libust/tracectl.c

   1 #define _GNU_SOURCE
   2 #include <stdio.h>
   3 #include <stdint.h>
   4 #include <signal.h>
   5 #include <sys/types.h>
   6 #include <sys/socket.h>
   7 #include <sys/un.h>
   8 #include <sched.h>
   9 #include <fcntl.h>
  10 #include <poll.h>
  11
  12 #include "marker.h"
  13 #include "tracer.h"
  14 #include "localerr.h"
  15 #include "ustcomm.h"
  16 #include "relay.h" /* FIXME: remove */
  17
  18 //#define USE_CLONE
  19
  20 #define USTSIGNAL SIGIO
  21
  22 #define MAX_MSG_SIZE (100)
  23 #define MSG_NOTIF 1
  24 #define MSG_REGISTER_NOTIF 2
  25
  26 char consumer_stack[10000];
  27
  28 struct list_head blocked_consumers = LIST_HEAD_INIT(blocked_consumers);
  29
  30 static struct ustcomm_app ustcomm_app;
  31
  32 struct tracecmd { /* no padding */
  33         uint32_t size;
  34         uint16_t command;
  35 };
  36
  37 //struct listener_arg {
  38 //      int pipe_fd;
  39 //};
  40
  41 struct trctl_msg {
  42         /* size: the size of all the fields except size itself */
  43         uint32_t size;
  44         uint16_t type;
  45         /* Only the necessary part of the payload is transferred. It
  46          * may even be none of it.
  47          */
  48         char payload[94];
  49 };
  50
  51 struct consumer_channel {
  52         int fd;
  53         struct ltt_channel_struct *chan;
  54 };
  55
  56 struct blocked_consumer {
  57         int fd_consumer;
  58         int fd_producer;
  59         int tmp_poll_idx;
  60
  61         /* args to ustcomm_send_reply */
  62         struct ustcomm_server server;
  63         struct ustcomm_source src;
  64
  65         /* args to ltt_do_get_subbuf */
  66         struct rchan_buf *rbuf;
  67         struct ltt_channel_buf_struct *lttbuf;
  68
  69         struct list_head list;
  70 };
  71
  72 static void print_markers(FILE *fp)
  73 {
  74         struct marker_iter iter;
  75
  76         lock_markers();
  77         marker_iter_reset(&iter);
  78         marker_iter_start(&iter);
  79
  80         while(iter.marker) {
  81                 fprintf(fp, "marker: %s_%s %d \"%s\"\n", iter.marker->channel, iter.marker->name, (int)imv_read(iter.marker->state), iter.marker->format);
  82                 marker_iter_next(&iter);
  83         }
  84         unlock_markers();
  85 }
  86
  87 void do_command(struct tracecmd *cmd)
  88 {
  89 }
  90
  91 void receive_commands()
  92 {
  93 }
  94
  95 int fd_notif = -1;
  96 void notif_cb(void)
  97 {
  98         int result;
  99         struct trctl_msg msg;
 100
 101         /* FIXME: fd_notif should probably be protected by a spinlock */
 102
 103         if(fd_notif == -1)
 104                 return;
 105
 106         msg.type = MSG_NOTIF;
 107         msg.size = sizeof(msg.type);
 108
 109         /* FIXME: don't block here */
 110         result = write(fd_notif, &msg, msg.size+sizeof(msg.size));
 111         if(result == -1) {
 112                 PERROR("write");
 113                 return;
 114         }
 115 }
 116
 117 static void inform_consumer_daemon(void)
 118 {
 119         ustcomm_request_consumer(getpid(), "metadata");
 120         ustcomm_request_consumer(getpid(), "ust");
 121 }
 122
 123 void process_blocked_consumers(void)
 124 {
 125         int n_fds = 0;
 126         struct pollfd *fds;
 127         struct blocked_consumer *bc;
 128         int idx = 0;
 129         char inbuf;
 130         int result;
 131
 132         list_for_each_entry(bc, &blocked_consumers, list) {
 133                 n_fds++;
 134         }
 135
 136         fds = (struct pollfd *) malloc(n_fds * sizeof(struct pollfd));
 137         if(fds == NULL) {
 138                 ERR("malloc returned NULL");
 139                 return;
 140         }
 141
 142         list_for_each_entry(bc, &blocked_consumers, list) {
 143                 fds[idx].fd = bc->fd_producer;
 144                 fds[idx].events = POLLIN;
 145                 bc->tmp_poll_idx = idx;
 146                 idx++;
 147         }
 148
 149         result = poll(fds, n_fds, 0);
 150         if(result == -1) {
 151                 PERROR("poll");
 152                 return;
 153         }
 154
 155         list_for_each_entry(bc, &blocked_consumers, list) {
 156                 if(fds[bc->tmp_poll_idx].revents) {
 157                         long consumed_old = 0;
 158                         char *reply;
 159
 160                         result = read(bc->fd_producer, &inbuf, 1);
 161                         if(result == -1) {
 162                                 PERROR("read");
 163                                 continue;
 164                         }
 165                         if(result == 0) {
 166                                 DBG("PRODUCER END");
 167
 168                                 close(bc->fd_producer);
 169
 170                                 list_del(&bc->list);
 171
 172                                 result = ustcomm_send_reply(&bc->server, "END", &bc->src);
 173                                 if(result < 0) {
 174                                         ERR("ustcomm_send_reply failed");
 175                                         continue;
 176                                 }
 177
 178                                 continue;
