libust/tracectl.c

   1 /* Copyright (C) 2009  Pierre-Marc Fournier
   2  *
   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.
   7  *
   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.
  12  *
  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
  16  */
  17
  18 #define _GNU_SOURCE
  19 #include <stdio.h>
  20 #include <stdint.h>
  21 #include <signal.h>
  22 #include <sys/types.h>
  23 #include <sys/socket.h>
  24 #include <sys/un.h>
  25 #include <sched.h>
  26 #include <fcntl.h>
  27 #include <poll.h>
  28 #include <regex.h>
  29
  30 #include <urcu-bp.h>
  31
  32 #include <ust/marker.h>
  33 #include "tracer.h"
  34 #include "usterr.h"
  35 #include "ustcomm.h"
  36 #include "relay.h" /* FIXME: remove */
  37 #include "marker-control.h"
  38
  39 //#define USE_CLONE
  40
  41 #define USTSIGNAL SIGIO
  42
  43 #define MAX_MSG_SIZE (100)
  44 #define MSG_NOTIF 1
  45 #define MSG_REGISTER_NOTIF 2
  46
  47 char consumer_stack[10000];
  48
  49 /* This should only be accessed by the constructor, before the creation
  50  * of the listener, and then only by the listener.
  51  */
  52 s64 pidunique = -1LL;
  53
  54 struct list_head blocked_consumers = LIST_HEAD_INIT(blocked_consumers);
  55
  56 static struct ustcomm_app ustcomm_app;
  57
  58 struct tracecmd { /* no padding */
  59         uint32_t size;
  60         uint16_t command;
  61 };
  62
  63 /* volatile because shared between the listener and the main thread */
  64 volatile sig_atomic_t buffers_to_export = 0;
  65
  66 struct trctl_msg {
  67         /* size: the size of all the fields except size itself */
  68         uint32_t size;
  69         uint16_t type;
  70         /* Only the necessary part of the payload is transferred. It
  71          * may even be none of it.
  72          */
  73         char payload[94];
  74 };
  75
  76 struct consumer_channel {
  77         int fd;
  78         struct ltt_channel_struct *chan;
  79 };
  80
  81 struct blocked_consumer {
  82         int fd_consumer;
  83         int fd_producer;
  84         int tmp_poll_idx;
  85
  86         /* args to ustcomm_send_reply */
  87         struct ustcomm_server server;
  88         struct ustcomm_source src;
  89
  90         /* args to ltt_do_get_subbuf */
  91         struct rchan_buf *rbuf;
  92         struct ltt_channel_buf_struct *lttbuf;
  93
  94         struct list_head list;
  95 };
  96
  97 static long long make_pidunique(void)
  98 {
  99         s64 retval;
 100         struct timeval tv;
 101
 102         gettimeofday(&tv, NULL);
 103
 104         retval = tv.tv_sec;
 105         retval <<= 32;
 106         retval |= tv.tv_usec;
 107
 108         return retval;
 109 }
 110
 111 static void print_markers(FILE *fp)
 112 {
 113         struct marker_iter iter;
 114
 115         lock_markers();
 116         marker_iter_reset(&iter);
 117         marker_iter_start(&iter);
 118
 119         while(iter.marker) {
 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);
 122         }
 123         unlock_markers();
 124 }
 125
 126 static int init_socket(void);
 127
 128 /* This needs to be called whenever a new thread is created. It notifies
 129  * liburcu of the new thread.
 130  */
 131
 132 void ust_register_thread(void)
 133 {
 134         rcu_register_thread();
 135 }
 136
 137 int fd_notif = -1;
 138 void notif_cb(void)
 139 {
 140         int result;
 141         struct trctl_msg msg;
 142
 143         /* FIXME: fd_notif should probably be protected by a spinlock */
 144
 145         if(fd_notif == -1)
 146                 return;
 147
 148         msg.type = MSG_NOTIF;
 149         msg.size = sizeof(msg.type);
 150
 151         /* FIXME: don't block here */
 152         result = write(fd_notif, &msg, msg.size+sizeof(msg.size));
 153         if(result == -1) {
 154                 PERROR("write");
 155                 return;
 156         }
 157 }
 158
 159 /* Ask the daemon to collect a trace called trace_name and being
 160  * produced by this pid.
 161  *
 162  * The trace must be at least allocated. (It can also be started.)
 163  * This is because _ltt_trace_find is used.
