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 "buffers.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 ust_buffers_do_get_subbuf */
  91         struct ust_buffer *buf;
  92
  93         struct list_head list;
  94 };
  95
  96 static long long make_pidunique(void)
  97 {
  98         s64 retval;
  99         struct timeval tv;
 100
 101         gettimeofday(&tv, NULL);
 102
 103         retval = tv.tv_sec;
 104         retval <<= 32;
 105         retval |= tv.tv_usec;
 106
 107         return retval;
 108 }
 109
 110 static void print_markers(FILE *fp)
 111 {
 112         struct marker_iter iter;
 113
 114         lock_markers();
 115         marker_iter_reset(&iter);
 116         marker_iter_start(&iter);
 117
 118         while(iter.marker) {
 119                 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);
 120                 marker_iter_next(&iter);
 121         }
 122         unlock_markers();
 123 }
 124
 125 static int init_socket(void);
 126
 127 /* This needs to be called whenever a new thread is created. It notifies
 128  * liburcu of the new thread.
 129  */
 130
 131 void ust_register_thread(void)
 132 {
 133         rcu_register_thread();
 134 }
 135
 136 int fd_notif = -1;
 137 void notif_cb(void)
 138 {
 139         int result;
 140         struct trctl_msg msg;
 141
 142         /* FIXME: fd_notif should probably be protected by a spinlock */
 143
 144         if(fd_notif == -1)
 145                 return;
 146
 147         msg.type = MSG_NOTIF;
 148         msg.size = sizeof(msg.type);
 149
 150         /* FIXME: don't block here */
 151         result = write(fd_notif, &msg, msg.size+sizeof(msg.size));
 152         if(result == -1) {
 153                 PERROR("write");
 154                 return;
 155         }
 156 }
 157
 158 /* Ask the daemon to collect a trace called trace_name and being
 159  * produced by this pid.
 160  *
 161  * The trace must be at least allocated. (It can also be started.)
 162  * This is because _ltt_trace_find is used.
 163  */
 164
 165 static void inform_consumer_daemon(const char *trace_name)
 166 {
 167         int i;
 168         struct ltt_trace_struct *trace;
 169         pid_t pid = getpid();
 170         int result;
 171
 172         ltt_lock_traces();
 173
 174         trace = _ltt_trace_find(trace_name);
 175         if(trace == NULL) {
 176                 WARN("inform_consumer_daemon: could not find trace \"%s\"; it is probably already destroyed", trace_name);
 177                 goto finish;
 178         }
 179
 180         for(i=0; i < trace->nr_channels; i++) {
 181                 result = ustcomm_request_consumer(pid, trace->channels[i].channel_name);
 182                 if(result == -1) {
 183                         WARN("Failed to request collection for channel %s. Is the daemon available?", trace->channels[i].channel_name);
 184                         /* continue even if fail */
 185                 }
 186                 buffers_to_export++;
 187         }
 188
 189         finish:
 190         ltt_unlock_traces();
 191 }
 192
 193 void process_blocked_consumers(void)
 194 {
 195         int n_fds = 0;
 196         struct pollfd *fds;
 197         struct blocked_consumer *bc;
 198         int idx = 0;
 199         char inbuf;
 200         int result;
 201
 202         list_for_each_entry(bc, &blocked_consumers, list) {
 203                 n_fds++;
 204         }
 205
 206         fds = (struct pollfd *) malloc(n_fds * sizeof(struct pollfd));
 207         if(fds == NULL) {
 208                 ERR("malloc returned NULL");
 209                 return;
 210         }
 211
 212         list_for_each_entry(bc, &blocked_consumers, list) {
 213                 fds[idx].fd = bc->fd_producer;
 214                 fds[idx].events = POLLIN;
 215                 bc->tmp_poll_idx = idx;
 216                 idx++;
 217         }
 218
 219         while((result = poll(fds, n_fds, 0)) == -1 && errno == EINTR)
 220                 /* nothing */;
 221         if(result == -1) {
 222                 PERROR("poll");
 223                 return;
 224         }
 225
 226         list_for_each_entry(bc, &blocked_consumers, list) {
 227                 if(fds[bc->tmp_poll_idx].revents) {
 228                         long consumed_old = 0;
 229                         char *reply;
 230
 231                         result = read(bc->fd_producer, &inbuf, 1);
 232                         if(result == -1) {
 233                                 PERROR("read");
 234                                 continue;
 235                         }
 236                         if(result == 0) {
 237                                 DBG("PRODUCER END");
 238
 239                                 close(bc->fd_producer);
 240
 241                                 list_del(&bc->list);
 242
 243                                 result = ustcomm_send_reply(&bc->server, "END", &bc->src);
 244                                 if(result < 0) {
 245                                         ERR("ustcomm_send_reply failed");
 246                                         continue;
 247                                 }
 248
 249                                 continue;
 250                         }
 251
 252                         result = ust_buffers_do_get_subbuf(bc->buf, &consumed_old);
 253                         if(result == -EAGAIN) {
 254                                 WARN("missed buffer?");
 255                                 continue;
 256                         }
