1 /* Copyright (C) 2009 Pierre-Marc Fournier
3 * This library is free software; you can redistribute it and/or
4 * modify it under the terms of the GNU Lesser General Public
5 * License as published by the Free Software Foundation; either
6 * version 2.1 of the License, or (at your option) any later version.
8 * This library 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 GNU
11 * Lesser General Public License for more details.
13 * You should have received a copy of the GNU Lesser General Public
14 * License along with this library; if not, write to the Free Software
15 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18 /* This file contains the implementation of the UST listener thread, which
19 * receives trace control commands. It also coordinates the initialization of
29 #include <sys/epoll.h>
31 #include <sys/types.h>
32 #include <sys/socket.h>
36 #include <urcu/uatomic_arch.h>
37 #include <urcu/list.h>
39 #include <ust/marker.h>
40 #include <ust/tracepoint.h>
41 #include <ust/tracectl.h>
42 #include <ust/clock.h>
47 #include "marker-control.h"
49 /* This should only be accessed by the constructor, before the creation
50 * of the listener, and then only by the listener.
54 /* The process pid is used to detect a non-traceable fork
55 * and allow the non-traceable fork to be ignored
56 * by destructor sequences in libust
58 static pid_t processpid
= 0;
60 static struct ustcomm_header _receive_header
;
61 static struct ustcomm_header
*receive_header
= &_receive_header
;
62 static char receive_buffer
[USTCOMM_BUFFER_SIZE
];
63 static char send_buffer
[USTCOMM_BUFFER_SIZE
];
68 * Listener thread data vs fork() protection mechanism. Ensures that no listener
69 * thread mutexes and data structures are being concurrently modified or held by
70 * other threads when fork() is executed.
72 static pthread_mutex_t listener_thread_data_mutex
= PTHREAD_MUTEX_INITIALIZER
;
74 /* Mutex protecting listen_sock. Nests inside listener_thread_data_mutex. */
75 static pthread_mutex_t listen_sock_mutex
= PTHREAD_MUTEX_INITIALIZER
;
76 static struct ustcomm_sock
*listen_sock
;
78 extern struct chan_info_struct chan_infos
[];
80 static struct cds_list_head open_buffers_list
= CDS_LIST_HEAD_INIT(open_buffers_list
);
82 static struct cds_list_head ust_socks
= CDS_LIST_HEAD_INIT(ust_socks
);
84 /* volatile because shared between the listener and the main thread */
85 int buffers_to_export
= 0;
89 static long long make_pidunique(void)
94 gettimeofday(&tv
, NULL
);
103 static void print_markers(FILE *fp
)
105 struct marker_iter iter
;
108 marker_iter_reset(&iter
);
109 marker_iter_start(&iter
);
111 while (iter
.marker
) {
112 fprintf(fp
, "marker: %s/%s %d \"%s\" %p\n",
113 (*iter
.marker
)->channel
,
114 (*iter
.marker
)->name
,
115 (int)imv_read((*iter
.marker
)->state
),
116 (*iter
.marker
)->format
,
117 (*iter
.marker
)->location
);
118 marker_iter_next(&iter
);
123 static void print_trace_events(FILE *fp
)
125 struct trace_event_iter iter
;
128 trace_event_iter_reset(&iter
);
129 trace_event_iter_start(&iter
);
131 while (iter
.trace_event
) {
132 fprintf(fp
, "trace_event: %s\n", (*iter
.trace_event
)->name
);
133 trace_event_iter_next(&iter
);
135 unlock_trace_events();
138 static int connect_ustconsumer(void)
141 char default_daemon_path
[] = SOCK_DIR
"/ustconsumer";
142 char *explicit_daemon_path
, *daemon_path
;
144 explicit_daemon_path
= getenv("UST_DAEMON_SOCKET");
145 if (explicit_daemon_path
) {
146 daemon_path
= explicit_daemon_path
;
148 daemon_path
= default_daemon_path
;
151 DBG("Connecting to daemon_path %s", daemon_path
);
153 result
= ustcomm_connect_path(daemon_path
, &fd
);
155 WARN("connect_ustconsumer failed, daemon_path: %s",
164 static void request_buffer_consumer(int sock
,
169 struct ustcomm_header send_header
, recv_header
;
170 struct ustcomm_buffer_info buf_inf
;
173 result
= ustcomm_pack_buffer_info(&send_header
,
180 ERR("failed to pack buffer info message %s_%d",
185 buf_inf
.pid
= getpid();
186 send_header
.command
= CONSUME_BUFFER
;
188 result
= ustcomm_req(sock
, &send_header
, (char *) &buf_inf
,
191 PERROR("request for buffer consumer failed, is the daemon online?");
197 /* Ask the daemon to collect a trace called trace_name and being
198 * produced by this pid.
200 * The trace must be at least allocated. (It can also be started.)
201 * This is because _ltt_trace_find is used.
