--- /dev/null
+/*
+ * Copyright (C) 2013 - David Goulet <dgoulet@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.
+ *
+ * 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
+#include <assert.h>
+
+#include <common/common.h>
+#include <common/utils.h>
+
+#include "fd-limit.h"
+#include "lttng-sessiond.h"
+#include "notify-apps.h"
+#include "health-sessiond.h"
+#include "testpoint.h"
+#include "utils.h"
+#include "thread.h"
+
+struct thread_notifiers {
+ struct lttng_pipe *quit_pipe;
+ int apps_cmd_notify_pipe_read_fd;
+};
+
+/*
+ * This thread manage application notify communication.
+ */
+static void *thread_application_notification(void *data)
+{
+ int i, ret, pollfd, err = -1;
+ ssize_t size_ret;
+ uint32_t revents, nb_fd;
+ struct lttng_poll_event events;
+ struct thread_notifiers *notifiers = data;
+ const int quit_pipe_read_fd = lttng_pipe_get_readfd(notifiers->quit_pipe);
+
+ DBG("[ust-thread] Manage application notify command");
+
+ rcu_register_thread();
+ rcu_thread_online();
+
+ health_register(health_sessiond,
+ HEALTH_SESSIOND_TYPE_APP_MANAGE_NOTIFY);
+
+ if (testpoint(sessiond_thread_app_manage_notify)) {
+ goto error_testpoint;
+ }
+
+ health_code_update();
+
+ ret = lttng_poll_create(&events, 2, LTTNG_CLOEXEC);
+ if (ret < 0) {
+ goto error_poll_create;
+ }
+
+ /* Add notify pipe to the pollset. */
+ ret = lttng_poll_add(&events, notifiers->apps_cmd_notify_pipe_read_fd,
+ LPOLLIN | LPOLLERR | LPOLLHUP | LPOLLRDHUP);
+ if (ret < 0) {
+ goto error;
+ }
+
+ ret = lttng_poll_add(&events, quit_pipe_read_fd,
+ LPOLLIN | LPOLLERR);
+ if (ret < 0) {
+ goto error;
+ }
+
+ health_code_update();
+
+ while (1) {
+ DBG3("[ust-thread] Manage notify polling");
+
+ /* Inifinite blocking call, waiting for transmission */
+restart:
+ health_poll_entry();
+ ret = lttng_poll_wait(&events, -1);
+ DBG3("[ust-thread] Manage notify return from poll on %d fds",
+ LTTNG_POLL_GETNB(&events));
+ health_poll_exit();
+ if (ret < 0) {
+ /*
+ * Restart interrupted system call.
+ */
+ if (errno == EINTR) {
+ goto restart;
+ }
+ goto error;
+ }
+
+ nb_fd = ret;
+
+ for (i = 0; i < nb_fd; i++) {
+ health_code_update();
+
+ /* Fetch once the poll data */
+ revents = LTTNG_POLL_GETEV(&events, i);
+ pollfd = LTTNG_POLL_GETFD(&events, i);
+
+ if (!revents) {
+ /* No activity for this FD (poll implementation). */
+ continue;
+ }
+
+ /* Thread quit pipe has been closed. Killing thread. */
+ if (pollfd == quit_pipe_read_fd) {
+ err = 0;
+ goto exit;
+ } else if (pollfd == notifiers->apps_cmd_notify_pipe_read_fd) {
+ /* Inspect the apps cmd pipe */
+ int sock;
+
+ if (revents & LPOLLIN) {
+ /* Get socket from dispatch thread. */
+ size_ret = lttng_read(notifiers->apps_cmd_notify_pipe_read_fd,
+ &sock, sizeof(sock));
+ if (size_ret < sizeof(sock)) {
+ PERROR("read apps notify pipe");
+ goto error;
+ }
+ health_code_update();
+
+ ret = lttng_poll_add(&events, sock,
+ LPOLLIN | LPOLLERR | LPOLLHUP | LPOLLRDHUP);
+ if (ret < 0) {
+ /*
+ * It's possible we've reached the max poll fd allowed.
+ * Let's close the socket but continue normal execution.
+ */
+ ret = close(sock);
+ if (ret) {
+ PERROR("close notify socket %d", sock);
+ }
+ lttng_fd_put(LTTNG_FD_APPS, 1);
+ continue;
+ }
+ DBG3("UST thread notify added sock %d to pollset", sock);
+ } else if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
+ ERR("Apps notify command pipe error");
+ goto error;
+ } else {
+ ERR("Unexpected poll events %u for sock %d", revents, pollfd);
+ goto error;
+ }
+ } else {
+ /*
+ * At this point, we know that a registered application
+ * triggered the event.
+ */
+ if (revents & (LPOLLIN | LPOLLPRI)) {
+ ret = ust_app_recv_notify(pollfd);
+ if (ret < 0) {
+ /* Removing from the poll set */
+ ret = lttng_poll_del(&events, pollfd);
+ if (ret < 0) {
+ goto error;
+ }
+
+ /* The socket is closed after a grace period here. */
+ ust_app_notify_sock_unregister(pollfd);
+ }
+ } else if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
+ /* Removing from the poll set */
+ ret = lttng_poll_del(&events, pollfd);
+ if (ret < 0) {
+ goto error;
+ }
+
+ /* The socket is closed after a grace period here. */
+ ust_app_notify_sock_unregister(pollfd);
+ } else {
+ ERR("Unexpected poll events %u for sock %d", revents, pollfd);
+ goto error;
+ }
+ health_code_update();
+ }
+ }
+ }
+
+exit:
+error:
+ lttng_poll_clean(&events);
+error_poll_create:
+error_testpoint:
+
+ DBG("Application notify communication apps thread cleanup complete");
+ if (err) {
+ health_error();
+ ERR("Health error occurred in %s", __func__);
+ }
+ health_unregister(health_sessiond);
+ rcu_thread_offline();
+ rcu_unregister_thread();
+ return NULL;
+}
+
+static bool shutdown_application_notification_thread(void *data)
+{
+ struct thread_notifiers *notifiers = data;
+ const int write_fd = lttng_pipe_get_writefd(notifiers->quit_pipe);
+
+ return notify_thread_pipe(write_fd) == 1;
+}
+
+static void cleanup_application_notification_thread(void *data)
+{
+ struct thread_notifiers *notifiers = data;
+
+ lttng_pipe_destroy(notifiers->quit_pipe);
+ free(notifiers);
+}
+
+bool launch_application_notification_thread(int apps_cmd_notify_pipe_read_fd)
+{
+ struct lttng_thread *thread;
+ struct thread_notifiers *notifiers;
+ struct lttng_pipe *quit_pipe;
+
+ notifiers = zmalloc(sizeof(*notifiers));
+ if (!notifiers) {
+ goto error;
+ }
+ notifiers->apps_cmd_notify_pipe_read_fd = apps_cmd_notify_pipe_read_fd;
+
+ quit_pipe = lttng_pipe_open(FD_CLOEXEC);
+ if (!quit_pipe) {
+ goto error;
+ }
+ notifiers->quit_pipe = quit_pipe;
+
+ thread = lttng_thread_create("Application notification",
+ thread_application_notification,
+ shutdown_application_notification_thread,
+ cleanup_application_notification_thread,
+ notifiers);
+ if (!thread) {
+ goto error;
+ }
+ lttng_thread_put(thread);
+ return true;
+error:
+ cleanup_application_notification_thread(notifiers);
+ return false;
+}
projects / lttng-tools.git / blobdiff