 164  */
 165
 166 static void inform_consumer_daemon(const char *trace_name)
 167 {
 168         int i;
 169         struct ltt_trace_struct *trace;
 170         pid_t pid = getpid();
 171         int result;
 172
 173         ltt_lock_traces();
 174
 175         trace = _ltt_trace_find(trace_name);
 176         if(trace == NULL) {
 177                 WARN("inform_consumer_daemon: could not find trace \"%s\"; it is probably already destroyed", trace_name);
 178                 goto finish;
 179         }
 180
 181         for(i=0; i < trace->nr_channels; i++) {
 182                 result = ustcomm_request_consumer(pid, trace->channels[i].channel_name);
 183                 if(result == -1) {
 184                         WARN("Failed to request collection for channel %s. Is the daemon available?", trace->channels[i].channel_name);
 185                         /* continue even if fail */
 186                 }
 187                 buffers_to_export++;
 188         }
 189
 190         finish:
 191         ltt_unlock_traces();
 192 }
 193
 194 void process_blocked_consumers(void)
 195 {
 196         int n_fds = 0;
 197         struct pollfd *fds;
 198         struct blocked_consumer *bc;
 199         int idx = 0;
 200         char inbuf;
 201         int result;
 202
 203         list_for_each_entry(bc, &blocked_consumers, list) {
 204                 n_fds++;
 205         }
 206
 207         fds = (struct pollfd *) malloc(n_fds * sizeof(struct pollfd));
 208         if(fds == NULL) {
 209                 ERR("malloc returned NULL");
 210                 return;
 211         }
 212
 213         list_for_each_entry(bc, &blocked_consumers, list) {
 214                 fds[idx].fd = bc->fd_producer;
 215                 fds[idx].events = POLLIN;
 216                 bc->tmp_poll_idx = idx;
 217                 idx++;
 218         }
 219
 220         while((result = poll(fds, n_fds, 0)) == -1 && errno == EINTR)
 221                 /* nothing */;
 222         if(result == -1) {
 223                 PERROR("poll");
 224                 return;
 225         }
 226
 227         list_for_each_entry(bc, &blocked_consumers, list) {
 228                 if(fds[bc->tmp_poll_idx].revents) {
 229                         long consumed_old = 0;
 230                         char *reply;
 231
 232                         result = read(bc->fd_producer, &inbuf, 1);
 233                         if(result == -1) {
 234                                 PERROR("read");
 235                                 continue;
 236                         }
 237                         if(result == 0) {
 238                                 DBG("PRODUCER END");
 239
 240                                 close(bc->fd_producer);
 241
 242                                 list_del(&bc->list);
 243
 244                                 result = ustcomm_send_reply(&bc->server, "END", &bc->src);
 245                                 if(result < 0) {
 246                                         ERR("ustcomm_send_reply failed");
 247                                         continue;
 248                                 }
 249
 250                                 continue;
 251                         }
 252
 253                         result = ltt_do_get_subbuf(bc->rbuf, bc->lttbuf, &consumed_old);
 254                         if(result == -EAGAIN) {
 255                                 WARN("missed buffer?");
 256                                 continue;
 257                         }
 258                         else if(result < 0) {
 259                                 DBG("ltt_do_get_subbuf: error: %s", strerror(-result));
 260                         }
 261                         asprintf(&reply, "%s %ld", "OK", consumed_old);
 262                         result = ustcomm_send_reply(&bc->server, reply, &bc->src);
 263                         if(result < 0) {
 264                                 ERR("ustcomm_send_reply failed");
 265                                 free(reply);
 266                                 continue;
 267                         }
 268                         free(reply);
 269
 270                         list_del(&bc->list);
 271                 }
 272         }
 273
 274 }
 275
 276 void *listener_main(void *p)
 277 {
 278         int result;
 279
 280         ust_register_thread();
 281
 282         DBG("LISTENER");
 283
 284         for(;;) {
 285                 char trace_name[] = "auto";
 286                 char trace_type[] = "ustrelay";
 287                 char *recvbuf;
 288                 int len;
 289                 struct ustcomm_source src;
 290
 291                 process_blocked_consumers();
 292
 293                 result = ustcomm_app_recv_message(&ustcomm_app, &recvbuf, &src, 5);
 294                 if(result < 0) {
 295                         WARN("error in ustcomm_app_recv_message");
 296                         continue;
 297                 }
 298                 else if(result == 0) {
 299                         /* no message */
 300                         continue;
 301                 }
 302
 303                 DBG("received a message! it's: %s", recvbuf);
 304                 len = strlen(recvbuf);
 305
 306                 if(!strcmp(recvbuf, "print_markers")) {
 307                         print_markers(stderr);
 308                 }
 309                 else if(!strcmp(recvbuf, "list_markers")) {
 310                         char *ptr;
 311                         size_t size;
 312                         FILE *fp;
 313
 314                         fp = open_memstream(&ptr, &size);
 315                         print_markers(fp);
 316                         fclose(fp);
 317
 318                         result = ustcomm_send_reply(&ustcomm_app.server, ptr, &src);
 319
 320                         free(ptr);
 321                 }
 322                 else if(!strcmp(recvbuf, "start")) {
 323                         /* start is an operation that setups the trace, allocates it and starts it */
 324                         result = ltt_trace_setup(trace_name);
 325                         if(result < 0) {
