#include <getopt.h>
#include <grp.h>
#include <limits.h>
+#include <paths.h>
#include <pthread.h>
#include <signal.h>
#include <stdio.h>
static int opt_no_kernel;
static int is_root; /* Set to 1 if the daemon is running as root */
static pid_t ppid; /* Parent PID for --sig-parent option */
+static pid_t child_ppid; /* Internal parent PID use with daemonize. */
static char *rundir;
+/* Set to 1 when a SIGUSR1 signal is received. */
+static int recv_child_signal;
+
/*
* Consumer daemon specific control data. Every value not initialized here is
* set to 0 by the static definition.
static void *thread_manage_kernel(void *data)
{
int ret, i, pollfd, update_poll_flag = 1, err = -1;
- ssize_t size_ret;
uint32_t revents, nb_fd;
char tmp;
struct lttng_poll_event events;
{
ret = cmd_enable_event(cmd_ctx->session, &cmd_ctx->lsm->domain,
cmd_ctx->lsm->u.enable.channel_name,
- &cmd_ctx->lsm->u.enable.event, NULL, kernel_poll_pipe[1]);
+ &cmd_ctx->lsm->u.enable.event, NULL, NULL, kernel_poll_pipe[1]);
break;
}
case LTTNG_ENABLE_ALL_EVENT:
ret = cmd_enable_event(cmd_ctx->session, &cmd_ctx->lsm->domain,
cmd_ctx->lsm->u.enable.channel_name,
- &cmd_ctx->lsm->u.enable.event, bytecode, kernel_poll_pipe[1]);
+ &cmd_ctx->lsm->u.enable.event, bytecode, NULL, kernel_poll_pipe[1]);
break;
}
case LTTNG_DATA_PENDING:
/*
* Notify parent pid that we are ready to accept command for client side.
+ * This ppid is the one from the external process that spawned us.
*/
if (opt_sig_parent) {
kill(ppid, SIGUSR1);
}
+ /* Notify the parent of the fork() process that we are ready. */
+ if (opt_daemon) {
+ kill(child_ppid, SIGUSR1);
+ }
+
if (testpoint(thread_manage_clients_before_loop)) {
goto error;
}
fprintf(stderr, " -d, --daemonize Start as a daemon.\n");
fprintf(stderr, " -g, --group NAME Specify the tracing group name. (default: tracing)\n");
fprintf(stderr, " -V, --version Show version number.\n");
- fprintf(stderr, " -S, --sig-parent Send SIGCHLD to parent pid to notify readiness.\n");
+ fprintf(stderr, " -S, --sig-parent Send SIGUSR1 to parent pid to notify readiness.\n");
fprintf(stderr, " -q, --quiet No output at all.\n");
fprintf(stderr, " -v, --verbose Verbose mode. Activate DBG() macro.\n");
fprintf(stderr, " -p, --pidfile FILE Write a pid to FILE name overriding the default value.\n");
DBG("SIGTERM caught");
stop_threads();
break;
+ case SIGUSR1:
+ CMM_STORE_SHARED(recv_child_signal, 1);
+ break;
default:
break;
}
return ret;
}
- DBG("Signal handler set for SIGTERM, SIGPIPE and SIGINT");
+ if ((ret = sigaction(SIGUSR1, &sa, NULL)) < 0) {
+ PERROR("sigaction");
+ return ret;
+ }
+
+ DBG("Signal handler set for SIGTERM, SIGUSR1, SIGPIPE and SIGINT");
return ret;
}
return;
}
+/*
+ * Daemonize this process by forking and making the parent wait for the child
+ * to signal it indicating readiness. Once received, the parent successfully
+ * quits.
+ *
+ * The child process undergoes the same action that daemon(3) does meaning
+ * setsid, chdir, and dup /dev/null into 0, 1 and 2.
+ *
+ * Return 0 on success else -1 on error.
+ */
+static int daemonize(void)
+{
+ int ret;
+ pid_t pid;
+
+ /* Get parent pid of this process. */
+ child_ppid = getppid();
+
+ pid = fork();
+ if (pid < 0) {
+ PERROR("fork");
+ goto error;
+ } else if (pid == 0) {
+ int fd;
+ pid_t sid;
+
+ /* Child */
+
+ /*
+ * Get the newly created parent pid so we can signal that process when
+ * we are ready to operate.
+ */
+ child_ppid = getppid();
+
+ sid = setsid();
+ if (sid < 0) {
+ PERROR("setsid");
+ goto error;
+ }
+
+ /* Try to change directory to /. If we can't well at least notify. */
+ ret = chdir("/");
+ if (ret < 0) {
+ PERROR("chdir");
+ }
+
+ fd = open(_PATH_DEVNULL, O_RDWR, 0);
+ if (fd < 0) {
+ PERROR("open %s", _PATH_DEVNULL);
+ /* Let 0, 1 and 2 open since we can't bind them to /dev/null. */
+ } else {
+ (void) dup2(fd, STDIN_FILENO);
+ (void) dup2(fd, STDOUT_FILENO);
+ (void) dup2(fd, STDERR_FILENO);
+ if (fd > 2) {
+ ret = close(fd);
+ if (ret < 0) {
+ PERROR("close");
+ }
+ }
+ }
+ goto end;
+ } else {
+ /* Parent */
+
+ /*
+ * Waiting for child to notify this parent that it can exit. 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 (!CMM_LOAD_SHARED(recv_child_signal)) {
+ sleep(1);
+ }
+
+ /*
+ * From this point on, the parent can exit and the child is now an
+ * operationnal session daemon ready to serve clients and applications.
+ */
+ exit(EXIT_SUCCESS);
+ }
+
+end:
+ return 0;
+
+error:
+ return -1;
+}
+
/*
* main
*/
rcu_register_thread();
+ if ((ret = set_signal_handler()) < 0) {
+ goto error;
+ }
+
setup_consumerd_path();
page_size = sysconf(_SC_PAGESIZE);
if (opt_daemon) {
int i;
- /*
- * fork
- * child: setsid, close FD 0, 1, 2, chdir /
- * parent: exit (if fork is successful)
- */
- ret = daemon(0, 0);
+ ret = daemonize();
if (ret < 0) {
- PERROR("daemon");
goto error;
}
+
/*
- * We are in the child. Make sure all other file
- * descriptors are closed, in case we are called with
- * more opened file descriptors than the standard ones.
+ * We are in the child. Make sure all other file descriptors are
+ * closed, in case we are called with more opened file descriptors than
+ * the standard ones.
*/
for (i = 3; i < sysconf(_SC_OPEN_MAX); i++) {
(void) close(i);
goto exit;
}
- if ((ret = set_signal_handler()) < 0) {
- goto exit;
- }
-
/* Setup the needed unix socket */
if ((ret = init_daemon_socket()) < 0) {
goto exit;
goto exit_health_sessiond_cleanup;
}
- /* Create thread to manage the client socket */
+ /* Create thread to clean up RCU hash tables */
ret = pthread_create(&ht_cleanup_thread, NULL,
thread_ht_cleanup, (void *) NULL);
if (ret != 0) {
goto exit_ht_cleanup;
}
- /* Create thread to manage the client socket */
+ /* Create health-check thread */
ret = pthread_create(&health_thread, NULL,
thread_manage_health, (void *) NULL);
if (ret != 0) {
projects / lttng-tools.git / blobdiff