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 static int init_socket(void);
 108
 109 /* This needs to be called whenever a new thread is created. It notifies
 110  * liburcu of the new thread.
 111  */
 112
 113 void ust_register_thread(void)
 114 {
 115         rcu_register_thread();
 116 }
 117
 118 int fd_notif = -1;
 119 void notif_cb(void)
 120 {
 121         int result;
 122         struct trctl_msg msg;
 123
 124         /* FIXME: fd_notif should probably be protected by a spinlock */
 125
 126         if(fd_notif == -1)
 127                 return;
 128
 129         msg.type = MSG_NOTIF;
 130         msg.size = sizeof(msg.type);
 131
 132         /* FIXME: don't block here */
 133         result = write(fd_notif, &msg, msg.size+sizeof(msg.size));
 134         if(result == -1) {
 135                 PERROR("write");
 136                 return;
 137         }
 138 }
 139
 140 static void inform_consumer_daemon(void)
 141 {
 142         ustcomm_request_consumer(getpid(), "metadata");
 143         ustcomm_request_consumer(getpid(), "ust");
 144 }
 145
 146 void process_blocked_consumers(void)
 147 {
 148         int n_fds = 0;
 149         struct pollfd *fds;
 150         struct blocked_consumer *bc;
 151         int idx = 0;
 152         char inbuf;
 153         int result;
 154
 155         list_for_each_entry(bc, &blocked_consumers, list) {
 156                 n_fds++;
 157         }
 158
 159         fds = (struct pollfd *) malloc(n_fds * sizeof(struct pollfd));
 160         if(fds == NULL) {
 161                 ERR("malloc returned NULL");
 162                 return;
 163         }
 164
 165         list_for_each_entry(bc, &blocked_consumers, list) {
 166                 fds[idx].fd = bc->fd_producer;
 167                 fds[idx].events = POLLIN;
 168                 bc->tmp_poll_idx = idx;
 169                 idx++;
 170         }
 171
 172         while((result = poll(fds, n_fds, 0)) == -1 && errno == EINTR)
 173                 /* nothing */;
 174         if(result == -1) {
 175                 PERROR("poll");
 176                 return;
 177         }
 178
 179         list_for_each_entry(bc, &blocked_consumers, list) {
 180                 if(fds[bc->tmp_poll_idx].revents) {
 181                         long consumed_old = 0;
 182                         char *reply;
 183
 184                         result = read(bc->fd_producer, &inbuf, 1);
 185                         if(result == -1) {
 186                                 PERROR("read");
 187                                 continue;
 188                         }
 189                         if(result == 0) {
 190                                 DBG("PRODUCER END");
 191
 192                                 close(bc->fd_producer);
 193
 194                                 list_del(&bc->list);
 195
 196                                 result = ustcomm_send_reply(&bc->server, "END", &bc->src);
 197                                 if(result < 0) {
 198                                         ERR("ustcomm_send_reply failed");
 199                                         continue;
 200                                 }
 201
 202                                 continue;
 203                         }
 204
 205                         result = ltt_do_get_subbuf(bc->rbuf, bc->lttbuf, &consumed_old);
 206                         if(result == -EAGAIN) {
 207                                 WARN("missed buffer?");
 208                                 continue;
 209                         }
 210                         else if(result < 0) {
 211                                 DBG("ltt_do_get_subbuf: error: %s", strerror(-result));
 212                         }
 213                         asprintf(&reply, "%s %ld", "OK", consumed_old);
 214                         result = ustcomm_send_reply(&bc->server, reply, &bc->src);
 215                         if(result < 0) {
 216                                 ERR("ustcomm_send_reply failed");
 217                                 free(reply);
 218                                 continue;
 219                         }
 220                         free(reply);
 221
 222                         list_del(&bc->list);
 223                 }
 224         }
 225
 226 }
 227
 228 void *listener_main(void *p)
 229 {
 230         int result;
 231
 232         ust_register_thread();
 233
 234         DBG("LISTENER");
 235
 236         for(;;) {
 237                 char trace_name[] = "auto";
 238                 char trace_type[] = "ustrelay";
 239                 char *recvbuf;
 240                 int len;
 241                 struct ustcomm_source src;
 242
 243                 process_blocked_consumers();
 244
 245                 result = ustcomm_app_recv_message(&ustcomm_app, &recvbuf, &src, 5);
 246                 if(result < 0) {
 247                         WARN("error in ustcomm_app_recv_message");
 248                         continue;
 249                 }
 250                 else if(result == 0) {
 251                         /* no message */
 252                         continue;
 253                 }
 254
