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
  29 #include <urcu.h>
  30
  31 #include "marker.h"
  32 #include "tracer.h"
  33 #include "localerr.h"
  34 #include "ustcomm.h"
  35 #include "relay.h" /* FIXME: remove */
  36 #include "marker-control.h"
  37
  38 //#define USE_CLONE
  39
  40 #define USTSIGNAL SIGIO
  41
  42 #define MAX_MSG_SIZE (100)
  43 #define MSG_NOTIF 1
  44 #define MSG_REGISTER_NOTIF 2
  45
  46 char consumer_stack[10000];
  47
  48 struct list_head blocked_consumers = LIST_HEAD_INIT(blocked_consumers);
  49
  50 static struct ustcomm_app ustcomm_app;
  51
  52 struct tracecmd { /* no padding */
  53         uint32_t size;
  54         uint16_t command;
  55 };
  56
  57 //struct listener_arg {
  58 //      int pipe_fd;
  59 //};
  60
  61 struct trctl_msg {
  62         /* size: the size of all the fields except size itself */
  63         uint32_t size;
  64         uint16_t type;
  65         /* Only the necessary part of the payload is transferred. It
  66          * may even be none of it.
  67          */
  68         char payload[94];
  69 };
  70
  71 struct consumer_channel {
  72         int fd;
  73         struct ltt_channel_struct *chan;
  74 };
  75
  76 struct blocked_consumer {
  77         int fd_consumer;
  78         int fd_producer;
  79         int tmp_poll_idx;
  80
  81         /* args to ustcomm_send_reply */
  82         struct ustcomm_server server;
  83         struct ustcomm_source src;
  84
  85         /* args to ltt_do_get_subbuf */
  86         struct rchan_buf *rbuf;
  87         struct ltt_channel_buf_struct *lttbuf;
  88
  89         struct list_head list;
  90 };
  91
  92 static void print_markers(FILE *fp)
  93 {
  94         struct marker_iter iter;
  95
  96         lock_markers();
  97         marker_iter_reset(&iter);
  98         marker_iter_start(&iter);
  99
 100         while(iter.marker) {
 101                 fprintf(fp, "marker: %s_%s %d \"%s\"\n", iter.marker->channel, iter.marker->name, (int)imv_read(iter.marker->state), iter.marker->format);
 102                 marker_iter_next(&iter);
 103         }
 104         unlock_markers();
 105 }
 106
 107 void do_command(struct tracecmd *cmd)
 108 {
 109 }
 110
 111 /* This needs to be called whenever a new thread is created. It notifies
 112  * liburcu of the new thread.
 113  */
 114
 115 void ust_register_thread(void)
 116 {
 117         rcu_register_thread();
 118 }
 119
 120 int fd_notif = -1;
 121 void notif_cb(void)
 122 {
 123         int result;
 124         struct trctl_msg msg;
 125
 126         /* FIXME: fd_notif should probably be protected by a spinlock */
 127
 128         if(fd_notif == -1)
 129                 return;
 130
 131         msg.type = MSG_NOTIF;
 132         msg.size = sizeof(msg.type);
 133
 134         /* FIXME: don't block here */
 135         result = write(fd_notif, &msg, msg.size+sizeof(msg.size));
 136         if(result == -1) {
 137                 PERROR("write");
 138                 return;
 139         }
 140 }
 141
 142 static void inform_consumer_daemon(void)
 143 {
 144         ustcomm_request_consumer(getpid(), "metadata");
 145         ustcomm_request_consumer(getpid(), "ust");
 146 }
 147
 148 void process_blocked_consumers(void)
 149 {
 150         int n_fds = 0;
 151         struct pollfd *fds;
 152         struct blocked_consumer *bc;
 153         int idx = 0;
 154         char inbuf;
 155         int result;
 156
 157         list_for_each_entry(bc, &blocked_consumers, list) {
 158                 n_fds++;
 159         }
 160
 161         fds = (struct pollfd *) malloc(n_fds * sizeof(struct pollfd));
 162         if(fds == NULL) {
 163                 ERR("malloc returned NULL");
 164                 return;
 165         }
 166
 167         list_for_each_entry(bc, &blocked_consumers, list) {
 168                 fds[idx].fd = bc->fd_producer;
 169                 fds[idx].events = POLLIN;
 170                 bc->tmp_poll_idx = idx;
 171                 idx++;
 172         }
 173
 174         while((result = poll(fds, n_fds, 0)) == -1 && errno == EINTR)
 175                 /* nothing */;
 176         if(result == -1) {
 177                 PERROR("poll");
 178                 return;
 179         }
 180
 181         list_for_each_entry(bc, &blocked_consumers, list) {
 182                 if(fds[bc->tmp_poll_idx].revents) {
 183                         long consumed_old = 0;
 184                         char *reply;
 185
 186                         result = read(bc->fd_producer, &inbuf, 1);
 187                         if(result == -1) {
 188                                 PERROR("read");
 189                                 continue;
 190                         }
 191                         if(result == 0) {
 192                                 DBG("PRODUCER END");
 193
 194                                 close(bc->fd_producer);
 195
 196                                 list_del(&bc->list);
 197
 198                                 result = ustcomm_send_reply(&bc->server, "END", &bc->src);
 199                                 if(result < 0) {
 200                                         ERR("ustcomm_send_reply failed");
 201                                         continue;
 202                                 }
