libust/tracectl.c

   1 /* Copyright (C) 2009  Pierre-Marc Fournier
   2  *
   3  * This library is free software; you can redistribute it and/or
   4  * modify it under the terms of the GNU Lesser General Public
   5  * License as published by the Free Software Foundation; either
   6  * version 2.1 of the License, or (at your option) any later version.
   7  *
   8  * This library is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * Lesser General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU Lesser General Public
  14  * License along with this library; if not, write to the Free Software
  15  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
  16  */
  17
  18 #define _GNU_SOURCE
  19 #include <stdio.h>
  20 #include <stdint.h>
  21 #include <signal.h>
  22 #include <sys/types.h>
  23 #include <sys/socket.h>
  24 #include <sys/un.h>
  25 #include <sched.h>
  26 #include <fcntl.h>
  27 #include <poll.h>
  28 #include <regex.h>
  29
  30 #include <urcu.h>
  31
  32 #include "marker.h"
  33 #include "tracer.h"
  34 #include "localerr.h"
  35 #include "ustcomm.h"
  36 #include "relay.h" /* FIXME: remove */
  37 #include "marker-control.h"
  38
  39 //#define USE_CLONE
  40
  41 #define USTSIGNAL SIGIO
  42
  43 #define MAX_MSG_SIZE (100)
  44 #define MSG_NOTIF 1
  45 #define MSG_REGISTER_NOTIF 2
  46
  47 char consumer_stack[10000];
  48
  49 struct list_head blocked_consumers = LIST_HEAD_INIT(blocked_consumers);
  50
  51 static struct ustcomm_app ustcomm_app;
  52
  53 struct tracecmd { /* no padding */
  54         uint32_t size;
  55         uint16_t command;
  56 };
  57
  58 //struct listener_arg {
  59 //      int pipe_fd;
  60 //};
  61
  62 struct trctl_msg {
  63         /* size: the size of all the fields except size itself */
  64         uint32_t size;
  65         uint16_t type;
  66         /* Only the necessary part of the payload is transferred. It
  67          * may even be none of it.
  68          */
  69         char payload[94];
  70 };
  71
  72 struct consumer_channel {
  73         int fd;
  74         struct ltt_channel_struct *chan;
  75 };
  76
  77 struct blocked_consumer {
  78         int fd_consumer;
  79         int fd_producer;
  80         int tmp_poll_idx;
  81
  82         /* args to ustcomm_send_reply */
  83         struct ustcomm_server server;
  84         struct ustcomm_source src;
  85
  86         /* args to ltt_do_get_subbuf */
  87         struct rchan_buf *rbuf;
  88         struct ltt_channel_buf_struct *lttbuf;
  89
  90         struct list_head list;
  91 };
  92
  93 static void print_markers(FILE *fp)
  94 {
  95         struct marker_iter iter;
  96
  97         lock_markers();
  98         marker_iter_reset(&iter);
  99         marker_iter_start(&iter);
 100
 101         while(iter.marker) {
 102                 fprintf(fp, "marker: %s_%s %d \"%s\"\n", iter.marker->channel, iter.marker->name, (int)imv_read(iter.marker->state), iter.marker->format);
 103                 marker_iter_next(&iter);
 104         }
 105         unlock_markers();
 106 }
 107
 108 static int init_socket(void);
 109
 110 /* This needs to be called whenever a new thread is created. It notifies
 111  * liburcu of the new thread.
 112  */
 113
 114 void ust_register_thread(void)
 115 {
 116         rcu_register_thread();
 117 }
 118
 119 int fd_notif = -1;
 120 void notif_cb(void)
 121 {
 122         int result;
 123         struct trctl_msg msg;
 124
 125         /* FIXME: fd_notif should probably be protected by a spinlock */
 126
 127         if(fd_notif == -1)
 128                 return;
 129
 130         msg.type = MSG_NOTIF;
 131         msg.size = sizeof(msg.type);
 132
 133         /* FIXME: don't block here */
 134         result = write(fd_notif, &msg, msg.size+sizeof(msg.size));
 135         if(result == -1) {
 136                 PERROR("write");
 137                 return;
 138         }
 139 }
 140
 141 /* Ask the daemon to collect a trace called trace_name and being
 142  * produced by this pid.
