Fix initial semaphore+timeout

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

diff --git a/libust/lttng-ust-comm.c b/libust/lttng-ust-comm.c
index 1496408f12356d382567f13fe25ea527fb178a72..657b5686765b9ce6e8f66cc3ae187620405cf6de 100644 (file)
--- a/libust/lttng-ust-comm.c
+++ b/libust/lttng-ust-comm.c
@@ -30,6 +30,7 @@
 #include <semaphore.h>
 #include <time.h>
 #include <assert.h>
+#include <urcu/uatomic.h>
 
 /*
  * communication thread mutex. Held when handling a command, also held
@@ -51,6 +52,7 @@ static int lttng_ust_comm_should_quit;
  *   daemon problems).
  */
 static sem_t constructor_wait;
+static int sem_count = { 2 };
 
 /*
  * Info about socket and associated listener thread.
@@ -141,8 +143,11 @@ int handle_register_done(void)
 {
        int ret;
 
-       ret = sem_post(&constructor_wait);
-       assert(!ret);
+       ret = uatomic_add_return(&sem_count, -1);
+       if (ret == 0) {
+               ret = sem_post(&constructor_wait);
+               assert(!ret);
+       }
        return 0;
 }
 
@@ -369,9 +374,9 @@ int get_timeout(struct timespec *constructor_timeout)
        if (ret) {
                return -1;
        }
-
-       constructor_timeout->tv_nsec =
-               constructor_timeout->tv_nsec + (constructor_delay_ms * 1000000UL);
+       constructor_timeout->tv_sec += constructor_delay_ms / 1000UL;
+       constructor_timeout->tv_nsec +=
+               (constructor_delay_ms % 1000UL) * 1000000UL;
        if (constructor_timeout->tv_nsec >= 1000000000UL) {
                constructor_timeout->tv_sec++;
                constructor_timeout->tv_nsec -= 1000000000UL;
@@ -395,7 +400,7 @@ void __attribute__((constructor)) lttng_ust_comm_init(void)
 
        timeout_mode = get_timeout(&constructor_timeout);
 
-       ret = sem_init(&constructor_wait, 0, 2);
+       ret = sem_init(&constructor_wait, 0, 0);
        assert(!ret);
 
        ret = setup_local_apps_socket();
@@ -403,13 +408,6 @@ void __attribute__((constructor)) lttng_ust_comm_init(void)
                ERR("Error setting up to local apps socket");
        }
 
-       /*
-        * Wait for the pthread cond to let us continue to main program
-        * execution. Hold mutex across thread creation, so we start
-        * waiting for the condition before the threads can signal its
-        * completion.
-        */
-       pthread_mutex_lock(&lttng_ust_comm_mutex);
        ret = pthread_create(&global_apps.ust_listener, NULL,
                        ust_listener_thread, &global_apps);
        ret = pthread_create(&local_apps.ust_listener, NULL,
@@ -417,7 +415,10 @@ void __attribute__((constructor)) lttng_ust_comm_init(void)
 
        switch (timeout_mode) {
        case 1: /* timeout wait */
-               ret = sem_timedwait(&constructor_wait, &constructor_timeout);
+               do {
+                       ret = sem_timedwait(&constructor_wait,
+                                       &constructor_timeout);
+               } while (ret < 0 && errno == EINTR);
                if (ret < 0 && errno == ETIMEDOUT) {
                        ERR("Timed out waiting for ltt-sessiond");
                } else {
@@ -425,13 +426,14 @@ void __attribute__((constructor)) lttng_ust_comm_init(void)
                }
                break;
        case -1:/* wait forever */
-               ret = sem_wait(&constructor_wait);
+               do {
+                       ret = sem_wait(&constructor_wait);
+               } while (ret < 0 && errno == EINTR);
                assert(!ret);
                break;
        case 0: /* no timeout */
                break;
        }
-       pthread_mutex_unlock(&lttng_ust_comm_mutex);
 }
 
 void __attribute__((destructor)) lttng_ust_comm_exit(void)