 203
 204                                 continue;
 205                         }
 206
 207                         result = ltt_do_get_subbuf(bc->rbuf, bc->lttbuf, &consumed_old);
 208                         if(result == -EAGAIN) {
 209                                 WARN("missed buffer?");
 210                                 continue;
 211                         }
 212                         else if(result < 0) {
 213                                 DBG("ltt_do_get_subbuf: error: %s", strerror(-result));
 214                         }
 215                         asprintf(&reply, "%s %ld", "OK", consumed_old);
 216                         result = ustcomm_send_reply(&bc->server, reply, &bc->src);
 217                         if(result < 0) {
 218                                 ERR("ustcomm_send_reply failed");
 219                                 free(reply);
 220                                 continue;
 221                         }
 222                         free(reply);
 223
 224                         list_del(&bc->list);
 225                 }
 226         }
 227
 228 }
 229
 230 void *listener_main(void *p)
 231 {
 232         int result;
 233
 234         ust_register_thread();
 235
 236         DBG("LISTENER");
 237
 238         for(;;) {
 239                 char trace_name[] = "auto";
 240                 char trace_type[] = "ustrelay";
 241                 char *recvbuf;
 242                 int len;
 243                 struct ustcomm_source src;
 244
 245                 process_blocked_consumers();
 246
 247                 result = ustcomm_app_recv_message(&ustcomm_app, &recvbuf, &src, 5);
 248                 if(result < 0) {
 249                         WARN("error in ustcomm_app_recv_message");
 250                         continue;
 251                 }
 252                 else if(result == 0) {
 253                         /* no message */
 254                         continue;
 255                 }
 256
 257                 DBG("received a message! it's: %s\n", recvbuf);
 258                 len = strlen(recvbuf);
 259
 260                 if(!strcmp(recvbuf, "print_markers")) {
 261                         print_markers(stderr);
 262                 }
 263                 else if(!strcmp(recvbuf, "list_markers")) {
 264                         char *ptr;
 265                         size_t size;
 266                         FILE *fp;
 267
 268                         fp = open_memstream(&ptr, &size);
 269                         print_markers(fp);
 270                         fclose(fp);
 271
 272                         result = ustcomm_send_reply(&ustcomm_app.server, ptr, &src);
 273
 274                         free(ptr);
 275                 }
 276                 else if(!strcmp(recvbuf, "start")) {
 277                         /* start is an operation that setups the trace, allocates it and starts it */
 278                         result = ltt_trace_setup(trace_name);
 279                         if(result < 0) {
 280                                 ERR("ltt_trace_setup failed");
 281                                 return (void *)1;
 282                         }
 283
 284                         result = ltt_trace_set_type(trace_name, trace_type);
 285                         if(result < 0) {
 286                                 ERR("ltt_trace_set_type failed");
 287                                 return (void *)1;
 288                         }
 289
 290                         result = ltt_trace_alloc(trace_name);
 291                         if(result < 0) {
 292                                 ERR("ltt_trace_alloc failed");
 293                                 return (void *)1;
 294                         }
 295
 296                         inform_consumer_daemon();
 297
 298                         result = ltt_trace_start(trace_name);
 299                         if(result < 0) {
 300                                 ERR("ltt_trace_start failed");
 301                                 continue;
 302                         }
 303                 }
 304                 else if(!strcmp(recvbuf, "trace_setup")) {
 305                         DBG("trace setup");
 306
 307                         result = ltt_trace_setup(trace_name);
 308                         if(result < 0) {
 309                                 ERR("ltt_trace_setup failed");
 310                                 return (void *)1;
 311                         }
 312
 313                         result = ltt_trace_set_type(trace_name, trace_type);
 314                         if(result < 0) {
 315                                 ERR("ltt_trace_set_type failed");
 316                                 return (void *)1;
 317                         }
 318                 }
 319                 else if(!strcmp(recvbuf, "trace_alloc")) {
 320                         DBG("trace alloc");
 321
 322                         result = ltt_trace_alloc(trace_name);
 323                         if(result < 0) {
 324                                 ERR("ltt_trace_alloc failed");
 325                                 return (void *)1;
 326                         }
 327                 }
 328                 else if(!strcmp(recvbuf, "trace_start")) {
 329                         DBG("trace start");
