout;
 
-       lttng_ust_alloc_tls();
+       lttng_ust_common_init_thread(0);
        /*
         * If available, add '-ust' to the end of this thread's
         * process name
@@ -2176,7 +2185,7 @@ void lttng_ust_ctor(void)
         * to be the dynamic linker mutex) and ust_lock, taken within
         * the ust lock.
         */
-       lttng_ust_alloc_tls();
+       lttng_ust_common_init_thread(0);
 
        lttng_ust_loaded = 1;
 
@@ -2490,7 +2499,7 @@ void lttng_ust_before_fork(sigset_t *save_sigset)
        int ret;
 
        /* Allocate lttng-ust TLS. */
-       lttng_ust_alloc_tls();
+       lttng_ust_common_init_thread(0);
 
        if (URCU_TLS(lttng_ust_nest_count))
                return;