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
22 #include <sys/types.h>
23 #include <sys/socket.h>
32 #include <ust/marker.h>
33 #include <ust/tracectl.h>
38 #include "marker-control.h"
42 #define USTSIGNAL SIGIO
44 #define MAX_MSG_SIZE (100)
46 #define MSG_REGISTER_NOTIF 2
48 char consumer_stack
[10000];
50 /* This should only be accessed by the constructor, before the creation
51 * of the listener, and then only by the listener.
55 struct list_head blocked_consumers
= LIST_HEAD_INIT(blocked_consumers
);
57 static struct ustcomm_app ustcomm_app
;
59 struct tracecmd
{ /* no padding */
64 /* volatile because shared between the listener and the main thread */
65 volatile sig_atomic_t buffers_to_export
= 0;
68 /* size: the size of all the fields except size itself */
71 /* Only the necessary part of the payload is transferred. It
72 * may even be none of it.
77 struct consumer_channel
{
79 struct ltt_channel_struct
*chan
;
82 struct blocked_consumer
{
87 /* args to ustcomm_send_reply */
88 struct ustcomm_server server
;
89 struct ustcomm_source src
;
91 /* args to ust_buffers_get_subbuf */
92 struct ust_buffer
*buf
;
94 struct list_head list
;
97 static long long make_pidunique(void)
102 gettimeofday(&tv
, NULL
);
106 retval
|= tv
.tv_usec
;
111 static void print_markers(FILE *fp
)
113 struct marker_iter iter
;
116 marker_iter_reset(&iter
);
117 marker_iter_start(&iter
);
120 fprintf(fp
, "marker: %s/%s %d \"%s\" %p\n", iter
.marker
->channel
, iter
.marker
->name
, (int)imv_read(iter
.marker
->state
), iter
.marker
->format
, iter
.marker
->location
);
121 marker_iter_next(&iter
);
126 static int init_socket(void);
128 /* This needs to be called whenever a new thread is created. It notifies
129 * liburcu of the new thread.
132 void ust_register_thread(void)
134 rcu_register_thread();
141 struct trctl_msg msg
;
143 /* FIXME: fd_notif should probably be protected by a spinlock */
148 msg
.type
= MSG_NOTIF
;
149 msg
.size
= sizeof(msg
.type
);
151 /* FIXME: don't block here */
152 result
= write(fd_notif
, &msg
, msg
.size
+sizeof(msg
.size
));
159 /* Ask the daemon to collect a trace called trace_name and being
160 * produced by this pid.
162 * The trace must be at least allocated. (It can also be started.)
163 * This is because _ltt_trace_find is used.
166 static void inform_consumer_daemon(const char *trace_name
)
169 struct ust_trace
*trace
;
170 pid_t pid
= getpid();
175 trace
= _ltt_trace_find(trace_name
);
177 WARN("inform_consumer_daemon: could not find trace \"%s\"; it is probably already destroyed", trace_name
);
181 for(i
=0; i
< trace
->nr_channels
; i
++) {
182 /* iterate on all cpus */
183 for(j
=0; j
<trace
->channels
[i
].n_cpus
; j
++) {
185 asprintf(&buf
, "%s_%d", trace
->channels
[i
].channel_name
, j
);
186 result
= ustcomm_request_consumer(pid
, buf
);
188 WARN("Failed to request collection for channel %s. Is the daemon available?", trace
->channels
[i
].channel_name
);
189 /* continue even if fail */
200 void process_blocked_consumers(void)