 255                 DBG("received a message! it's: %s\n", recvbuf);
 256                 len = strlen(recvbuf);
 257
 258                 if(!strcmp(recvbuf, "print_markers")) {
 259                         print_markers(stderr);
 260                 }
 261                 else if(!strcmp(recvbuf, "list_markers")) {
 262                         char *ptr;
 263                         size_t size;
 264                         FILE *fp;
 265
 266                         fp = open_memstream(&ptr, &size);
 267                         print_markers(fp);
 268                         fclose(fp);
 269
 270                         result = ustcomm_send_reply(&ustcomm_app.server, ptr, &src);
 271
 272                         free(ptr);
 273                 }
 274                 else if(!strcmp(recvbuf, "start")) {
 275                         /* start is an operation that setups the trace, allocates it and starts it */
 276                         result = ltt_trace_setup(trace_name);
 277                         if(result < 0) {
 278                                 ERR("ltt_trace_setup failed");
 279                                 return (void *)1;
 280                         }
 281
 282                         result = ltt_trace_set_type(trace_name, trace_type);
 283                         if(result < 0) {
 284                                 ERR("ltt_trace_set_type failed");
 285                                 return (void *)1;
 286                         }
 287
 288                         result = ltt_trace_alloc(trace_name);
 289                         if(result < 0) {
 290                                 ERR("ltt_trace_alloc failed");
 291                                 return (void *)1;
 292                         }
 293
 294                         inform_consumer_daemon();
 295
 296                         result = ltt_trace_start(trace_name);
 297                         if(result < 0) {
 298                                 ERR("ltt_trace_start failed");
 299                                 continue;
 300                         }
 301                 }
 302                 else if(!strcmp(recvbuf, "trace_setup")) {
 303                         DBG("trace setup");
 304
 305                         result = ltt_trace_setup(trace_name);
 306                         if(result < 0) {
 307                                 ERR("ltt_trace_setup failed");
 308                                 return (void *)1;
 309                         }
 310
 311                         result = ltt_trace_set_type(trace_name, trace_type);
 312                         if(result < 0) {
 313                                 ERR("ltt_trace_set_type failed");
 314                                 return (void *)1;
 315                         }
 316                 }
 317                 else if(!strcmp(recvbuf, "trace_alloc")) {
 318                         DBG("trace alloc");
 319
 320                         result = ltt_trace_alloc(trace_name);
 321                         if(result < 0) {
 322                                 ERR("ltt_trace_alloc failed");
 323                                 return (void *)1;
 324                         }
 325                 }
 326                 else if(!strcmp(recvbuf, "trace_start")) {
 327                         DBG("trace start");
 328
 329                         result = ltt_trace_start(trace_name);
 330                         if(result < 0) {
 331                                 ERR("ltt_trace_start failed");
 332                                 continue;
 333                         }
 334                 }
 335                 else if(!strcmp(recvbuf, "trace_stop")) {
 336                         DBG("trace stop");
 337
 338                         result = ltt_trace_stop(trace_name);
 339                         if(result < 0) {
 340                                 ERR("ltt_trace_stop failed");
 341                                 return (void *)1;
 342                         }
 343                 }
 344                 else if(!strcmp(recvbuf, "trace_destroy")) {
 345
 346                         DBG("trace destroy");
 347
 348                         result = ltt_trace_destroy(trace_name);
 349                         if(result < 0) {
 350                                 ERR("ltt_trace_destroy failed");
 351                                 return (void *)1;
 352                         }
 353                 }
 354                 else if(nth_token_is(recvbuf, "get_shmid", 0) == 1) {
 355                         struct ltt_trace_struct *trace;
 356                         char trace_name[] = "auto";
 357                         int i;
 358                         char *channel_name;
 359
 360                         DBG("get_shmid");
 361
 362                         channel_name = nth_token(recvbuf, 1);
 363                         if(channel_name == NULL) {
 364                                 ERR("get_shmid: cannot parse channel");
 365                                 goto next_cmd;
 366                         }
 367
 368                         ltt_lock_traces();
 369                         trace = _ltt_trace_find(trace_name);
 370                         ltt_unlock_traces();