 179                         }
 180
 181                         result = ltt_do_get_subbuf(bc->rbuf, bc->lttbuf, &consumed_old);
 182                         if(result == -EAGAIN) {
 183                                 WARN("missed buffer?");
 184                                 continue;
 185                         }
 186                         else if(result < 0) {
 187                                 DBG("ltt_do_get_subbuf: error: %s", strerror(-result));
 188                         }
 189                         asprintf(&reply, "%s %ld", "OK", consumed_old);
 190                         result = ustcomm_send_reply(&bc->server, reply, &bc->src);
 191                         if(result < 0) {
 192                                 ERR("ustcomm_send_reply failed");
 193                                 free(reply);
 194                                 continue;
 195                         }
 196                         free(reply);
 197
 198                         list_del(&bc->list);
 199                 }
 200         }
 201
 202 }
 203
 204 void *listener_main(void *p)
 205 {
 206         int result;
 207
 208         DBG("LISTENER");
 209
 210         for(;;) {
 211                 uint32_t size;
 212                 struct sockaddr_un addr;
 213                 socklen_t addrlen = sizeof(addr);
 214                 char trace_name[] = "auto";
 215                 char trace_type[] = "ustrelay";
 216                 char *recvbuf;
 217                 int len;
 218                 struct ustcomm_source src;
 219
 220                 process_blocked_consumers();
 221
 222                 result = ustcomm_app_recv_message(&ustcomm_app, &recvbuf, &src, 5);
 223                 if(result < 0) {
 224                         WARN("error in ustcomm_app_recv_message");
 225                         continue;
 226                 }
 227                 else if(result == 0) {
 228                         /* no message */
 229                         continue;
 230                 }
 231
 232                 DBG("received a message! it's: %s\n", recvbuf);
 233                 len = strlen(recvbuf);
 234
 235                 if(!strcmp(recvbuf, "print_markers")) {
 236                         print_markers(stderr);
 237                 }
 238                 else if(!strcmp(recvbuf, "list_markers")) {
 239                         char *ptr;
 240                         size_t size;
 241                         FILE *fp;
 242
 243                         fp = open_memstream(&ptr, &size);
 244                         print_markers(fp);
 245                         fclose(fp);
 246
 247                         result = ustcomm_send_reply(&ustcomm_app.server, ptr, &src);
 248
 249                         free(ptr);
 250                 }
 251                 else if(!strcmp(recvbuf, "start")) {
 252                         /* start is an operation that setups the trace, allocates it and starts it */
 253                         result = ltt_trace_setup(trace_name);
 254                         if(result < 0) {
 255                                 ERR("ltt_trace_setup failed");
 256                                 return (void *)1;
 257                         }
 258
 259                         result = ltt_trace_set_type(trace_name, trace_type);
 260                         if(result < 0) {
 261                                 ERR("ltt_trace_set_type failed");
 262                                 return (void *)1;
 263                         }
 264
 265                         result = ltt_trace_alloc(trace_name);
 266                         if(result < 0) {
 267                                 ERR("ltt_trace_alloc failed");
 268                                 return (void *)1;
 269                         }
 270
 271                         inform_consumer_daemon();
 272
 273                         result = ltt_trace_start(trace_name);
 274                         if(result < 0) {
 275                                 ERR("ltt_trace_start failed");
 276                                 continue;
 277                         }
 278                 }
 279                 else if(!strcmp(recvbuf, "trace_setup")) {
 280                         DBG("trace setup");
 281
 282                         result = ltt_trace_setup(trace_name);
 283                         if(result < 0) {
 284                                 ERR("ltt_trace_setup failed");
 285                                 return (void *)1;
 286                         }
 287
 288                         result = ltt_trace_set_type(trace_name, trace_type);
 289                         if(result < 0) {
 290                                 ERR("ltt_trace_set_type failed");
 291                                 return (void *)1;
 292                         }
 293                 }
 294                 else if(!strcmp(recvbuf, "trace_alloc")) {
 295                         DBG("trace alloc");
 296
 297                         result = ltt_trace_alloc(trace_name);
 298                         if(result < 0) {
 299                                 ERR("ltt_trace_alloc failed");
 300                                 return (void *)1;
 301                         }
 302                 }
 303                 else if(!strcmp(recvbuf, "trace_start")) {
