Add debugging output to ht-cleanup thread
[lttng-tools.git] / src / bin / lttng-sessiond / ht-cleanup.c
CommitLineData
0b2dc8df
MD
1/*
2 * Copyright (C) 2013 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License, version 2 only,
6 * as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License along
14 * with this program; if not, write to the Free Software Foundation, Inc.,
15 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
16 */
17
18#define _GNU_SOURCE
6c1c0768 19#define _LGPL_SOURCE
0b2dc8df
MD
20#include <assert.h>
21
22#include <common/hashtable/hashtable.h>
23#include <common/common.h>
24#include <common/utils.h>
25
26#include "lttng-sessiond.h"
8782cc74 27#include "health-sessiond.h"
9ad42ec1 28#include "testpoint.h"
0b2dc8df
MD
29
30void *thread_ht_cleanup(void *data)
31{
32 int ret, i, pollfd, err = -1;
6cd525e8 33 ssize_t size_ret;
0b2dc8df
MD
34 uint32_t revents, nb_fd;
35 struct lttng_poll_event events;
36
37 DBG("[ht-thread] startup.");
38
39 rcu_register_thread();
40 rcu_thread_online();
41
6c71277b 42 health_register(health_sessiond, HEALTH_SESSIOND_TYPE_HT_CLEANUP);
0b2dc8df 43
9ad42ec1 44 if (testpoint(sessiond_thread_ht_cleanup)) {
74588b4d 45 DBG("[ht-thread] testpoint.");
9ad42ec1
MD
46 goto error_testpoint;
47 }
48
0b2dc8df
MD
49 health_code_update();
50
4a15001e 51 ret = sessiond_set_ht_cleanup_thread_pollset(&events, 2);
0b2dc8df 52 if (ret < 0) {
74588b4d 53 DBG("[ht-thread] sessiond_set_ht_cleanup_thread_pollset error %d.", ret);
0b2dc8df
MD
54 goto error_poll_create;
55 }
56
57 /* Add pipe to the pollset. */
58 ret = lttng_poll_add(&events, ht_cleanup_pipe[0], LPOLLIN | LPOLLERR);
59 if (ret < 0) {
74588b4d 60 DBG("[ht-thread] lttng_poll_add error %d.", ret);
0b2dc8df
MD
61 goto error;
62 }
63
64 health_code_update();
65
66 while (1) {
4a15001e
MD
67 int handled_event;
68
0b2dc8df
MD
69 DBG3("[ht-thread] Polling on %d fds.",
70 LTTNG_POLL_GETNB(&events));
71
72 /* Inifinite blocking call, waiting for transmission */
73restart:
4a15001e 74 handled_event = 0;
0b2dc8df
MD
75 health_poll_entry();
76 ret = lttng_poll_wait(&events, -1);
77 health_poll_exit();
78 if (ret < 0) {
79 /*
80 * Restart interrupted system call.
81 */
82 if (errno == EINTR) {
83 goto restart;
84 }
85 goto error;
86 }
87
88 nb_fd = ret;
89
90 for (i = 0; i < nb_fd; i++) {
91 struct lttng_ht *ht;
92
93 health_code_update();
94
95 /* Fetch once the poll data */
96 revents = LTTNG_POLL_GETEV(&events, i);
97 pollfd = LTTNG_POLL_GETFD(&events, i);
98
4a15001e
MD
99 if (pollfd != ht_cleanup_pipe[0]) {
100 continue;
0b2dc8df 101 }
0b2dc8df
MD
102
103 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
104 ERR("ht cleanup pipe error");
105 goto error;
106 } else if (!(revents & LPOLLIN)) {
107 /* No POLLIN and not a catched error, stop the thread. */
108 ERR("ht cleanup failed. revent: %u", revents);
109 goto error;
110 }
111
6cd525e8
MD
112 /* Get socket from dispatch thread. */
113 size_ret = lttng_read(ht_cleanup_pipe[0], &ht,
114 sizeof(ht));
115 if (size_ret < sizeof(ht)) {
0b2dc8df
MD
116 PERROR("ht cleanup notify pipe");
117 goto error;
118 }
119 health_code_update();
120 /*
121 * The whole point of this thread is to call
122 * lttng_ht_destroy from a context that is NOT:
123 * 1) a read-side RCU lock,
124 * 2) a call_rcu thread.
125 */
126 lttng_ht_destroy(ht);
127
128 health_code_update();
129 }
4a15001e
MD
130
131 /* Only check cleanup quit when no more work to do. */
132 if (handled_event) {
133 continue;
134 }
135
136 for (i = 0; i < nb_fd; i++) {
137 health_code_update();
138
139 /* Fetch once the poll data */
140 revents = LTTNG_POLL_GETEV(&events, i);
141 pollfd = LTTNG_POLL_GETFD(&events, i);
142
143 if (pollfd == ht_cleanup_pipe[0]) {
144 continue;
145 }
146
147 /* Thread quit pipe has been closed. Killing thread. */
148 ret = sessiond_check_ht_cleanup_quit(pollfd, revents);
149 if (ret) {
150 err = 0;
74588b4d 151 DBG("[ht-cleanup] quit.");
4a15001e
MD
152 goto exit;
153 }
154 }
0b2dc8df
MD
155 }
156
157exit:
158error:
159 lttng_poll_clean(&events);
160error_poll_create:
9ad42ec1 161error_testpoint:
4a15001e 162 DBG("[ht-cleanup] Thread terminates.");
0b2dc8df
MD
163 if (err) {
164 health_error();
165 ERR("Health error occurred in %s", __func__);
166 }
8782cc74 167 health_unregister(health_sessiond);
0b2dc8df
MD
168 rcu_thread_offline();
169 rcu_unregister_thread();
170 return NULL;
171}
This page took 0.056663 seconds and 4 git commands to generate.