 143  *
 144  * The trace must be at least allocated. (It can also be started.)
 145  * This is because _ltt_trace_find is used.
 146  */
 147
 148 static void inform_consumer_daemon(const char *trace_name)
 149 {
 150         int i;
 151         struct ltt_trace_struct *trace;
 152         pid_t pid = getpid();
 153         int result;
 154
 155         ltt_lock_traces();
 156
 157         trace = _ltt_trace_find(trace_name);
 158         if(trace == NULL) {
 159                 WARN("inform_consumer_daemon: could not find trace \"%s\"; it is probably already destroyed", trace_name);
 160                 goto finish;
 161         }
 162
 163         for(i=0; i < trace->nr_channels; i++) {
 164                 result = ustcomm_request_consumer(pid, trace->channels[i].channel_name);
 165                 if(result == -1) {
 166                         WARN("Failed to request collection for channel %s. Is the daemon available?", trace->channels[i].channel_name);
 167                         /* continue even if fail */
 168                 }
 169         }
 170
 171         finish:
 172         ltt_unlock_traces();
 173 }
 174
 175 void process_blocked_consumers(void)
 176 {
 177         int n_fds = 0;
 178         struct pollfd *fds;
 179         struct blocked_consumer *bc;
 180         int idx = 0;
 181         char inbuf;
 182         int result;
 183
 184         list_for_each_entry(bc, &blocked_consumers, list) {
 185                 n_fds++;
 186         }
 187
 188         fds = (struct pollfd *) malloc(n_fds * sizeof(struct pollfd));
 189         if(fds == NULL) {
 190                 ERR("malloc returned NULL");
 191                 return;
 192         }
 193
 194         list_for_each_entry(bc, &blocked_consumers, list) {
 195                 fds[idx].fd = bc->fd_producer;
 196                 fds[idx].events = POLLIN;
 197                 bc->tmp_poll_idx = idx;
 198                 idx++;
 199         }
 200
 201         while((result = poll(fds, n_fds, 0)) == -1 && errno == EINTR)
 202                 /* nothing */;
 203         if(result == -1) {
 204                 PERROR("poll");
 205                 return;
 206         }
 207
 208         list_for_each_entry(bc, &blocked_consumers, list) {
 209                 if(fds[bc->tmp_poll_idx].revents) {
 210                         long consumed_old = 0;
 211                         char *reply;
 212
 213                         result = read(bc->fd_producer, &inbuf, 1);
 214                         if(result == -1) {
 215                                 PERROR("read");
 216                                 continue;
 217                         }
 218                         if(result == 0) {
 219                                 DBG("PRODUCER END");
 220
 221                                 close(bc->fd_producer);
 222
 223                                 list_del(&bc->list);
 224
 225                                 result = ustcomm_send_reply(&bc->server, "END", &bc->src);
 226                                 if(result < 0) {
 227                                         ERR("ustcomm_send_reply failed");
 228                                         continue;
 229                                 }
 230
 231                                 continue;
 232                         }
 233
 234                         result = ltt_do_get_subbuf(bc->rbuf, bc->lttbuf, &consumed_old);
 235                         if(result == -EAGAIN) {
 236                                 WARN("missed buffer?");
 237                                 continue;
 238                         }
 239                         else if(result < 0) {
 240                                 DBG("ltt_do_get_subbuf: error: %s", strerror(-result));
 241                         }
 242                         asprintf(&reply, "%s %ld", "OK", consumed_old);
 243                         result = ustcomm_send_reply(&bc->server, reply, &bc->src);
 244                         if(result < 0) {
 245                                 ERR("ustcomm_send_reply failed");
 246                                 free(reply);
 247                                 continue;
 248                         }
 249                         free(reply);
 250
 251                         list_del(&bc->list);
 252                 }
 253         }
 254
 255 }
 256
 257 void *listener_main(void *p)
 258 {
 259         int result;
 260
 261         ust_register_thread();
 262
 263         DBG("LISTENER");
 264
 265         for(;;) {
 266                 char trace_name[] = "auto";
 267                 char trace_type[] = "ustrelay";
 268                 char *recvbuf;
 269                 int len;
 270                 struct ustcomm_source src;
 271
 272                 process_blocked_consumers();
 273
 274                 result = ustcomm_app_recv_message(&ustcomm_app, &recvbuf, &src, 5);
 275                 if(result < 0) {
 276                         WARN("error in ustcomm_app_recv_message");
 277                         continue;
 278                 }
 279                 else if(result == 0) {
 280                         /* no message */
 281                         continue;
 282                 }
 283
 284                 DBG("received a message! it's: %s", recvbuf);
 285                 len = strlen(recvbuf);