 371
 372                         if(trace == NULL) {
 373                                 ERR("cannot find trace!");
 374                                 return (void *)1;
 375                         }
 376
 377                         for(i=0; i<trace->nr_channels; i++) {
 378                                 struct rchan *rchan = trace->channels[i].trans_channel_data;
 379                                 struct rchan_buf *rbuf = rchan->buf;
 380                                 struct ltt_channel_struct *ltt_channel = (struct ltt_channel_struct *)rchan->private_data;
 381
 382                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 383                                         char *reply;
 384
 385                                         DBG("the shmid for the requested channel is %d", rbuf->shmid);
 386                                         DBG("the shmid for its buffer structure is %d", ltt_channel->buf_shmid);
 387                                         asprintf(&reply, "%d %d", rbuf->shmid, ltt_channel->buf_shmid);
 388
 389                                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 390                                         if(result) {
 391                                                 ERR("listener: get_shmid: ustcomm_send_reply failed");
 392                                                 goto next_cmd;
 393                                         }
 394
 395                                         free(reply);
 396
 397                                         break;
 398                                 }
 399                         }
 400                 }
 401                 else if(nth_token_is(recvbuf, "get_n_subbufs", 0) == 1) {
 402                         struct ltt_trace_struct *trace;
 403                         char trace_name[] = "auto";
 404                         int i;
 405                         char *channel_name;
 406
 407                         DBG("get_n_subbufs");
 408
 409                         channel_name = nth_token(recvbuf, 1);
 410                         if(channel_name == NULL) {
 411                                 ERR("get_n_subbufs: cannot parse channel");
 412                                 goto next_cmd;
 413                         }
 414
 415                         ltt_lock_traces();
 416                         trace = _ltt_trace_find(trace_name);
 417                         ltt_unlock_traces();
 418
 419                         if(trace == NULL) {
 420                                 ERR("cannot find trace!");
 421                                 return (void *)1;
 422                         }
 423
 424                         for(i=0; i<trace->nr_channels; i++) {
 425                                 struct rchan *rchan = trace->channels[i].trans_channel_data;
 426
 427                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 428                                         char *reply;
 429
 430                                         DBG("the n_subbufs for the requested channel is %zd", rchan->n_subbufs);
 431                                         asprintf(&reply, "%zd", rchan->n_subbufs);
 432
 433                                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 434                                         if(result) {
 435                                                 ERR("listener: get_n_subbufs: ustcomm_send_reply failed");
 436                                                 goto next_cmd;
 437                                         }
 438
 439                                         free(reply);
 440
 441                                         break;
 442                                 }
 443                         }
 444                 }
 445                 else if(nth_token_is(recvbuf, "get_subbuf_size", 0) == 1) {
 446                         struct ltt_trace_struct *trace;
 447                         char trace_name[] = "auto";
 448                         int i;
 449                         char *channel_name;
 450
 451                         DBG("get_subbuf_size");
 452
 453                         channel_name = nth_token(recvbuf, 1);
 454                         if(channel_name == NULL) {
 455                                 ERR("get_subbuf_size: cannot parse channel");
 456                                 goto next_cmd;
 457                         }
 458
 459                         ltt_lock_traces();
 460                         trace = _ltt_trace_find(trace_name);
 461                         ltt_unlock_traces();
 462
 463                         if(trace == NULL) {
 464                                 ERR("cannot find trace!");
 465                                 return (void *)1;
 466                         }
 467
 468                         for(i=0; i<trace->nr_channels; i++) {
 469                                 struct rchan *rchan = trace->channels[i].trans_channel_data;
 470
 471                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 472                                         char *reply;
 473
 474                                         DBG("the subbuf_size for the requested channel is %zd", rchan->subbuf_size);