 330
 331                         result = ltt_trace_start(trace_name);
 332                         if(result < 0) {
 333                                 ERR("ltt_trace_start failed");
 334                                 continue;
 335                         }
 336                 }
 337                 else if(!strcmp(recvbuf, "trace_stop")) {
 338                         DBG("trace stop");
 339
 340                         result = ltt_trace_stop(trace_name);
 341                         if(result < 0) {
 342                                 ERR("ltt_trace_stop failed");
 343                                 return (void *)1;
 344                         }
 345                 }
 346                 else if(!strcmp(recvbuf, "trace_destroy")) {
 347
 348                         DBG("trace destroy");
 349
 350                         result = ltt_trace_destroy(trace_name);
 351                         if(result < 0) {
 352                                 ERR("ltt_trace_destroy failed");
 353                                 return (void *)1;
 354                         }
 355                 }
 356                 else if(nth_token_is(recvbuf, "get_shmid", 0) == 1) {
 357                         struct ltt_trace_struct *trace;
 358                         char trace_name[] = "auto";
 359                         int i;
 360                         char *channel_name;
 361
 362                         DBG("get_shmid");
 363
 364                         channel_name = nth_token(recvbuf, 1);
 365                         if(channel_name == NULL) {
 366                                 ERR("get_shmid: cannot parse channel");
 367                                 goto next_cmd;
 368                         }
 369
 370                         ltt_lock_traces();
 371                         trace = _ltt_trace_find(trace_name);
 372                         ltt_unlock_traces();
 373
 374                         if(trace == NULL) {
 375                                 ERR("cannot find trace!");
 376                                 return (void *)1;
 377                         }
 378
 379                         for(i=0; i<trace->nr_channels; i++) {
 380                                 struct rchan *rchan = trace->channels[i].trans_channel_data;
 381                                 struct rchan_buf *rbuf = rchan->buf;
 382                                 struct ltt_channel_struct *ltt_channel = (struct ltt_channel_struct *)rchan->private_data;
 383
 384                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 385                                         char *reply;
 386
 387                                         DBG("the shmid for the requested channel is %d", rbuf->shmid);
 388                                         DBG("the shmid for its buffer structure is %d", ltt_channel->buf_shmid);
 389                                         asprintf(&reply, "%d %d", rbuf->shmid, ltt_channel->buf_shmid);
 390
 391                                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 392                                         if(result) {
 393                                                 ERR("listener: get_shmid: ustcomm_send_reply failed");
 394                                                 goto next_cmd;
 395                                         }
 396
 397                                         free(reply);
 398
 399                                         break;
 400                                 }
 401                         }
 402                 }
 403                 else if(nth_token_is(recvbuf, "get_n_subbufs", 0) == 1) {
 404                         struct ltt_trace_struct *trace;
 405                         char trace_name[] = "auto";
 406                         int i;
 407                         char *channel_name;
 408
 409                         DBG("get_n_subbufs");
 410
 411                         channel_name = nth_token(recvbuf, 1);
 412                         if(channel_name == NULL) {
 413                                 ERR("get_n_subbufs: cannot parse channel");
 414                                 goto next_cmd;
 415                         }
 416
 417                         ltt_lock_traces();
 418                         trace = _ltt_trace_find(trace_name);
 419                         ltt_unlock_traces();
 420
 421                         if(trace == NULL) {
 422                                 ERR("cannot find trace!");
 423                                 return (void *)1;
 424                         }
 425
 426                         for(i=0; i<trace->nr_channels; i++) {
 427                                 struct rchan *rchan = trace->channels[i].trans_channel_data;
 428
 429                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 430                                         char *reply;
 431
 432                                         DBG("the n_subbufs for the requested channel is %zd", rchan->n_subbufs);
 433                                         asprintf(&reply, "%zd", rchan->n_subbufs);
 434
 435                                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 436                                         if(result) {
 437                                                 ERR("listener: get_n_subbufs: ustcomm_send_reply failed");