204 static void inform_consumer_daemon(const char *trace_name
)
207 struct ust_trace
*trace
;
210 sock
= connect_ustconsumer();
215 DBG("Connected to ustconsumer");
219 trace
= _ltt_trace_find(trace_name
);
221 WARN("inform_consumer_daemon: could not find trace \"%s\"; it is probably already destroyed", trace_name
);
225 for (i
=0; i
< trace
->nr_channels
; i
++) {
226 if (trace
->channels
[i
].request_collection
) {
227 /* iterate on all cpus */
228 for (j
=0; j
<trace
->channels
[i
].n_cpus
; j
++) {
229 ch_name
= trace
->channels
[i
].channel_name
;
230 request_buffer_consumer(sock
, trace_name
,
232 CMM_STORE_SHARED(buffers_to_export
,
233 CMM_LOAD_SHARED(buffers_to_export
)+1);
244 static struct ust_channel
*find_channel(const char *ch_name
,
245 struct ust_trace
*trace
)
249 for (i
=0; i
<trace
->nr_channels
; i
++) {
250 if (!strcmp(trace
->channels
[i
].channel_name
, ch_name
)) {
251 return &trace
->channels
[i
];
258 static int get_buffer_shmid_pipe_fd(const char *trace_name
, const char *ch_name
,
261 int *buf_struct_shmid
,
264 struct ust_trace
*trace
;
265 struct ust_channel
*channel
;
266 struct ust_buffer
*buf
;
268 DBG("get_buffer_shmid_pipe_fd");
271 trace
= _ltt_trace_find(trace_name
);
275 ERR("cannot find trace!");
279 channel
= find_channel(ch_name
, trace
);
281 ERR("cannot find channel %s!", ch_name
);
285 buf
= channel
->buf
[ch_cpu
];
287 *buf_shmid
= buf
->shmid
;
288 *buf_struct_shmid
= channel
->buf_struct_shmids
[ch_cpu
];
289 *buf_pipe_fd
= buf
->data_ready_fd_read
;
294 static int get_subbuf_num_size(const char *trace_name
, const char *ch_name
,
297 struct ust_trace
*trace
;
298 struct ust_channel
*channel
;
300 DBG("get_subbuf_size");
303 trace
= _ltt_trace_find(trace_name
);
307 ERR("cannot find trace!");
311 channel
= find_channel(ch_name
, trace
);
313 ERR("unable to find channel");
317 *num
= channel
->subbuf_cnt
;
318 *size
= channel
->subbuf_size
;
323 /* Return the power of two which is equal or higher to v */
325 static unsigned int pow2_higher_or_eq(unsigned int v
)
328 int retval
= 1<<(hb
-1);
336 static int set_subbuf_size(const char *trace_name
, const char *ch_name
,
341 struct ust_trace
*trace
;
342 struct ust_channel
*channel
;
344 DBG("set_subbuf_size");
346 power
= pow2_higher_or_eq(size
);
347 power
= max_t(unsigned int, 2u, power
);
349 WARN("using the next power of two for buffer size = %u\n", power
);
353 trace
= _ltt_trace_find_setup(trace_name
);
355 ERR("cannot find trace!");
360 channel
= find_channel(ch_name
, trace
);
362 ERR("unable to find channel");
367 channel
->subbuf_size
= power
;
368 DBG("the set_subbuf_size for the requested channel is %zu", channel
->subbuf_size
);
376 static int set_subbuf_num(const char *trace_name
, const char *ch_name
,
379 struct ust_trace
*trace
;
380 struct ust_channel
*channel
;
383 DBG("set_subbuf_num");
386 ERR("subbuffer count should be greater than 2");
391 trace
= _ltt_trace_find_setup(trace_name
);
393 ERR("cannot find trace!");
398 channel
= find_channel(ch_name
, trace
);
400 ERR("unable to find channel");
405 channel
->subbuf_cnt
= num
;
406 DBG("the set_subbuf_cnt for the requested channel is %u", channel
->subbuf_cnt
);
413 static int get_subbuffer(const char *trace_name
, const char *ch_name
,
414 int ch_cpu
, long *consumed_old
)
417 struct ust_trace
*trace
;
418 struct ust_channel
*channel
;
419 struct ust_buffer
*buf
;
426 trace
= _ltt_trace_find(trace_name
);
429 DBG("Cannot find trace. It was likely destroyed by the user.");
434 channel
= find_channel(ch_name
, trace
);
436 ERR("unable to find channel");
441 buf
= channel
->buf
[ch_cpu
];
443 retval
= ust_buffers_get_subbuf(buf
, consumed_old
);
445 WARN("missed buffer?");
455 static int notify_buffer_mapped(const char *trace_name
,
460 struct ust_trace
*trace
;
461 struct ust_channel
*channel
;
462 struct ust_buffer
*buf
;
464 DBG("get_buffer_fd");
467 trace
= _ltt_trace_find(trace_name
);
471 DBG("Cannot find trace. It was likely destroyed by the user.");
475 channel
= find_channel(ch_name
, trace
);
478 ERR("unable to find channel");
482 buf
= channel
->buf
[ch_cpu
];
484 /* Being here is the proof the daemon has mapped the buffer in its
485 * memory. We may now decrement buffers_to_export.