 326                                 ERR("ltt_trace_setup failed");
 327                                 return (void *)1;
 328                         }
 329
 330                         result = ltt_trace_set_type(trace_name, trace_type);
 331                         if(result < 0) {
 332                                 ERR("ltt_trace_set_type failed");
 333                                 return (void *)1;
 334                         }
 335
 336                         result = ltt_trace_alloc(trace_name);
 337                         if(result < 0) {
 338                                 ERR("ltt_trace_alloc failed");
 339                                 return (void *)1;
 340                         }
 341
 342                         inform_consumer_daemon(trace_name);
 343
 344                         result = ltt_trace_start(trace_name);
 345                         if(result < 0) {
 346                                 ERR("ltt_trace_start failed");
 347                                 continue;
 348                         }
 349                 }
 350                 else if(!strcmp(recvbuf, "trace_setup")) {
 351                         DBG("trace setup");
 352
 353                         result = ltt_trace_setup(trace_name);
 354                         if(result < 0) {
 355                                 ERR("ltt_trace_setup failed");
 356                                 return (void *)1;
 357                         }
 358
 359                         result = ltt_trace_set_type(trace_name, trace_type);
 360                         if(result < 0) {
 361                                 ERR("ltt_trace_set_type failed");
 362                                 return (void *)1;
 363                         }
 364                 }
 365                 else if(!strcmp(recvbuf, "trace_alloc")) {
 366                         DBG("trace alloc");
 367
 368                         result = ltt_trace_alloc(trace_name);
 369                         if(result < 0) {
 370                                 ERR("ltt_trace_alloc failed");
 371                                 return (void *)1;
 372                         }
 373                 }
 374                 else if(!strcmp(recvbuf, "trace_start")) {
 375                         DBG("trace start");
 376
 377                         result = ltt_trace_start(trace_name);
 378                         if(result < 0) {
 379                                 ERR("ltt_trace_start failed");
 380                                 continue;
 381                         }
 382                 }
 383                 else if(!strcmp(recvbuf, "trace_stop")) {
 384                         DBG("trace stop");
 385
 386                         result = ltt_trace_stop(trace_name);
 387                         if(result < 0) {
 388                                 ERR("ltt_trace_stop failed");
 389                                 return (void *)1;
 390                         }
 391                 }
 392                 else if(!strcmp(recvbuf, "trace_destroy")) {
 393
 394                         DBG("trace destroy");
 395
 396                         result = ltt_trace_destroy(trace_name);
 397                         if(result < 0) {
 398                                 ERR("ltt_trace_destroy failed");
 399                                 return (void *)1;
 400                         }
 401                 }
 402                 else if(nth_token_is(recvbuf, "get_shmid", 0) == 1) {
 403                         struct ltt_trace_struct *trace;
 404                         char trace_name[] = "auto";
 405                         int i;
 406                         char *channel_name;
 407
 408                         DBG("get_shmid");
 409
 410                         channel_name = nth_token(recvbuf, 1);
 411                         if(channel_name == NULL) {
 412                                 ERR("get_shmid: cannot parse channel");
 413                                 goto next_cmd;
 414                         }
 415
 416                         ltt_lock_traces();
 417                         trace = _ltt_trace_find(trace_name);
 418                         ltt_unlock_traces();
 419
 420                         if(trace == NULL) {
 421                                 ERR("cannot find trace!");
 422                                 return (void *)1;
 423                         }
 424
 425                         for(i=0; i<trace->nr_channels; i++) {
 426                                 struct rchan *rchan = trace->channels[i].trans_channel_data;
 427                                 struct rchan_buf *rbuf = rchan->buf;
 428                                 struct ltt_channel_struct *ltt_channel = (struct ltt_channel_struct *)rchan->private_data;
 429
 430                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 431                                         char *reply;
 432
 433                                         DBG("the shmid for the requested channel is %d", rbuf->shmid);
 434                                         DBG("the shmid for its buffer structure is %d", ltt_channel->buf_shmid);
 435                                         asprintf(&reply, "%d %d", rbuf->shmid, ltt_channel->buf_shmid);
 436
 437                                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 438                                         if(result) {
 439                                                 ERR("listener: get_shmid: ustcomm_send_reply failed");
 440                                                 goto next_cmd;
 441                                         }
 442
 443                                         free(reply);
 444
 445                                         break;
 446                                 }
 447                         }
 448
 449                         buffers_to_export--;
 450                 }
 451                 else if(nth_token_is(recvbuf, "get_n_subbufs", 0) == 1) {
 452                         struct ltt_trace_struct *trace;
 453                         char trace_name[] = "auto";
 454                         int i;