 257                         else if(result < 0) {
 258                                 DBG("ust_buffers_do_get_subbuf: error: %s", strerror(-result));
 259                         }
 260                         asprintf(&reply, "%s %ld", "OK", consumed_old);
 261                         result = ustcomm_send_reply(&bc->server, reply, &bc->src);
 262                         if(result < 0) {
 263                                 ERR("ustcomm_send_reply failed");
 264                                 free(reply);
 265                                 continue;
 266                         }
 267                         free(reply);
 268
 269                         list_del(&bc->list);
 270                 }
 271         }
 272
 273 }
 274
 275 void *listener_main(void *p)
 276 {
 277         int result;
 278
 279         ust_register_thread();
 280
 281         DBG("LISTENER");
 282
 283         for(;;) {
 284                 char trace_name[] = "auto";
 285                 char trace_type[] = "ustrelay";
 286                 char *recvbuf;
 287                 int len;
 288                 struct ustcomm_source src;
 289
 290                 process_blocked_consumers();
 291
 292                 result = ustcomm_app_recv_message(&ustcomm_app, &recvbuf, &src, 5);
 293                 if(result < 0) {
 294                         WARN("error in ustcomm_app_recv_message");
 295                         continue;
 296                 }
 297                 else if(result == 0) {
 298                         /* no message */
 299                         continue;
 300                 }
 301
 302                 DBG("received a message! it's: %s", recvbuf);
 303                 len = strlen(recvbuf);
 304
 305                 if(!strcmp(recvbuf, "print_markers")) {
 306                         print_markers(stderr);
 307                 }
 308                 else if(!strcmp(recvbuf, "list_markers")) {
 309                         char *ptr;
 310                         size_t size;
 311                         FILE *fp;
 312
 313                         fp = open_memstream(&ptr, &size);
 314                         print_markers(fp);
 315                         fclose(fp);
 316
 317                         result = ustcomm_send_reply(&ustcomm_app.server, ptr, &src);
 318
 319                         free(ptr);
 320                 }
 321                 else if(!strcmp(recvbuf, "start")) {
 322                         /* start is an operation that setups the trace, allocates it and starts it */
 323                         result = ltt_trace_setup(trace_name);
 324                         if(result < 0) {
 325                                 ERR("ltt_trace_setup failed");
 326                                 return (void *)1;
 327                         }
 328
 329                         result = ltt_trace_set_type(trace_name, trace_type);
 330                         if(result < 0) {
 331                                 ERR("ltt_trace_set_type failed");
 332                                 return (void *)1;
 333                         }
 334
 335                         result = ltt_trace_alloc(trace_name);
 336                         if(result < 0) {
 337                                 ERR("ltt_trace_alloc failed");
 338                                 return (void *)1;
 339                         }
 340
 341                         inform_consumer_daemon(trace_name);
 342
 343                         result = ltt_trace_start(trace_name);
 344                         if(result < 0) {
 345                                 ERR("ltt_trace_start failed");
 346                                 continue;
 347                         }
 348                 }
 349                 else if(!strcmp(recvbuf, "trace_setup")) {
 350                         DBG("trace setup");
 351
 352                         result = ltt_trace_setup(trace_name);
 353                         if(result < 0) {
 354                                 ERR("ltt_trace_setup failed");
 355                                 return (void *)1;
 356                         }
 357
 358                         result = ltt_trace_set_type(trace_name, trace_type);
 359                         if(result < 0) {
 360                                 ERR("ltt_trace_set_type failed");
 361                                 return (void *)1;
 362                         }
 363                 }
 364                 else if(!strcmp(recvbuf, "trace_alloc")) {
 365                         DBG("trace alloc");
 366
 367                         result = ltt_trace_alloc(trace_name);
 368                         if(result < 0) {
 369                                 ERR("ltt_trace_alloc failed");
 370                                 return (void *)1;
 371                         }
 372                 }
 373                 else if(!strcmp(recvbuf, "trace_create")) {
 374                         DBG("trace create");
 375
 376                         result = ltt_trace_setup(trace_name);
 377                         if(result < 0) {
 378                                 ERR("ltt_trace_setup failed");
 379                                 return (void *)1;
 380                         }
 381
 382                         result = ltt_trace_set_type(trace_name, trace_type);
 383                         if(result < 0) {
 384                                 ERR("ltt_trace_set_type failed");
 385                                 return (void *)1;
 386                         }
 387
 388                         result = ltt_trace_alloc(trace_name);