 304                         DBG("trace start");
 305
 306                         result = ltt_trace_start(trace_name);
 307                         if(result < 0) {
 308                                 ERR("ltt_trace_start failed");
 309                                 continue;
 310                         }
 311                 }
 312                 else if(!strcmp(recvbuf, "trace_stop")) {
 313                         DBG("trace stop");
 314
 315                         result = ltt_trace_stop(trace_name);
 316                         if(result < 0) {
 317                                 ERR("ltt_trace_stop failed");
 318                                 return (void *)1;
 319                         }
 320                 }
 321                 else if(!strcmp(recvbuf, "trace_destroy")) {
 322
 323                         DBG("trace destroy");
 324
 325                         result = ltt_trace_destroy(trace_name);
 326                         if(result < 0) {
 327                                 ERR("ltt_trace_destroy failed");
 328                                 return (void *)1;
 329                         }
 330                 }
 331                 else if(nth_token_is(recvbuf, "get_shmid", 0) == 1) {
 332                         struct ltt_trace_struct *trace;
 333                         char trace_name[] = "auto";
 334                         int i;
 335                         char *channel_name;
 336
 337                         DBG("get_shmid");
 338
 339                         channel_name = nth_token(recvbuf, 1);
 340                         if(channel_name == NULL) {
 341                                 ERR("get_shmid: cannot parse channel");
 342                                 goto next_cmd;
 343                         }
 344
 345                         ltt_lock_traces();
 346                         trace = _ltt_trace_find(trace_name);
 347                         ltt_unlock_traces();
 348
 349                         if(trace == NULL) {
 350                                 CPRINTF("cannot find trace!");
 351                                 return (void *)1;
 352                         }
 353
 354                         for(i=0; i<trace->nr_channels; i++) {
 355                                 struct rchan *rchan = trace->channels[i].trans_channel_data;
 356                                 struct rchan_buf *rbuf = rchan->buf;
 357                                 struct ltt_channel_struct *ltt_channel = (struct ltt_channel_struct *)rchan->private_data;
 358                                 struct ltt_channel_buf_struct *ltt_buf = ltt_channel->buf;
 359
 360                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 361                                         char *reply;
 362
 363                                         DBG("the shmid for the requested channel is %d", rbuf->shmid);
 364                                         DBG("the shmid for its buffer structure is %d", ltt_channel->buf_shmid);
 365                                         asprintf(&reply, "%d %d", rbuf->shmid, ltt_channel->buf_shmid);
 366
 367                                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 368                                         if(result) {
 369                                                 ERR("listener: get_shmid: ustcomm_send_reply failed");
 370                                                 goto next_cmd;
 371                                         }
 372
 373                                         free(reply);
 374
 375                                         break;
 376                                 }
 377                         }
 378                 }
 379                 else if(nth_token_is(recvbuf, "get_n_subbufs", 0) == 1) {
 380                         struct ltt_trace_struct *trace;
 381                         char trace_name[] = "auto";
 382                         int i;
 383                         char *channel_name;
 384
 385                         DBG("get_n_subbufs");
 386
 387                         channel_name = nth_token(recvbuf, 1);
 388                         if(channel_name == NULL) {
 389                                 ERR("get_n_subbufs: cannot parse channel");
 390                                 goto next_cmd;
 391                         }
 392
 393                         ltt_lock_traces();
 394                         trace = _ltt_trace_find(trace_name);
 395                         ltt_unlock_traces();
 396
 397                         if(trace == NULL) {
 398                                 CPRINTF("cannot find trace!");
 399                                 return (void *)1;
 400                         }
 401
 402                         for(i=0; i<trace->nr_channels; i++) {
 403                                 struct rchan *rchan = trace->channels[i].trans_channel_data;
 404
 405                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 406                                         char *reply;
 407
 408                                         DBG("the n_subbufs for the requested channel is %zd", rchan->n_subbufs);
 409                                         asprintf(&reply, "%zd", rchan->n_subbufs);
 410