 286
 287                 if(!strcmp(recvbuf, "print_markers")) {
 288                         print_markers(stderr);
 289                 }
 290                 else if(!strcmp(recvbuf, "list_markers")) {
 291                         char *ptr;
 292                         size_t size;
 293                         FILE *fp;
 294
 295                         fp = open_memstream(&ptr, &size);
 296                         print_markers(fp);
 297                         fclose(fp);
 298
 299                         result = ustcomm_send_reply(&ustcomm_app.server, ptr, &src);
 300
 301                         free(ptr);
 302                 }
 303                 else if(!strcmp(recvbuf, "start")) {
 304                         /* start is an operation that setups the trace, allocates it and starts it */
 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                         result = ltt_trace_alloc(trace_name);
 318                         if(result < 0) {
 319                                 ERR("ltt_trace_alloc failed");
 320                                 return (void *)1;
 321                         }
 322
 323                         inform_consumer_daemon(trace_name);
 324
 325                         result = ltt_trace_start(trace_name);
 326                         if(result < 0) {
 327                                 ERR("ltt_trace_start failed");
 328                                 continue;
 329                         }
 330                 }
 331                 else if(!strcmp(recvbuf, "trace_setup")) {
 332                         DBG("trace setup");
 333
 334                         result = ltt_trace_setup(trace_name);
 335                         if(result < 0) {
 336                                 ERR("ltt_trace_setup failed");
 337                                 return (void *)1;
 338                         }
 339
 340                         result = ltt_trace_set_type(trace_name, trace_type);
 341                         if(result < 0) {
 342                                 ERR("ltt_trace_set_type failed");
 343                                 return (void *)1;
 344                         }
 345                 }
 346                 else if(!strcmp(recvbuf, "trace_alloc")) {
 347                         DBG("trace alloc");
 348
 349                         result = ltt_trace_alloc(trace_name);
 350                         if(result < 0) {
 351                                 ERR("ltt_trace_alloc failed");
 352                                 return (void *)1;
 353                         }
 354                 }
 355                 else if(!strcmp(recvbuf, "trace_start")) {
 356                         DBG("trace start");
 357
 358                         result = ltt_trace_start(trace_name);
 359                         if(result < 0) {
 360                                 ERR("ltt_trace_start failed");
 361                                 continue;
 362                         }
 363                 }
 364                 else if(!strcmp(recvbuf, "trace_stop")) {
 365                         DBG("trace stop");
 366
 367                         result = ltt_trace_stop(trace_name);
 368                         if(result < 0) {
 369                                 ERR("ltt_trace_stop failed");
 370                                 return (void *)1;
 371                         }
 372                 }
 373                 else if(!strcmp(recvbuf, "trace_destroy")) {
 374
 375                         DBG("trace destroy");
 376
 377                         result = ltt_trace_destroy(trace_name);
 378                         if(result < 0) {
 379                                 ERR("ltt_trace_destroy failed");
 380                                 return (void *)1;
 381                         }
 382                 }
 383                 else if(nth_token_is(recvbuf, "get_shmid", 0) == 1) {
 384                         struct ltt_trace_struct *trace;
 385                         char trace_name[] = "auto";
 386                         int i;
 387                         char *channel_name;
 388
 389                         DBG("get_shmid");
 390
 391                         channel_name = nth_token(recvbuf, 1);
 392                         if(channel_name == NULL) {
 393                                 ERR("get_shmid: cannot parse channel");
 394                                 goto next_cmd;
 395                         }
 396
 397                         ltt_lock_traces();
 398                         trace = _ltt_trace_find(trace_name);
 399                         ltt_unlock_traces();
 400
 401                         if(trace == NULL) {
 402                                 ERR("cannot find trace!");
 403                                 return (void *)1;
 404                         }
 405
 406                         for(i=0; i<trace->nr_channels; i++) {
 407                                 struct rchan *rchan = trace->channels[i].trans_channel_data;
 408                                 struct rchan_buf *rbuf = rchan->buf;
 409                                 struct ltt_channel_struct *ltt_channel = (struct ltt_channel_struct *)rchan->private_data;
 410
 411                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 412                                         char *reply;
