sessiond: notification: maintain an id to notification_client ht
[lttng-tools.git] / src / bin / lttng-sessiond / notification-thread.c
index c47b36533e2bdef05ad3ba4c609b9382e10856ed..c964e7c910b062a82753c50c58b78d728a9454c1 100644 (file)
@@ -1,18 +1,8 @@
 /*
- * Copyright (C) 2017 Jérémie Galarneau <jeremie.galarneau@efficios.com>
+ * Copyright (C) 2017 Jérémie Galarneau <jeremie.galarneau@efficios.com>
  *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License, version 2 only, as
- * published by the Free Software Foundation.
+ * SPDX-License-Identifier: GPL-2.0-only
  *
- * This program is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
- * more details.
- *
- * You should have received a copy of the GNU General Public License along with
- * this program; if not, write to the Free Software Foundation, Inc., 51
- * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
 #define _LGPL_SOURCE
@@ -37,6 +27,7 @@
 #include "notification-thread-commands.h"
 #include "lttng-sessiond.h"
 #include "health-sessiond.h"
+#include "thread.h"
 
 #include <urcu.h>
 #include <urcu/list.h>
@@ -56,6 +47,7 @@ void notification_thread_handle_destroy(
 
        assert(cds_list_empty(&handle->cmd_queue.list));
        pthread_mutex_destroy(&handle->cmd_queue.lock);
+       sem_destroy(&handle->ready);
 
        if (handle->cmd_queue.event_pipe) {
                lttng_pipe_destroy(handle->cmd_queue.event_pipe);
@@ -96,7 +88,9 @@ struct notification_thread_handle *notification_thread_handle_create(
                goto end;
        }
 
-       event_pipe = lttng_pipe_open(O_CLOEXEC);
+       sem_init(&handle->ready, 0, 0);
+
+       event_pipe = lttng_pipe_open(FD_CLOEXEC);
        if (!event_pipe) {
                ERR("event_pipe creation");
                goto error;
@@ -168,7 +162,7 @@ char *get_notification_channel_sock_path(void)
                        goto error;
                }
        } else {
-               char *home_path = utils_get_home_dir();
+               const char *home_path = utils_get_home_dir();
 
                if (!home_path) {
                        ERR("Can't get HOME directory for socket creation");
@@ -235,8 +229,16 @@ int notification_channel_socket_create(void)
        }
 
        if (getuid() == 0) {
-               ret = chown(sock_path, 0,
-                               utils_get_group_id(tracing_group_name));
+               gid_t gid;
+
+               ret =  utils_get_group_id(config.tracing_group_name.value, true,
+                               &gid);
+               if (ret) {
+                       /* Default to root group. */
+                       gid = 0;
+               }
+
+               ret = chown(sock_path, 0, gid);
                if (ret) {
                        ERR("Failed to set the notification channel socket's group");
                        ret = -1;
@@ -330,6 +332,10 @@ void fini_thread_state(struct notification_thread_state *state)
                ret = cds_lfht_destroy(state->client_socket_ht, NULL);
                assert(!ret);
        }
+       if (state->client_id_ht) {
+               ret = cds_lfht_destroy(state->client_id_ht, NULL);
+               assert(!ret);
+       }
        if (state->triggers_ht) {
                ret = handle_notification_thread_trigger_unregister_all(state);
                assert(!ret);
@@ -350,11 +356,21 @@ void fini_thread_state(struct notification_thread_state *state)
                assert(!ret);
        }
        if (state->channels_ht) {
-               ret = cds_lfht_destroy(state->channels_ht,
-                               NULL);
+               ret = cds_lfht_destroy(state->channels_ht, NULL);
+               assert(!ret);
+       }
+       if (state->sessions_ht) {
+               ret = cds_lfht_destroy(state->sessions_ht, NULL);
+               assert(!ret);
+       }
+       /*
+        * Must be destroyed after all channels have been destroyed.
+        * See comment in struct lttng_session_trigger_list.
+        */
+       if (state->session_triggers_ht) {
+               ret = cds_lfht_destroy(state->session_triggers_ht, NULL);
                assert(!ret);
        }
-
        if (state->notification_channel_socket >= 0) {
                notification_channel_socket_destroy(
                                state->notification_channel_socket);
@@ -362,6 +378,21 @@ void fini_thread_state(struct notification_thread_state *state)
        lttng_poll_clean(&state->events);
 }
 
