-/*
- * 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;
-}
-
-/*
- * check_sessiond
- *
- * Check if the session daemon is available using
- * the liblttngctl API for the check. If not, try to
- * spawn a daemon.
- */
-static int check_sessiond(void)
-{
- int ret;
- char *pathname = NULL;
-
- ret = lttng_session_daemon_alive();
- if (ret == 0) { /* not alive */
- /* Try command line option path */
- pathname = opt_sessiond_path;
-
- /* Try LTTNG_SESSIOND_PATH env variable */
- if (pathname == NULL) {
- pathname = getenv(DEFAULT_SESSIOND_PATH_ENV);
- }
-
- /* Try with configured path */
- if (pathname == NULL) {
- if (CONFIG_SESSIOND_BIN[0] != '\0') {
- pathname = CONFIG_SESSIOND_BIN;
- }
- }
-
- /* Let's rock and roll while trying the default path */
- if (pathname == NULL) {
- pathname = INSTALL_BIN_PATH "/lttng-sessiond";
- }
-
- DBG("Session daemon at: %s", pathname);
-
- /* Check existence and permissions */
- ret = access(pathname, F_OK | X_OK);
- if (ret < 0) {
- ERR("No such file or access denied: %s", pathname);
- goto end;
- }
-
- ret = spawn_sessiond(pathname);
- if (ret < 0) {
- ERR("Problem occurred when starting %s", pathname);
- }
- }
-end:
- return ret;
-}
-
-/*
- * Check args for specific options that *must* not trigger a session daemon
- * execution.
- *
- * Return 1 if match else 0.
- */
-static int check_args_no_sessiond(int argc, char **argv)
-{
- int i;
-
- for (i = 0; i < argc; i++) {
- if ((strncmp(argv[i], "-h", sizeof("-h")) == 0) ||
- strncmp(argv[i], "--h", sizeof("--h")) == 0 ||
- strncmp(argv[i], "--list-options", sizeof("--list-options")) == 0 ||
- strncmp(argv[i], "--list-commands", sizeof("--list-commands")) == 0 ||
- strncmp(argv[i], "version", sizeof("version")) == 0 ||
- strncmp(argv[i], "view", sizeof("view")) == 0) {
- return 1;
- }
- }
-
- return 0;
-}
-