 413
 414                                         DBG("the shmid for the requested channel is %d", rbuf->shmid);
 415                                         DBG("the shmid for its buffer structure is %d", ltt_channel->buf_shmid);
 416                                         asprintf(&reply, "%d %d", rbuf->shmid, ltt_channel->buf_shmid);
 417
 418                                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 419                                         if(result) {
 420                                                 ERR("listener: get_shmid: ustcomm_send_reply failed");
 421                                                 goto next_cmd;
 422                                         }
 423
 424                                         free(reply);
 425
 426                                         break;
 427                                 }
 428                         }
 429                 }
 430                 else if(nth_token_is(recvbuf, "get_n_subbufs", 0) == 1) {
 431                         struct ltt_trace_struct *trace;
 432                         char trace_name[] = "auto";
 433                         int i;
 434                         char *channel_name;
 435
 436                         DBG("get_n_subbufs");
 437
 438                         channel_name = nth_token(recvbuf, 1);
 439                         if(channel_name == NULL) {
 440                                 ERR("get_n_subbufs: cannot parse channel");
 441                                 goto next_cmd;
 442                         }
 443
 444                         ltt_lock_traces();
 445                         trace = _ltt_trace_find(trace_name);
 446                         ltt_unlock_traces();
 447
 448                         if(trace == NULL) {
 449                                 ERR("cannot find trace!");
 450                                 return (void *)1;
 451                         }
 452
 453                         for(i=0; i<trace->nr_channels; i++) {
 454                                 struct rchan *rchan = trace->channels[i].trans_channel_data;
 455
 456                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 457                                         char *reply;
 458
 459                                         DBG("the n_subbufs for the requested channel is %zd", rchan->n_subbufs);
 460                                         asprintf(&reply, "%zd", rchan->n_subbufs);
 461
 462                                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 463                                         if(result) {
 464                                                 ERR("listener: get_n_subbufs: ustcomm_send_reply failed");
 465                                                 goto next_cmd;
 466                                         }
 467
 468                                         free(reply);
 469
 470                                         break;
 471                                 }
 472                         }
 473                 }
 474                 else if(nth_token_is(recvbuf, "get_subbuf_size", 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_size");
 481
 482                         channel_name = nth_token(recvbuf, 1);
 483                         if(channel_name == NULL) {
 484                                 ERR("get_subbuf_size: 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                                 ERR("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                                         char *reply;
 502
 503                                         DBG("the subbuf_size for the requested channel is %zd", rchan->subbuf_size);
 504                                         asprintf(&reply, "%zd", rchan->subbuf_size);
 505
 506                                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 507                                         if(result) {
 508                                                 ERR("listener: get_subbuf_size: ustcomm_send_reply failed");
 509                                                 goto next_cmd;
 510                                         }
 511
 512                                         free(reply);
 513
 514                                         break;
 515                                 }
 516                         }
 517                 }
 518                 else if(nth_token_is(recvbuf, "load_probe_lib", 0) == 1) {
 519                         char *libfile;
 520
 521                         libfile = nth_token(recvbuf, 1);
 522
 523                         DBG("load_probe_lib loading %s", libfile);
 524                 }
 525                 else if(nth_token_is(recvbuf, "get_subbuffer", 0) == 1) {
 526                         struct ltt_trace_struct *trace;
 527                         char trace_name[] = "auto";
 528                         int i;
 529                         char *channel_name;
 530
 531                         DBG("get_subbuf");
 532
 533                         channel_name = nth_token(recvbuf, 1);
 534                         if(channel_name == NULL) {
 535                                 ERR("get_subbuf: cannot parse channel");
 536                                 goto next_cmd;
