Fix: add -b, --background option
[lttng-tools.git] / src / bin / lttng-sessiond / main.c
index 54b47567dea05cbc2acf0e7796a499134d2cb987..bbdf141b2409825ee1b900453b2914ec03d7c9d3 100644 (file)
@@ -20,6 +20,7 @@
 #include <getopt.h>
 #include <grp.h>
 #include <limits.h>
+#include <paths.h>
 #include <pthread.h>
 #include <signal.h>
 #include <stdio.h>
@@ -44,6 +45,7 @@
 #include <common/futex.h>
 #include <common/relayd/relayd.h>
 #include <common/utils.h>
+#include <common/daemonize.h>
 
 #include "lttng-sessiond.h"
 #include "buffer-registry.h"
@@ -72,12 +74,16 @@ static const char *tracing_group_name = DEFAULT_TRACING_GROUP;
 static const char *opt_pidfile;
 static int opt_sig_parent;
 static int opt_verbose_consumer;
-static int opt_daemon;
+static int opt_daemon, opt_background;
 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.
@@ -238,6 +244,38 @@ struct health_app *health_sessiond;
 /* JUL TCP port for registration. Used by the JUL thread. */
 unsigned int jul_tcp_port = DEFAULT_JUL_TCP_PORT;
 
+/*
+ * Whether sessiond is ready for commands/health check requests.
+ * NR_LTTNG_SESSIOND_READY must match the number of calls to
+ * lttng_sessiond_notify_ready().
+ */
+#define NR_LTTNG_SESSIOND_READY                2
+int lttng_sessiond_ready = NR_LTTNG_SESSIOND_READY;
+
+/* Notify parents that we are ready for cmd and health check */
+static
+void lttng_sessiond_notify_ready(void)
+{
+       if (uatomic_sub_return(&lttng_sessiond_ready, 1) == 0) {
+               /*
+                * 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 || opt_background) {
+                       kill(child_ppid, SIGUSR1);
+               }
+       }
+}
+
 static
 void setup_consumerd_path(void)
 {
@@ -796,13 +834,13 @@ static void *thread_manage_kernel(void *data)
         */
        lttng_poll_init(&events);
 
-       if (testpoint(thread_manage_kernel)) {
+       if (testpoint(sessiond_thread_manage_kernel)) {
                goto error_testpoint;
        }
 
        health_code_update();
 
-       if (testpoint(thread_manage_kernel_before_loop)) {
+       if (testpoint(sessiond_thread_manage_kernel_before_loop)) {
                goto error_testpoint;
        }
 
@@ -871,9 +909,8 @@ static void *thread_manage_kernel(void *data)
 
                        /* Check for data on kernel pipe */
                        if (pollfd == kernel_poll_pipe[0] && (revents & LPOLLIN)) {
-                               do {
-                                       ret = read(kernel_poll_pipe[0], &tmp, 1);
-                               } while (ret < 0 && errno == EINTR);
+                               (void) lttng_read(kernel_poll_pipe[0],
+                                       &tmp, 1);
                                /*
                                 * Ret value is useless here, if this pipe gets any actions an
                                 * update is required anyway.
@@ -983,7 +1020,7 @@ static void *thread_manage_consumer(void *data)
 restart:
        health_poll_entry();
 
-       if (testpoint(thread_manage_consumer)) {
+       if (testpoint(sessiond_thread_manage_consumer)) {
                goto error;
        }
 
@@ -1245,6 +1282,7 @@ error_poll:
 static void *thread_manage_apps(void *data)
 {
        int i, ret, pollfd, err = -1;
+       ssize_t size_ret;
        uint32_t revents, nb_fd;
        struct lttng_poll_event events;
 
@@ -1255,7 +1293,7 @@ static void *thread_manage_apps(void *data)
 
        health_register(health_sessiond, HEALTH_SESSIOND_TYPE_APP_MANAGE);
 
-       if (testpoint(thread_manage_apps)) {
+       if (testpoint(sessiond_thread_manage_apps)) {
                goto error_testpoint;
        }
 
@@ -1271,7 +1309,7 @@ static void *thread_manage_apps(void *data)
                goto error;
        }
 
-       if (testpoint(thread_manage_apps_before_loop)) {
+       if (testpoint(sessiond_thread_manage_apps_before_loop)) {
                goto error;
        }
 