 411                                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 412                                         if(result) {
 413                                                 ERR("listener: get_n_subbufs: ustcomm_send_reply failed");
 414                                                 goto next_cmd;
 415                                         }
 416
 417                                         free(reply);
 418
 419                                         break;
 420                                 }
 421                         }
 422                 }
 423                 else if(nth_token_is(recvbuf, "get_subbuf_size", 0) == 1) {
 424                         struct ltt_trace_struct *trace;
 425                         char trace_name[] = "auto";
 426                         int i;
 427                         char *channel_name;
 428
 429                         DBG("get_subbuf_size");
 430
 431                         channel_name = nth_token(recvbuf, 1);
 432                         if(channel_name == NULL) {
 433                                 ERR("get_subbuf_size: cannot parse channel");
 434                                 goto next_cmd;
 435                         }
 436
 437                         ltt_lock_traces();
 438                         trace = _ltt_trace_find(trace_name);
 439                         ltt_unlock_traces();
 440
 441                         if(trace == NULL) {
 442                                 CPRINTF("cannot find trace!");
 443                                 return (void *)1;
 444                         }
 445
 446                         for(i=0; i<trace->nr_channels; i++) {
 447                                 struct rchan *rchan = trace->channels[i].trans_channel_data;
 448
 449                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 450                                         char *reply;
 451
 452                                         DBG("the subbuf_size for the requested channel is %zd", rchan->subbuf_size);
 453                                         asprintf(&reply, "%zd", rchan->subbuf_size);
 454
 455                                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 456                                         if(result) {
 457                                                 ERR("listener: get_subbuf_size: ustcomm_send_reply failed");
 458                                                 goto next_cmd;
 459                                         }
 460
 461                                         free(reply);
 462
 463                                         break;
 464                                 }
 465                         }
 466                 }
 467                 else if(nth_token_is(recvbuf, "load_probe_lib", 0) == 1) {
 468                         char *libfile;
 469
 470                         libfile = nth_token(recvbuf, 1);
 471
 472                         DBG("load_probe_lib loading %s", libfile);
 473                 }
 474                 else if(nth_token_is(recvbuf, "get_subbuffer", 0) == 1) {
 475                         struct ltt_trace_struct *trace;
 476                         char trace_name[] = "auto";
 477                         int i;
 478                         char *channel_name;
 479
 480                         DBG("get_subbuf");
 481
 482                         channel_name = nth_token(recvbuf, 1);
 483                         if(channel_name == NULL) {
 484                                 ERR("get_subbuf: cannot parse channel");
 485                                 goto next_cmd;
 486                         }
 487
 488                         ltt_lock_traces();
 489                         trace = _ltt_trace_find(trace_name);
 490                         ltt_unlock_traces();
 491
 492                         if(trace == NULL) {
 493                                 CPRINTF("cannot find trace!");
 494                                 return (void *)1;
 495                         }
 496
 497                         for(i=0; i<trace->nr_channels; i++) {
 498                                 struct rchan *rchan = trace->channels[i].trans_channel_data;
 499
 500                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 501                                         struct rchan_buf *rbuf = rchan->buf;
 502                                         struct ltt_channel_buf_struct *lttbuf = trace->channels[i].buf;
 503                                         char *reply;
 504                                         long consumed_old=0;
 505                                         int fd;
 506                                         struct blocked_consumer *bc;
 507
 508                                         bc = (struct blocked_consumer *) malloc(sizeof(struct blocked_consumer));
 509                                         if(bc == NULL) {
 510                                                 ERR("malloc returned NULL");
 511                                                 goto next_cmd;
 512                                         }
 513                                         bc->fd_consumer = src.fd;
 514                                         bc->fd_producer = lttbuf->data_ready_fd_read;
 515                                         bc->rbuf = rbuf;