 438                                                 goto next_cmd;
 439                                         }
 440
 441                                         free(reply);
 442
 443                                         break;
 444                                 }
 445                         }
 446                 }
 447                 else if(nth_token_is(recvbuf, "get_subbuf_size", 0) == 1) {
 448                         struct ltt_trace_struct *trace;
 449                         char trace_name[] = "auto";
 450                         int i;
 451                         char *channel_name;
 452
 453                         DBG("get_subbuf_size");
 454
 455                         channel_name = nth_token(recvbuf, 1);
 456                         if(channel_name == NULL) {
 457                                 ERR("get_subbuf_size: cannot parse channel");
 458                                 goto next_cmd;
 459                         }
 460
 461                         ltt_lock_traces();
 462                         trace = _ltt_trace_find(trace_name);
 463                         ltt_unlock_traces();
 464
 465                         if(trace == NULL) {
 466                                 ERR("cannot find trace!");
 467                                 return (void *)1;
 468                         }
 469
 470                         for(i=0; i<trace->nr_channels; i++) {
 471                                 struct rchan *rchan = trace->channels[i].trans_channel_data;
 472
 473                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 474                                         char *reply;
 475
 476                                         DBG("the subbuf_size for the requested channel is %zd", rchan->subbuf_size);
 477                                         asprintf(&reply, "%zd", rchan->subbuf_size);
 478
 479                                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 480                                         if(result) {
 481                                                 ERR("listener: get_subbuf_size: ustcomm_send_reply failed");
 482                                                 goto next_cmd;
 483                                         }
 484
 485                                         free(reply);
 486
 487                                         break;
 488                                 }
 489                         }
 490                 }
 491                 else if(nth_token_is(recvbuf, "load_probe_lib", 0) == 1) {
 492                         char *libfile;
 493
 494                         libfile = nth_token(recvbuf, 1);
 495
 496                         DBG("load_probe_lib loading %s", libfile);
 497                 }
 498                 else if(nth_token_is(recvbuf, "get_subbuffer", 0) == 1) {
 499                         struct ltt_trace_struct *trace;
 500                         char trace_name[] = "auto";
 501                         int i;
 502                         char *channel_name;
 503
 504                         DBG("get_subbuf");
 505
 506                         channel_name = nth_token(recvbuf, 1);
 507                         if(channel_name == NULL) {
 508                                 ERR("get_subbuf: cannot parse channel");
 509                                 goto next_cmd;
 510                         }
 511
 512                         ltt_lock_traces();
 513                         trace = _ltt_trace_find(trace_name);
 514                         ltt_unlock_traces();
 515
 516                         if(trace == NULL) {
 517                                 ERR("cannot find trace!");
 518                                 return (void *)1;
 519                         }
 520
 521                         for(i=0; i<trace->nr_channels; i++) {
 522                                 struct rchan *rchan = trace->channels[i].trans_channel_data;
 523
 524                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 525                                         struct rchan_buf *rbuf = rchan->buf;
 526                                         struct ltt_channel_buf_struct *lttbuf = trace->channels[i].buf;
 527                                         struct blocked_consumer *bc;
 528
 529                                         bc = (struct blocked_consumer *) malloc(sizeof(struct blocked_consumer));
 530                                         if(bc == NULL) {
 531                                                 ERR("malloc returned NULL");
 532                                                 goto next_cmd;
 533                                         }
 534                                         bc->fd_consumer = src.fd;
 535                                         bc->fd_producer = lttbuf->data_ready_fd_read;
 536                                         bc->rbuf = rbuf;
 537                                         bc->lttbuf = lttbuf;
 538                                         bc->src = src;
 539                                         bc->server = ustcomm_app.server;
 540
 541                                         list_add(&bc->list, &blocked_consumers);
 542
 543                                         break;