@@ -1320,10 +1358,8 @@ static void *thread_manage_apps(void *data)
                                        int sock;
 
                                        /* Empty pipe */
-                                       do {
-                                               ret = read(apps_cmd_pipe[0], &sock, sizeof(sock));
-                                       } while (ret < 0 && errno == EINTR);
-                                       if (ret < 0 || ret < sizeof(sock)) {
+                                       size_ret = lttng_read(apps_cmd_pipe[0], &sock, sizeof(sock));
+                                       if (size_ret < sizeof(sock)) {
                                                PERROR("read apps cmd pipe");
                                                goto error;
                                        }
@@ -1342,10 +1378,6 @@ static void *thread_manage_apps(void *data)
                                        }
 
                                        DBG("Apps with sock %d added to poll set", sock);
-
-                                       health_code_update();
-
-                                       break;
                                }
                        } else {
                                /*
@@ -1361,7 +1393,6 @@ static void *thread_manage_apps(void *data)
 
                                        /* Socket closed on remote end. */
                                        ust_app_unregister(pollfd);
-                                       break;
                                }
                        }
 
@@ -1406,7 +1437,7 @@ error_testpoint:
  */
 static int send_socket_to_thread(int fd, int sock)
 {
-       int ret;
+       ssize_t ret;
 
        /*
         * It's possible that the FD is set as invalid with -1 concurrently just
@@ -1417,10 +1448,8 @@ static int send_socket_to_thread(int fd, int sock)
                goto error;
        }
 
-       do {
-               ret = write(fd, &sock, sizeof(sock));
-       } while (ret < 0 && errno == EINTR);
-       if (ret < 0 || ret != sizeof(sock)) {
+       ret = lttng_write(fd, &sock, sizeof(sock));
+       if (ret < sizeof(sock)) {
                PERROR("write apps pipe %d", fd);
                if (ret < 0) {
                        ret = -errno;
@@ -1431,7 +1460,7 @@ static int send_socket_to_thread(int fd, int sock)
        /* All good. Don't send back the write positive ret value. */
        ret = 0;
 error:
-       return ret;
+       return (int) ret;
 }
 
 /*
@@ -1535,6 +1564,10 @@ static void *thread_dispatch_ust_registration(void *data)
 
        health_register(health_sessiond, HEALTH_SESSIOND_TYPE_APP_REG_DISPATCH);
 
+       if (testpoint(sessiond_thread_app_reg_dispatch)) {
+               goto error_testpoint;
+       }
+
        health_code_update();
 
        CDS_INIT_LIST_HEAD(&wait_queue.head);
@@ -1739,6 +1772,7 @@ error:
                free(wait_node);
        }
 
+error_testpoint:
        DBG("Dispatch thread dying");
        if (err) {
                health_error();
@@ -1766,7 +1800,7 @@ static void *thread_registration_apps(void *data)
 
        health_register(health_sessiond, HEALTH_SESSIOND_TYPE_APP_REG);
 
-       if (testpoint(thread_registration_apps)) {
+       if (testpoint(sessiond_thread_registration_apps)) {
                goto error_testpoint;
        }
 
@@ -1927,11 +1961,6 @@ static void *thread_registration_apps(void *data)
 
 exit:
 error:
-       if (err) {
-               health_error();
-               ERR("Health error occurred in %s", __func__);
-       }
-
        /* Notify that the registration thread is gone */
        notify_ust_apps(0);
 
@@ -1956,6 +1985,10 @@ error_listen:
 error_create_poll:
 error_testpoint:
        DBG("UST Registration thread cleanup complete");
+       if (err) {
+               health_error();
+               ERR("Health error occurred in %s", __func__);
+       }
        health_unregister(health_sessiond);
 
