Initial import of the snapshot ABI/API in lttng-ctl
[lttng-tools.git] / src / bin / lttng-sessiond / main.c
index f6e7094bfca08947c3cddb5d1693818a350ee5dc..31f48a2739fb0216ef9645ca4bb4a51162244ed6 100644 (file)
@@ -161,6 +161,7 @@ static pthread_t client_thread;
 static pthread_t kernel_thread;
 static pthread_t dispatch_thread;
 static pthread_t health_thread;
+static pthread_t ht_cleanup_thread;
 
 /*
  * UST registration command queue. This queue is tied with a futex and uses a N
@@ -1333,25 +1334,116 @@ error:
        return ret;
 }
 
+/*
+ * Sanitize the wait queue of the dispatch registration thread meaning removing
+ * invalid nodes from it. This is to avoid memory leaks for the case the UST
+ * notify socket is never received.
+ */
+static void sanitize_wait_queue(struct ust_reg_wait_queue *wait_queue)
+{
+       int ret, nb_fd = 0, i;
+       unsigned int fd_added = 0;
+       struct lttng_poll_event events;
+       struct ust_reg_wait_node *wait_node = NULL, *tmp_wait_node;
+
+       assert(wait_queue);
+
+       lttng_poll_init(&events);
+
+       /* Just skip everything for an empty queue. */
+       if (!wait_queue->count) {
+               goto end;
+       }
+
+       ret = lttng_poll_create(&events, wait_queue->count, LTTNG_CLOEXEC);
+       if (ret < 0) {
+               goto error_create;
+       }
+
+       cds_list_for_each_entry_safe(wait_node, tmp_wait_node,
+                       &wait_queue->head, head) {
+               assert(wait_node->app);
+               ret = lttng_poll_add(&events, wait_node->app->sock,
+                               LPOLLHUP | LPOLLERR);
+               if (ret < 0) {
+                       goto error;
+               }
+
+               fd_added = 1;
+       }
+
+       if (!fd_added) {
+               goto end;
+       }
+
+       /*
+        * Poll but don't block so we can quickly identify the faulty events and
+        * clean them afterwards from the wait queue.
+        */
+       ret = lttng_poll_wait(&events, 0);
+       if (ret < 0) {
+               goto error;
+       }
+       nb_fd = ret;
+
+       for (i = 0; i < nb_fd; i++) {
+               /* Get faulty FD. */
+               uint32_t revents = LTTNG_POLL_GETEV(&events, i);
+               int pollfd = LTTNG_POLL_GETFD(&events, i);
+
+               cds_list_for_each_entry_safe(wait_node, tmp_wait_node,
+                               &wait_queue->head, head) {
+                       if (pollfd == wait_node->app->sock &&
+                                       (revents & (LPOLLHUP | LPOLLERR))) {
+                               cds_list_del(&wait_node->head);
+                               wait_queue->count--;
+                               ust_app_destroy(wait_node->app);
+                               free(wait_node);
+                               break;
+                       }
+               }
+       }
+
+       if (nb_fd > 0) {
+               DBG("Wait queue sanitized, %d node were cleaned up", nb_fd);
+       }
+
+end:
+       lttng_poll_clean(&events);
+       return;
+
+error:
+       lttng_poll_clean(&events);
+error_create:
+       ERR("Unable to sanitize wait queue");
+       return;
+}
+
 /*
  * Dispatch request from the registration threads to the application
  * communication thread.
  */
 static void *thread_dispatch_ust_registration(void *data)
 {
-       int ret;
+       int ret, err = -1;
        struct cds_wfq_node *node;
        struct ust_command *ust_cmd = NULL;
-       struct {
-               struct ust_app *app;
-               struct cds_list_head head;
-       } *wait_node = NULL, *tmp_wait_node;
+       struct ust_reg_wait_node *wait_node = NULL, *tmp_wait_node;
+       struct ust_reg_wait_queue wait_queue = {
+               .count = 0,
+       };
+
+       health_register(HEALTH_TYPE_APP_REG_DISPATCH);
 
-       CDS_LIST_HEAD(wait_queue);
+       health_code_update();
+
+       CDS_INIT_LIST_HEAD(&wait_queue.head);
 