 455                         char *channel_name;
 456
 457                         DBG("get_n_subbufs");
 458
 459                         channel_name = nth_token(recvbuf, 1);
 460                         if(channel_name == NULL) {
 461                                 ERR("get_n_subbufs: cannot parse channel");
 462                                 goto next_cmd;
 463                         }
 464
 465                         ltt_lock_traces();
 466                         trace = _ltt_trace_find(trace_name);
 467                         ltt_unlock_traces();
 468
 469                         if(trace == NULL) {
 470                                 ERR("cannot find trace!");
 471                                 return (void *)1;
 472                         }
 473
 474                         for(i=0; i<trace->nr_channels; i++) {
 475                                 struct rchan *rchan = trace->channels[i].trans_channel_data;
 476
 477                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 478                                         char *reply;
 479
 480                                         DBG("the n_subbufs for the requested channel is %zd", rchan->n_subbufs);
 481                                         asprintf(&reply, "%zd", rchan->n_subbufs);
 482
 483                                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 484                                         if(result) {
 485                                                 ERR("listener: get_n_subbufs: ustcomm_send_reply failed");
 486                                                 goto next_cmd;
 487                                         }
 488
 489                                         free(reply);
 490
 491                                         break;
 492                                 }
 493                         }
 494                 }
 495                 else if(nth_token_is(recvbuf, "get_subbuf_size", 0) == 1) {
 496                         struct ltt_trace_struct *trace;
 497                         char trace_name[] = "auto";
 498                         int i;
 499                         char *channel_name;
 500
 501                         DBG("get_subbuf_size");
 502
 503                         channel_name = nth_token(recvbuf, 1);
 504                         if(channel_name == NULL) {
 505                                 ERR("get_subbuf_size: cannot parse channel");
 506                                 goto next_cmd;
 507                         }
 508
 509                         ltt_lock_traces();
 510                         trace = _ltt_trace_find(trace_name);
 511                         ltt_unlock_traces();
 512
 513                         if(trace == NULL) {
 514                                 ERR("cannot find trace!");
 515                                 return (void *)1;
 516                         }
 517
 518                         for(i=0; i<trace->nr_channels; i++) {
 519                                 struct rchan *rchan = trace->channels[i].trans_channel_data;
 520
 521                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 522                                         char *reply;
 523
 524                                         DBG("the subbuf_size for the requested channel is %zd", rchan->subbuf_size);
 525                                         asprintf(&reply, "%zd", rchan->subbuf_size);
 526
 527                                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 528                                         if(result) {
 529                                                 ERR("listener: get_subbuf_size: ustcomm_send_reply failed");
 530                                                 goto next_cmd;
 531                                         }
 532
 533                                         free(reply);
 534
 535                                         break;
 536                                 }
 537                         }
 538                 }
 539                 else if(nth_token_is(recvbuf, "load_probe_lib", 0) == 1) {
 540                         char *libfile;
 541
 542                         libfile = nth_token(recvbuf, 1);
 543
 544                         DBG("load_probe_lib loading %s", libfile);
 545                 }
 546                 else if(nth_token_is(recvbuf, "get_subbuffer", 0) == 1) {
 547                         struct ltt_trace_struct *trace;
 548                         char trace_name[] = "auto";
 549                         int i;
 550                         char *channel_name;
 551
 552                         DBG("get_subbuf");
 553
 554                         channel_name = nth_token(recvbuf, 1);
 555                         if(channel_name == NULL) {
 556                                 ERR("get_subbuf: cannot parse channel");
 557                                 goto next_cmd;
 558                         }
 559
 560                         ltt_lock_traces();
 561                         trace = _ltt_trace_find(trace_name);
 562                         ltt_unlock_traces();
 563
 564                         if(trace == NULL) {
 565                                 ERR("cannot find trace!");
 566                                 return (void *)1;
 567                         }
 568
 569                         for(i=0; i<trace->nr_channels; i++) {
 570                                 struct rchan *rchan = trace->channels[i].trans_channel_data;
 571
 572                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 573                                         struct rchan_buf *rbuf = rchan->buf;
 574                                         struct ltt_channel_buf_struct *lttbuf = trace->channels[i].buf;
 575                                         struct blocked_consumer *bc;
 576
 577                                         bc = (struct blocked_consumer *) malloc(sizeof(struct blocked_consumer));
 578                                         if(bc == NULL) {
 579                                                 ERR("malloc returned NULL");
 580                                                 goto next_cmd;