 516                                         bc->lttbuf = lttbuf;
 517                                         bc->src = src;
 518                                         bc->server = ustcomm_app.server;
 519
 520                                         list_add(&bc->list, &blocked_consumers);
 521
 522                                         break;
 523                                 }
 524                         }
 525                 }
 526                 else if(nth_token_is(recvbuf, "put_subbuffer", 0) == 1) {
 527                         struct ltt_trace_struct *trace;
 528                         char trace_name[] = "auto";
 529                         int i;
 530                         char *channel_name;
 531                         long consumed_old;
 532                         char *consumed_old_str;
 533                         char *endptr;
 534
 535                         DBG("put_subbuf");
 536
 537                         channel_name = strdup_malloc(nth_token(recvbuf, 1));
 538                         if(channel_name == NULL) {
 539                                 ERR("put_subbuf_size: cannot parse channel");
 540                                 goto next_cmd;
 541                         }
 542
 543                         consumed_old_str = strdup_malloc(nth_token(recvbuf, 2));
 544                         if(consumed_old_str == NULL) {
 545                                 ERR("put_subbuf: cannot parse consumed_old");
 546                                 goto next_cmd;
 547                         }
 548                         consumed_old = strtol(consumed_old_str, &endptr, 10);
 549                         if(*endptr != '\0') {
 550                                 ERR("put_subbuf: invalid value for consumed_old");
 551                                 goto next_cmd;
 552                         }
 553
 554                         ltt_lock_traces();
 555                         trace = _ltt_trace_find(trace_name);
 556                         ltt_unlock_traces();
 557
 558                         if(trace == NULL) {
 559                                 CPRINTF("cannot find trace!");
 560                                 return (void *)1;
 561                         }
 562
 563                         for(i=0; i<trace->nr_channels; i++) {
 564                                 struct rchan *rchan = trace->channels[i].trans_channel_data;
 565
 566                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 567                                         struct rchan_buf *rbuf = rchan->buf;
 568                                         struct ltt_channel_buf_struct *lttbuf = trace->channels[i].buf;
 569                                         char *reply;
 570                                         long consumed_old=0;
 571
 572                                         result = ltt_do_put_subbuf(rbuf, lttbuf, consumed_old);
 573                                         if(result < 0) {
 574                                                 WARN("ltt_do_put_subbuf: error (subbuf=%s)", channel_name);
 575                                                 asprintf(&reply, "%s", "ERROR");
 576                                         }
 577                                         else {
 578                                                 DBG("ltt_do_put_subbuf: success (subbuf=%s)", channel_name);
 579                                                 asprintf(&reply, "%s", "OK");
 580                                         }
 581
 582                                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 583                                         if(result) {
 584                                                 ERR("listener: put_subbuf: ustcomm_send_reply failed");
 585                                                 goto next_cmd;
 586                                         }
 587
 588                                         free(reply);
 589
 590                                         break;
 591                                 }
 592                         }
 593
 594                         free(channel_name);
 595                         free(consumed_old_str);
 596                 }
 597                 else if(nth_token_is(recvbuf, "enable_marker", 0) == 1) {
 598                         char *channel_slash_name = nth_token(recvbuf, 1);
 599                         char channel_name[256]="";
 600                         char marker_name[256]="";
 601                         struct marker_iter iter;
 602
 603                         result = sscanf(channel_slash_name, "%255[^/]/%255s", channel_name, marker_name);
 604
 605                         if(channel_name == NULL || marker_name == NULL) {
 606                                 WARN("invalid marker name");
 607                                 goto next_cmd;
 608                         }
 609                         printf("%s %s\n", channel_name, marker_name);
 610
 611                         result = ltt_marker_connect(channel_name, marker_name, "default");
 612                         if(result < 0) {
 613                                 WARN("could not enable marker; channel=%s, name=%s", channel_name, marker_name);
 614                         }
 615                 }