 537                         }
 538
 539                         ltt_lock_traces();
 540                         trace = _ltt_trace_find(trace_name);
 541                         ltt_unlock_traces();
 542
 543                         if(trace == NULL) {
 544                                 ERR("cannot find trace!");
 545                                 return (void *)1;
 546                         }
 547
 548                         for(i=0; i<trace->nr_channels; i++) {
 549                                 struct rchan *rchan = trace->channels[i].trans_channel_data;
 550
 551                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 552                                         struct rchan_buf *rbuf = rchan->buf;
 553                                         struct ltt_channel_buf_struct *lttbuf = trace->channels[i].buf;
 554                                         struct blocked_consumer *bc;
 555
 556                                         bc = (struct blocked_consumer *) malloc(sizeof(struct blocked_consumer));
 557                                         if(bc == NULL) {
 558                                                 ERR("malloc returned NULL");
 559                                                 goto next_cmd;
 560                                         }
 561                                         bc->fd_consumer = src.fd;
 562                                         bc->fd_producer = lttbuf->data_ready_fd_read;
 563                                         bc->rbuf = rbuf;
 564                                         bc->lttbuf = lttbuf;
 565                                         bc->src = src;
 566                                         bc->server = ustcomm_app.server;
 567
 568                                         list_add(&bc->list, &blocked_consumers);
 569
 570                                         break;
 571                                 }
 572                         }
 573                 }
 574                 else if(nth_token_is(recvbuf, "put_subbuffer", 0) == 1) {
 575                         struct ltt_trace_struct *trace;
 576                         char trace_name[] = "auto";
 577                         int i;
 578                         char *channel_name;
 579                         long consumed_old;
 580                         char *consumed_old_str;
 581                         char *endptr;
 582
 583                         DBG("put_subbuf");
 584
 585                         channel_name = strdup_malloc(nth_token(recvbuf, 1));
 586                         if(channel_name == NULL) {
 587                                 ERR("put_subbuf_size: cannot parse channel");
 588                                 goto next_cmd;
 589                         }
 590
 591                         consumed_old_str = strdup_malloc(nth_token(recvbuf, 2));
 592                         if(consumed_old_str == NULL) {
 593                                 ERR("put_subbuf: cannot parse consumed_old");
 594                                 goto next_cmd;
 595                         }
 596                         consumed_old = strtol(consumed_old_str, &endptr, 10);
 597                         if(*endptr != '\0') {
 598                                 ERR("put_subbuf: invalid value for consumed_old");
 599                                 goto next_cmd;
 600                         }
 601
 602                         ltt_lock_traces();
 603                         trace = _ltt_trace_find(trace_name);
 604                         ltt_unlock_traces();
 605
 606                         if(trace == NULL) {
 607                                 ERR("cannot find trace!");
 608                                 return (void *)1;
 609                         }
 610
 611                         for(i=0; i<trace->nr_channels; i++) {
 612                                 struct rchan *rchan = trace->channels[i].trans_channel_data;
 613
 614                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 615                                         struct rchan_buf *rbuf = rchan->buf;
 616                                         struct ltt_channel_buf_struct *lttbuf = trace->channels[i].buf;
 617                                         char *reply;
 618                                         long consumed_old=0;
 619
 620                                         result = ltt_do_put_subbuf(rbuf, lttbuf, consumed_old);
 621                                         if(result < 0) {
 622                                                 WARN("ltt_do_put_subbuf: error (subbuf=%s)", channel_name);
 623                                                 asprintf(&reply, "%s", "ERROR");
 624                                         }
 625                                         else {
 626                                                 DBG("ltt_do_put_subbuf: success (subbuf=%s)", channel_name);
 627                                                 asprintf(&reply, "%s", "OK");
 628                                         }
 629
 630                                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 631                                         if(result) {
 632                                                 ERR("listener: put_subbuf: ustcomm_send_reply failed");