 581                                         }
 582                                         bc->fd_consumer = src.fd;
 583                                         bc->fd_producer = lttbuf->data_ready_fd_read;
 584                                         bc->rbuf = rbuf;
 585                                         bc->lttbuf = lttbuf;
 586                                         bc->src = src;
 587                                         bc->server = ustcomm_app.server;
 588
 589                                         list_add(&bc->list, &blocked_consumers);
 590
 591                                         break;
 592                                 }
 593                         }
 594                 }
 595                 else if(nth_token_is(recvbuf, "put_subbuffer", 0) == 1) {
 596                         struct ltt_trace_struct *trace;
 597                         char trace_name[] = "auto";
 598                         int i;
 599                         char *channel_name;
 600                         long consumed_old;
 601                         char *consumed_old_str;
 602                         char *endptr;
 603
 604                         DBG("put_subbuf");
 605
 606                         channel_name = strdup_malloc(nth_token(recvbuf, 1));
 607                         if(channel_name == NULL) {
 608                                 ERR("put_subbuf_size: cannot parse channel");
 609                                 goto next_cmd;
 610                         }
 611
 612                         consumed_old_str = strdup_malloc(nth_token(recvbuf, 2));
 613                         if(consumed_old_str == NULL) {
 614                                 ERR("put_subbuf: cannot parse consumed_old");
 615                                 goto next_cmd;
 616                         }
 617                         consumed_old = strtol(consumed_old_str, &endptr, 10);
 618                         if(*endptr != '\0') {
 619                                 ERR("put_subbuf: invalid value for consumed_old");
 620                                 goto next_cmd;
 621                         }
 622
 623                         ltt_lock_traces();
 624                         trace = _ltt_trace_find(trace_name);
 625                         ltt_unlock_traces();
 626
 627                         if(trace == NULL) {
 628                                 ERR("cannot find trace!");
 629                                 return (void *)1;
 630                         }
 631
 632                         for(i=0; i<trace->nr_channels; i++) {
 633                                 struct rchan *rchan = trace->channels[i].trans_channel_data;
 634
 635                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 636                                         struct rchan_buf *rbuf = rchan->buf;
 637                                         struct ltt_channel_buf_struct *lttbuf = trace->channels[i].buf;
 638                                         char *reply;
 639                                         long consumed_old=0;
 640
 641                                         result = ltt_do_put_subbuf(rbuf, lttbuf, consumed_old);
 642                                         if(result < 0) {
 643                                                 WARN("ltt_do_put_subbuf: error (subbuf=%s)", channel_name);
 644                                                 asprintf(&reply, "%s", "ERROR");
 645                                         }
 646                                         else {
 647                                                 DBG("ltt_do_put_subbuf: success (subbuf=%s)", channel_name);
 648                                                 asprintf(&reply, "%s", "OK");
 649                                         }
 650
 651                                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 652                                         if(result) {
 653                                                 ERR("listener: put_subbuf: ustcomm_send_reply failed");
 654                                                 goto next_cmd;
 655                                         }
 656
 657                                         free(reply);
 658
 659                                         break;
 660                                 }
 661                         }
 662
 663                         free(channel_name);
 664                         free(consumed_old_str);
 665                 }
 666                 else if(nth_token_is(recvbuf, "enable_marker", 0) == 1) {
 667                         char *channel_slash_name = nth_token(recvbuf, 1);
 668                         char channel_name[256]="";
 669                         char marker_name[256]="";
 670
 671                         result = sscanf(channel_slash_name, "%255[^/]/%255s", channel_name, marker_name);
 672
 673                         if(channel_name == NULL || marker_name == NULL) {
 674                                 WARN("invalid marker name");
 675                                 goto next_cmd;
 676                         }
 677                         printf("%s %s\n", channel_name, marker_name);
 678
 679                         result = ltt_marker_connect(channel_name, marker_name, "default");
 680                         if(result < 0) {
 681                                 WARN("could not enable marker; channel=%s, name=%s", channel_name, marker_name);
 682                         }
 683                 }
 684                 else if(nth_token_is(recvbuf, "disable_marker", 0) == 1) {
 685                         char *channel_slash_name = nth_token(recvbuf, 1);
 686                         char *marker_name;
 687                         char *channel_name;
 688
 689                         result = sscanf(channel_slash_name, "%a[^/]/%as", &channel_name, &marker_name);
 690
 691                         if(marker_name == NULL) {
 692                         }
 693                         printf("%s %s\n", channel_name, marker_name);
 694
 695                         result = ltt_marker_disconnect(channel_name, marker_name, "default");