 616                 else if(nth_token_is(recvbuf, "disable_marker", 0) == 1) {
 617                         char *channel_slash_name = nth_token(recvbuf, 1);
 618                         char *marker_name;
 619                         char *channel_name;
 620                         struct marker_iter iter;
 621
 622                         result = sscanf(channel_slash_name, "%a[^/]/%as", &channel_name, &marker_name);
 623
 624                         if(marker_name == NULL) {
 625                         }
 626                         printf("%s %s\n", channel_name, marker_name);
 627
 628                         result = ltt_marker_disconnect(channel_name, marker_name, "default");
 629                         if(result < 0) {
 630                                 WARN("could not disable marker; channel=%s, name=%s", channel_name, marker_name);
 631                         }
 632                 }
 633 //              else if(nth_token_is(recvbuf, "get_notifications", 0) == 1) {
 634 //                      struct ltt_trace_struct *trace;
 635 //                      char trace_name[] = "auto";
 636 //                      int i;
 637 //                      char *channel_name;
 638 //
 639 //                      DBG("get_notifications");
 640 //
 641 //                      channel_name = strdup_malloc(nth_token(recvbuf, 1));
 642 //                      if(channel_name == NULL) {
 643 //                              ERR("put_subbuf_size: cannot parse channel");
 644 //                              goto next_cmd;
 645 //                      }
 646 //
 647 //                      ltt_lock_traces();
 648 //                      trace = _ltt_trace_find(trace_name);
 649 //                      ltt_unlock_traces();
 650 //
 651 //                      if(trace == NULL) {
 652 //                              CPRINTF("cannot find trace!");
 653 //                              return (void *)1;
 654 //                      }
 655 //
 656 //                      for(i=0; i<trace->nr_channels; i++) {
 657 //                              struct rchan *rchan = trace->channels[i].trans_channel_data;
 658 //                              int fd;
 659 //
 660 //                              if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 661 //                                      struct rchan_buf *rbuf = rchan->buf;
 662 //                                      struct ltt_channel_buf_struct *lttbuf = trace->channels[i].buf;
 663 //
 664 //                                      result = fd = ustcomm_app_detach_client(&ustcomm_app, &src);
 665 //                                      if(result == -1) {
 666 //                                              ERR("ustcomm_app_detach_client failed");
 667 //                                              goto next_cmd;
 668 //                                      }
 669 //
 670 //                                      lttbuf->wake_consumer_arg = (void *) fd;
 671 //
 672 //                                      smp_wmb();
 673 //
 674 //                                      lttbuf->call_wake_consumer = 1;
 675 //
 676 //                                      break;
 677 //                              }
 678 //                      }
 679 //
 680 //                      free(channel_name);
 681 //              }
 682                 else {
 683                         ERR("unable to parse message: %s", recvbuf);
 684                 }
 685
 686         next_cmd:
 687                 free(recvbuf);
 688         }
 689 }
 690
 691 static char listener_stack[16384];
 692
 693 void create_listener(void)
 694 {
 695         int result;
 696         static char listener_stack[16384];
 697         //char *listener_stack = malloc(16384);
 698
 699 #ifdef USE_CLONE
 700         result = clone(listener_main, listener_stack+sizeof(listener_stack)-1, CLONE_FS | CLONE_FILES | CLONE_VM | CLONE_SIGHAND | CLONE_THREAD, NULL);
 701         if(result == -1) {
 702                 perror("clone");
 703         }
 704 #else
 705         pthread_t thread;
 706
 707         pthread_create(&thread, NULL, listener_main, NULL);
 708 #endif
 709 }
 710
 711 /* The signal handler itself. Signals must be setup so there cannot be
 712    nested signals. */
 713
 714 void sighandler(int sig)
 715 {
 716         static char have_listener = 0;
 717         DBG("sighandler");
 718
 719         if(!have_listener) {
 720                 create_listener();
 721                 have_listener = 1;
 722         }
 723 }
 724
 725 /* Called by the app signal handler to chain it to us. */
 726
 727 void chain_signal(void)
 728 {
 729         sighandler(USTSIGNAL);
 730 }
 731
 732 static int init_socket(void)
 733 {
 734         return ustcomm_init_app(getpid(), &ustcomm_app);
 735 }
 736
 737 static void destroy_socket(void)
 738 {
 739 //      int result;
 740 //
 741 //      if(mysocketfile[0] == '\0')
 742 //              return;
 743 //
 744 //      result = unlink(mysocketfile);
 745 //      if(result == -1) {
 746 //              PERROR("unlink");
 747 //      }
 748 }
 749
 750 static int init_signal_handler(void)
 751 {
 752         /* Attempt to handler SIGIO. If the main program wants to
 753          * handle it, fine, it'll override us. They it'll have to
 754          * use the chaining function.