 475                                         asprintf(&reply, "%zd", rchan->subbuf_size);
 476
 477                                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 478                                         if(result) {
 479                                                 ERR("listener: get_subbuf_size: ustcomm_send_reply failed");
 480                                                 goto next_cmd;
 481                                         }
 482
 483                                         free(reply);
 484
 485                                         break;
 486                                 }
 487                         }
 488                 }
 489                 else if(nth_token_is(recvbuf, "load_probe_lib", 0) == 1) {
 490                         char *libfile;
 491
 492                         libfile = nth_token(recvbuf, 1);
 493
 494                         DBG("load_probe_lib loading %s", libfile);
 495                 }
 496                 else if(nth_token_is(recvbuf, "get_subbuffer", 0) == 1) {
 497                         struct ltt_trace_struct *trace;
 498                         char trace_name[] = "auto";
 499                         int i;
 500                         char *channel_name;
 501
 502                         DBG("get_subbuf");
 503
 504                         channel_name = nth_token(recvbuf, 1);
 505                         if(channel_name == NULL) {
 506                                 ERR("get_subbuf: cannot parse channel");
 507                                 goto next_cmd;
 508                         }
 509
 510                         ltt_lock_traces();
 511                         trace = _ltt_trace_find(trace_name);
 512                         ltt_unlock_traces();
 513
 514                         if(trace == NULL) {
 515                                 ERR("cannot find trace!");
 516                                 return (void *)1;
 517                         }
 518
 519                         for(i=0; i<trace->nr_channels; i++) {
 520                                 struct rchan *rchan = trace->channels[i].trans_channel_data;
 521
 522                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 523                                         struct rchan_buf *rbuf = rchan->buf;
 524                                         struct ltt_channel_buf_struct *lttbuf = trace->channels[i].buf;
 525                                         struct blocked_consumer *bc;
 526
 527                                         bc = (struct blocked_consumer *) malloc(sizeof(struct blocked_consumer));
 528                                         if(bc == NULL) {
 529                                                 ERR("malloc returned NULL");
 530                                                 goto next_cmd;
 531                                         }
 532                                         bc->fd_consumer = src.fd;
 533                                         bc->fd_producer = lttbuf->data_ready_fd_read;
 534                                         bc->rbuf = rbuf;
 535                                         bc->lttbuf = lttbuf;
 536                                         bc->src = src;
 537                                         bc->server = ustcomm_app.server;
 538
 539                                         list_add(&bc->list, &blocked_consumers);
 540
 541                                         break;
 542                                 }
 543                         }
 544                 }
 545                 else if(nth_token_is(recvbuf, "put_subbuffer", 0) == 1) {
 546                         struct ltt_trace_struct *trace;
 547                         char trace_name[] = "auto";
 548                         int i;
 549                         char *channel_name;
 550                         long consumed_old;
 551                         char *consumed_old_str;
 552                         char *endptr;
 553
 554                         DBG("put_subbuf");
 555
 556                         channel_name = strdup_malloc(nth_token(recvbuf, 1));
 557                         if(channel_name == NULL) {
 558                                 ERR("put_subbuf_size: cannot parse channel");
 559                                 goto next_cmd;
 560                         }
 561
 562                         consumed_old_str = strdup_malloc(nth_token(recvbuf, 2));
 563                         if(consumed_old_str == NULL) {
 564                                 ERR("put_subbuf: cannot parse consumed_old");
 565                                 goto next_cmd;
 566                         }
 567                         consumed_old = strtol(consumed_old_str, &endptr, 10);
 568                         if(*endptr != '\0') {
 569                                 ERR("put_subbuf: invalid value for consumed_old");
 570                                 goto next_cmd;
 571                         }
 572
 573                         ltt_lock_traces();
 574                         trace = _ltt_trace_find(trace_name);
 575                         ltt_unlock_traces();