487 if (uatomic_read(&buf
->consumed
) == 0) {
488 DBG("decrementing buffers_to_export");
489 CMM_STORE_SHARED(buffers_to_export
, CMM_LOAD_SHARED(buffers_to_export
)-1);
492 /* The buffer has been exported, ergo, we can add it to the
493 * list of open buffers
495 cds_list_add(&buf
->open_buffers_list
, &open_buffers_list
);
503 static int put_subbuffer(const char *trace_name
, const char *ch_name
,
504 int ch_cpu
, long consumed_old
)
507 struct ust_trace
*trace
;
508 struct ust_channel
*channel
;
509 struct ust_buffer
*buf
;
514 trace
= _ltt_trace_find(trace_name
);
518 DBG("Cannot find trace. It was likely destroyed by the user.");
522 channel
= find_channel(ch_name
, trace
);
525 ERR("unable to find channel");
529 buf
= channel
->buf
[ch_cpu
];
531 retval
= ust_buffers_put_subbuf(buf
, consumed_old
);
533 WARN("ust_buffers_put_subbuf: error (subbuf=%s_%d)",
536 DBG("ust_buffers_put_subbuf: success (subbuf=%s_%d)",
546 static void release_listener_mutex(void *ptr
)
548 pthread_mutex_unlock(&listener_thread_data_mutex
);
551 static void listener_cleanup(void *ptr
)
553 pthread_mutex_lock(&listen_sock_mutex
);
555 ustcomm_del_named_sock(listen_sock
, 0);
558 pthread_mutex_unlock(&listen_sock_mutex
);
561 static int force_subbuf_switch(const char *trace_name
)
563 struct ust_trace
*trace
;
564 int i
, j
, retval
= 0;
567 trace
= _ltt_trace_find(trace_name
);
570 DBG("Cannot find trace. It was likely destroyed by the user.");
574 for (i
= 0; i
< trace
->nr_channels
; i
++) {
575 for (j
= 0; j
< trace
->channels
[i
].n_cpus
; j
++) {
576 ltt_force_switch(trace
->channels
[i
].buf
[j
],
587 static int process_trace_cmd(int command
, char *trace_name
)
590 char trace_type
[] = "ustrelay";
594 /* start is an operation that setups the trace, allocates it and starts it */
595 result
= ltt_trace_setup(trace_name
);
597 ERR("ltt_trace_setup failed");
601 result
= ltt_trace_set_type(trace_name
, trace_type
);
603 ERR("ltt_trace_set_type failed");
607 result
= ltt_trace_alloc(trace_name
);
609 ERR("ltt_trace_alloc failed");
613 inform_consumer_daemon(trace_name
);
615 result
= ltt_trace_start(trace_name
);
617 ERR("ltt_trace_start failed");
625 result
= ltt_trace_setup(trace_name
);
627 ERR("ltt_trace_setup failed");
631 result
= ltt_trace_set_type(trace_name
, trace_type
);
633 ERR("ltt_trace_set_type failed");
641 result
= ltt_trace_alloc(trace_name
);
643 ERR("ltt_trace_alloc failed");
646 inform_consumer_daemon(trace_name
);
653 result
= ltt_trace_setup(trace_name
);
655 ERR("ltt_trace_setup failed");
659 result
= ltt_trace_set_type(trace_name
, trace_type
);
661 ERR("ltt_trace_set_type failed");
669 result
= ltt_trace_alloc(trace_name
);
671 ERR("ltt_trace_alloc failed");
675 inform_consumer_daemon(trace_name
);
678 result
= ltt_trace_start(trace_name
);
680 ERR("ltt_trace_start failed");
688 result
= ltt_trace_stop(trace_name
);
690 ERR("ltt_trace_stop failed");
696 DBG("trace destroy");
698 result
= ltt_trace_destroy(trace_name
, 0);
700 ERR("ltt_trace_destroy failed");
704 case FORCE_SUBBUF_SWITCH
:
707 result
= force_subbuf_switch(trace_name
);
709 ERR("force_subbuf_switch failed");
719 static void process_channel_cmd(int sock
, int command
,
720 struct ustcomm_channel_info
*ch_inf
)
722 struct ustcomm_header _reply_header
;
723 struct ustcomm_header
*reply_header
= &_reply_header
;
724 struct ustcomm_channel_info
*reply_msg
=
725 (struct ustcomm_channel_info
*)send_buffer
;
726 int result
, offset
= 0, num
, size
;
728 memset(reply_header
, 0, sizeof(*reply_header
));
731 case GET_SUBBUF_NUM_SIZE
:
732 result
= get_subbuf_num_size(ch_inf
->trace
,
736 reply_header
->result
= result
;
740 reply_msg
->channel
= USTCOMM_POISON_PTR
;
741 reply_msg
->subbuf_num
= num
;
742 reply_msg
->subbuf_size
= size
;