 389                         if(result < 0) {
 390                                 ERR("ltt_trace_alloc failed");
 391                                 return (void *)1;
 392                         }
 393
 394                         inform_consumer_daemon(trace_name);
 395                 }
 396                 else if(!strcmp(recvbuf, "trace_start")) {
 397                         DBG("trace start");
 398
 399                         result = ltt_trace_start(trace_name);
 400                         if(result < 0) {
 401                                 ERR("ltt_trace_start failed");
 402                                 continue;
 403                         }
 404                 }
 405                 else if(!strcmp(recvbuf, "trace_stop")) {
 406                         DBG("trace stop");
 407
 408                         result = ltt_trace_stop(trace_name);
 409                         if(result < 0) {
 410                                 ERR("ltt_trace_stop failed");
 411                                 return (void *)1;
 412                         }
 413                 }
 414                 else if(!strcmp(recvbuf, "trace_destroy")) {
 415
 416                         DBG("trace destroy");
 417
 418                         result = ltt_trace_destroy(trace_name);
 419                         if(result < 0) {
 420                                 ERR("ltt_trace_destroy failed");
 421                                 return (void *)1;
 422                         }
 423                 }
 424                 else if(nth_token_is(recvbuf, "get_shmid", 0) == 1) {
 425                         struct ltt_trace_struct *trace;
 426                         char trace_name[] = "auto";
 427                         int i;
 428                         char *channel_name;
 429
 430                         DBG("get_shmid");
 431
 432                         channel_name = nth_token(recvbuf, 1);
 433                         if(channel_name == NULL) {
 434                                 ERR("get_shmid: cannot parse channel");
 435                                 goto next_cmd;
 436                         }
 437
 438                         ltt_lock_traces();
 439                         trace = _ltt_trace_find(trace_name);
 440                         ltt_unlock_traces();
 441
 442                         if(trace == NULL) {
 443                                 ERR("cannot find trace!");
 444                                 return (void *)1;
 445                         }
 446
 447                         for(i=0; i<trace->nr_channels; i++) {
 448                                 struct ust_channel *channel = &trace->channels[i];
 449                                 struct ust_buffer *buf = channel->buf;
 450
 451                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 452                                         char *reply;
 453
 454                                         DBG("the shmid for the requested channel is %d", buf->shmid);
 455                                         DBG("the shmid for its buffer structure is %d", channel->buf_shmid);
 456                                         asprintf(&reply, "%d %d", buf->shmid, channel->buf_shmid);
 457
 458                                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 459                                         if(result) {
 460                                                 ERR("listener: get_shmid: ustcomm_send_reply failed");
 461                                                 goto next_cmd;
 462                                         }
 463
 464                                         free(reply);
 465
 466                                         break;
 467                                 }
 468                         }
 469
 470                         buffers_to_export--;
 471                 }
 472                 else if(nth_token_is(recvbuf, "get_n_subbufs", 0) == 1) {
 473                         struct ltt_trace_struct *trace;
 474                         char trace_name[] = "auto";
 475                         int i;
 476                         char *channel_name;
 477
 478                         DBG("get_n_subbufs");
 479
 480                         channel_name = nth_token(recvbuf, 1);
 481                         if(channel_name == NULL) {
 482                                 ERR("get_n_subbufs: cannot parse channel");
 483                                 goto next_cmd;
 484                         }
 485
 486                         ltt_lock_traces();
 487                         trace = _ltt_trace_find(trace_name);
 488                         ltt_unlock_traces();
 489
 490                         if(trace == NULL) {
 491                                 ERR("cannot find trace!");
 492                                 return (void *)1;
 493                         }
 494
 495                         for(i=0; i<trace->nr_channels; i++) {
 496                                 struct ust_channel *channel = &trace->channels[i];
 497
 498                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 499                                         char *reply;
 500
 501                                         DBG("the n_subbufs for the requested channel is %d", channel->subbuf_cnt);
 502                                         asprintf(&reply, "%d", channel->subbuf_cnt);
 503
 504                                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 505                                         if(result) {
