/*
- * Copyright (C) 2012 - David Goulet <dgoulet@efficios.com>
+ * Copyright (C) 2012 David Goulet <dgoulet@efficios.com>
+ * Copyright (C) 2018 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 _GNU_SOURCE
-#include <assert.h>
-#include <inttypes.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <time.h>
-
-#include <common/defaults.h>
+#include "lttng-sessiond.h"
+#include "health-sessiond.h"
+#include <common/macros.h>
#include <common/error.h>
+#include <common/utils.h>
+#include <common/pipe.h>
+#include <inttypes.h>
+#include <sys/stat.h>
+#include "utils.h"
+#include "thread.h"
-#include "health.h"
-
-static const struct timespec time_delta = {
- .tv_sec = DEFAULT_HEALTH_CHECK_DELTA_S,
- .tv_nsec = DEFAULT_HEALTH_CHECK_DELTA_NS,
-};
-
-/* Define TLS health state. */
-DEFINE_URCU_TLS(struct health_state, health_state);
-
-/*
- * It ensures that TLS memory used for the node and its container structure
- * don't get reclaimed after the TLS owner thread exits until we have finished
- * using it.
- */
-static pthread_mutex_t health_mutex = PTHREAD_MUTEX_INITIALIZER;
-
-static struct health_tls_state_list health_state_list = {
- .head = CDS_LIST_HEAD_INIT(health_state_list.head),
+struct thread_notifiers {
+ struct lttng_pipe *quit_pipe;
+ sem_t ready;
};
-/*
- * This keeps track of the error state for unregistered thread. A thread
- * reporting a health error, normally unregisters and quits. This makes the TLS
- * health state not available to the health_check_state() call so on unregister
- * we update this global error array so we can keep track of which thread was
- * on error if the TLS health state has been removed.
- */
-static enum health_flags global_error_state[HEALTH_NUM_TYPE];
-
-/*
- * Lock health state global list mutex.
- */
-static void state_lock(void)
+static
+void mark_thread_as_ready(struct thread_notifiers *notifiers)
{
- pthread_mutex_lock(&health_mutex);
+ DBG("Marking health management thread as ready");
+ sem_post(¬ifiers->ready);
}
-/*
- * Unlock health state global list mutex.
- */
-static void state_unlock(void)
+static
+void wait_until_thread_is_ready(struct thread_notifiers *notifiers)
{
- pthread_mutex_unlock(&health_mutex);
+ DBG("Waiting for health management thread to be ready");
+ sem_wait(¬ifiers->ready);
+ DBG("Health management thread is ready");
}
-/*
- * Set time difference in res from time_a and time_b.
- */
-static void time_diff(const struct timespec *time_a,
- const struct timespec *time_b, struct timespec *res)
+static void cleanup_health_management_thread(void *data)
{
- if (time_a->tv_nsec - time_b->tv_nsec < 0) {
- res->tv_sec = time_a->tv_sec - time_b->tv_sec - 1;
- res->tv_nsec = 1000000000L + time_a->tv_sec - time_b->tv_sec;
- } else {
- res->tv_sec = time_a->tv_sec - time_b->tv_sec;
- res->tv_nsec = time_a->tv_nsec - time_b->tv_nsec;
- }
+ struct thread_notifiers *notifiers = data;
+
+ lttng_pipe_destroy(notifiers->quit_pipe);
+ sem_destroy(¬ifiers->ready);
+ free(notifiers);
}
/*
- * Return true if time_a - time_b > diff, else false.
+ * Thread managing health check socket.
*/
-static int time_diff_gt(const struct timespec *time_a,
- const struct timespec *time_b, const struct timespec *diff)
+static void *thread_manage_health(void *data)
{
- struct timespec res;
+ const bool is_root = (getuid() == 0);
+ int sock = -1, new_sock = -1, ret, i, pollfd, err = -1;
+ uint32_t revents, nb_fd;
+ struct lttng_poll_event events;
+ struct health_comm_msg msg;
+ struct health_comm_reply reply;
+ /* Thread-specific quit pipe. */
+ struct thread_notifiers *notifiers = data;
+ const int quit_pipe_read_fd = lttng_pipe_get_readfd(
+ notifiers->quit_pipe);
- time_diff(time_a, time_b, &res);
- time_diff(&res, diff, &res);
+ DBG("[thread] Manage health check started");
- if (res.tv_sec > 0) {
- return 1;
- } else if (res.tv_sec == 0 && res.tv_nsec > 0) {
- return 1;
- }
+ rcu_register_thread();
- return 0;
-}
-
-/*
- * Health mutex MUST be held across use of the returned struct health_state to
- * provide existence guarantee.
- *
- * Return the health_state object or NULL if not found.