 576
 577                         if(trace == NULL) {
 578                                 ERR("cannot find trace!");
 579                                 return (void *)1;
 580                         }
 581
 582                         for(i=0; i<trace->nr_channels; i++) {
 583                                 struct rchan *rchan = trace->channels[i].trans_channel_data;
 584
 585                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 586                                         struct rchan_buf *rbuf = rchan->buf;
 587                                         struct ltt_channel_buf_struct *lttbuf = trace->channels[i].buf;
 588                                         char *reply;
 589                                         long consumed_old=0;
 590
 591                                         result = ltt_do_put_subbuf(rbuf, lttbuf, consumed_old);
 592                                         if(result < 0) {
 593                                                 WARN("ltt_do_put_subbuf: error (subbuf=%s)", channel_name);
 594                                                 asprintf(&reply, "%s", "ERROR");
 595                                         }
 596                                         else {
 597                                                 DBG("ltt_do_put_subbuf: success (subbuf=%s)", channel_name);
 598                                                 asprintf(&reply, "%s", "OK");
 599                                         }
 600
 601                                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 602                                         if(result) {
 603                                                 ERR("listener: put_subbuf: ustcomm_send_reply failed");
 604                                                 goto next_cmd;
 605                                         }
 606
 607                                         free(reply);
 608
 609                                         break;
 610                                 }
 611                         }
 612
 613                         free(channel_name);
 614                         free(consumed_old_str);
 615                 }
 616                 else if(nth_token_is(recvbuf, "enable_marker", 0) == 1) {
 617                         char *channel_slash_name = nth_token(recvbuf, 1);
 618                         char channel_name[256]="";
 619                         char marker_name[256]="";
 620
 621                         result = sscanf(channel_slash_name, "%255[^/]/%255s", channel_name, marker_name);
 622
 623                         if(channel_name == NULL || marker_name == NULL) {
 624                                 WARN("invalid marker name");
 625                                 goto next_cmd;
 626                         }
 627                         printf("%s %s\n", channel_name, marker_name);
 628
 629                         result = ltt_marker_connect(channel_name, marker_name, "default");
 630                         if(result < 0) {
 631                                 WARN("could not enable marker; channel=%s, name=%s", channel_name, marker_name);
 632                         }
 633                 }
 634                 else if(nth_token_is(recvbuf, "disable_marker", 0) == 1) {
 635                         char *channel_slash_name = nth_token(recvbuf, 1);
 636                         char *marker_name;
 637                         char *channel_name;
 638
 639                         result = sscanf(channel_slash_name, "%a[^/]/%as", &channel_name, &marker_name);
 640
 641                         if(marker_name == NULL) {
 642                         }
 643                         printf("%s %s\n", channel_name, marker_name);
 644
 645                         result = ltt_marker_disconnect(channel_name, marker_name, "default");
 646                         if(result < 0) {
 647                                 WARN("could not disable marker; channel=%s, name=%s", channel_name, marker_name);
 648                         }
 649                 }
 650 //              else if(nth_token_is(recvbuf, "get_notifications", 0) == 1) {
 651 //                      struct ltt_trace_struct *trace;
 652 //                      char trace_name[] = "auto";
 653 //                      int i;
 654 //                      char *channel_name;
 655 //
 656 //                      DBG("get_notifications");
 657 //
 658 //                      channel_name = strdup_malloc(nth_token(recvbuf, 1));
 659 //                      if(channel_name == NULL) {
 660 //                              ERR("put_subbuf_size: cannot parse channel");
 661 //                              goto next_cmd;
 662 //                      }
 663 //
 664 //                      ltt_lock_traces();
 665 //                      trace = _ltt_trace_find(trace_name);
 666 //                      ltt_unlock_traces();
 667 //
 668 //                      if(trace == NULL) {
 669 //                              ERR("cannot find trace!");
 670 //                              return (void *)1;
 671 //                      }
 672 //
 673 //                      for(i=0; i<trace->nr_channels; i++) {