204 struct blocked_consumer
*bc
;
209 list_for_each_entry(bc
, &blocked_consumers
, list
) {
213 fds
= (struct pollfd
*) malloc(n_fds
* sizeof(struct pollfd
));
215 ERR("malloc returned NULL");
219 list_for_each_entry(bc
, &blocked_consumers
, list
) {
220 fds
[idx
].fd
= bc
->fd_producer
;
221 fds
[idx
].events
= POLLIN
;
222 bc
->tmp_poll_idx
= idx
;
226 while((result
= poll(fds
, n_fds
, 0)) == -1 && errno
== EINTR
)
233 list_for_each_entry(bc
, &blocked_consumers
, list
) {
234 if(fds
[bc
->tmp_poll_idx
].revents
) {
235 long consumed_old
= 0;
238 result
= read(bc
->fd_producer
, &inbuf
, 1);
246 close(bc
->fd_producer
);
250 result
= ustcomm_send_reply(&bc
->server
, "END", &bc
->src
);
252 ERR("ustcomm_send_reply failed");
259 result
= ust_buffers_get_subbuf(bc
->buf
, &consumed_old
);
260 if(result
== -EAGAIN
) {
261 WARN("missed buffer?");
264 else if(result
< 0) {
265 DBG("ust_buffers_get_subbuf: error: %s", strerror(-result
));
267 asprintf(&reply
, "%s %ld", "OK", consumed_old
);
268 result
= ustcomm_send_reply(&bc
->server
, reply
, &bc
->src
);
270 ERR("ustcomm_send_reply failed");
282 void seperate_channel_cpu(const char *channel_and_cpu
, char **channel
, int *cpu
)
286 sep
= rindex(channel_and_cpu
, '_');
289 sep
= channel_and_cpu
+ strlen(channel_and_cpu
);
295 asprintf(channel
, "%.*s", (int)(sep
-channel_and_cpu
), channel_and_cpu
);
298 static int do_cmd_get_shmid(const char *recvbuf
, struct ustcomm_source
*src
)
301 struct ust_trace
*trace
;
302 char trace_name
[] = "auto";
304 char *channel_and_cpu
;
312 channel_and_cpu
= nth_token(recvbuf
, 1);
313 if(channel_and_cpu
== NULL
) {
314 ERR("get_shmid: cannot parse channel");
318 seperate_channel_cpu(channel_and_cpu
, &ch_name
, &ch_cpu
);
320 ERR("Problem parsing channel name");
321 goto free_short_chan_name
;
325 trace
= _ltt_trace_find(trace_name
);
329 ERR("cannot find trace!");
331 goto free_short_chan_name
;
334 for(i
=0; i
<trace
->nr_channels
; i
++) {
335 struct ust_channel
*channel
= &trace
->channels
[i
];
336 struct ust_buffer
*buf
= channel
->buf
[ch_cpu
];
338 if(!strcmp(trace
->channels
[i
].channel_name
, ch_name
)) {
341 // DBG("the shmid for the requested channel is %d", buf->shmid);
342 // DBG("the shmid for its buffer structure is %d", channel->buf_struct_shmids);
343 asprintf(&reply
, "%d %d", buf
->shmid
, channel
->buf_struct_shmids
[ch_cpu
]);
345 result
= ustcomm_send_reply(&ustcomm_app
.server
, reply
, src
);
347 ERR("listener: get_shmid: ustcomm_send_reply failed");
350 goto free_short_chan_name
;
364 ERR("get_shmid: channel not found (%s)", channel_and_cpu
);
367 free_short_chan_name
:
374 static int do_cmd_get_n_subbufs(const char *recvbuf
, struct ustcomm_source
*src
)
377 struct ust_trace
*trace
;
378 char trace_name
[] = "auto";
380 char *channel_and_cpu
;
386 DBG("get_n_subbufs");
388 channel_and_cpu
= nth_token(recvbuf
, 1);
389 if(channel_and_cpu
== NULL
) {
390 ERR("get_n_subbufs: cannot parse channel");
394 seperate_channel_cpu(channel_and_cpu