 696                         if(result < 0) {
 697                                 WARN("could not disable marker; channel=%s, name=%s", channel_name, marker_name);
 698                         }
 699                 }
 700                 else if(nth_token_is(recvbuf, "get_pidunique", 0) == 1) {
 701                         char *reply;
 702
 703                         asprintf(&reply, "%lld", pidunique);
 704
 705                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 706                         if(result) {
 707                                 ERR("listener: get_pidunique: ustcomm_send_reply failed");
 708                                 goto next_cmd;
 709                         }
 710
 711                         free(reply);
 712                 }
 713 //              else if(nth_token_is(recvbuf, "get_notifications", 0) == 1) {
 714 //                      struct ltt_trace_struct *trace;
 715 //                      char trace_name[] = "auto";
 716 //                      int i;
 717 //                      char *channel_name;
 718 //
 719 //                      DBG("get_notifications");
 720 //
 721 //                      channel_name = strdup_malloc(nth_token(recvbuf, 1));
 722 //                      if(channel_name == NULL) {
 723 //                              ERR("put_subbuf_size: cannot parse channel");
 724 //                              goto next_cmd;
 725 //                      }
 726 //
 727 //                      ltt_lock_traces();
 728 //                      trace = _ltt_trace_find(trace_name);
 729 //                      ltt_unlock_traces();
 730 //
 731 //                      if(trace == NULL) {
 732 //                              ERR("cannot find trace!");
 733 //                              return (void *)1;
 734 //                      }
 735 //
 736 //                      for(i=0; i<trace->nr_channels; i++) {
 737 //                              struct rchan *rchan = trace->channels[i].trans_channel_data;
 738 //                              int fd;
 739 //
 740 //                              if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 741 //                                      struct rchan_buf *rbuf = rchan->buf;
 742 //                                      struct ltt_channel_buf_struct *lttbuf = trace->channels[i].buf;
 743 //
 744 //                                      result = fd = ustcomm_app_detach_client(&ustcomm_app, &src);
 745 //                                      if(result == -1) {
 746 //                                              ERR("ustcomm_app_detach_client failed");
 747 //                                              goto next_cmd;
 748 //                                      }
 749 //
 750 //                                      lttbuf->wake_consumer_arg = (void *) fd;
 751 //
 752 //                                      smp_wmb();
 753 //
 754 //                                      lttbuf->call_wake_consumer = 1;
 755 //
 756 //                                      break;
 757 //                              }
 758 //                      }
 759 //
 760 //                      free(channel_name);
 761 //              }
 762                 else {
 763                         ERR("unable to parse message: %s", recvbuf);
 764                 }
 765
 766         next_cmd:
 767                 free(recvbuf);
 768         }
 769 }
 770
 771 volatile sig_atomic_t have_listener = 0;
 772
 773 void create_listener(void)
 774 {
 775 #ifdef USE_CLONE
 776         static char listener_stack[16384];
 777         int result;
 778 #else
 779         pthread_t thread;
 780 #endif
 781
 782         if(have_listener) {
 783                 WARN("not creating listener because we already had one");
 784                 return;
 785         }
 786
 787 #ifdef USE_CLONE
 788         result = clone((int (*)(void *)) listener_main, listener_stack+sizeof(listener_stack)-1, CLONE_FS | CLONE_FILES | CLONE_VM | CLONE_SIGHAND | CLONE_THREAD, NULL);
 789         if(result == -1) {
 790                 perror("clone");
 791                 return;
 792         }
 793 #else
 794
 795         pthread_create(&thread, NULL, listener_main, NULL);
 796 #endif
 797
 798         have_listener = 1;
 799 }
 800
 801 static int init_socket(void)
 802 {
 803         return ustcomm_init_app(getpid(), &ustcomm_app);
 804 }
 805
 806 #define AUTOPROBE_DISABLED      0
 807 #define AUTOPROBE_ENABLE_ALL    1
 808 #define AUTOPROBE_ENABLE_REGEX  2
 809 static int autoprobe_method = AUTOPROBE_DISABLED;
 810 static regex_t autoprobe_regex;
 811
 812 static void auto_probe_connect(struct marker *m)
 813 {
 814         int result;
 815
 816         char* concat_name = NULL;
 817         const char *probe_name = "default";
 818
 819         if(autoprobe_method == AUTOPROBE_DISABLED) {
 820                 return;
 821         }
 822         else if(autoprobe_method == AUTOPROBE_ENABLE_REGEX) {
 823                 result = asprintf(&concat_name, "%s/%s", m->channel, m->name);
 824                 if(result == -1) {
 825                         ERR("auto_probe_connect: asprintf failed (marker %s/%s)",
 826                                 m->channel, m->name);
 827                         return;
 828                 }
 829                 if (regexec(&autoprobe_regex, concat_name, 0, NULL, 0)) {
 830                         free(concat_name);
 831                         return;
 832                 }
 833                 free(concat_name);
 834         }
 835
 836         result = ltt_marker_connect(m->channel, m->name, probe_name);
 837         if(result && result != -EEXIST)
 838                 ERR("ltt_marker_connect (marker = %s/%s, errno = %d)", m->channel, m->name, -result);
 839
 840         DBG("auto connected marker %s (addr: %p) %s to probe default", m->channel, m, m->name);
 841
 842 }
 843
 844 static void __attribute__((constructor)) init()
 845 {
 846         int result;
 847         char* autoprobe_val = NULL;
 848
 849         /* Assign the pidunique, to be able to differentiate the processes with same
 850          * pid, (before and after an exec).