 674 //                              struct rchan *rchan = trace->channels[i].trans_channel_data;
 675 //                              int fd;
 676 //
 677 //                              if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 678 //                                      struct rchan_buf *rbuf = rchan->buf;
 679 //                                      struct ltt_channel_buf_struct *lttbuf = trace->channels[i].buf;
 680 //
 681 //                                      result = fd = ustcomm_app_detach_client(&ustcomm_app, &src);
 682 //                                      if(result == -1) {
 683 //                                              ERR("ustcomm_app_detach_client failed");
 684 //                                              goto next_cmd;
 685 //                                      }
 686 //
 687 //                                      lttbuf->wake_consumer_arg = (void *) fd;
 688 //
 689 //                                      smp_wmb();
 690 //
 691 //                                      lttbuf->call_wake_consumer = 1;
 692 //
 693 //                                      break;
 694 //                              }
 695 //                      }
 696 //
 697 //                      free(channel_name);
 698 //              }
 699                 else {
 700                         ERR("unable to parse message: %s", recvbuf);
 701                 }
 702
 703         next_cmd:
 704                 free(recvbuf);
 705         }
 706 }
 707
 708 int have_listener = 0;
 709
 710 void create_listener(void)
 711 {
 712 #ifdef USE_CLONE
 713         static char listener_stack[16384];
 714 #else
 715         pthread_t thread;
 716 #endif
 717
 718         if(have_listener)
 719                 return;
 720
 721 #ifdef USE_CLONE
 722         result = clone(listener_main, listener_stack+sizeof(listener_stack)-1, CLONE_FS | CLONE_FILES | CLONE_VM | CLONE_SIGHAND | CLONE_THREAD, NULL);
 723         if(result == -1) {
 724                 perror("clone");
 725                 return;
 726         }
 727 #else
 728
 729         pthread_create(&thread, NULL, listener_main, NULL);
 730 #endif
 731
 732         have_listener = 1;
 733 }
 734
 735 /* The signal handler itself. Signals must be setup so there cannot be
 736    nested signals. */
 737
 738 void sighandler(int sig)
 739 {
 740         static char have_listener = 0;
 741         DBG("sighandler");
 742
 743         if(!have_listener) {
 744                 create_listener();
 745                 have_listener = 1;
 746         }
 747 }
 748
 749 /* Called by the app signal handler to chain it to us. */
 750
 751 void chain_signal(void)
 752 {
 753         sighandler(USTSIGNAL);
 754 }
 755
 756 static int init_socket(void)
 757 {
 758         return ustcomm_init_app(getpid(), &ustcomm_app);
 759 }
 760
 761 /* FIXME: reenable this to delete socket file. */
 762
 763 #if 0
 764 static void destroy_socket(void)
 765 {
 766         int result;
 767
 768         if(mysocketfile[0] == '\0')
 769                 return;
 770
 771         result = unlink(mysocketfile);
 772         if(result == -1) {
 773                 PERROR("unlink");
 774         }
 775 }
 776 #endif
 777
 778 static int init_signal_handler(void)
 779 {
 780         /* Attempt to handler SIGIO. If the main program wants to
 781          * handle it, fine, it'll override us. They it'll have to
 782          * use the chaining function.
 783          */
 784
 785         int result;
 786         struct sigaction act;
 787
 788         result = sigemptyset(&act.sa_mask);
 789         if(result == -1) {
 790                 PERROR("sigemptyset");
 791                 return -1;
 792         }
 793
 794         act.sa_handler = sighandler;
 795         act.sa_flags = SA_RESTART;
 796
 797         /* Only defer ourselves. Also, try to restart interrupted
 798          * syscalls to disturb the traced program as little as possible.
 799          */
 800         result = sigaction(SIGIO, &act, NULL);
 801         if(result == -1) {
 802                 PERROR("sigaction");
 803                 return -1;
 804         }
 805
 806         return 0;
 807 }
 808
 809 static void auto_probe_connect(struct marker *m)
 810 {
 811         int result;
 812
 813         result = ltt_marker_connect(m->channel, m->name, "default");
 814         if(result && result != -EEXIST)
 815                 ERR("ltt_marker_connect (marker = %s/%s, errno = %d)", m->channel, m->name, -result);
 816
 817         DBG("just auto connected marker %s %s to probe default", m->channel, m->name);
 818 }
 819
 820 static void __attribute__((constructor(101))) init0()
 821 {
 822         DBG("UST_AUTOPROBE constructor");
 823 }
 824
 825 static void __attribute__((constructor(1000))) init()
 826 {
 827         int result;
 828
 829         /* Initialize RCU in case the constructor order is not good. */
 830         urcu_init();
 831
 832         /* It is important to do this before events start to be generated. */
 833         ust_register_thread();
 834
 835         DBG("UST_TRACE constructor");
 836
 837         /* Must create socket before signal handler to prevent races.