 544                                 }
 545                         }
 546                 }
 547                 else if(nth_token_is(recvbuf, "put_subbuffer", 0) == 1) {
 548                         struct ltt_trace_struct *trace;
 549                         char trace_name[] = "auto";
 550                         int i;
 551                         char *channel_name;
 552                         long consumed_old;
 553                         char *consumed_old_str;
 554                         char *endptr;
 555
 556                         DBG("put_subbuf");
 557
 558                         channel_name = strdup_malloc(nth_token(recvbuf, 1));
 559                         if(channel_name == NULL) {
 560                                 ERR("put_subbuf_size: cannot parse channel");
 561                                 goto next_cmd;
 562                         }
 563
 564                         consumed_old_str = strdup_malloc(nth_token(recvbuf, 2));
 565                         if(consumed_old_str == NULL) {
 566                                 ERR("put_subbuf: cannot parse consumed_old");
 567                                 goto next_cmd;
 568                         }
 569                         consumed_old = strtol(consumed_old_str, &endptr, 10);
 570                         if(*endptr != '\0') {
 571                                 ERR("put_subbuf: invalid value for consumed_old");
 572                                 goto next_cmd;
 573                         }
 574
 575                         ltt_lock_traces();
 576                         trace = _ltt_trace_find(trace_name);
 577                         ltt_unlock_traces();
 578
 579                         if(trace == NULL) {
 580                                 ERR("cannot find trace!");
 581                                 return (void *)1;
 582                         }
 583
 584                         for(i=0; i<trace->nr_channels; i++) {
 585                                 struct rchan *rchan = trace->channels[i].trans_channel_data;
 586
 587                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 588                                         struct rchan_buf *rbuf = rchan->buf;
 589                                         struct ltt_channel_buf_struct *lttbuf = trace->channels[i].buf;
 590                                         char *reply;
 591                                         long consumed_old=0;
 592
 593                                         result = ltt_do_put_subbuf(rbuf, lttbuf, consumed_old);
 594                                         if(result < 0) {
 595                                                 WARN("ltt_do_put_subbuf: error (subbuf=%s)", channel_name);
 596                                                 asprintf(&reply, "%s", "ERROR");
 597                                         }
 598                                         else {
 599                                                 DBG("ltt_do_put_subbuf: success (subbuf=%s)", channel_name);
 600                                                 asprintf(&reply, "%s", "OK");
 601                                         }
 602
 603                                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 604                                         if(result) {
 605                                                 ERR("listener: put_subbuf: ustcomm_send_reply failed");
 606                                                 goto next_cmd;
 607                                         }
 608
 609                                         free(reply);
 610
 611                                         break;
 612                                 }
 613                         }
 614
 615                         free(channel_name);
 616                         free(consumed_old_str);
 617                 }
 618                 else if(nth_token_is(recvbuf, "enable_marker", 0) == 1) {
 619                         char *channel_slash_name = nth_token(recvbuf, 1);
 620                         char channel_name[256]="";
 621                         char marker_name[256]="";
 622
 623                         result = sscanf(channel_slash_name, "%255[^/]/%255s", channel_name, marker_name);
 624
 625                         if(channel_name == NULL || marker_name == NULL) {
 626                                 WARN("invalid marker name");
 627                                 goto next_cmd;
 628                         }
 629                         printf("%s %s\n", channel_name, marker_name);
 630
 631                         result = ltt_marker_connect(channel_name, marker_name, "default");
 632                         if(result < 0) {
 633                                 WARN("could not enable marker; channel=%s, name=%s", channel_name, marker_name);
 634                         }
 635                 }
 636                 else if(nth_token_is(recvbuf, "disable_marker", 0) == 1) {
 637                         char *channel_slash_name = nth_token(recvbuf, 1);
 638                         char *marker_name;
 639                         char *channel_name;
 640
 641                         result = sscanf(channel_slash_name, "%a[^/]/%as", &channel_name, &marker_name);
 642
 643                         if(marker_name == NULL) {
 644                         }