 506                                                 ERR("listener: get_n_subbufs: ustcomm_send_reply failed");
 507                                                 goto next_cmd;
 508                                         }
 509
 510                                         free(reply);
 511
 512                                         break;
 513                                 }
 514                         }
 515                 }
 516                 else if(nth_token_is(recvbuf, "get_subbuf_size", 0) == 1) {
 517                         struct ltt_trace_struct *trace;
 518                         char trace_name[] = "auto";
 519                         int i;
 520                         char *channel_name;
 521
 522                         DBG("get_subbuf_size");
 523
 524                         channel_name = nth_token(recvbuf, 1);
 525                         if(channel_name == NULL) {
 526                                 ERR("get_subbuf_size: cannot parse channel");
 527                                 goto next_cmd;
 528                         }
 529
 530                         ltt_lock_traces();
 531                         trace = _ltt_trace_find(trace_name);
 532                         ltt_unlock_traces();
 533
 534                         if(trace == NULL) {
 535                                 ERR("cannot find trace!");
 536                                 return (void *)1;
 537                         }
 538
 539                         for(i=0; i<trace->nr_channels; i++) {
 540                                 struct ust_channel *channel = &trace->channels[i];
 541
 542                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 543                                         char *reply;
 544
 545                                         DBG("the subbuf_size for the requested channel is %zd", channel->subbuf_size);
 546                                         asprintf(&reply, "%zd", channel->subbuf_size);
 547
 548                                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 549                                         if(result) {
 550                                                 ERR("listener: get_subbuf_size: ustcomm_send_reply failed");
 551                                                 goto next_cmd;
 552                                         }
 553
 554                                         free(reply);
 555
 556                                         break;
 557                                 }
 558                         }
 559                 }
 560                 else if(nth_token_is(recvbuf, "load_probe_lib", 0) == 1) {
 561                         char *libfile;
 562
 563                         libfile = nth_token(recvbuf, 1);
 564
 565                         DBG("load_probe_lib loading %s", libfile);
 566                 }
 567                 else if(nth_token_is(recvbuf, "get_subbuffer", 0) == 1) {
 568                         struct ltt_trace_struct *trace;
 569                         char trace_name[] = "auto";
 570                         int i;
 571                         char *channel_name;
 572
 573                         DBG("get_subbuf");
 574
 575                         channel_name = nth_token(recvbuf, 1);
 576                         if(channel_name == NULL) {
 577                                 ERR("get_subbuf: cannot parse channel");
 578                                 goto next_cmd;
 579                         }
 580
 581                         ltt_lock_traces();
 582                         trace = _ltt_trace_find(trace_name);
 583                         ltt_unlock_traces();
 584
 585                         if(trace == NULL) {
 586                                 ERR("cannot find trace!");
 587                                 return (void *)1;
 588                         }
 589
 590                         for(i=0; i<trace->nr_channels; i++) {
 591                                 struct ust_channel *channel = &trace->channels[i];
 592
 593                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 594                                         struct ust_buffer *buf = channel->buf;
 595                                         struct blocked_consumer *bc;
 596
 597                                         bc = (struct blocked_consumer *) malloc(sizeof(struct blocked_consumer));
 598                                         if(bc == NULL) {
 599                                                 ERR("malloc returned NULL");
 600                                                 goto next_cmd;
 601                                         }
 602                                         bc->fd_consumer = src.fd;
 603                                         bc->fd_producer = buf->data_ready_fd_read;
 604                                         bc->buf = buf;
 605                                         bc->src = src;
 606                                         bc->server = ustcomm_app.server;
 607
 608                                         list_add(&bc->list, &blocked_consumers);
 609
 610                                         break;
 611                                 }
 612                         }
 613                 }
 614                 else if(nth_token_is(recvbuf, "put_subbuffer", 0) == 1) {
 615                         struct ltt_trace_struct *trace;
 616                         char trace_name[] = "auto";
 617                         int i;
 618                         char *channel_name;
 619                         long consumed_old;
