- ret = -1;
-
-end:
- return ret;
-}
-
-/*
- * spawn_sessiond
- *
- * Spawn a session daemon by forking and execv.
- */
-static int spawn_sessiond(char *pathname)
-{
- int ret = 0;
- pid_t pid;
-
- MSG("Spawning a session daemon");
- recv_child_signal = 0;
- pid = fork();
- if (pid == 0) {
- /*
- * Spawn session daemon and tell
- * it to signal us when ready.
- */
- execlp(pathname, "lttng-sessiond", "--sig-parent", "--quiet", NULL);
- /* execlp only returns if error happened */
- if (errno == ENOENT) {
- ERR("No session daemon found. Use --sessiond-path.");
- } else {
- perror("execlp");
- }
- kill(getppid(), SIGTERM); /* wake parent */
- exit(EXIT_FAILURE);
- } else if (pid > 0) {
- sessiond_pid = pid;
- /*
- * Wait for lttng-sessiond to start. We need to use a flag to check if
- * the signal has been sent to us, because the child can be scheduled
- * before the parent, and thus send the signal before this check. In
- * the signal handler, we set the recv_child_signal flag, so anytime we
- * check it after the fork is fine. Note that sleep() is interrupted
- * before the 1 second delay as soon as the signal is received, so it
- * will not cause visible delay for the user.
- */
- while (!recv_child_signal) {
- sleep(1);
- }
- /*
- * The signal handler will nullify sessiond_pid on SIGCHLD
- */
- if (!sessiond_pid) {
- exit(EXIT_FAILURE);
- }
- goto end;
- } else {
- perror("fork");
- ret = -1;
- goto end;
- }
-
-end:
- return ret;
-}