 755          */
 756
 757         int result;
 758         struct sigaction act;
 759
 760         result = sigemptyset(&act.sa_mask);
 761         if(result == -1) {
 762                 PERROR("sigemptyset");
 763                 return -1;
 764         }
 765
 766         act.sa_handler = sighandler;
 767         act.sa_flags = SA_RESTART;
 768
 769         /* Only defer ourselves. Also, try to restart interrupted
 770          * syscalls to disturb the traced program as little as possible.
 771          */
 772         result = sigaction(SIGIO, &act, NULL);
 773         if(result == -1) {
 774                 PERROR("sigaction");
 775                 return -1;
 776         }
 777
 778         return 0;
 779 }
 780
 781 static void auto_probe_connect(struct marker *m)
 782 {
 783         int result;
 784
 785         result = ltt_marker_connect(m->channel, m->name, "default");
 786         if(result)
 787                 ERR("ltt_marker_connect");
 788
 789         DBG("just auto connected marker %s %s to probe default", m->channel, m->name);
 790 }
 791
 792 static void __attribute__((constructor(101))) init0()
 793 {
 794         DBG("UST_AUTOPROBE constructor");
 795         if(getenv("UST_AUTOPROBE")) {
 796                 marker_set_new_marker_cb(auto_probe_connect);
 797         }
 798 }
 799
 800 static void fini(void);
 801
 802 static void __attribute__((constructor(1000))) init()
 803 {
 804         int result;
 805
 806         DBG("UST_TRACE constructor");
 807
 808         /* Must create socket before signal handler to prevent races.
 809          */
 810         result = init_socket();
 811         if(result == -1) {
 812                 ERR("init_socket error");
 813                 return;
 814         }
 815         result = init_signal_handler();
 816         if(result == -1) {
 817                 ERR("init_signal_handler error");
 818                 return;
 819         }
 820
 821         if(getenv("UST_TRACE")) {
 822                 char trace_name[] = "auto";
 823                 char trace_type[] = "ustrelay";
 824
 825                 DBG("starting early tracing");
 826
 827                 /* Ensure marker control is initialized */
 828                 init_marker_control();
 829
 830                 /* Ensure relay is initialized */
 831                 init_ustrelay_transport();
 832
 833                 /* Ensure markers are initialized */
 834                 init_markers();
 835
 836                 /* In case. */
 837                 ltt_channels_register("ust");
 838
 839                 result = ltt_trace_setup(trace_name);
 840                 if(result < 0) {
 841                         ERR("ltt_trace_setup failed");
 842                         return;
 843                 }
 844
 845                 result = ltt_trace_set_type(trace_name, trace_type);
 846                 if(result < 0) {
 847                         ERR("ltt_trace_set_type failed");
 848                         return;
 849                 }
 850
 851                 result = ltt_trace_alloc(trace_name);
 852                 if(result < 0) {
 853                         ERR("ltt_trace_alloc failed");
 854                         return;
 855                 }
 856
 857                 result = ltt_trace_start(trace_name);
 858                 if(result < 0) {
 859                         ERR("ltt_trace_start failed");
 860                         return;
 861                 }
 862                 inform_consumer_daemon();
 863         }
 864
 865
 866         return;
 867
 868         /* should decrementally destroy stuff if error */
 869
 870 }
 871
 872 /* This is only called if we terminate normally, not with an unhandled signal,
 873  * so we cannot rely on it. */
 874
 875 /* This destructor probably isn't needed, because ustd can do crash recovery. */
 876 #if 0
 877 static void __attribute__((destructor)) fini()
 878 {
 879         int result;
 880
 881         /* if trace running, finish it */
 882
 883         DBG("destructor stopping traces");
 884
 885         result = ltt_trace_stop("auto");
 886         if(result == -1) {
 887                 ERR("ltt_trace_stop error");
 888         }
 889
 890         result = ltt_trace_destroy("auto");
 891         if(result == -1) {
 892                 ERR("ltt_trace_destroy error");
 893         }
 894
 895         destroy_socket();
 896 }
 897 #endif