 620                         char *consumed_old_str;
 621                         char *endptr;
 622
 623                         DBG("put_subbuf");
 624
 625                         channel_name = strdup_malloc(nth_token(recvbuf, 1));
 626                         if(channel_name == NULL) {
 627                                 ERR("put_subbuf_size: cannot parse channel");
 628                                 goto next_cmd;
 629                         }
 630
 631                         consumed_old_str = strdup_malloc(nth_token(recvbuf, 2));
 632                         if(consumed_old_str == NULL) {
 633                                 ERR("put_subbuf: cannot parse consumed_old");
 634                                 goto next_cmd;
 635                         }
 636                         consumed_old = strtol(consumed_old_str, &endptr, 10);
 637                         if(*endptr != '\0') {
 638                                 ERR("put_subbuf: invalid value for consumed_old");
 639                                 goto next_cmd;
 640                         }
 641
 642                         ltt_lock_traces();
 643                         trace = _ltt_trace_find(trace_name);
 644                         ltt_unlock_traces();
 645
 646                         if(trace == NULL) {
 647                                 ERR("cannot find trace!");
 648                                 return (void *)1;
 649                         }
 650
 651                         for(i=0; i<trace->nr_channels; i++) {
 652                                 struct ust_channel *channel = &trace->channels[i];
 653
 654                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 655                                         struct ust_buffer *buf = channel->buf;
 656                                         char *reply;
 657                                         long consumed_old=0;
 658
 659                                         result = ust_buffers_do_put_subbuf(buf, consumed_old);
 660                                         if(result < 0) {
 661                                                 WARN("ust_buffers_do_put_subbuf: error (subbuf=%s)", channel_name);
 662                                                 asprintf(&reply, "%s", "ERROR");
 663                                         }
 664                                         else {
 665                                                 DBG("ust_buffers_do_put_subbuf: success (subbuf=%s)", channel_name);
 666                                                 asprintf(&reply, "%s", "OK");
 667                                         }
 668
 669                                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 670                                         if(result) {
 671                                                 ERR("listener: put_subbuf: ustcomm_send_reply failed");
 672                                                 goto next_cmd;
 673                                         }
 674
 675                                         free(reply);
 676
 677                                         break;
 678                                 }
 679                         }
 680
 681                         free(channel_name);
 682                         free(consumed_old_str);
 683                 }
 684                 else if(nth_token_is(recvbuf, "enable_marker", 0) == 1) {
 685                         char *channel_slash_name = nth_token(recvbuf, 1);
 686                         char channel_name[256]="";
 687                         char marker_name[256]="";
 688
 689                         result = sscanf(channel_slash_name, "%255[^/]/%255s", channel_name, marker_name);
 690
 691                         if(channel_name == NULL || marker_name == NULL) {
 692                                 WARN("invalid marker name");
 693                                 goto next_cmd;
 694                         }
 695                         printf("%s %s\n", channel_name, marker_name);
 696
 697                         result = ltt_marker_connect(channel_name, marker_name, "default");
 698                         if(result < 0) {
 699                                 WARN("could not enable marker; channel=%s, name=%s", channel_name, marker_name);
 700                         }
 701                 }
 702                 else if(nth_token_is(recvbuf, "disable_marker", 0) == 1) {
 703                         char *channel_slash_name = nth_token(recvbuf, 1);
 704                         char *marker_name;
 705                         char *channel_name;
 706
 707                         result = sscanf(channel_slash_name, "%a[^/]/%as", &channel_name, &marker_name);
 708
 709                         if(marker_name == NULL) {
 710                         }
 711                         printf("%s %s\n", channel_name, marker_name);
 712
 713                         result = ltt_marker_disconnect(channel_name, marker_name, "default");
 714                         if(result < 0) {
 715                                 WARN("could not disable marker; channel=%s, name=%s", channel_name, marker_name);
 716                         }
 717                 }
 718                 else if(nth_token_is(recvbuf, "get_pidunique", 0) == 1) {
 719                         char *reply;
 720
 721                         asprintf(&reply, "%lld", pidunique);
 722
 723                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 724                         if(result) {