        DBG("[thread] Dispatch UST command started");
 
        while (!CMM_LOAD_SHARED(dispatch_thread_exit)) {
+               health_code_update();
+
                /* Atomically prepare the queue futex */
                futex_nto1_prepare(&ust_cmd_queue.futex);
 
@@ -1359,6 +1451,14 @@ static void *thread_dispatch_ust_registration(void *data)
                        struct ust_app *app = NULL;
                        ust_cmd = NULL;
 
+                       /*
+                        * Make sure we don't have node(s) that have hung up before receiving
+                        * the notify socket. This is to clean the list in order to avoid
+                        * memory leaks from notify socket that are never seen.
+                        */
+                       sanitize_wait_queue(&wait_queue);
+
+                       health_code_update();
                        /* Dequeue command for registration */
                        node = cds_wfq_dequeue_blocking(&ust_cmd_queue.queue);
                        if (node == NULL) {
@@ -1407,7 +1507,8 @@ static void *thread_dispatch_ust_registration(void *data)
                                 * Add application to the wait queue so we can set the notify
                                 * socket before putting this object in the global ht.
                                 */
-                               cds_list_add(&wait_node->head, &wait_queue);
+                               cds_list_add(&wait_node->head, &wait_queue.head);
+                               wait_queue.count++;
 
                                free(ust_cmd);
                                /*
@@ -1422,10 +1523,12 @@ static void *thread_dispatch_ust_registration(void *data)
                                 * notify socket if found.
                                 */
                                cds_list_for_each_entry_safe(wait_node, tmp_wait_node,
-                                               &wait_queue, head) {
+                                               &wait_queue.head, head) {
+                                       health_code_update();
                                        if (wait_node->app->pid == ust_cmd->reg_msg.pid) {
                                                wait_node->app->notify_sock = ust_cmd->sock;
                                                cds_list_del(&wait_node->head);
+                                               wait_queue.count--;
                                                app = wait_node->app;
                                                free(wait_node);
                                                DBG3("UST app notify socket %d is set", ust_cmd->sock);
@@ -1509,19 +1612,29 @@ static void *thread_dispatch_ust_registration(void *data)
                        }
                } while (node != NULL);
 
+               health_poll_entry();
                /* Futex wait on queue. Blocking call on futex() */
                futex_nto1_wait(&ust_cmd_queue.futex);
+               health_poll_exit();
        }
+       /* Normal exit, no error */
+       err = 0;
 
 error:
        /* Clean up wait queue. */
        cds_list_for_each_entry_safe(wait_node, tmp_wait_node,
-                       &wait_queue, head) {
+                       &wait_queue.head, head) {
                cds_list_del(&wait_node->head);
+               wait_queue.count--;
                free(wait_node);
        }
 
        DBG("Dispatch thread dying");
+       if (err) {
+               health_error();
+               ERR("Health error occurred in %s", __func__);
+       }
+       health_unregister();
        return NULL;
 }
 