 851          */
 852         pidunique = make_pidunique();
 853
 854         /* Initialize RCU in case the constructor order is not good. */
 855         urcu_init();
 856
 857         /* It is important to do this before events start to be generated. */
 858         ust_register_thread();
 859
 860         DBG("Tracectl constructor");
 861
 862         /* Must create socket before signal handler to prevent races.
 863          */
 864         result = init_socket();
 865         if(result == -1) {
 866                 ERR("init_socket error");
 867                 return;
 868         }
 869
 870         create_listener();
 871
 872         autoprobe_val = getenv("UST_AUTOPROBE");
 873         if(autoprobe_val) {
 874                 struct marker_iter iter;
 875
 876                 DBG("Autoprobe enabled.");
 877
 878                 /* Ensure markers are initialized */
 879                 //init_markers();
 880
 881                 /* Ensure marker control is initialized, for the probe */
 882                 init_marker_control();
 883
 884                 /* first, set the callback that will connect the
 885                  * probe on new markers
 886                  */
 887                 if(autoprobe_val[0] == '/') {
 888                         result = regcomp(&autoprobe_regex, autoprobe_val+1, 0);
 889                         if (result) {
 890                                 char regexerr[150];
 891
 892                                 regerror(result, &autoprobe_regex, regexerr, sizeof(regexerr));
 893                                 ERR("cannot parse regex %s (%s), will ignore UST_AUTOPROBE", autoprobe_val, regexerr);
 894                                 /* don't crash the application just for this */
 895                         }
 896                         else {
 897                                 autoprobe_method = AUTOPROBE_ENABLE_REGEX;
 898                         }
 899                 }
 900                 else {
 901                         /* just enable all instrumentation */
 902                         autoprobe_method = AUTOPROBE_ENABLE_ALL;
 903                 }
 904
 905                 marker_set_new_marker_cb(auto_probe_connect);
 906
 907                 /* Now, connect the probes that were already registered. */
 908                 marker_iter_reset(&iter);
 909                 marker_iter_start(&iter);
 910
 911                 DBG("now iterating on markers already registered");
 912                 while(iter.marker) {
 913                         DBG("now iterating on marker %s", iter.marker->name);
 914                         auto_probe_connect(iter.marker);
 915                         marker_iter_next(&iter);
 916                 }
 917         }
 918
 919         if(getenv("UST_TRACE")) {
 920                 char trace_name[] = "auto";
 921                 char trace_type[] = "ustrelay";
 922
 923                 DBG("starting early tracing");
 924
 925                 /* Ensure marker control is initialized */
 926                 init_marker_control();
 927
 928                 /* Ensure relay is initialized */
 929                 init_ustrelay_transport();
 930
 931                 /* Ensure markers are initialized */
 932                 init_markers();
 933
 934                 /* In case. */
 935                 ltt_channels_register("ust");
 936
 937                 result = ltt_trace_setup(trace_name);
 938                 if(result < 0) {
 939                         ERR("ltt_trace_setup failed");
 940                         return;
 941                 }
 942
 943                 result = ltt_trace_set_type(trace_name, trace_type);
 944                 if(result < 0) {
 945                         ERR("ltt_trace_set_type failed");
 946                         return;
 947                 }
 948
 949                 result = ltt_trace_alloc(trace_name);
 950                 if(result < 0) {
 951                         ERR("ltt_trace_alloc failed");
 952                         return;
 953                 }
 954
 955                 result = ltt_trace_start(trace_name);
 956                 if(result < 0) {
 957                         ERR("ltt_trace_start failed");
 958                         return;
 959                 }
 960
 961                 /* Do this after the trace is started in order to avoid creating confusion
 962                  * if the trace fails to start. */
 963                 inform_consumer_daemon(trace_name);
 964         }
 965
 966
 967         return;
 968
 969         /* should decrementally destroy stuff if error */
 970
 971 }
 972
 973 /* This is only called if we terminate normally, not with an unhandled signal,
 974  * so we cannot rely on it. However, for now, LTTV requires that the header of
 975  * the last sub-buffer contain a valid end time for the trace. This is done
 976  * automatically only when the trace is properly stopped.