 725                                 ERR("listener: get_pidunique: ustcomm_send_reply failed");
 726                                 goto next_cmd;
 727                         }
 728
 729                         free(reply);
 730                 }
 731 //              else if(nth_token_is(recvbuf, "get_notifications", 0) == 1) {
 732 //                      struct ltt_trace_struct *trace;
 733 //                      char trace_name[] = "auto";
 734 //                      int i;
 735 //                      char *channel_name;
 736 //
 737 //                      DBG("get_notifications");
 738 //
 739 //                      channel_name = strdup_malloc(nth_token(recvbuf, 1));
 740 //                      if(channel_name == NULL) {
 741 //                              ERR("put_subbuf_size: cannot parse channel");
 742 //                              goto next_cmd;
 743 //                      }
 744 //
 745 //                      ltt_lock_traces();
 746 //                      trace = _ltt_trace_find(trace_name);
 747 //                      ltt_unlock_traces();
 748 //
 749 //                      if(trace == NULL) {
 750 //                              ERR("cannot find trace!");
 751 //                              return (void *)1;
 752 //                      }
 753 //
 754 //                      for(i=0; i<trace->nr_channels; i++) {
 755 //                              struct rchan *rchan = trace->channels[i].trans_channel_data;
 756 //                              int fd;
 757 //
 758 //                              if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 759 //                                      struct rchan_buf *rbuf = rchan->buf;
 760 //                                      struct ltt_channel_buf_struct *lttbuf = trace->channels[i].buf;
 761 //
 762 //                                      result = fd = ustcomm_app_detach_client(&ustcomm_app, &src);
 763 //                                      if(result == -1) {
 764 //                                              ERR("ustcomm_app_detach_client failed");
 765 //                                              goto next_cmd;
 766 //                                      }
 767 //
 768 //                                      lttbuf->wake_consumer_arg = (void *) fd;
 769 //
 770 //                                      smp_wmb();
 771 //
 772 //                                      lttbuf->call_wake_consumer = 1;
 773 //
 774 //                                      break;
 775 //                              }
 776 //                      }
 777 //
 778 //                      free(channel_name);
 779 //              }
 780                 else {
 781                         ERR("unable to parse message: %s", recvbuf);
 782                 }
 783
 784         next_cmd:
 785                 free(recvbuf);
 786         }
 787 }
 788
 789 volatile sig_atomic_t have_listener = 0;
 790
 791 void create_listener(void)
 792 {
 793 #ifdef USE_CLONE
 794         static char listener_stack[16384];
 795         int result;
 796 #else
 797         pthread_t thread;
 798 #endif
 799
 800         if(have_listener) {
 801                 WARN("not creating listener because we already had one");
 802                 return;
 803         }
 804
 805 #ifdef USE_CLONE
 806         result = clone((int (*)(void *)) listener_main, listener_stack+sizeof(listener_stack)-1, CLONE_FS | CLONE_FILES | CLONE_VM | CLONE_SIGHAND | CLONE_THREAD, NULL);
 807         if(result == -1) {
 808                 perror("clone");
 809                 return;
 810         }
 811 #else
 812
 813         pthread_create(&thread, NULL, listener_main, NULL);
 814 #endif
 815
 816         have_listener = 1;
 817 }
 818
 819 static int init_socket(void)
 820 {
 821         return ustcomm_init_app(getpid(), &ustcomm_app);
 822 }
 823
 824 #define AUTOPROBE_DISABLED      0
 825 #define AUTOPROBE_ENABLE_ALL    1
 826 #define AUTOPROBE_ENABLE_REGEX  2
 827 static int autoprobe_method = AUTOPROBE_DISABLED;
 828 static regex_t autoprobe_regex;
 829
 830 static void auto_probe_connect(struct marker *m)
 831 {
 832         int result;
 833
 834         char* concat_name = NULL;
 835         const char *probe_name = "default";
 836
 837         if(autoprobe_method == AUTOPROBE_DISABLED) {
 838                 return;
 839         }
 840         else if(autoprobe_method == AUTOPROBE_ENABLE_REGEX) {
 841                 result = asprintf(&concat_name, "%s/%s", m->channel, m->name);
 842                 if(result == -1) {
 843                         ERR("auto_probe_connect: asprintf failed (marker %s/%s)",
 844                                 m->channel, m->name);
 845                         return;
 846                 }
 847                 if (regexec(&autoprobe_regex, concat_name, 0, NULL, 0)) {
 848                         free(concat_name);
 849                         return;
 850                 }
 851                 free(concat_name);
 852         }
 853
 854         result = ltt_marker_connect(m->channel, m->name, probe_name);
 855         if(result && result != -EEXIST)
 856                 ERR("ltt_marker_connect (marker = %s/%s, errno = %d)", m->channel, m->name, -result);
 857
 858         DBG("auto connected marker %s (addr: %p) %s to probe default", m->channel, m, m->name);
 859
 860 }
 861
 862 static void __attribute__((constructor)) init()
 863 {
 864         int result;
 865         char* autoprobe_val = NULL;
 866
 867         /* Assign the pidunique, to be able to differentiate the processes with same
 868          * pid, (before and after an exec).
