#include <sys/types.h>
#include <time.h>
#include <unistd.h>
+#include <signal.h>
#include <common/mi-lttng.h>
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;
+}
+
+/*
+ * launch_sessiond
+ *
+ * Check if the session daemon is available using
+ * the liblttngctl API for the check. If not, try to
+ * spawn a daemon.
+ */
+static int launch_sessiond(void)
+{
+ int ret;
+ char *pathname = NULL;
+
+ ret = lttng_session_daemon_alive();
+ if (ret) {
+ /* Sessiond is alive, not an error */
+ ret = 0;
+ goto end;
+ }
+
+ /* 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;
+ }
+ }
+
+ /* Try the default path */
+ if (pathname == NULL) {
+ pathname = INSTALL_BIN_PATH "/lttng-sessiond";
+ }
+
+ DBG("Session daemon binary path: %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;
+}
+
/*
* The 'create <options>' first level command
*
goto end;
}
+ /* Spawn a session daemon if needed */
+ if (!opt_no_sessiond) {
+ ret = launch_sessiond();
+ if (ret) {
+ ret = CMD_ERROR;
+ goto end;
+ }
+ }
+
/* MI initialization */
if (lttng_opt_mi) {
writer = mi_lttng_writer_create(fileno(stdout), lttng_opt_mi);
/* Variables */
static char *progname;
-static int opt_no_sessiond;
-static char *opt_sessiond_path;
-static pid_t sessiond_pid;
-static volatile int recv_child_signal;
+int opt_no_sessiond;
+char *opt_sessiond_path;
+pid_t sessiond_pid;
+volatile int recv_child_signal;
char *opt_relayd_path;
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;
-}
-
-/*
- * 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;
-}
-
/*
* Parse command line arguments.
*
lttng_opt_verbose = 0;
}
- /* Spawn session daemon if needed */
- if (opt_no_sessiond == 0 && check_args_no_sessiond(argc, argv) == 0 &&
- (check_sessiond() < 0)) {
- ret = 1;
- goto error;
- }
-
/* No leftovers, print usage and quit */
if ((argc - optind) == 0) {
usage(stderr);
}
/* Thanks Mathieu */
- /*
+ /*
* Handle leftovers which is a first level command with the trailing
* options.
*/
projects / lttng-tools.git / commitdiff
