--- /dev/null
+/*
+ * Copyright (C) 2013 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-only
+ *
+ */
+
+#define _LGPL_SOURCE
+
+#include <common/hashtable/hashtable.h>
+#include <common/common.h>
+#include <common/utils.h>
+#include <pthread.h>
+
+#include "lttng-sessiond.h"
+#include "health-sessiond.h"
+#include "testpoint.h"
+#include "utils.h"
+#include "ht-cleanup.h"
+
+static int ht_cleanup_quit_pipe[2] = { -1, -1 };
+
+/*
+ * Check if the ht_cleanup thread quit pipe was triggered.
+ *
+ * Return true if it was triggered else false;
+ */
+static bool check_quit_pipe(int fd, uint32_t events)
+{
+ return (fd == ht_cleanup_quit_pipe[0] && (events & LPOLLIN));
+}
+
+static int init_pipe(int *pipe_fds)
+{
+ int ret, i;
+
+ ret = pipe(pipe_fds);
+ if (ret < 0) {
+ PERROR("ht_cleanup thread quit pipe");
+ goto error;
+ }
+
+ for (i = 0; i < 2; i++) {
+ ret = fcntl(pipe_fds[i], F_SETFD, FD_CLOEXEC);
+ if (ret < 0) {
+ PERROR("fcntl ht_cleanup_quit_pipe");
+ goto error;
+ }
+ }
+error:
+ return ret;
+}
+
+/*
+ * Create a poll set with O_CLOEXEC and add the thread quit pipe to the set.
+ */
+static int set_pollset(struct lttng_poll_event *events, size_t size)
+{
+ int ret;
+
+ ret = lttng_poll_create(events, size, LTTNG_CLOEXEC);
+ if (ret < 0) {
+ goto error;
+ }
+
+ ret = lttng_poll_add(events, ht_cleanup_quit_pipe[0],
+ LPOLLIN | LPOLLERR);
+ if (ret < 0) {
+ goto error;
+ }
+
+ ret = lttng_poll_add(events, the_ht_cleanup_pipe[0], LPOLLIN | LPOLLERR);
+ if (ret < 0) {
+ DBG("lttng_poll_add error %d.", ret);
+ goto error;
+ }
+
+ return 0;
+
+error:
+ return ret;
+}
+
+static void cleanup_ht_cleanup_thread(void *data)
+{
+ utils_close_pipe(ht_cleanup_quit_pipe);
+ utils_close_pipe(the_ht_cleanup_pipe);
+}
+
+static void *thread_ht_cleanup(void *data)
+{
+ int ret, i, pollfd, err = -1;
+ ssize_t size_ret;
+ uint32_t revents, nb_fd;
+ struct lttng_poll_event events;
+
+ DBG("startup.");
+
+ rcu_register_thread();
+ rcu_thread_online();
+
+ health_register(the_health_sessiond, HEALTH_SESSIOND_TYPE_HT_CLEANUP);
+
+ if (testpoint(sessiond_thread_ht_cleanup)) {
+ DBG("testpoint.");
+ goto error_testpoint;
+ }
+
+ health_code_update();
+
+ ret = set_pollset(&events, 2);
+ if (ret < 0) {
+ DBG("sessiond_set_ht_cleanup_thread_pollset error %d.", ret);
+ goto error_poll_create;
+ }
+
+ health_code_update();
+
+ while (1) {
+ restart:
+ DBG3("Polling.");
+ health_poll_entry();
+ ret = lttng_poll_wait(&events, -1);
+ DBG3("Returning from poll on %d fds.",
+ LTTNG_POLL_GETNB(&events));
+ health_poll_exit();
+ if (ret < 0) {
+ /*
+ * Restart interrupted system call.
+ */
+ if (errno == EINTR) {
+ continue;
+ }
+ goto error;
+ }
+
+ nb_fd = ret;
+ for (i = 0; i < nb_fd; i++) {
+ struct lttng_ht *ht;
+
+ health_code_update();
+
+ /* Fetch once the poll data */
+ revents = LTTNG_POLL_GETEV(&events, i);
+ pollfd = LTTNG_POLL_GETFD(&events, i);
+
+ if (pollfd != the_ht_cleanup_pipe[0]) {
+ continue;
+ }
+
+ if (revents & LPOLLIN) {
+ /* Get socket from dispatch thread. */
+ size_ret = lttng_read(the_ht_cleanup_pipe[0],
+ &ht, sizeof(ht));
+ if (size_ret < sizeof(ht)) {
+ PERROR("ht cleanup notify pipe");
+ goto error;
+ }
+ health_code_update();
+ /*
+ * The whole point of this thread is to call
+ * lttng_ht_destroy from a context that is NOT:
+ * 1) a read-side RCU lock,
+ * 2) a call_rcu thread.
+ */
+ lttng_ht_destroy(ht);
+
+ health_code_update();
+
+ /*
+ * Ensure that we never process the quit pipe
+ * event while there is still data available
+ * on the ht clean pipe.
+ */
+ goto restart;
+ } else if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
+ ERR("ht cleanup pipe error");
+ goto error;
+ } else {
+ ERR("Unexpected poll events %u for sock %d", revents, pollfd);
+ goto error;
+ }
+ }
+
+ 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;
+ }
+
+ if (pollfd == the_ht_cleanup_pipe[0]) {
+ continue;
+ }
+
+ /* Thread quit pipe has been closed. Killing thread. */
+ ret = check_quit_pipe(pollfd, revents);
+ if (ret) {
+ err = 0;
+ DBG("[ht-cleanup] quit.");
+ goto exit;
+ }
+ }
+ }
+
+exit:
+error:
+ lttng_poll_clean(&events);
+error_poll_create:
+error_testpoint:
+ DBG("[ht-cleanup] Thread terminates.");
+ if (err) {
+ health_error();
+ ERR("Health error occurred in %s", __func__);
+ }
+ health_unregister(the_health_sessiond);
+ rcu_thread_offline();
+ rcu_unregister_thread();
+ return NULL;
+}
+
+static bool shutdown_ht_cleanup_thread(void *data)
+{
+ int ret;
+
+ ret = notify_thread_pipe(ht_cleanup_quit_pipe[1]);
+ if (ret < 0) {
+ ERR("write error on ht_cleanup quit pipe");
+ goto end;
+ }
+end:
+ return ret;
+}
+
+struct lttng_thread *launch_ht_cleanup_thread(void)
+{
+ int ret;
+ struct lttng_thread *thread;
+
+ ret = init_pipe(the_ht_cleanup_pipe);
+ if (ret) {
+ goto error;
+ }
+
+ ret = init_pipe(ht_cleanup_quit_pipe);
+ if (ret) {
+ goto error;
+ }
+
+ thread = lttng_thread_create("HT cleanup",
+ thread_ht_cleanup,
+ shutdown_ht_cleanup_thread,
+ cleanup_ht_cleanup_thread,
+ NULL);
+ if (!thread) {
+ goto error;
+ }
+ return thread;
+error:
+ cleanup_ht_cleanup_thread(NULL);
+ return NULL;
+}
projects / lttng-tools.git / blobdiff