        return NULL;
@@ -2936,9 +2969,74 @@ skip_domain:
        }
        case LTTNG_ENABLE_EVENT:
        {
+               struct lttng_event_exclusion *exclusion = NULL;
+               struct lttng_filter_bytecode *bytecode = NULL;
+
+               /* Handle exclusion events and receive it from the client. */
+               if (cmd_ctx->lsm->u.enable.exclusion_count > 0) {
+                       size_t count = cmd_ctx->lsm->u.enable.exclusion_count;
+
+                       exclusion = zmalloc(sizeof(struct lttng_event_exclusion) +
+                                       (count * LTTNG_SYMBOL_NAME_LEN));
+                       if (!exclusion) {
+                               ret = LTTNG_ERR_EXCLUSION_NOMEM;
+                               goto error;
+                       }
+
+                       DBG("Receiving var len exclusion event list from client ...");
+                       exclusion->count = count;
+                       ret = lttcomm_recv_unix_sock(sock, exclusion->names,
+                                       count * LTTNG_SYMBOL_NAME_LEN);
+                       if (ret <= 0) {
+                               DBG("Nothing recv() from client var len data... continuing");
+                               *sock_error = 1;
+                               free(exclusion);
+                               ret = LTTNG_ERR_EXCLUSION_INVAL;
+                               goto error;
+                       }
+               }
+
+               /* Handle filter and get bytecode from client. */
+               if (cmd_ctx->lsm->u.enable.bytecode_len > 0) {
+                       size_t bytecode_len = cmd_ctx->lsm->u.enable.bytecode_len;
+
+                       if (bytecode_len > LTTNG_FILTER_MAX_LEN) {
+                               ret = LTTNG_ERR_FILTER_INVAL;
+                               free(exclusion);
+                               goto error;
+                       }
+
+                       bytecode = zmalloc(bytecode_len);
+                       if (!bytecode) {
+                               free(exclusion);
+                               ret = LTTNG_ERR_FILTER_NOMEM;
+                               goto error;
+                       }
+
+                       /* Receive var. len. data */
+                       DBG("Receiving var len filter's bytecode from client ...");
+                       ret = lttcomm_recv_unix_sock(sock, bytecode, bytecode_len);
+                       if (ret <= 0) {
+                               DBG("Nothing recv() from client car len data... continuing");
+                               *sock_error = 1;
+                               free(bytecode);
+                               free(exclusion);
+                               ret = LTTNG_ERR_FILTER_INVAL;
+                               goto error;
+                       }
+
+                       if ((bytecode->len + sizeof(*bytecode)) != bytecode_len) {
+                               free(bytecode);
+                               free(exclusion);
+                               ret = LTTNG_ERR_FILTER_INVAL;
+                               goto error;
+                       }
+               }
+
                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, bytecode, exclusion,
+                               kernel_poll_pipe[1]);
                break;
        }
        case LTTNG_ENABLE_ALL_EVENT:
@@ -3262,46 +3360,6 @@ skip_domain:
                                cmd_ctx->lsm->u.reg.path, cdata);
                break;
        }
-       case LTTNG_ENABLE_EVENT_WITH_FILTER:
-       {
-               struct lttng_filter_bytecode *bytecode;
-
-               if (cmd_ctx->lsm->u.enable.bytecode_len > LTTNG_FILTER_MAX_LEN) {
-                       ret = LTTNG_ERR_FILTER_INVAL;
-                       goto error;
-               }
-               if (cmd_ctx->lsm->u.enable.bytecode_len == 0) {
-                       ret = LTTNG_ERR_FILTER_INVAL;
-                       goto error;
-               }
-               bytecode = zmalloc(cmd_ctx->lsm->u.enable.bytecode_len);
-               if (!bytecode) {
-                       ret = LTTNG_ERR_FILTER_NOMEM;
-                       goto error;
-               }
-               /* Receive var. len. data */
-               DBG("Receiving var len data from client ...");
-               ret = lttcomm_recv_unix_sock(sock, bytecode,
-                               cmd_ctx->lsm->u.enable.bytecode_len);
-               if (ret <= 0) {
-                       DBG("Nothing recv() from client var len data... continuing");
-                       *sock_error = 1;
-                       ret = LTTNG_ERR_FILTER_INVAL;
-                       goto error;
-               }
-
-               if (bytecode->len + sizeof(*bytecode)
-                               != cmd_ctx->lsm->u.enable.bytecode_len) {
-                       free(bytecode);
-                       ret = LTTNG_ERR_FILTER_INVAL;
-                       goto error;
-               }
-
-               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]);
-               break;
-       }
        case LTTNG_DATA_PENDING:
        {
                ret = cmd_data_pending(cmd_ctx->session);
@@ -3544,6 +3602,8 @@ static void *thread_manage_health(void *data)
                goto error;
        }
 
+       lttng_sessiond_notify_ready();
+
        while (1) {
                DBG("Health check ready");
 
@@ -3672,10 +3732,6 @@ static void *thread_manage_clients(void *data)
 
        health_register(health_sessiond, HEALTH_SESSIOND_TYPE_CMD);
 