 869          */
 870         pidunique = make_pidunique();
 871
 872         /* Initialize RCU in case the constructor order is not good. */
 873         urcu_init();
 874
 875         /* It is important to do this before events start to be generated. */
 876         ust_register_thread();
 877
 878         DBG("Tracectl constructor");
 879
 880         /* Must create socket before signal handler to prevent races.
 881          */
 882         result = init_socket();
 883         if(result == -1) {
 884                 ERR("init_socket error");
 885                 return;
 886         }
 887
 888         create_listener();
 889
 890         autoprobe_val = getenv("UST_AUTOPROBE");
 891         if(autoprobe_val) {
 892                 struct marker_iter iter;
 893
 894                 DBG("Autoprobe enabled.");
 895
 896                 /* Ensure markers are initialized */
 897                 //init_markers();
 898
 899                 /* Ensure marker control is initialized, for the probe */
 900                 init_marker_control();
 901
 902                 /* first, set the callback that will connect the
 903                  * probe on new markers
 904                  */
 905                 if(autoprobe_val[0] == '/') {
 906                         result = regcomp(&autoprobe_regex, autoprobe_val+1, 0);
 907                         if (result) {
 908                                 char regexerr[150];
 909
 910                                 regerror(result, &autoprobe_regex, regexerr, sizeof(regexerr));
 911                                 ERR("cannot parse regex %s (%s), will ignore UST_AUTOPROBE", autoprobe_val, regexerr);
 912                                 /* don't crash the application just for this */
 913                         }
 914                         else {
 915                                 autoprobe_method = AUTOPROBE_ENABLE_REGEX;
 916                         }
 917                 }
 918                 else {
 919                         /* just enable all instrumentation */
 920                         autoprobe_method = AUTOPROBE_ENABLE_ALL;
 921                 }
 922
 923                 marker_set_new_marker_cb(auto_probe_connect);
 924
 925                 /* Now, connect the probes that were already registered. */
 926                 marker_iter_reset(&iter);
 927                 marker_iter_start(&iter);
 928
 929                 DBG("now iterating on markers already registered");
 930                 while(iter.marker) {
 931                         DBG("now iterating on marker %s", iter.marker->name);
 932                         auto_probe_connect(iter.marker);
 933                         marker_iter_next(&iter);
 934                 }
 935         }
 936
 937         if(getenv("UST_TRACE")) {
 938                 char trace_name[] = "auto";
 939                 char trace_type[] = "ustrelay";
 940
 941                 DBG("starting early tracing");
 942
 943                 /* Ensure marker control is initialized */
 944                 init_marker_control();
 945
 946                 /* Ensure relay is initialized */
 947                 init_ustrelay_transport();
 948
 949                 /* Ensure markers are initialized */
 950                 init_markers();
 951
 952                 /* In case. */
 953                 ltt_channels_register("ust");
 954
 955                 result = ltt_trace_setup(trace_name);
 956                 if(result < 0) {
 957                         ERR("ltt_trace_setup failed");
 958                         return;
 959                 }
 960
 961                 result = ltt_trace_set_type(trace_name, trace_type);
 962                 if(result < 0) {
 963                         ERR("ltt_trace_set_type failed");
 964                         return;
 965                 }
 966
 967                 result = ltt_trace_alloc(trace_name);
 968                 if(result < 0) {
 969                         ERR("ltt_trace_alloc failed");
 970                         return;
 971                 }
 972
 973                 result = ltt_trace_start(trace_name);
 974                 if(result < 0) {
 975                         ERR("ltt_trace_start failed");
 976                         return;
 977                 }
 978
 979                 /* Do this after the trace is started in order to avoid creating confusion
 980                  * if the trace fails to start. */
 981                 inform_consumer_daemon(trace_name);
 982         }
 983
 984
 985         return;
 986
 987         /* should decrementally destroy stuff if error */
 988
 989 }
 990
 991 /* This is only called if we terminate normally, not with an unhandled signal,
 992  * so we cannot rely on it. However, for now, LTTV requires that the header of
 993  * the last sub-buffer contain a valid end time for the trace. This is done
 994  * automatically only when the trace is properly stopped.