, &ch_name
, &ch_cpu
);
396 ERR("Problem parsing channel name");
397 goto free_short_chan_name
;
401 trace
= _ltt_trace_find(trace_name
);
405 ERR("cannot find trace!");
407 goto free_short_chan_name
;
410 for(i
=0; i
<trace
->nr_channels
; i
++) {
411 struct ust_channel
*channel
= &trace
->channels
[i
];
413 if(!strcmp(trace
->channels
[i
].channel_name
, ch_name
)) {
416 DBG("the n_subbufs for the requested channel is %d", channel
->subbuf_cnt
);
417 asprintf(&reply
, "%d", channel
->subbuf_cnt
);
419 result
= ustcomm_send_reply(&ustcomm_app
.server
, reply
, src
);
421 ERR("listener: get_n_subbufs: ustcomm_send_reply failed");
424 goto free_short_chan_name
;
433 ERR("get_n_subbufs: unable to find channel");
436 free_short_chan_name
:
443 static int do_cmd_get_subbuf_size(const char *recvbuf
, struct ustcomm_source
*src
)
446 struct ust_trace
*trace
;
447 char trace_name
[] = "auto";
449 char *channel_and_cpu
;
455 DBG("get_subbuf_size");
457 channel_and_cpu
= nth_token(recvbuf
, 1);
458 if(channel_and_cpu
== NULL
) {
459 ERR("get_subbuf_size: cannot parse channel");
463 seperate_channel_cpu(channel_and_cpu
, &ch_name
, &ch_cpu
);
465 ERR("Problem parsing channel name");
466 goto free_short_chan_name
;
470 trace
= _ltt_trace_find(trace_name
);
474 ERR("cannot find trace!");
476 goto free_short_chan_name
;
479 for(i
=0; i
<trace
->nr_channels
; i
++) {
480 struct ust_channel
*channel
= &trace
->channels
[i
];
482 if(!strcmp(trace
->channels
[i
].channel_name
, ch_name
)) {
485 DBG("the subbuf_size for the requested channel is %zd", channel
->subbuf_size
);
486 asprintf(&reply
, "%zd", channel
->subbuf_size
);
488 result
= ustcomm_send_reply(&ustcomm_app
.server
, reply
, src
);
490 ERR("listener: get_subbuf_size: ustcomm_send_reply failed");
493 goto free_short_chan_name
;
502 ERR("get_subbuf_size: unable to find channel");
505 free_short_chan_name
:
512 static int do_cmd_get_subbuffer(const char *recvbuf
, struct ustcomm_source
*src
)
515 struct ust_trace
*trace
;
516 char trace_name
[] = "auto";
518 char *channel_and_cpu
;
525 channel_and_cpu
= nth_token(recvbuf
, 1);
526 if(channel_and_cpu
== NULL
) {
527 ERR("get_subbuf: cannot parse channel");
531 seperate_channel_cpu(channel_and_cpu
, &ch_name
, &ch_cpu
);
533 ERR("Problem parsing channel name");
534 goto free_short_chan_name
;
538 trace
= _ltt_trace_find(trace_name
);
542 ERR("cannot find trace!");
544 goto free_short_chan_name
;
547 for(i
=0; i
<trace
->nr_channels
; i
++) {
548 struct ust_channel
*channel
= &trace
->channels
[i
];
550 if(!strcmp(trace
->channels
[i
].channel_name
, ch_name
)) {
551 struct ust_buffer
*buf
= channel
->buf
[ch_cpu
];
552 struct blocked_consumer
*bc
;
556 bc
= (struct blocked_consumer
*) malloc(sizeof(struct blocked_consumer
));
558 ERR("malloc returned NULL");
559 goto free_short_chan_name
;
561 bc
->fd_consumer
= src
->fd
;
562 bc
->fd_producer
= buf
->data_ready_fd_read
;
565 bc
->server
= ustcomm_app
.server
;
567 list_add(&bc
->list
, &blocked_consumers
);