745 reply_header
->size
= COMPUTE_MSG_SIZE(reply_msg
, offset
);
749 reply_header
->result
= set_subbuf_num(ch_inf
->trace
,
754 case SET_SUBBUF_SIZE
:
755 reply_header
->result
= set_subbuf_size(ch_inf
->trace
,
757 ch_inf
->subbuf_size
);
762 if (ustcomm_send(sock
, reply_header
, (char *)reply_msg
) < 0) {
763 ERR("ustcomm_send failed");
767 static void process_buffer_cmd(int sock
, int command
,
768 struct ustcomm_buffer_info
*buf_inf
)
770 struct ustcomm_header _reply_header
;
771 struct ustcomm_header
*reply_header
= &_reply_header
;
772 struct ustcomm_buffer_info
*reply_msg
=
773 (struct ustcomm_buffer_info
*)send_buffer
;
774 int result
, offset
= 0, buf_shmid
, buf_struct_shmid
, buf_pipe_fd
;
777 memset(reply_header
, 0, sizeof(*reply_header
));
780 case GET_BUF_SHMID_PIPE_FD
:
781 result
= get_buffer_shmid_pipe_fd(buf_inf
->trace
,
788 reply_header
->result
= result
;
792 reply_msg
->channel
= USTCOMM_POISON_PTR
;
793 reply_msg
->buf_shmid
= buf_shmid
;
794 reply_msg
->buf_struct_shmid
= buf_struct_shmid
;
796 reply_header
->size
= COMPUTE_MSG_SIZE(reply_msg
, offset
);
797 reply_header
->fd_included
= 1;
799 if (ustcomm_send_fd(sock
, reply_header
, (char *)reply_msg
,
801 ERR("ustcomm_send failed");
805 case NOTIFY_BUF_MAPPED
:
806 reply_header
->result
=
807 notify_buffer_mapped(buf_inf
->trace
,
812 result
= get_subbuffer(buf_inf
->trace
, buf_inf
->channel
,
813 buf_inf
->ch_cpu
, &consumed_old
);
815 reply_header
->result
= result
;
819 reply_msg
->channel
= USTCOMM_POISON_PTR
;
820 reply_msg
->consumed_old
= consumed_old
;
822 reply_header
->size
= COMPUTE_MSG_SIZE(reply_msg
, offset
);
826 result
= put_subbuffer(buf_inf
->trace
, buf_inf
->channel
,
828 buf_inf
->consumed_old
);
829 reply_header
->result
= result
;
834 if (ustcomm_send(sock
, reply_header
, (char *)reply_msg
) < 0) {
835 ERR("ustcomm_send failed");
840 static void process_marker_cmd(int sock
, int command
,
841 struct ustcomm_marker_info
*marker_inf
)
843 struct ustcomm_header _reply_header
;
844 struct ustcomm_header
*reply_header
= &_reply_header
;
847 memset(reply_header
, 0, sizeof(*reply_header
));
852 result
= ltt_marker_connect(marker_inf
->channel
,
856 WARN("could not enable marker; channel=%s,"
864 result
= ltt_marker_disconnect(marker_inf
->channel
,
868 WARN("could not disable marker; channel=%s,"
876 reply_header
->result
= result
;
878 if (ustcomm_send(sock
, reply_header
, NULL
) < 0) {
879 ERR("ustcomm_send failed");
883 static void process_client_cmd(struct ustcomm_header
*recv_header
,
884 char *recv_buf
, int sock
)
887 struct ustcomm_header _reply_header
;
888 struct ustcomm_header
*reply_header
= &_reply_header
;
889 char *send_buf
= send_buffer
;
891 memset(reply_header
, 0, sizeof(*reply_header
));
892 memset(send_buf
, 0, sizeof(send_buffer
));
894 switch(recv_header
->command
) {
895 case GET_SUBBUF_NUM_SIZE
:
897 case SET_SUBBUF_SIZE
:
899 struct ustcomm_channel_info
*ch_inf
;
900 ch_inf
= (struct ustcomm_channel_info
*)recv_buf
;
901 result
= ustcomm_unpack_channel_info(ch_inf
);
903 ERR("couldn't unpack channel info");
904 reply_header
->result
= -EINVAL
;
907 process_channel_cmd(sock
, recv_header
->command
, ch_inf
);
910 case GET_BUF_SHMID_PIPE_FD
:
911 case NOTIFY_BUF_MAPPED
:
915 struct ustcomm_buffer_info
*buf_inf
;
916 buf_inf
= (struct ustcomm_buffer_info
*)recv_buf
;
917 result
= ustcomm_unpack_buffer_info(buf_inf
);
919 ERR("couldn't unpack buffer info");
920 reply_header
->result
= -EINVAL
;
923 process_buffer_cmd(sock
, recv_header
->command
, buf_inf
);
929 struct ustcomm_marker_info
*marker_inf
;
930 marker_inf
= (struct ustcomm_marker_info
*)recv_buf
;
931 result
= ustcomm_unpack_marker_info(marker_inf
);
933 ERR("couldn't unpack marker info");
934 reply_header
->result
= -EINVAL