- */
-static struct health_state *find_health_state(enum health_type type)
-{
- struct health_state *state;
-
- /* Find the right health state in the global TLS list. */
- cds_list_for_each_entry(state, &health_state_list.head, node) {
- if (state->type == type) {
- return state;
- }
+ /*
+ * Created with a size of two for:
+ * - client socket
+ * - thread quit pipe
+ */
+ ret = lttng_poll_create(&events, 2, LTTNG_CLOEXEC);
+ if (ret < 0) {
+ goto error;
}
- return NULL;
-}
+ /* Create unix socket */
+ sock = lttcomm_create_unix_sock(config.health_unix_sock_path.value);
+ if (sock < 0) {
+ ERR("Unable to create health check Unix socket");
+ goto error;
+ }
-/*
- * Check health of a specific health type. Note that if a thread has not yet
- * initialize its health subsystem or has quit, it's considered in a good
- * state.
- *
- * Return 0 if health is bad or else 1.
- */
-int health_check_state(enum health_type type)
-{
- int retval = 1, ret;
- unsigned long current, last;
- struct timespec current_time;
- struct health_state *state;
+ if (is_root) {
+ /* lttng health client socket path permissions */
+ gid_t gid;
- assert(type < HEALTH_NUM_TYPE);
+ ret = utils_get_group_id(config.tracing_group_name.value, true, &gid);
+ if (ret) {
+ /* Default to root group. */
+ gid = 0;
+ }
- state_lock();
+ ret = chown(config.health_unix_sock_path.value, 0, gid);
+ if (ret < 0) {
+ ERR("Unable to set group on %s", config.health_unix_sock_path.value);
+ PERROR("chown");
+ goto error;
+ }
- state = find_health_state(type);
- if (!state) {
- /* Check the global state since the state is not visiable anymore. */
- if (global_error_state[type] & HEALTH_ERROR) {
- retval = 0;
+ ret = chmod(config.health_unix_sock_path.value,
+ S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
+ if (ret < 0) {
+ ERR("Unable to set permissions on %s", config.health_unix_sock_path.value);
+ PERROR("chmod");
+ goto error;
}
- goto not_found;
}
- last = state->last;
- current = uatomic_read(&state->current);
+ /*
+ * Set the CLOEXEC flag. Return code is useless because either way, the
+ * show must go on.
+ */
+ (void) utils_set_fd_cloexec(sock);
+
+ ret = lttcomm_listen_unix_sock(sock);
+ if (ret < 0) {
+ goto error;
+ }
- ret = clock_gettime(CLOCK_MONOTONIC, ¤t_time);
+ ret = lttng_poll_add(&events, quit_pipe_read_fd, LPOLLIN | LPOLLERR);
if (ret < 0) {
- PERROR("Error reading time\n");
- /* error */
- retval = 0;
- goto end;
+ goto error;
}
- /*
- * Thread is in bad health if flag HEALTH_ERROR is set. It is also in bad
- * health if, after the delta delay has passed, its the progress counter
- * has not moved and it has NOT been waiting for a poll() call.
- */
- if (uatomic_read(&state->flags) & HEALTH_ERROR) {
- retval = 0;
- goto end;
+ /* Add the application registration socket */
+ ret = lttng_poll_add(&events, sock, LPOLLIN | LPOLLPRI);
+ if (ret < 0) {
+ goto error;
}
- /*
- * Initial condition need to update the last counter and sample time, but
- * should not check health in this initial case, because we don't know how
- * much time has passed.
- */
- if (state->last_time.tv_sec == 0 && state->last_time.tv_nsec == 0) {
- /* update last counter and last sample time */
- state->last = current;
- memcpy(&state->last_time, ¤t_time, sizeof(current_time));
- } else {
- if (time_diff_gt(¤t_time, &state->last_time, &time_delta)) {
- if (current == last && !HEALTH_IS_IN_POLL(current)) {
- /* error */
- retval = 0;
+ mark_thread_as_ready(notifiers);
+ while (1) {
+ DBG("Health check ready");
+
+ /* Infinite blocking call, waiting for transmission */
+restart:
+ ret = lttng_poll_wait(&events, -1);
+ if (ret < 0) {
+ /*
+ * Restart interrupted system call.
+ */
+ if (errno == EINTR) {
+ goto restart;
}
- /* update last counter and last sample time */
- state->last = current;
- memcpy(&state->last_time, ¤t_time, sizeof(current_time));
+ goto error;
}
- }
-end:
- DBG("Health state current %lu, last %lu, ret %d",
- current, last, ret);
-not_found:
- state_unlock();
+ nb_fd = ret;
+
+ for (i = 0; i < nb_fd; i++) {
+ /* Fetch once the poll data */
+ revents = LTTNG_POLL_GETEV(&events, i);
+ pollfd = LTTNG_POLL_GETFD(&events, i);
+
+ /* Event on the registration socket */
+ if (pollfd == sock) {
+ if (revents & LPOLLIN) {
+ continue;
+ } else if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
+ ERR("Health socket poll error");
+ goto error;
+ } else {
+ ERR("Unexpected poll events %u for sock %d", revents, pollfd);
+ goto error;
+ }
+ } else {
+ /* Event on the thread's quit pipe. */
+ err = 0;
+ goto exit;
+ }
+ }
- return retval;
-}
+ new_sock = lttcomm_accept_unix_sock(sock);
+ if (new_sock < 0) {
+ goto error;
+ }
-/*
- * Init health state.