-       if (testpoint(thread_manage_clients)) {
-               goto error_testpoint;
-       }
-
        health_code_update();
 
        ret = lttcomm_listen_unix_sock(client_sock);
@@ -3698,14 +3754,14 @@ static void *thread_manage_clients(void *data)
                goto error;
        }
 
-       /*
-        * Notify parent pid that we are ready to accept command for client side.
-        */
-       if (opt_sig_parent) {
-               kill(ppid, SIGUSR1);
+       lttng_sessiond_notify_ready();
+
+       /* This testpoint is after we signal readiness to the parent. */
+       if (testpoint(sessiond_thread_manage_clients)) {
+               goto error;
        }
 
-       if (testpoint(thread_manage_clients_before_loop)) {
+       if (testpoint(sessiond_thread_manage_clients_before_loop)) {
                goto error;
        }
 
@@ -3880,7 +3936,6 @@ error:
 
 error_listen:
 error_create_poll:
-error_testpoint:
        unlink(client_unix_sock_path);
        if (client_sock >= 0) {
                ret = close(client_sock);
@@ -3923,9 +3978,10 @@ static void usage(void)
        fprintf(stderr, "      --consumerd64-path PATH     Specify path for the 64-bit UST consumer daemon binary\n");
        fprintf(stderr, "      --consumerd64-libdir PATH   Specify path for the 64-bit UST consumer daemon libraries\n");
        fprintf(stderr, "  -d, --daemonize                    Start as a daemon.\n");
+       fprintf(stderr, "  -b, --background                   Start as a daemon, keeping console open.\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");
@@ -3965,12 +4021,13 @@ static int parse_args(int argc, char **argv)
                { "no-kernel", 0, 0, 'N' },
                { "pidfile", 1, 0, 'p' },
                { "jul-tcp-port", 1, 0, 'J' },
+               { "background", 0, 0, 'b' },
                { NULL, 0, 0, 0 }
        };
 
        while (1) {
                int option_index = 0;
-               c = getopt_long(argc, argv, "dhqvVSN" "a:c:g:s:C:E:D:F:Z:u:t:p:J:",
+               c = getopt_long(argc, argv, "dhqvVSN" "a:c:g:s:C:E:D:F:Z:u:t:p:J:b",
                                long_options, &option_index);
                if (c == -1) {
                        break;
@@ -3992,6 +4049,9 @@ static int parse_args(int argc, char **argv)
                case 'd':
                        opt_daemon = 1;
                        break;
+               case 'b':
+                       opt_background = 1;
+                       break;
                case 'g':
                        tracing_group_name = optarg;
                        break;
@@ -4346,6 +4406,9 @@ static void sighandler(int sig)
                DBG("SIGTERM caught");
                stop_threads();
                break;
+       case SIGUSR1:
+               CMM_STORE_SHARED(recv_child_signal, 1);
+               break;
        default:
                break;
        }
@@ -4384,7 +4447,12 @@ static int set_signal_handler(void)
                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;
 }
@@ -4481,6 +4549,10 @@ int main(int argc, char **argv)
 
        rcu_register_thread();
 
+       if ((ret = set_signal_handler()) < 0) {
+               goto error;
+       }
+
        setup_consumerd_path();
 
        page_size = sysconf(_SC_PAGESIZE);
@@ -4497,23 +4569,19 @@ int main(int argc, char **argv)
        }
 
        /* Daemonize */
-       if (opt_daemon) {
+       if (opt_daemon || opt_background) {
                int i;
 
-               /*
-                * fork
-                * child: setsid, close FD 0, 1, 2, chdir /
-                * parent: exit (if fork is successful)
-                */
-               ret = daemon(0, 0);
+               ret = lttng_daemonize(&child_ppid, &recv_child_signal,
+                       !opt_background);
                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);
@@ -4706,10 +4774,6 @@ int main(int argc, char **argv)
                goto exit;
        }
 
-       if ((ret = set_signal_handler()) < 0) {
-               goto exit;
-       }
-
        /* Setup the needed unix socket */
        if ((ret = init_daemon_socket()) < 0) {
                goto exit;
@@ -4791,7 +4855,7 @@ int main(int argc, char **argv)
                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) {
@@ -4799,7 +4863,7 @@ int main(int argc, char **argv)
                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) {
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