;
937 process_marker_cmd(sock
, recv_header
->command
, marker_inf
);
946 fp
= open_memstream(&ptr
, &size
);
948 ERR("opening memstream failed");
954 reply_header
->size
= size
+ 1; /* Include final \0 */
956 result
= ustcomm_send(sock
, reply_header
, ptr
);
961 PERROR("failed to send markers list");
966 case LIST_TRACE_EVENTS
:
972 fp
= open_memstream(&ptr
, &size
);
974 ERR("opening memstream failed");
977 print_trace_events(fp
);
980 reply_header
->size
= size
+ 1; /* Include final \0 */
982 result
= ustcomm_send(sock
, reply_header
, ptr
);
987 ERR("list_trace_events failed");
997 /* FIXME: No functionality at all... */
1000 DBG("load_probe_lib loading %s", libfile
);
1006 struct ustcomm_pidunique
*pid_msg
;
1007 pid_msg
= (struct ustcomm_pidunique
*)send_buf
;
1009 pid_msg
->pidunique
= pidunique
;
1010 reply_header
->size
= sizeof(pid_msg
);
1017 struct ustcomm_single_field
*sock_msg
;
1018 char *sock_path_env
;
1020 sock_msg
= (struct ustcomm_single_field
*)send_buf
;
1022 sock_path_env
= getenv("UST_DAEMON_SOCKET");
1024 if (!sock_path_env
) {
1025 result
= ustcomm_pack_single_field(reply_header
,
1027 SOCK_DIR
"/ustconsumer");
1030 result
= ustcomm_pack_single_field(reply_header
,
1034 reply_header
->result
= result
;
1040 struct ustcomm_single_field
*sock_msg
;
1041 sock_msg
= (struct ustcomm_single_field
*)recv_buf
;
1042 result
= ustcomm_unpack_single_field(sock_msg
);
1044 reply_header
->result
= -EINVAL
;
1048 reply_header
->result
= setenv("UST_DAEMON_SOCKET",
1049 sock_msg
->field
, 1);
1060 case FORCE_SUBBUF_SWITCH
:
1062 struct ustcomm_single_field
*trace_inf
=
1063 (struct ustcomm_single_field
*)recv_buf
;
1065 result
= ustcomm_unpack_single_field(trace_inf
);
1067 ERR("couldn't unpack trace info");
1068 reply_header
->result
= -EINVAL
;
1072 reply_header
->result
=
1073 process_trace_cmd(recv_header
->command
,
1079 reply_header
->result
= -EINVAL
;
1087 ustcomm_send(sock
, reply_header
, send_buf
);
1090 #define MAX_EVENTS 10
1092 void *listener_main(void *p
)
1094 struct ustcomm_sock
*epoll_sock
;
1095 struct epoll_event events
[MAX_EVENTS
];
1096 struct sockaddr addr
;
1097 int accept_fd
, nfds
, result
, i
, addr_size
;
1101 pthread_cleanup_push(listener_cleanup
, NULL
);
1104 nfds
= epoll_wait(epoll_fd
, events
, MAX_EVENTS
, -1);
1106 PERROR("listener_main: epoll_wait failed");
1110 for (i
= 0; i
< nfds
; i
++) {
1111 pthread_mutex_lock(&listener_thread_data_mutex
);
1112 pthread_cleanup_push(release_listener_mutex
, NULL
);
1113 epoll_sock
= (struct ustcomm_sock
*)events
[i
].data
.ptr
;
1114 if (epoll_sock
== listen_sock
) {
1115 addr_size
= sizeof(struct sockaddr
);
1116 accept_fd
= accept(epoll_sock
->fd
,
1118 (socklen_t
*)&addr_size
);
1119 if (accept_fd
== -1) {
1120 PERROR("listener_main: accept failed");
1123 ustcomm_init_sock(accept_fd
, epoll_fd
,
1126 memset(receive_header
, 0,
1127 sizeof(*receive_header
));
1128 memset(receive_buffer
, 0,
1129 sizeof(receive_buffer
));
1130 result
= ustcomm_recv(epoll_sock
->fd
,
1134 ustcomm_del_sock(epoll_sock
, 0);
1136 process_client_cmd(receive_header
,
1141 pthread_cleanup_pop(1); /* release listener mutex */
1145 pthread_cleanup_pop(1);
1148 /* These should only be accessed in the parent thread,
1151 static volatile sig_atomic_t have_listener
= 0;
1152 static pthread_t listener_thread
;
1154 void create_listener(void)
1157 sigset_t sig_all_blocked
;
1158 sigset_t orig_parent_mask
;
1160 if (have_listener
) {
1161 WARN("not creating listener because we already had one");
1165 /* A new thread created by pthread_create inherits the signal mask
1166 * from the parent. To avoid any signal being received by the
1167 * listener thread, we block all signals temporarily in the parent,
1168 * while we create the listener thread.