573 ERR("get_subbuf: unable to find channel");
576 free_short_chan_name
:
583 static int do_cmd_put_subbuffer(const char *recvbuf
, struct ustcomm_source
*src
)
586 struct ust_trace
*trace
;
587 char trace_name
[] = "auto";
589 char *channel_and_cpu
;
595 char *consumed_old_str
;
600 channel_and_cpu
= strdup_malloc(nth_token(recvbuf
, 1));
601 if(channel_and_cpu
== NULL
) {
602 ERR("put_subbuf_size: cannot parse channel");
607 consumed_old_str
= strdup_malloc(nth_token(recvbuf
, 2));
608 if(consumed_old_str
== NULL
) {
609 ERR("put_subbuf: cannot parse consumed_old");
611 goto free_channel_and_cpu
;
613 consumed_old
= strtol(consumed_old_str
, &endptr
, 10);
614 if(*endptr
!= '\0') {
615 ERR("put_subbuf: invalid value for consumed_old");
617 goto free_consumed_old_str
;
620 seperate_channel_cpu(channel_and_cpu
, &ch_name
, &ch_cpu
);
622 ERR("Problem parsing channel name");
624 goto free_short_chan_name
;
628 trace
= _ltt_trace_find(trace_name
);
632 ERR("cannot find trace!");
634 goto free_short_chan_name
;
637 for(i
=0; i
<trace
->nr_channels
; i
++) {
638 struct ust_channel
*channel
= &trace
->channels
[i
];
640 if(!strcmp(trace
->channels
[i
].channel_name
, ch_name
)) {
641 struct ust_buffer
*buf
= channel
->buf
[ch_cpu
];
646 result
= ust_buffers_put_subbuf(buf
, consumed_old
);
648 WARN("ust_buffers_put_subbuf: error (subbuf=%s)", channel_and_cpu
);
649 asprintf(&reply
, "%s", "ERROR");
652 DBG("ust_buffers_put_subbuf: success (subbuf=%s)", channel_and_cpu
);
653 asprintf(&reply
, "%s", "OK");
656 result
= ustcomm_send_reply(&ustcomm_app
.server
, reply
, src
);
658 ERR("listener: put_subbuf: ustcomm_send_reply failed");
661 goto free_channel_and_cpu
;
669 ERR("get_subbuf_size: unable to find channel");
672 free_channel_and_cpu
:
673 free(channel_and_cpu
);
674 free_consumed_old_str
:
675 free(consumed_old_str
);
676 free_short_chan_name
:
683 void *listener_main(void *p
)
687 ust_register_thread();
692 char trace_name
[] = "auto";
693 char trace_type
[] = "ustrelay";
696 struct ustcomm_source src
;
698 process_blocked_consumers();
700 result
= ustcomm_app_recv_message(&ustcomm_app
, &recvbuf
, &src
, 5);
702 WARN("error in ustcomm_app_recv_message");
705 else if(result
== 0) {
710 DBG("received a message! it's: %s", recvbuf
);
711 len
= strlen(recvbuf
);
713 if(!strcmp(recvbuf
, "print_markers")) {
714 print_markers(stderr
);
716 else if(!strcmp(recvbuf
, "list_markers")) {
721 fp
= open_memstream(&ptr
, &size
);
725 result
= ustcomm_send_reply(&ustcomm_app
.server
, ptr
, &src
);
729 else if(!strcmp(recvbuf
, "start")) {
730 /* start is an operation that setups the trace, allocates it and starts it */
731 result
= ltt_trace_setup(trace_name
);
733 ERR("ltt_trace_setup failed");
737 result
= ltt_trace_set_type(trace_name
, trace_type
);
739 ERR("ltt_trace_set_type failed");
743 result
= ltt_trace_alloc(trace_name
);
745 ERR("ltt_trace_alloc failed");
749 inform_consumer_daemon(trace_name
);
751 result
= ltt_trace_start(trace_name
);
753 ERR("ltt_trace_start failed");