+static
+void mark_thread_as_ready(struct notification_thread_handle *handle)
+{
+       DBG("Marking notification thread as ready");
+       sem_post(&handle->ready);
+}
+
+static
+void wait_until_thread_is_ready(struct notification_thread_handle *handle)
+{
+       DBG("Waiting for notification thread to be ready");
+       sem_wait(&handle->ready);
+       DBG("Notification thread is ready");
+}
+
 static
 int init_thread_state(struct notification_thread_handle *handle,
                struct notification_thread_state *state)
@@ -397,12 +428,24 @@ int init_thread_state(struct notification_thread_handle *handle,
                goto error;
        }
 
+       state->client_id_ht = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0,
+                       CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL);
+       if (!state->client_id_ht) {
+               goto error;
+       }
+
        state->channel_triggers_ht = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0,
                        CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL);
        if (!state->channel_triggers_ht) {
                goto error;
        }
 
+       state->session_triggers_ht = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0,
+                       CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL);
+       if (!state->session_triggers_ht) {
+               goto error;
+       }
+
        state->channel_state_ht = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0,
                        CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL);
        if (!state->channel_state_ht) {
@@ -420,12 +463,17 @@ int init_thread_state(struct notification_thread_handle *handle,
        if (!state->channels_ht) {
                goto error;
        }
-
+       state->sessions_ht = cds_lfht_new(DEFAULT_HT_SIZE,
+                       1, 0, CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL);
+       if (!state->sessions_ht) {
+               goto error;
+       }
        state->triggers_ht = cds_lfht_new(DEFAULT_HT_SIZE,
                        1, 0, CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL);
        if (!state->triggers_ht) {
                goto error;
        }
+       mark_thread_as_ready(handle);
 end:
        return 0;
 error:
@@ -473,6 +521,7 @@ end:
  * This thread services notification channel clients and commands received
  * from various lttng-sessiond components over a command queue.
  */
+static
 void *thread_notification(void *data)
 {
        int ret;
@@ -481,15 +530,15 @@ void *thread_notification(void *data)
 
        DBG("[notification-thread] Started notification thread");
 
+       health_register(health_sessiond, HEALTH_SESSIOND_TYPE_NOTIFICATION);
+       rcu_register_thread();
+       rcu_thread_online();
+
        if (!handle) {
                ERR("[notification-thread] Invalid thread context provided");
                goto end;
        }
 
-       rcu_register_thread();
-       rcu_thread_online();
-
-       health_register(health_sessiond, HEALTH_SESSIOND_TYPE_NOTIFICATION);
        health_code_update();
 
        ret = init_thread_state(handle, &state);
@@ -497,9 +546,6 @@ void *thread_notification(void *data)
                goto end;
        }
 
-       /* Ready to handle client connections. */
-       sessiond_notify_ready();
-
        while (true) {
                int fd_count, i;
 
@@ -524,9 +570,6 @@ void *thread_notification(void *data)
                        int fd = LTTNG_POLL_GETFD(&state.events, i);
                        uint32_t revents = LTTNG_POLL_GETEV(&state.events, i);
 
-                       if (!revents) {
-                               continue;
-                       }
                        DBG("[notification-thread] Handling fd (%i) activity (%u)", fd, revents);
 
                        if (fd == state.notification_channel_socket) {
@@ -599,9 +642,43 @@ void *thread_notification(void *data)
 exit:
 error:
        fini_thread_state(&state);
-       health_unregister(health_sessiond);
+end:
        rcu_thread_offline();
        rcu_unregister_thread();
-end:
+       health_unregister(health_sessiond);
+       return NULL;
+}
+
+static
+bool shutdown_notification_thread(void *thread_data)
+{
+       struct notification_thread_handle *handle = thread_data;
+
+       notification_thread_command_quit(handle);
+       return true;
+}
+
+struct lttng_thread *launch_notification_thread(
+               struct notification_thread_handle *handle)
+{
+       struct lttng_thread *thread;
+
+       thread = lttng_thread_create("Notification",
+                       thread_notification,
+                       shutdown_notification_thread,
+                       NULL,
+                       handle);
+       if (!thread) {
+               goto error;
+       }
+
+       /*
+        * Wait for the thread to be marked as "ready" before returning
+        * as other subsystems depend on the notification subsystem
+        * (e.g. rotation thread).
+        */
+       wait_until_thread_is_ready(handle);
+       return thread;
+error:
        return NULL;
 }
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