 995  *
 996  * If the traced program crashed, it is always possible to manually add the
 997  * right value in the header, or to open the trace in text mode.
 998  *
 999  * FIXME: Fix LTTV so it doesn't need this.
1000  */
1001
1002 static void destroy_traces(void)
1003 {
1004         int result;
1005
1006         /* if trace running, finish it */
1007
1008         DBG("destructor stopping traces");
1009
1010         result = ltt_trace_stop("auto");
1011         if(result == -1) {
1012                 ERR("ltt_trace_stop error");
1013         }
1014
1015         result = ltt_trace_destroy("auto");
1016         if(result == -1) {
1017                 ERR("ltt_trace_destroy error");
1018         }
1019 }
1020
1021 static int trace_recording(void)
1022 {
1023         int retval = 0;
1024         struct ltt_trace_struct *trace;
1025
1026         ltt_lock_traces();
1027
1028         list_for_each_entry(trace, &ltt_traces.head, list) {
1029                 if(trace->active) {
1030                         retval = 1;
1031                         break;
1032                 }
1033         }
1034
1035         ltt_unlock_traces();
1036
1037         return retval;
1038 }
1039
1040 #if 0
1041 static int have_consumer(void)
1042 {
1043         return !list_empty(&blocked_consumers);
1044 }
1045 #endif
1046
1047 int restarting_usleep(useconds_t usecs)
1048 {
1049         struct timespec tv;
1050         int result;
1051
1052         tv.tv_sec = 0;
1053         tv.tv_nsec = usecs * 1000;
1054
1055         do {
1056                 result = nanosleep(&tv, &tv);
1057         } while(result == -1 && errno == EINTR);
1058
1059         return result;
1060 }
1061
1062 /* This destructor keeps the process alive for a few seconds in order
1063  * to leave time to ustd to connect to its buffers. This is necessary
1064  * for programs whose execution is very short. It is also useful in all
1065  * programs when tracing is started close to the end of the program
1066  * execution.
1067  *
1068  * FIXME: For now, this only works for the first trace created in a
1069  * process.
1070  */
1071
1072 static void __attribute__((destructor)) keepalive()
1073 {
1074         if(trace_recording() && buffers_to_export) {
1075                 int total = 0;
1076                 DBG("Keeping process alive for consumer daemon...");
1077                 while(buffers_to_export) {
1078                         const int interv = 200000;
1079                         restarting_usleep(interv);
1080                         total += interv;
1081
1082                         if(total >= 3000000) {
1083                                 WARN("non-consumed buffers remaining after wait limit; not waiting anymore");
1084                                 break;
1085                         }
1086                 }
1087                 DBG("Finally dying...");
1088         }
1089
1090         destroy_traces();
1091
1092         ustcomm_fini_app(&ustcomm_app);
1093 }
1094
1095 void ust_potential_exec(void)
1096 {
1097         trace_mark(ust, potential_exec, MARK_NOARGS);
1098
1099         DBG("test");
1100
1101         keepalive();
1102 }
1103
1104 /* Notify ust that there was a fork. This needs to be called inside
1105  * the new process, anytime a process whose memory is not shared with
1106  * the parent is created. If this function is not called, the events
1107  * of the new process will not be collected.
1108  */
1109
1110 void ust_fork(void)
1111 {
1112         struct blocked_consumer *bc;
1113         struct blocked_consumer *deletable_bc = NULL;
1114         int result;
1115
1116         DBG("ust: forking");
1117         ltt_trace_stop("auto");
1118         ltt_trace_destroy("auto");
1119         /* Delete all active connections */
1120         ustcomm_close_all_connections(&ustcomm_app.server);
1121
1122         /* Delete all blocked consumers */
1123         list_for_each_entry(bc, &blocked_consumers, list) {
1124                 close(bc->fd_producer);
1125                 close(bc->fd_consumer);
1126                 free(deletable_bc);
1127                 deletable_bc = bc;
1128                 list_del(&bc->list);
1129         }
1130
1131         have_listener = 0;
1132         create_listener();
1133         init_socket();
1134         ltt_trace_setup("auto");
1135         result = ltt_trace_set_type("auto", "ustrelay");
1136         if(result < 0) {
1137                 ERR("ltt_trace_set_type failed");
1138                 return;
1139         }
1140
1141         ltt_trace_alloc("auto");
1142         ltt_trace_start("auto");
1143         inform_consumer_daemon("auto");
1144 }
1145