 838          */
 839         result = init_socket();
 840         if(result == -1) {
 841                 ERR("init_socket error");
 842                 return;
 843         }
 844         result = init_signal_handler();
 845         if(result == -1) {
 846                 ERR("init_signal_handler error");
 847                 return;
 848         }
 849
 850         if(getenv("UST_AUTOPROBE")) {
 851                 struct marker_iter iter;
 852
 853                 DBG("IN AUTOPROBE\n");
 854
 855                 /* Ensure markers are initialized */
 856                 //init_markers();
 857
 858                 /* Ensure marker control is initialized, for the probe */
 859                 init_marker_control();
 860
 861                 /* first, set the callback that will connect the
 862                  * probe on new markers
 863                  */
 864                 marker_set_new_marker_cb(auto_probe_connect);
 865
 866                 /* Now, connect the probes that were already registered. */
 867                 marker_iter_reset(&iter);
 868                 marker_iter_start(&iter);
 869
 870                 DBG("now iterating on markers already registered\n");
 871                 while(iter.marker) {
 872                         DBG("now iterating on marker %s\n", iter.marker->name);
 873                         auto_probe_connect(iter.marker);
 874                         marker_iter_next(&iter);
 875                 }
 876         }
 877
 878         if(getenv("UST_TRACE")) {
 879                 char trace_name[] = "auto";
 880                 char trace_type[] = "ustrelay";
 881
 882                 DBG("starting early tracing");
 883
 884                 /* Ensure marker control is initialized */
 885                 init_marker_control();
 886
 887                 /* Ensure relay is initialized */
 888                 init_ustrelay_transport();
 889
 890                 /* Ensure markers are initialized */
 891                 init_markers();
 892
 893                 /* In case. */
 894                 ltt_channels_register("ust");
 895
 896                 result = ltt_trace_setup(trace_name);
 897                 if(result < 0) {
 898                         ERR("ltt_trace_setup failed");
 899                         return;
 900                 }
 901
 902                 result = ltt_trace_set_type(trace_name, trace_type);
 903                 if(result < 0) {
 904                         ERR("ltt_trace_set_type failed");
 905                         return;
 906                 }
 907
 908                 result = ltt_trace_alloc(trace_name);
 909                 if(result < 0) {
 910                         ERR("ltt_trace_alloc failed");
 911                         return;
 912                 }
 913
 914                 result = ltt_trace_start(trace_name);
 915                 if(result < 0) {
 916                         ERR("ltt_trace_start failed");
 917                         return;
 918                 }
 919                 inform_consumer_daemon();
 920         }
 921
 922
 923         return;
 924
 925         /* should decrementally destroy stuff if error */
 926
 927 }
 928
 929 /* This is only called if we terminate normally, not with an unhandled signal,
 930  * so we cannot rely on it. */
 931
 932 /* This destructor probably isn't needed, because ustd can do crash recovery. */
 933 #if 0
 934 static void __attribute__((destructor)) fini()
 935 {
 936         int result;
 937
 938         /* if trace running, finish it */
 939
 940         DBG("destructor stopping traces");
 941
 942         result = ltt_trace_stop("auto");
 943         if(result == -1) {
 944                 ERR("ltt_trace_stop error");
 945         }
 946
 947         result = ltt_trace_destroy("auto");
 948         if(result == -1) {
 949                 ERR("ltt_trace_destroy error");
 950         }
 951
 952         destroy_socket();
 953 }
 954 #endif
 955
 956 /* Notify ust that there was a fork. This needs to be called inside
 957  * the new process, anytime a process whose memory is not shared with
 958  * the parent is created. If this function is not called, the events
 959  * of the new process will not be collected.
 960  */
 961
 962 void ust_fork(void)
 963 {
 964         DBG("ust: forking");
 965         ltt_trace_stop("auto");
 966         ltt_trace_destroy("auto");
 967         ltt_trace_alloc("auto");
 968         ltt_trace_start("auto");
 969         init_socket();
 970         have_listener = 0;
 971         create_listener();
 972         ustcomm_request_consumer(getpid(), "metadata");
 973         ustcomm_request_consumer(getpid(), "ust");
 974 }
 975