 977  *
 978  * If the traced program crashed, it is always possible to manually add the
 979  * right value in the header, or to open the trace in text mode.
 980  *
 981  * FIXME: Fix LTTV so it doesn't need this.
 982  */
 983
 984 static void destroy_traces(void)
 985 {
 986         int result;
 987
 988         /* if trace running, finish it */
 989
 990         DBG("destructor stopping traces");
 991
 992         result = ltt_trace_stop("auto");
 993         if(result == -1) {
 994                 ERR("ltt_trace_stop error");
 995         }
 996
 997         result = ltt_trace_destroy("auto");
 998         if(result == -1) {
 999                 ERR("ltt_trace_destroy error");
1000         }
1001 }
1002
1003 static int trace_recording(void)
1004 {
1005         int retval = 0;
1006         struct ltt_trace_struct *trace;
1007
1008         ltt_lock_traces();
1009
1010         list_for_each_entry(trace, &ltt_traces.head, list) {
1011                 if(trace->active) {
1012                         retval = 1;
1013                         break;
1014                 }
1015         }
1016
1017         ltt_unlock_traces();
1018
1019         return retval;
1020 }
1021
1022 #if 0
1023 static int have_consumer(void)
1024 {
1025         return !list_empty(&blocked_consumers);
1026 }
1027 #endif
1028
1029 int restarting_usleep(useconds_t usecs)
1030 {
1031         struct timespec tv;
1032         int result;
1033
1034         tv.tv_sec = 0;
1035         tv.tv_nsec = usecs * 1000;
1036
1037         do {
1038                 result = nanosleep(&tv, &tv);
1039         } while(result == -1 && errno == EINTR);
1040
1041         return result;
1042 }
1043
1044 /* This destructor keeps the process alive for a few seconds in order
1045  * to leave time to ustd to connect to its buffers. This is necessary
1046  * for programs whose execution is very short. It is also useful in all
1047  * programs when tracing is started close to the end of the program
1048  * execution.
1049  *
1050  * FIXME: For now, this only works for the first trace created in a
1051  * process.
1052  */
1053
1054 static void __attribute__((destructor)) keepalive()
1055 {
1056         if(trace_recording() && buffers_to_export) {
1057                 int total = 0;
1058                 DBG("Keeping process alive for consumer daemon...");
1059                 while(buffers_to_export) {
1060                         const int interv = 200000;
1061                         restarting_usleep(interv);
1062                         total += interv;
1063
1064                         if(total >= 3000000) {
1065                                 WARN("non-consumed buffers remaining after wait limit; not waiting anymore");
1066                                 break;
1067                         }
1068                 }
1069                 DBG("Finally dying...");
1070         }
1071
1072         destroy_traces();
1073
1074         ustcomm_fini_app(&ustcomm_app);
1075 }
1076
1077 void ust_potential_exec(void)
1078 {
1079         trace_mark(ust, potential_exec, MARK_NOARGS);
1080
1081         DBG("test");
1082
1083         keepalive();
1084 }
1085
1086 /* Notify ust that there was a fork. This needs to be called inside
1087  * the new process, anytime a process whose memory is not shared with
1088  * the parent is created. If this function is not called, the events
1089  * of the new process will not be collected.
1090  */
1091
1092 void ust_fork(void)
1093 {
1094         struct blocked_consumer *bc;
1095         struct blocked_consumer *deletable_bc = NULL;
1096         int result;
1097
1098         DBG("ust: forking");
1099         ltt_trace_stop("auto");
1100         ltt_trace_destroy("auto");
1101         /* Delete all active connections */
1102         ustcomm_close_all_connections(&ustcomm_app.server);
1103
1104         /* Delete all blocked consumers */
1105         list_for_each_entry(bc, &blocked_consumers, list) {
1106                 close(bc->fd_producer);
1107                 close(bc->fd_consumer);
1108                 free(deletable_bc);
1109                 deletable_bc = bc;
1110                 list_del(&bc->list);
1111         }
1112
1113         have_listener = 0;
1114         create_listener();
1115         init_socket();
1116         ltt_trace_setup("auto");
1117         result = ltt_trace_set_type("auto", "ustrelay");
1118         if(result < 0) {
1119                 ERR("ltt_trace_set_type failed");
1120                 return;
1121         }
1122
1123         ltt_trace_alloc("auto");
1124         ltt_trace_start("auto");
1125         inform_consumer_daemon("auto");
1126 }
1127