 645                         printf("%s %s\n", channel_name, marker_name);
 646
 647                         result = ltt_marker_disconnect(channel_name, marker_name, "default");
 648                         if(result < 0) {
 649                                 WARN("could not disable marker; channel=%s, name=%s", channel_name, marker_name);
 650                         }
 651                 }
 652 //              else if(nth_token_is(recvbuf, "get_notifications", 0) == 1) {
 653 //                      struct ltt_trace_struct *trace;
 654 //                      char trace_name[] = "auto";
 655 //                      int i;
 656 //                      char *channel_name;
 657 //
 658 //                      DBG("get_notifications");
 659 //
 660 //                      channel_name = strdup_malloc(nth_token(recvbuf, 1));
 661 //                      if(channel_name == NULL) {
 662 //                              ERR("put_subbuf_size: cannot parse channel");
 663 //                              goto next_cmd;
 664 //                      }
 665 //
 666 //                      ltt_lock_traces();
 667 //                      trace = _ltt_trace_find(trace_name);
 668 //                      ltt_unlock_traces();
 669 //
 670 //                      if(trace == NULL) {
 671 //                              ERR("cannot find trace!");
 672 //                              return (void *)1;
 673 //                      }
 674 //
 675 //                      for(i=0; i<trace->nr_channels; i++) {
 676 //                              struct rchan *rchan = trace->channels[i].trans_channel_data;
 677 //                              int fd;
 678 //
 679 //                              if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 680 //                                      struct rchan_buf *rbuf = rchan->buf;
 681 //                                      struct ltt_channel_buf_struct *lttbuf = trace->channels[i].buf;
 682 //
 683 //                                      result = fd = ustcomm_app_detach_client(&ustcomm_app, &src);
 684 //                                      if(result == -1) {
 685 //                                              ERR("ustcomm_app_detach_client failed");
 686 //                                              goto next_cmd;
 687 //                                      }
 688 //
 689 //                                      lttbuf->wake_consumer_arg = (void *) fd;
 690 //
 691 //                                      smp_wmb();
 692 //
 693 //                                      lttbuf->call_wake_consumer = 1;
 694 //
 695 //                                      break;
 696 //                              }
 697 //                      }
 698 //
 699 //                      free(channel_name);
 700 //              }
 701                 else {
 702                         ERR("unable to parse message: %s", recvbuf);
 703                 }
 704
 705         next_cmd:
 706                 free(recvbuf);
 707         }
 708 }
 709
 710 void create_listener(void)
 711 {
 712 #ifdef USE_CLONE
 713         static char listener_stack[16384];
 714 #endif
 715
 716 #ifdef USE_CLONE
 717         result = clone(listener_main, listener_stack+sizeof(listener_stack)-1, CLONE_FS | CLONE_FILES | CLONE_VM | CLONE_SIGHAND | CLONE_THREAD, NULL);
 718         if(result == -1) {
 719                 perror("clone");
 720         }
 721 #else
 722         pthread_t thread;
 723
 724         pthread_create(&thread, NULL, listener_main, NULL);
 725 #endif
 726 }
 727
 728 /* The signal handler itself. Signals must be setup so there cannot be
 729    nested signals. */
 730
 731 void sighandler(int sig)
 732 {
 733         static char have_listener = 0;
 734         DBG("sighandler");
 735
 736         if(!have_listener) {
 737                 create_listener();
 738                 have_listener = 1;
 739         }
 740 }
 741
 742 /* Called by the app signal handler to chain it to us. */
 743
 744 void chain_signal(void)
 745 {
 746         sighandler(USTSIGNAL);
 747 }
 748
 749 static int init_socket(void)
 750 {
 751         return ustcomm_init_app(getpid(), &ustcomm_app);
 752 }
 753
 754 /* FIXME: reenable this to delete socket file. */
 755
 756 #if 0
 757 static void destroy_socket(void)
 758 {
 759         int result;
 760
 761         if(mysocketfile[0] == '\0')
 762                 return;
 763
 764         result = unlink(mysocketfile);
 765         if(result == -1) {
 766                 PERROR("unlink");
 767         }
 768 }
 769 #endif
 770
 771 static int init_signal_handler(void)
 772 {
 773         /* Attempt to handler SIGIO. If the main program wants to
 774          * handle it, fine, it'll override us. They it'll have to
 775          * use the chaining function.
 776          */
 777
 778         int result;
 779         struct sigaction act;
 780
 781         result = sigemptyset(&act.sa_mask);
 782         if(result == -1) {
 783                 PERROR("sigemptyset");
 784                 return -1;
 785         }
 786
 787         act.sa_handler = sighandler;
 788         act.sa_flags = SA_RESTART;
 789
 790         /* Only defer ourselves. Also, try to restart interrupted
 791          * syscalls to disturb the traced program as little as possible.