757 else if(!strcmp(recvbuf
, "trace_setup")) {
760 result
= ltt_trace_setup(trace_name
);
762 ERR("ltt_trace_setup failed");
766 result
= ltt_trace_set_type(trace_name
, trace_type
);
768 ERR("ltt_trace_set_type failed");
772 else if(!strcmp(recvbuf
, "trace_alloc")) {
775 result
= ltt_trace_alloc(trace_name
);
777 ERR("ltt_trace_alloc failed");
781 else if(!strcmp(recvbuf
, "trace_create")) {
784 result
= ltt_trace_setup(trace_name
);
786 ERR("ltt_trace_setup failed");
790 result
= ltt_trace_set_type(trace_name
, trace_type
);
792 ERR("ltt_trace_set_type failed");
796 result
= ltt_trace_alloc(trace_name
);
798 ERR("ltt_trace_alloc failed");
802 inform_consumer_daemon(trace_name
);
804 else if(!strcmp(recvbuf
, "trace_start")) {
807 result
= ltt_trace_start(trace_name
);
809 ERR("ltt_trace_start failed");
813 else if(!strcmp(recvbuf
, "trace_stop")) {
816 result
= ltt_trace_stop(trace_name
);
818 ERR("ltt_trace_stop failed");
822 else if(!strcmp(recvbuf
, "trace_destroy")) {
824 DBG("trace destroy");
826 result
= ltt_trace_destroy(trace_name
);
828 ERR("ltt_trace_destroy failed");
832 else if(nth_token_is(recvbuf
, "get_shmid", 0) == 1) {
833 do_cmd_get_shmid(recvbuf
, &src
);
835 else if(nth_token_is(recvbuf
, "get_n_subbufs", 0) == 1) {
836 do_cmd_get_n_subbufs(recvbuf
, &src
);
838 else if(nth_token_is(recvbuf
, "get_subbuf_size", 0) == 1) {
839 do_cmd_get_subbuf_size(recvbuf
, &src
);
841 else if(nth_token_is(recvbuf
, "load_probe_lib", 0) == 1) {
844 libfile
= nth_token(recvbuf
, 1);
846 DBG("load_probe_lib loading %s", libfile
);
850 else if(nth_token_is(recvbuf
, "get_subbuffer", 0) == 1) {
851 do_cmd_get_subbuffer(recvbuf
, &src
);
853 else if(nth_token_is(recvbuf
, "put_subbuffer", 0) == 1) {
854 do_cmd_put_subbuffer(recvbuf
, &src
);
856 else if(nth_token_is(recvbuf
, "enable_marker", 0) == 1) {
857 char *channel_slash_name
= nth_token(recvbuf
, 1);
858 char channel_name
[256]="";
859 char marker_name
[256]="";
861 result
= sscanf(channel_slash_name
, "%255[^/]/%255s", channel_name
, marker_name
);
863 if(channel_name
== NULL
|| marker_name
== NULL
) {
864 WARN("invalid marker name");
868 result
= ltt_marker_connect(channel_name
, marker_name
, "default");
870 WARN("could not enable marker; channel=%s, name=%s", channel_name
, marker_name
);
873 else if(nth_token_is(recvbuf
, "disable_marker", 0) == 1) {
874 char *channel_slash_name
= nth_token(recvbuf
, 1);
878 result
= sscanf(channel_slash_name
, "%a[^/]/%as", &channel_name
, &marker_name
);
880 if(marker_name
== NULL
) {
883 result
= ltt_marker_disconnect(channel_name
, marker_name
, "default");
885 WARN("could not disable marker; channel=%s, name=%s", channel_name
, marker_name
);
888 else if(nth_token_is(recvbuf
, "get_pidunique", 0) == 1) {
891 asprintf(&reply
, "%lld", pidunique
);
893 result
= ustcomm_send_reply(&ustcomm_app
.server
, reply
, &src
);
895 ERR("listener: get_pidunique: ustcomm_send_reply failed");
901 // else if(nth_token_is(recvbuf, "get_notifications", 0) == 1) {
