#include <stdio.h>
#include <stdlib.h>
#include <string.h>
+#include <sys/types.h>
+#include <sys/wait.h>
#include <unistd.h>
#include <config.h>
#include <lttng/lttng.h>
-#include <common/lttngerr.h>
+#include <common/error.h>
#include "command.h"
int opt_verbose;
static int opt_no_sessiond;
static char *opt_sessiond_path;
+static pid_t sessiond_pid;
+static volatile int recv_child_signal;
enum {
OPT_SESSION_PATH,
static void usage(FILE *ofp)
{
fprintf(ofp, "LTTng Trace Control " VERSION"\n\n");
- fprintf(ofp, "usage: lttng [options] <command>\n");
+ fprintf(ofp, "usage: lttng [OPTIONS] <COMMAND>\n");
fprintf(ofp, "\n");
fprintf(ofp, "Options:\n");
fprintf(ofp, " -h, --help Show this help\n");
- fprintf(ofp, " -g, --group NAME Unix tracing group name. (default: tracing)\n");
- fprintf(ofp, " -v, --verbose Verbose mode\n");
+ fprintf(ofp, " --list-options Simple listing of lttng options\n");
+ fprintf(ofp, " --list-commands Simple listing of lttng commands\n");
+ fprintf(ofp, " -v, --verbose Increase verbosity\n");
fprintf(ofp, " -q, --quiet Quiet mode\n");
+ fprintf(ofp, " -g, --group NAME Unix tracing group name. (default: tracing)\n");
fprintf(ofp, " -n, --no-sessiond Don't spawn a session daemon\n");
fprintf(ofp, " --sessiond-path Session daemon full path\n");
- fprintf(ofp, " --list-options Simple listing of lttng options\n");
- fprintf(ofp, " --list-commands Simple listing of lttng commands\n");
fprintf(ofp, "\n");
fprintf(ofp, "Commands:\n");
- fprintf(ofp, " add-context Add context to event or/and channel\n");
+ fprintf(ofp, " add-context Add context to event and/or channel\n");
fprintf(ofp, " calibrate Quantify LTTng overhead\n");
fprintf(ofp, " create Create tracing session\n");
- fprintf(ofp, " destroy Teardown tracing session\n");
+ fprintf(ofp, " destroy Tear down tracing session\n");
fprintf(ofp, " enable-channel Enable tracing channel\n");
fprintf(ofp, " enable-event Enable tracing event\n");
fprintf(ofp, " disable-channel Disable tracing channel\n");
*/
static void sighandler(int sig)
{
+ int status;
+
switch (sig) {
case SIGTERM:
- DBG("SIGTERM catched");
+ DBG("SIGTERM caugth");
clean_exit(EXIT_FAILURE);
break;
case SIGCHLD:
+ DBG("SIGCHLD caugth");
+ waitpid(sessiond_pid, &status, 0);
+ recv_child_signal = 1;
+ /* Indicate that the session daemon died */
+ sessiond_pid = 0;
+ ERR("Session daemon died (exit status %d)", WEXITSTATUS(status));
+ break;
+ case SIGUSR1:
/* Notify is done */
- DBG("SIGCHLD catched");
+ recv_child_signal = 1;
+ DBG("SIGUSR1 caugth");
break;
default:
- DBG("Unknown signal %d catched", sig);
+ DBG("Unknown signal %d caugth", sig);
break;
}
sa.sa_handler = sighandler;
sa.sa_mask = sigset;
sa.sa_flags = 0;
- if ((ret = sigaction(SIGCHLD, &sa, NULL)) < 0) {
+ if ((ret = sigaction(SIGUSR1, &sa, NULL)) < 0) {
perror("sigaction");
goto end;
}
goto end;
}
+ if ((ret = sigaction(SIGCHLD, &sa, NULL)) < 0) {
+ perror("sigaction");
+ goto end;
+ }
+
end:
return ret;
}
case CMD_ERROR:
ERR("Command error");
break;
- case CMD_NOT_IMPLEMENTED:
- ERR("Options not implemented");
- break;
case CMD_UNDEFINED:
ERR("Undefined command");
break;
pid_t pid;
MSG("Spawning a session daemon");
+ recv_child_signal = 0;
pid = fork();
if (pid == 0) {
/*
} else {
perror("execlp");
}
- kill(getppid(), SIGTERM); /* unpause parent */
+ kill(getppid(), SIGTERM); /* wake parent */
exit(EXIT_FAILURE);
} else if (pid > 0) {
- /* Wait for lttng-sessiond to start */
- pause();
+ 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);
+ }
+ if (!sessiond_pid) {
+ exit(EXIT_FAILURE);
+ }
goto end;
} else {
perror("fork");
pathname = opt_sessiond_path;
} else {
/* Try LTTNG_SESSIOND_PATH env variable */
- pathname = getenv(LTTNG_SESSIOND_PATH_ENV);
+ pathname = getenv(DEFAULT_SESSIOND_PATH_ENV);
}
/* Let's rock and roll */
}
/*
- * Check for the "help" option in the argv. If found, return 1 else return 0.
+ * Check args for specific options that *must* not trigger a session daemon
+ * execution.
+ *
+ * Return 1 if match else 0.
*/
-static int check_help_command(int argc, char **argv)
+static int check_args_no_sessiond(int argc, char **argv)
{
int i;
for (i = 0; i < argc; i++) {
- if ((strncmp(argv[i], "-h", 2) == 0) ||
- strncmp(argv[i], "--h", 3) == 0) {
+ if ((strncmp(argv[i], "-h", sizeof("-h")) == 0) ||
+ strncmp(argv[i], "--h", sizeof("--h")) == 0 ||
+ strncmp(argv[i], "--list-options", sizeof("--list-options")) == 0) {
return 1;
}
}
}
/* Spawn session daemon if needed */
- if (opt_no_sessiond == 0 && check_help_command(argc, argv) == 0 &&
+ if (opt_no_sessiond == 0 && check_args_no_sessiond(argc, argv) == 0 &&
(check_sessiond() < 0)) {
goto error;
}
progname = argv[0] ? argv[0] : "lttng";
/* For Mathieu Desnoyers aka Dr Tracing */
- if (strncmp(progname, "drtrace", 7) == 0) {
- MSG("%c[%d;%dmWelcome back Dr Tracing!%c[%dm\n\n", 27,1,33,27,0);
+ if (strncmp(progname, "drtrace", 7) == 0 ||
+ strncmp("compudj", getenv("USER"), 7) == 0) {
+ MSG("%c[%d;%dmWelcome back Dr Tracing!%c[%dm\n", 27,1,33,27,0);
}
ret = set_signal_handler();
projects / lttng-tools.git / blobdiff