+/*
+ * Copyright (C) 2013 - Mathieu Desnoyers <mathieu.desnoyers@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 _GNU_SOURCE
+#include <assert.h>
+
+#include <common/hashtable/hashtable.h>
+#include <common/common.h>
+#include <common/utils.h>
+
+#include "lttng-sessiond.h"
+#include "health.h"
+
+void *thread_ht_cleanup(void *data)
+{
+ int ret, i, pollfd, err = -1;
+ uint32_t revents, nb_fd;
+ struct lttng_poll_event events;
+
+ DBG("[ht-thread] startup.");
+
+ rcu_register_thread();
+ rcu_thread_online();
+
+ health_register(HEALTH_TYPE_HT_CLEANUP);
+
+ health_code_update();
+
+ ret = sessiond_set_thread_pollset(&events, 2);
+ if (ret < 0) {
+ goto error_poll_create;
+ }
+
+ /* Add pipe to the pollset. */
+ ret = lttng_poll_add(&events, ht_cleanup_pipe[0], LPOLLIN | LPOLLERR);
+ if (ret < 0) {
+ goto error;
+ }
+
+ health_code_update();
+
+ while (1) {
+ DBG3("[ht-thread] Polling on %d fds.",
+ LTTNG_POLL_GETNB(&events));
+
+ /* Inifinite blocking call, waiting for transmission */
+restart:
+ health_poll_entry();
+ ret = lttng_poll_wait(&events, -1);
+ 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++) {
+ struct lttng_ht *ht;
+
+ health_code_update();
+
+ /* Fetch once the poll data */
+ revents = LTTNG_POLL_GETEV(&events, i);
+ pollfd = LTTNG_POLL_GETFD(&events, i);
+
+ /* Thread quit pipe has been closed. Killing thread. */
+ ret = sessiond_check_thread_quit_pipe(pollfd, revents);
+ if (ret) {
+ err = 0;
+ goto exit;
+ }
+ assert(pollfd == ht_cleanup_pipe[0]);
+
+ if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
+ ERR("ht cleanup pipe error");
+ goto error;
+ } else if (!(revents & LPOLLIN)) {
+ /* No POLLIN and not a catched error, stop the thread. */
+ ERR("ht cleanup failed. revent: %u", revents);
+ goto error;
+ }
+
+ do {
+ /* Get socket from dispatch thread. */
+ ret = read(ht_cleanup_pipe[0], &ht, sizeof(ht));
+ } while (ret < 0 && errno == EINTR);
+ if (ret < 0 || 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();
+ }
+ }
+
+exit:
+error:
+ lttng_poll_clean(&events);
+error_poll_create:
+ utils_close_pipe(ht_cleanup_pipe);
+ ht_cleanup_pipe[0] = ht_cleanup_pipe[1] = -1;
+ DBG("[ust-thread] cleanup complete.");
+ if (err) {
+ health_error();
+ ERR("Health error occurred in %s", __func__);
+ }
+ health_unregister();
+ rcu_thread_offline();
+ rcu_unregister_thread();
+ return NULL;
+}