902 // struct ust_trace *trace;
903 // char trace_name[] = "auto";
905 // char *channel_name;
907 // DBG("get_notifications");
909 // channel_name = strdup_malloc(nth_token(recvbuf, 1));
910 // if(channel_name == NULL) {
911 // ERR("put_subbuf_size: cannot parse channel");
915 // ltt_lock_traces();
916 // trace = _ltt_trace_find(trace_name);
917 // ltt_unlock_traces();
919 // if(trace == NULL) {
920 // ERR("cannot find trace!");
924 // for(i=0; i<trace->nr_channels; i++) {
925 // struct rchan *rchan = trace->channels[i].trans_channel_data;
928 // if(!strcmp(trace->channels[i].channel_name, channel_name)) {
929 // struct rchan_buf *rbuf = rchan->buf;
930 // struct ltt_channel_buf_struct *lttbuf = trace->channels[i].buf;
932 // result = fd = ustcomm_app_detach_client(&ustcomm_app, &src);
933 // if(result == -1) {
934 // ERR("ustcomm_app_detach_client failed");
938 // lttbuf->wake_consumer_arg = (void *) fd;
942 // lttbuf->call_wake_consumer = 1;
948 // free(channel_name);
951 ERR("unable to parse message: %s", recvbuf
);
959 volatile sig_atomic_t have_listener
= 0;
961 void create_listener(void)
964 static char listener_stack
[16384];
971 WARN("not creating listener because we already had one");
976 result
= clone((int (*)(void *)) listener_main
, listener_stack
+sizeof(listener_stack
)-1, CLONE_FS
| CLONE_FILES
| CLONE_VM
| CLONE_SIGHAND
| CLONE_THREAD
, NULL
);
983 pthread_create(&thread
, NULL
, listener_main
, NULL
);
989 static int init_socket(void)
991 return ustcomm_init_app(getpid(), &ustcomm_app
);
994 #define AUTOPROBE_DISABLED 0
995 #define AUTOPROBE_ENABLE_ALL 1
996 #define AUTOPROBE_ENABLE_REGEX 2
997 static int autoprobe_method
= AUTOPROBE_DISABLED
;
998 static regex_t autoprobe_regex
;
1000 static void auto_probe_connect(struct marker
*m
)
1004 char* concat_name
= NULL
;
1005 const char *probe_name
= "default";
1007 if(autoprobe_method
== AUTOPROBE_DISABLED
) {
1010 else if(autoprobe_method
== AUTOPROBE_ENABLE_REGEX
) {
1011 result
= asprintf(&concat_name
, "%s/%s", m
->channel
, m
->name
);
1013 ERR("auto_probe_connect: asprintf failed (marker %s/%s)",
1014 m
->channel
, m
->name
);
1017 if (regexec(&autoprobe_regex
, concat_name
, 0, NULL
, 0)) {
1024 result
= ltt_marker_connect(m
->channel
, m
->name
, probe_name
);
1025 if(result
&& result
!= -EEXIST
)
1026 ERR("ltt_marker_connect (marker = %s/%s, errno = %d)", m
->channel
, m
->name
, -result
);
1028 DBG("auto connected marker %s (addr: %p) %s to probe default", m
->channel
, m
, m
->name
);
1032 static void __attribute__((constructor
)) init()
1035 char* autoprobe_val
= NULL
;
1037 /* Assign the pidunique, to be able to differentiate the processes with same
1038 * pid, (before and after an exec).
1040 pidunique
= make_pidunique();
1042 /* Initialize RCU in case the constructor order is not good. */
1045 /* It is important to do this before events start to be generated. */
1046 ust_register_thread();
1048 DBG("Tracectl constructor");
1050 /* Must create socket before signal handler to prevent races.