1171 sigfillset(&sig_all_blocked
);
1173 result
= pthread_sigmask(SIG_SETMASK
, &sig_all_blocked
, &orig_parent_mask
);
1175 PERROR("pthread_sigmask: %s", strerror(result
));
1178 result
= pthread_create(&listener_thread
, NULL
, listener_main
, NULL
);
1180 PERROR("pthread_create");
1183 /* Restore original signal mask in parent */
1184 result
= pthread_sigmask(SIG_SETMASK
, &orig_parent_mask
, NULL
);
1186 PERROR("pthread_sigmask: %s", strerror(result
));
1192 #define AUTOPROBE_DISABLED 0
1193 #define AUTOPROBE_ENABLE_ALL 1
1194 #define AUTOPROBE_ENABLE_REGEX 2
1195 static int autoprobe_method
= AUTOPROBE_DISABLED
;
1196 static regex_t autoprobe_regex
;
1198 static void auto_probe_connect(struct marker
*m
)
1202 char* concat_name
= NULL
;
1203 const char *probe_name
= "default";
1205 if (autoprobe_method
== AUTOPROBE_DISABLED
) {
1207 } else if (autoprobe_method
== AUTOPROBE_ENABLE_REGEX
) {
1208 result
= asprintf(&concat_name
, "%s/%s", m
->channel
, m
->name
);
1210 ERR("auto_probe_connect: asprintf failed (marker %s/%s)",
1211 m
->channel
, m
->name
);
1214 if (regexec(&autoprobe_regex
, concat_name
, 0, NULL
, 0)) {
1221 result
= ltt_marker_connect(m
->channel
, m
->name
, probe_name
);
1222 if (result
&& result
!= -EEXIST
)
1223 ERR("ltt_marker_connect (marker = %s/%s, errno = %d)", m
->channel
, m
->name
, -result
);
1225 DBG("auto connected marker %s (addr: %p) %s to probe default", m
->channel
, m
, m
->name
);
1229 static struct ustcomm_sock
* init_app_socket(int epoll_fd
)
1233 struct ustcomm_sock
*sock
;
1235 result
= asprintf(&name
, "%s/%d", SOCK_DIR
, (int)getpid());
1237 ERR("string overflow allocating socket name, "
1238 "UST thread bailing");
1242 result
= ensure_dir_exists(SOCK_DIR
);
1244 ERR("Unable to create socket directory %s, UST thread bailing",
1249 sock
= ustcomm_init_named_socket(name
, epoll_fd
);
1251 ERR("Error initializing named socket (%s). Check that directory"
1252 "exists and that it is writable. UST thread bailing", name
);
1264 static void __attribute__((constructor
)) init()
1268 char* autoprobe_val
= NULL
;
1269 char* subbuffer_size_val
= NULL
;
1270 char* subbuffer_count_val
= NULL
;
1271 unsigned int subbuffer_size
;
1272 unsigned int subbuffer_count
;
1275 /* Assign the pidunique, to be able to differentiate the processes with same
1276 * pid, (before and after an exec).
1278 pidunique
= make_pidunique();
1279 processpid
= getpid();
1281 DBG("Tracectl constructor");
1284 epoll_fd
= epoll_create(MAX_EVENTS
);
1285 if (epoll_fd
== -1) {
1286 ERR("epoll_create failed, tracing shutting down");
1290 /* Create the socket */
1291 listen_sock
= init_app_socket(epoll_fd
);
1293 ERR("failed to create application socket,"
1294 " tracing shutting down");
1300 /* Get clock the clock source type */
1302 /* Default clock source */
1303 ust_clock_source
= CLOCK_TRACE
;
1304 if (clock_gettime(ust_clock_source
, &ts
) != 0) {
1305 ust_clock_source
= CLOCK_MONOTONIC
;
1306 DBG("UST traces will not be synchronized with LTTng traces");
1309 autoprobe_val
= getenv("UST_AUTOPROBE");
1310 if (autoprobe_val
) {
1311 struct marker_iter iter
;
1313 DBG("Autoprobe enabled.");
1315 /* Ensure markers are initialized */
1318 /* Ensure marker control is initialized, for the probe */
1319 init_marker_control();
1321 /* first, set the callback that will connect the
1322 * probe on new markers
1324 if (autoprobe_val
[0] == '/') {
1325 result
= regcomp(&autoprobe_regex
, autoprobe_val
+1, 0);
1329 regerror(result
, &autoprobe_regex
, regexerr
, sizeof(regexerr
));
1330 ERR("cannot parse regex %s (%s), will ignore UST_AUTOPROBE", autoprobe_val
, regexerr
);
1331 /* don't crash the application just for this */
1333 autoprobe_method
= AUTOPROBE_ENABLE_REGEX
;
1336 /* just enable all instrumentation */
1337 autoprobe_method
= AUTOPROBE_ENABLE_ALL
;
1340 marker_set_new_marker_cb(auto_probe_connect
);
1342 /* Now, connect the probes that were already registered. */
1343 marker_iter_reset(&iter
);
1344 marker_iter_start(&iter
);
1346 DBG("now iterating on markers already registered");
1347 while (iter
.marker
) {
1348 DBG("now iterating on marker %s", (*iter
.marker
)->name
);
1349 auto_probe_connect(*iter
.marker
);
1350 marker_iter_next(&iter
);
1354 if (getenv("UST_OVERWRITE")) {
1355 int val
= atoi(getenv("UST_OVERWRITE"));
1356 if (val
== 0 || val
== 1) {
1357 CMM_STORE_SHARED(ust_channels_overwrite_by_default
, val
);
1359 WARN("invalid value for UST_OVERWRITE");
1363 if (getenv("UST_AUTOCOLLECT")) {
1364 int val
= atoi(getenv("UST_AUTOCOLLECT"));
1365 if (val
== 0 || val
== 1) {
1366 CMM_STORE_SHARED(ust_channels_request_collection_by_default
, val
);
1368 WARN("invalid value for UST_AUTOCOLLECT");
1372 subbuffer_size_val
= getenv("UST_SUBBUF_SIZE");
1373 if (subbuffer_size_val
) {
1374 sscanf(subbuffer_size_val
, "%u", &subbuffer_size
);
1375 power
= pow2_higher_or_eq(subbuffer_size
);
1376 if (power
!= subbuffer_size
)
1377 WARN("using the next power of two for buffer size = %u\n", power
);
1378 chan_infos
[LTT_CHANNEL_UST
].def_subbufsize
= power
;
1381 subbuffer_count_val
= getenv("UST_SUBBUF_NUM");
1382 if (subbuffer_count_val
) {
1383 sscanf(subbuffer_count_val
, "%u", &subbuffer_count
);
1384 if (subbuffer_count
< 2)
1385 subbuffer_count
= 2;
1386 chan_infos
[LTT_CHANNEL_UST
].def_subbufcount
= subbuffer_count
;
1389 if (getenv("UST_TRACE")) {
1390 char trace_name
[] = "auto";
1391 char trace_type
[] = "ustrelay";
1393 DBG("starting early tracing");
1395 /* Ensure marker control is initialized */
1396 init_marker_control();
1398 /* Ensure markers are initialized */
1401 /* Ensure buffers are initialized, for the transport to be available.