- */
-void health_register(enum health_type type)
-{
- struct health_state *state;
+ /*
+ * Set the CLOEXEC flag. Return code is useless because either way, the
+ * show must go on.
+ */
+ (void) utils_set_fd_cloexec(new_sock);
+
+ DBG("Receiving data from client for health...");
+ ret = lttcomm_recv_unix_sock(new_sock, (void *)&msg, sizeof(msg));
+ if (ret <= 0) {
+ DBG("Nothing recv() from client... continuing");
+ ret = close(new_sock);
+ if (ret) {
+ PERROR("close");
+ }
+ continue;
+ }
- assert(type < HEALTH_NUM_TYPE);
+ rcu_thread_online();
- /* Init TLS state. */
- uatomic_set(&URCU_TLS(health_state).last, 0);
- uatomic_set(&URCU_TLS(health_state).last_time.tv_sec, 0);
- uatomic_set(&URCU_TLS(health_state).last_time.tv_nsec, 0);
- uatomic_set(&URCU_TLS(health_state).current, 0);
- uatomic_set(&URCU_TLS(health_state).flags, 0);
- uatomic_set(&URCU_TLS(health_state).type, type);
+ memset(&reply, 0, sizeof(reply));
+ for (i = 0; i < NR_HEALTH_SESSIOND_TYPES; i++) {
+ /*
+ * health_check_state returns 0 if health is
+ * bad.
+ */
+ if (!health_check_state(health_sessiond, i)) {
+ reply.ret_code |= 1ULL << i;
+ }
+ }
- /* Add it to the global TLS state list. */
- state_lock();
- state = find_health_state(type);
- /*
- * Duplicates are not accepted, since lookups don't handle them at the
- * moment.
- */
- assert(!state);
+ DBG2("Health check return value %" PRIx64, reply.ret_code);
- cds_list_add(&URCU_TLS(health_state).node, &health_state_list.head);
- state_unlock();
+ ret = lttcomm_send_unix_sock(new_sock, (void *) &reply,
+ sizeof(reply));
+ if (ret < 0) {
+ ERR("Failed to send health data back to client");
+ }
+
+ /* End of transmission */
+ ret = close(new_sock);
+ if (ret) {
+ PERROR("close");
+ }
+ }
+
+exit:
+error:
+ if (err) {
+ ERR("Health error occurred in %s", __func__);
+ }
+ DBG("Health check thread dying");
+ unlink(config.health_unix_sock_path.value);
+ if (sock >= 0) {
+ ret = close(sock);
+ if (ret) {
+ PERROR("close");
+ }
+ }
+
+ lttng_poll_clean(&events);
+ rcu_unregister_thread();
+ return NULL;
}
-/*
- * Remove node from global list.
- */
-void health_unregister(void)
+static bool shutdown_health_management_thread(void *data)
{
- state_lock();
- /*
- * On error, set the global_error_state since we are about to remove
- * the node from the global list.
- */
- if (uatomic_read(&URCU_TLS(health_state).flags) & HEALTH_ERROR) {
- uatomic_set(&global_error_state[URCU_TLS(health_state).type],
- HEALTH_ERROR);
+ struct thread_notifiers *notifiers = data;
+ const int write_fd = lttng_pipe_get_writefd(notifiers->quit_pipe);
+
+ return notify_thread_pipe(write_fd) == 1;
+}
+
+bool launch_health_management_thread(void)
+{
+ struct thread_notifiers *notifiers;
+ struct lttng_thread *thread;
+
+ notifiers = zmalloc(sizeof(*notifiers));
+ if (!notifiers) {
+ goto error_alloc;
+ }
+
+ sem_init(¬ifiers->ready, 0, 0);
+ notifiers->quit_pipe = lttng_pipe_open(FD_CLOEXEC);
+ if (!notifiers->quit_pipe) {
+ goto error;
}
- cds_list_del(&URCU_TLS(health_state).node);
- state_unlock();
+ thread = lttng_thread_create("Health management",
+ thread_manage_health,
+ shutdown_health_management_thread,
+ cleanup_health_management_thread,
+ notifiers);
+ if (!thread) {
+ goto error;
+ }
+
+ wait_until_thread_is_ready(notifiers);
+ lttng_thread_put(thread);
+ return true;
+error:
+ cleanup_health_management_thread(notifiers);
+error_alloc:
+ return false;
}
projects / lttng-tools.git / blobdiff