1052 result
= init_socket();
1054 ERR("init_socket error");
1060 autoprobe_val
= getenv("UST_AUTOPROBE");
1062 struct marker_iter iter
;
1064 DBG("Autoprobe enabled.");
1066 /* Ensure markers are initialized */
1069 /* Ensure marker control is initialized, for the probe */
1070 init_marker_control();
1072 /* first, set the callback that will connect the
1073 * probe on new markers
1075 if(autoprobe_val
[0] == '/') {
1076 result
= regcomp(&autoprobe_regex
, autoprobe_val
+1, 0);
1080 regerror(result
, &autoprobe_regex
, regexerr
, sizeof(regexerr
));
1081 ERR("cannot parse regex %s (%s), will ignore UST_AUTOPROBE", autoprobe_val
, regexerr
);
1082 /* don't crash the application just for this */
1085 autoprobe_method
= AUTOPROBE_ENABLE_REGEX
;
1089 /* just enable all instrumentation */
1090 autoprobe_method
= AUTOPROBE_ENABLE_ALL
;
1093 marker_set_new_marker_cb(auto_probe_connect
);
1095 /* Now, connect the probes that were already registered. */
1096 marker_iter_reset(&iter
);
1097 marker_iter_start(&iter
);
1099 DBG("now iterating on markers already registered");
1100 while(iter
.marker
) {
1101 DBG("now iterating on marker %s", iter
.marker
->name
);
1102 auto_probe_connect(iter
.marker
);
1103 marker_iter_next(&iter
);
1107 if(getenv("UST_TRACE")) {
1108 char trace_name
[] = "auto";
1109 char trace_type
[] = "ustrelay";
1111 DBG("starting early tracing");
1113 /* Ensure marker control is initialized */
1114 init_marker_control();
1116 /* Ensure markers are initialized */
1119 /* Ensure buffers are initialized, for the transport to be available.
1120 * We are about to set a trace type and it will fail without this.
1122 init_ustrelay_transport();
1124 /* FIXME: When starting early tracing (here), depending on the
1125 * order of constructors, it is very well possible some marker
1126 * sections are not yet registered. Because of this, some
1127 * channels may not be registered. Yet, we are about to ask the
1128 * daemon to collect the channels. Channels which are not yet
1129 * registered will not be collected.
1131 * Currently, in LTTng, there is no way to add a channel after
1132 * trace start. The reason for this is that it induces complex
1133 * concurrency issues on the trace structures, which can only
1134 * be resolved using RCU. This has not been done yet. As a
1135 * workaround, we are forcing the registration of the "ust"
1136 * channel here. This is the only channel (apart from metadata)
1137 * that can be reliably used in early tracing.
1139 * Non-early tracing does not have this problem and can use
1140 * arbitrary channel names.
1142 ltt_channels_register("ust");
1144 result
= ltt_trace_setup(trace_name
);
1146 ERR("ltt_trace_setup failed");
1150 result
= ltt_trace_set_type(trace_name
, trace_type
);
1152 ERR("ltt_trace_set_type failed");
1156 result
= ltt_trace_alloc(trace_name
);
1158 ERR("ltt_trace_alloc failed");
1162 result
= ltt_trace_start(trace_name
);
1164 ERR("ltt_trace_start failed");
1168 /* Do this after the trace is started in order to avoid creating confusion
1169 * if the trace fails to start. */
1170 inform_consumer_daemon(trace_name
);
1176 /* should decrementally destroy stuff if error */
1180 /* This is only called if we terminate normally, not with an unhandled signal,
1181 * so we cannot rely on it. However, for now, LTTV requires that the header of
1182 * the last sub-buffer contain a valid end time for the trace. This is done
1183 * automatically only when the trace is properly stopped.
1185 * If the traced program crashed, it is always possible to manually add the
1186 * right value in the header, or to open the trace in text mode.
1188 * FIXME: Fix LTTV so it doesn't need this.