1402 * We are about to set a trace type and it will fail without this.
1404 init_ustrelay_transport();
1406 /* FIXME: When starting early tracing (here), depending on the
1407 * order of constructors, it is very well possible some marker
1408 * sections are not yet registered. Because of this, some
1409 * channels may not be registered. Yet, we are about to ask the
1410 * daemon to collect the channels. Channels which are not yet
1411 * registered will not be collected.
1413 * Currently, in LTTng, there is no way to add a channel after
1414 * trace start. The reason for this is that it induces complex
1415 * concurrency issues on the trace structures, which can only
1416 * be resolved using RCU. This has not been done yet. As a
1417 * workaround, we are forcing the registration of the "ust"
1418 * channel here. This is the only channel (apart from metadata)
1419 * that can be reliably used in early tracing.
1421 * Non-early tracing does not have this problem and can use
1422 * arbitrary channel names.
1424 ltt_channels_register("ust");
1426 result
= ltt_trace_setup(trace_name
);
1428 ERR("ltt_trace_setup failed");
1432 result
= ltt_trace_set_type(trace_name
, trace_type
);
1434 ERR("ltt_trace_set_type failed");
1438 result
= ltt_trace_alloc(trace_name
);
1440 ERR("ltt_trace_alloc failed");
1444 result
= ltt_trace_start(trace_name
);
1446 ERR("ltt_trace_start failed");
1450 /* Do this after the trace is started in order to avoid creating confusion
1451 * if the trace fails to start. */
1452 inform_consumer_daemon(trace_name
);
1457 /* should decrementally destroy stuff if error */
1461 /* This is only called if we terminate normally, not with an unhandled signal,
1462 * so we cannot rely on it. However, for now, LTTV requires that the header of
1463 * the last sub-buffer contain a valid end time for the trace. This is done
1464 * automatically only when the trace is properly stopped.
1466 * If the traced program crashed, it is always possible to manually add the
1467 * right value in the header, or to open the trace in text mode.
1469 * FIXME: Fix LTTV so it doesn't need this.
1472 static void destroy_traces(void)
1476 /* if trace running, finish it */
1478 DBG("destructor stopping traces");
1480 result
= ltt_trace_stop("auto");
1482 ERR("ltt_trace_stop error");
1485 result
= ltt_trace_destroy("auto", 0);
1487 ERR("ltt_trace_destroy error");
1491 static int trace_recording(void)
1494 struct ust_trace
*trace
;
1498 cds_list_for_each_entry(trace
, <t_traces
.head
, list
) {
1499 if (trace
->active
) {
1505 ltt_unlock_traces();
1510 int restarting_usleep(useconds_t usecs
)
1516 tv
.tv_nsec
= usecs
* 1000;
1519 result
= nanosleep(&tv
, &tv
);
1520 } while (result
== -1 && errno
== EINTR
);
1525 static void stop_listener(void)
1532 result
= pthread_cancel(listener_thread
);
1534 ERR("pthread_cancel: %s", strerror(result
));
1536 result
= pthread_join(listener_thread
, NULL
);
1538 ERR("pthread_join: %s", strerror(result
));
1542 /* This destructor keeps the process alive for a few seconds in order
1543 * to leave time for ustconsumer to connect to its buffers. This is necessary
1544 * for programs whose execution is very short. It is also useful in all
1545 * programs when tracing is started close to the end of the program
1548 * FIXME: For now, this only works for the first trace created in a
1552 static void __attribute__((destructor
)) keepalive()
1554 if (processpid
!= getpid()) {
1558 if (trace_recording() && CMM_LOAD_SHARED(buffers_to_export
)) {
1560 DBG("Keeping process alive for consumer daemon...");
1561 while (CMM_LOAD_SHARED(buffers_to_export
)) {
1562 const int interv
= 200000;
1563 restarting_usleep(interv
);
1566 if (total
>= 3000000) {
1567 WARN("non-consumed buffers remaining after wait limit; not waiting anymore");
1571 DBG("Finally dying...");
1576 /* Ask the listener to stop and clean up. */
1580 void ust_potential_exec(void)
1582 trace_mark(ust
, potential_exec
, MARK_NOARGS
);
1589 /* Notify ust that there was a fork. This needs to be called inside
1590 * the new process, anytime a process whose memory is not shared with
1591 * the parent is created. If this function is not called, the events
1592 * of the new process will not be collected.