@@ -2381,6 +2494,10 @@ static int process_client_msg(struct command_ctx *cmd_ctx, int sock,
        case LTTNG_START_TRACE:
        case LTTNG_STOP_TRACE:
        case LTTNG_DATA_PENDING:
+       case LTTNG_SNAPSHOT_ADD_OUTPUT:
+       case LTTNG_SNAPSHOT_DEL_OUTPUT:
+       case LTTNG_SNAPSHOT_LIST_OUTPUT:
+       case LTTNG_SNAPSHOT_RECORD:
                need_domain = 0;
                break;
        default:
@@ -2449,12 +2566,7 @@ static int process_client_msg(struct command_ctx *cmd_ctx, int sock,
                session_lock_list();
                cmd_ctx->session = session_find_by_name(cmd_ctx->lsm->session.name);
                if (cmd_ctx->session == NULL) {
-                       if (cmd_ctx->lsm->session.name != NULL) {
-                               ret = LTTNG_ERR_SESS_NOT_FOUND;
-                       } else {
-                               /* If no session name specified */
-                               ret = LTTNG_ERR_SELECT_SESS;
-                       }
+                       ret = LTTNG_ERR_SESS_NOT_FOUND;
                        goto error;
                } else {
                        /* Acquire lock for the session */
@@ -3068,6 +3180,26 @@ skip_domain:
                ret = cmd_data_pending(cmd_ctx->session);
                break;
        }
+       case LTTNG_SNAPSHOT_ADD_OUTPUT:
+       {
+               ret = LTTNG_ERR_UND;
+               break;
+       }
+       case LTTNG_SNAPSHOT_DEL_OUTPUT:
+       {
+               ret = LTTNG_ERR_UND;
+               break;
+       }
+       case LTTNG_SNAPSHOT_LIST_OUTPUT:
+       {
+               ret = LTTNG_ERR_UND;
+               break;
+       }
+       case LTTNG_SNAPSHOT_RECORD:
+       {
+               ret = LTTNG_ERR_UND;
+               break;
+       }
        default:
                ret = LTTNG_ERR_UND;
                break;
@@ -3225,13 +3357,25 @@ restart:
                case LTTNG_HEALTH_CONSUMER:
                        reply.ret_code = check_consumer_health();
                        break;
+               case LTTNG_HEALTH_HT_CLEANUP:
+                       reply.ret_code = health_check_state(HEALTH_TYPE_HT_CLEANUP);
+                       break;
+               case LTTNG_HEALTH_APP_MANAGE_NOTIFY:
+                       reply.ret_code = health_check_state(HEALTH_TYPE_APP_MANAGE_NOTIFY);
+                       break;
+               case LTTNG_HEALTH_APP_REG_DISPATCH:
+                       reply.ret_code = health_check_state(HEALTH_TYPE_APP_REG_DISPATCH);
+                       break;
                case LTTNG_HEALTH_ALL:
                        reply.ret_code =
                                health_check_state(HEALTH_TYPE_APP_MANAGE) &&
                                health_check_state(HEALTH_TYPE_APP_REG) &&
                                health_check_state(HEALTH_TYPE_CMD) &&
                                health_check_state(HEALTH_TYPE_KERNEL) &&
-                               check_consumer_health();
+                               check_consumer_health() &&
+                               health_check_state(HEALTH_TYPE_HT_CLEANUP) &&
+                               health_check_state(HEALTH_TYPE_APP_MANAGE_NOTIFY) &&
+                               health_check_state(HEALTH_TYPE_APP_REG_DISPATCH);
                        break;
                default:
                        reply.ret_code = LTTNG_ERR_UND;
@@ -3276,12 +3420,6 @@ error:
                        PERROR("close");
                }
        }
-       if (new_sock >= 0) {
-               ret = close(new_sock);
-               if (ret) {
-                       PERROR("close");
-               }
-       }
 
        lttng_poll_clean(&events);
 
@@ -4142,7 +4280,7 @@ int main(int argc, char **argv)
                DBG2("Kernel consumer cmd path: %s",
                                kconsumer_data.cmd_unix_sock_path);
        } else {
-               home_path = get_home_dir();
+               home_path = utils_get_home_dir();
                if (home_path == NULL) {
                        /* TODO: Add --socket PATH option */
                        ERR("Can't get HOME directory for sockets creation.");
@@ -4299,6 +4437,11 @@ int main(int argc, char **argv)
                }
        }
 
+       /* Setup the thread ht_cleanup communication pipe. */
+       if (utils_create_pipe_cloexec(ht_cleanup_pipe) < 0) {
+               goto exit;
+       }
+
        /* Setup the thread apps communication pipe. */
        if ((ret = utils_create_pipe_cloexec(apps_cmd_pipe)) < 0) {
                goto exit;
@@ -4337,6 +4480,14 @@ int main(int argc, char **argv)
 
        write_pidfile();
 
+       /* Create thread to manage the client socket */
+       ret = pthread_create(&ht_cleanup_thread, NULL,
+                       thread_ht_cleanup, (void *) NULL);
+       if (ret != 0) {
+               PERROR("pthread_create ht_cleanup");
+               goto exit_ht_cleanup;
+       }
+
        /* Create thread to manage the client socket */
        ret = pthread_create(&health_thread, NULL,
                        thread_manage_health, (void *) NULL);
@@ -4456,6 +4607,12 @@ exit_client:
        }
 
 exit_health:
+       ret = pthread_join(ht_cleanup_thread, &status);
+       if (ret != 0) {
+               PERROR("pthread_join ht cleanup thread");
+               goto error;     /* join error, exit without cleanup */
+       }
+exit_ht_cleanup:
 exit:
        /*
         * cleanup() is called when no other thread is running.
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