1191 static void destroy_traces(void)
1195 /* if trace running, finish it */
1197 DBG("destructor stopping traces");
1199 result
= ltt_trace_stop("auto");
1201 ERR("ltt_trace_stop error");
1204 result
= ltt_trace_destroy("auto");
1206 ERR("ltt_trace_destroy error");
1210 static int trace_recording(void)
1213 struct ust_trace
*trace
;
1217 list_for_each_entry(trace
, <t_traces
.head
, list
) {
1224 ltt_unlock_traces();
1230 static int have_consumer(void)
1232 return !list_empty(&blocked_consumers
);
1236 int restarting_usleep(useconds_t usecs
)
1242 tv
.tv_nsec
= usecs
* 1000;
1245 result
= nanosleep(&tv
, &tv
);
1246 } while(result
== -1 && errno
== EINTR
);
1251 /* This destructor keeps the process alive for a few seconds in order
1252 * to leave time to ustd to connect to its buffers. This is necessary
1253 * for programs whose execution is very short. It is also useful in all
1254 * programs when tracing is started close to the end of the program
1257 * FIXME: For now, this only works for the first trace created in a
1261 static void __attribute__((destructor
)) keepalive()
1263 if(trace_recording() && buffers_to_export
) {
1265 DBG("Keeping process alive for consumer daemon...");
1266 while(buffers_to_export
) {
1267 const int interv
= 200000;
1268 restarting_usleep(interv
);
1271 if(total
>= 3000000) {
1272 WARN("non-consumed buffers remaining after wait limit; not waiting anymore");
1276 DBG("Finally dying...");
1281 ustcomm_fini_app(&ustcomm_app
);
1284 void ust_potential_exec(void)
1286 trace_mark(ust
, potential_exec
, MARK_NOARGS
);
1293 /* Notify ust that there was a fork. This needs to be called inside
1294 * the new process, anytime a process whose memory is not shared with
1295 * the parent is created. If this function is not called, the events
1296 * of the new process will not be collected.
1298 * Signals should be disabled before the fork and reenabled only after
1299 * this call in order to guarantee tracing is not started before ust_fork()
1300 * sanitizes the new process.
1303 static void ust_fork(void)
1305 struct blocked_consumer
*bc
;
1306 struct blocked_consumer
*deletable_bc
= NULL
;
1309 DBG("ust: forking");
1310 ltt_trace_stop("auto");
1311 ltt_trace_destroy("auto");
1312 /* Delete all active connections */
1313 ustcomm_close_all_connections(&ustcomm_app
.server
);
1315 /* Delete all blocked consumers */
1316 list_for_each_entry(bc
, &blocked_consumers
, list
) {
1317 close(bc
->fd_producer
);
1318 close(bc
->fd_consumer
);
1321 list_del(&bc
->list
);
1327 ltt_trace_setup("auto");
1328 result
= ltt_trace_set_type("auto", "ustrelay");
1330 ERR("ltt_trace_set_type failed");
1334 ltt_trace_alloc("auto");
1335 ltt_trace_start("auto");
1336 inform_consumer_daemon("auto");
1339 void ust_before_fork(ust_fork_info_t
*fork_info
)
1341 /* Disable signals. This is to avoid that the child
1342 * intervenes before it is properly setup for tracing. It is
1343 * safer to disable all signals, because then we know we are not
1344 * breaking anything by restoring the original mask.
1350 - only do this if tracing is active
1353 /* Disable signals */
1354 sigfillset(&all_sigs
);
1355 result
= sigprocmask(SIG_BLOCK
, &all_sigs
, &fork_info
->orig_sigs
);
1357 PERROR("sigprocmask");
1362 /* Don't call this function directly in a traced program */
1363 static void ust_after_fork_common(ust_fork_info_t
*fork_info
)
1367 /* Restore signals */
1368 result
= sigprocmask(SIG_SETMASK
, &fork_info
->orig_sigs
, NULL
);
1370 PERROR("sigprocmask");
1375 void ust_after_fork_parent(ust_fork_info_t
*fork_info
)
1377 /* Reenable signals */
1378 ust_after_fork_common(fork_info
);
1381 void ust_after_fork_child(ust_fork_info_t
*fork_info
)
1383 /* First sanitize the child */
1386 /* Then reenable interrupts */
1387 ust_after_fork_common(fork_info
);