1594 * Signals should be disabled before the fork and reenabled only after
1595 * this call in order to guarantee tracing is not started before ust_fork()
1596 * sanitizes the new process.
1599 static void ust_fork(void)
1601 struct ust_buffer
*buf
, *buf_tmp
;
1602 struct ustcomm_sock
*sock
, *sock_tmp
;
1603 struct ust_trace
*trace
, *trace_tmp
;
1606 /* FIXME: technically, the locks could have been taken before the fork */
1607 DBG("ust: forking");
1609 /* Get the pid of the new process */
1610 processpid
= getpid();
1613 * FIXME: This could be prettier, we loop over the list twice and
1614 * following good locking practice should lock around the loop
1616 cds_list_for_each_entry_safe(trace
, trace_tmp
, <t_traces
.head
, list
) {
1617 ltt_trace_stop(trace
->trace_name
);
1620 /* Delete all active connections, but leave them in the epoll set */
1621 cds_list_for_each_entry_safe(sock
, sock_tmp
, &ust_socks
, list
) {
1622 ustcomm_del_sock(sock
, 1);
1625 /* Delete all blocked consumers */
1626 cds_list_for_each_entry_safe(buf
, buf_tmp
, &open_buffers_list
,
1627 open_buffers_list
) {
1628 cds_list_del(&buf
->open_buffers_list
);
1632 * FIXME: This could be prettier, we loop over the list twice and
1633 * following good locking practice should lock around the loop
1635 cds_list_for_each_entry_safe(trace
, trace_tmp
, <t_traces
.head
, list
) {
1636 ltt_trace_destroy(trace
->trace_name
, 1);
1639 /* Clean up the listener socket and epoll, keeping the socket file */
1641 ustcomm_del_named_sock(listen_sock
, 1);
1646 /* Re-start the launch sequence */
1647 CMM_STORE_SHARED(buffers_to_export
, 0);
1651 epoll_fd
= epoll_create(MAX_EVENTS
);
1652 if (epoll_fd
== -1) {
1653 ERR("epoll_create failed, tracing shutting down");
1657 /* Create the socket */
1658 listen_sock
= init_app_socket(epoll_fd
);
1660 ERR("failed to create application socket,"
1661 " tracing shutting down");
1665 ltt_trace_setup("auto");
1666 result
= ltt_trace_set_type("auto", "ustrelay");
1668 ERR("ltt_trace_set_type failed");
1672 ltt_trace_alloc("auto");
1673 ltt_trace_start("auto");
1674 inform_consumer_daemon("auto");
1677 void ust_before_fork(ust_fork_info_t
*fork_info
)
1679 /* Disable signals. This is to avoid that the child
1680 * intervenes before it is properly setup for tracing. It is
1681 * safer to disable all signals, because then we know we are not
1682 * breaking anything by restoring the original mask.
1688 - only do this if tracing is active
1691 /* Disable signals */
1692 sigfillset(&all_sigs
);
1693 result
= sigprocmask(SIG_BLOCK
, &all_sigs
, &fork_info
->orig_sigs
);
1695 PERROR("sigprocmask");
1700 * Take the fork lock to make sure we are not in the middle of
1701 * something in the listener thread.
1703 pthread_mutex_lock(&listener_thread_data_mutex
);
1705 * Hold listen_sock_mutex to protect from listen_sock teardown.
1707 pthread_mutex_lock(&listen_sock_mutex
);
1708 rcu_bp_before_fork();
1711 /* Don't call this function directly in a traced program */
1712 static void ust_after_fork_common(ust_fork_info_t
*fork_info
)
1716 pthread_mutex_unlock(&listen_sock_mutex
);
1717 pthread_mutex_unlock(&listener_thread_data_mutex
);
1719 /* Restore signals */
1720 result
= sigprocmask(SIG_SETMASK
, &fork_info
->orig_sigs
, NULL
);
1722 PERROR("sigprocmask");
1727 void ust_after_fork_parent(ust_fork_info_t
*fork_info
)
1729 rcu_bp_after_fork_parent();
1730 /* Release mutexes and reenable signals */
1731 ust_after_fork_common(fork_info
);
1734 void ust_after_fork_child(ust_fork_info_t
*fork_info
)
1736 /* Release urcu mutexes */
1737 rcu_bp_after_fork_child();
1739 /* Sanitize the child */
1742 /* Then release mutexes and reenable signals */
1743 ust_after_fork_common(fork_info
);