 792          */
 793         result = sigaction(SIGIO, &act, NULL);
 794         if(result == -1) {
 795                 PERROR("sigaction");
 796                 return -1;
 797         }
 798
 799         return 0;
 800 }
 801
 802 static void auto_probe_connect(struct marker *m)
 803 {
 804         int result;
 805
 806         result = ltt_marker_connect(m->channel, m->name, "default");
 807         if(result && result != -EEXIST)
 808                 ERR("ltt_marker_connect (marker = %s/%s, errno = %d)", m->channel, m->name, -result);
 809
 810         DBG("just auto connected marker %s %s to probe default", m->channel, m->name);
 811 }
 812
 813 static void __attribute__((constructor(101))) init0()
 814 {
 815         /* Initialize RCU in case the constructor order is not good. */
 816         urcu_init();
 817
 818         /* It is important to do this before events start to be generated. */
 819         ust_register_thread();
 820
 821         DBG("UST_AUTOPROBE constructor");
 822         if(getenv("UST_AUTOPROBE")) {
 823                 marker_set_new_marker_cb(auto_probe_connect);
 824         }
 825 }
 826
 827 static void __attribute__((constructor(1000))) init()
 828 {
 829         int result;
 830
 831         DBG("UST_TRACE constructor");
 832
 833         /* Must create socket before signal handler to prevent races.
 834          */
 835         result = init_socket();
 836         if(result == -1) {
 837                 ERR("init_socket error");
 838                 return;
 839         }
 840         result = init_signal_handler();
 841         if(result == -1) {
 842                 ERR("init_signal_handler error");
 843                 return;
 844         }
 845
 846         if(getenv("UST_TRACE")) {
 847                 char trace_name[] = "auto";
 848                 char trace_type[] = "ustrelay";
 849
 850                 DBG("starting early tracing");
 851
 852                 /* Ensure marker control is initialized */
 853                 init_marker_control();
 854
 855                 /* Ensure relay is initialized */
 856                 init_ustrelay_transport();
 857
 858                 /* Ensure markers are initialized */
 859                 init_markers();
 860
 861                 /* In case. */
 862                 ltt_channels_register("ust");
 863
 864                 result = ltt_trace_setup(trace_name);
 865                 if(result < 0) {
 866                         ERR("ltt_trace_setup failed");
 867                         return;
 868                 }
 869
 870                 result = ltt_trace_set_type(trace_name, trace_type);
 871                 if(result < 0) {
 872                         ERR("ltt_trace_set_type failed");
 873                         return;
 874                 }
 875
 876                 result = ltt_trace_alloc(trace_name);
 877                 if(result < 0) {
 878                         ERR("ltt_trace_alloc failed");
 879                         return;
 880                 }
 881
 882                 result = ltt_trace_start(trace_name);
 883                 if(result < 0) {
 884                         ERR("ltt_trace_start failed");
 885                         return;
 886                 }
 887                 inform_consumer_daemon();
 888         }
 889
 890
 891         return;
 892
 893         /* should decrementally destroy stuff if error */
 894
 895 }
 896
 897 /* This is only called if we terminate normally, not with an unhandled signal,
 898  * so we cannot rely on it. */
 899
 900 /* This destructor probably isn't needed, because ustd can do crash recovery. */
 901 #if 0
 902 static void __attribute__((destructor)) fini()
 903 {
 904         int result;
 905
 906         /* if trace running, finish it */
 907
 908         DBG("destructor stopping traces");
 909
 910         result = ltt_trace_stop("auto");
 911         if(result == -1) {
 912                 ERR("ltt_trace_stop error");
 913         }
 914
 915         result = ltt_trace_destroy("auto");
 916         if(result == -1) {
 917                 ERR("ltt_trace_destroy error");
 918         }
 919
 920         destroy_socket();
 921 }
 922 #endif
 923
 924 /* Notify ust that there was a fork. This needs to be called inside
 925  * the new process, anytime a process whose memory is not shared with
 926  * the parent is created. If this function is not called, the events
 927  * of the new process will not be collected.
 928  */
 929
 930 void ust_fork(void)
 931 {
 932         DBG("ust: forking");
 933         ltt_trace_stop("auto");
 934         ltt_trace_destroy("auto");
 935         ltt_trace_alloc("auto");
 936         ltt_trace_start("auto");
 937         init_socket();
 938         have_listener = 0;
 939         create_listener();
 940         ustcomm_request_consumer(getpid(), "metadata");
 941         ustcomm_request_consumer(getpid(), "ust");
 942 }
 943