 633                                                 goto next_cmd;
 634                                         }
 635
 636                                         free(reply);
 637
 638                                         break;
 639                                 }
 640                         }
 641
 642                         free(channel_name);
 643                         free(consumed_old_str);
 644                 }
 645                 else if(nth_token_is(recvbuf, "enable_marker", 0) == 1) {
 646                         char *channel_slash_name = nth_token(recvbuf, 1);
 647                         char channel_name[256]="";
 648                         char marker_name[256]="";
 649
 650                         result = sscanf(channel_slash_name, "%255[^/]/%255s", channel_name, marker_name);
 651
 652                         if(channel_name == NULL || marker_name == NULL) {
 653                                 WARN("invalid marker name");
 654                                 goto next_cmd;
 655                         }
 656                         printf("%s %s\n", channel_name, marker_name);
 657
 658                         result = ltt_marker_connect(channel_name, marker_name, "default");
 659                         if(result < 0) {
 660                                 WARN("could not enable marker; channel=%s, name=%s", channel_name, marker_name);
 661                         }
 662                 }
 663                 else if(nth_token_is(recvbuf, "disable_marker", 0) == 1) {
 664                         char *channel_slash_name = nth_token(recvbuf, 1);
 665                         char *marker_name;
 666                         char *channel_name;
 667
 668                         result = sscanf(channel_slash_name, "%a[^/]/%as", &channel_name, &marker_name);
 669
 670                         if(marker_name == NULL) {
 671                         }
 672                         printf("%s %s\n", channel_name, marker_name);
 673
 674                         result = ltt_marker_disconnect(channel_name, marker_name, "default");
 675                         if(result < 0) {
 676                                 WARN("could not disable marker; channel=%s, name=%s", channel_name, marker_name);
 677                         }
 678                 }
 679 //              else if(nth_token_is(recvbuf, "get_notifications", 0) == 1) {
 680 //                      struct ltt_trace_struct *trace;
 681 //                      char trace_name[] = "auto";
 682 //                      int i;
 683 //                      char *channel_name;
 684 //
 685 //                      DBG("get_notifications");
 686 //
 687 //                      channel_name = strdup_malloc(nth_token(recvbuf, 1));
 688 //                      if(channel_name == NULL) {
 689 //                              ERR("put_subbuf_size: cannot parse channel");
 690 //                              goto next_cmd;
 691 //                      }
 692 //
 693 //                      ltt_lock_traces();
 694 //                      trace = _ltt_trace_find(trace_name);
 695 //                      ltt_unlock_traces();
 696 //
 697 //                      if(trace == NULL) {
 698 //                              ERR("cannot find trace!");
 699 //                              return (void *)1;
 700 //                      }
 701 //
 702 //                      for(i=0; i<trace->nr_channels; i++) {
 703 //                              struct rchan *rchan = trace->channels[i].trans_channel_data;
 704 //                              int fd;
 705 //
 706 //                              if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 707 //                                      struct rchan_buf *rbuf = rchan->buf;
 708 //                                      struct ltt_channel_buf_struct *lttbuf = trace->channels[i].buf;
 709 //
 710 //                                      result = fd = ustcomm_app_detach_client(&ustcomm_app, &src);
 711 //                                      if(result == -1) {
 712 //                                              ERR("ustcomm_app_detach_client failed");
 713 //                                              goto next_cmd;
 714 //                                      }
 715 //
 716 //                                      lttbuf->wake_consumer_arg = (void *) fd;
 717 //
 718 //                                      smp_wmb();
 719 //
 720 //                                      lttbuf->call_wake_consumer = 1;
 721 //
 722 //                                      break;
 723 //                              }
 724 //                      }
 725 //
 726 //                      free(channel_name);
 727 //              }
 728                 else {
 729                         ERR("unable to parse message: %s", recvbuf);
 730                 }
 731
 732         next_cmd:
 733                 free(recvbuf);
 734         }
 735 }
 736
 737 int have_listener = 0;
 738
 739 void create_listener(void)
 740 {
 741 #ifdef USE_CLONE
 742         static char listener_stack[16384];
 743 #else
 744         pthread_t thread;
 745 #endif
 746
 747         if(have_listener)
 748                 return;
 749
 750 #ifdef USE_CLONE
 751         result = clone(listener_main, listener_stack+sizeof(listener_stack)-1, CLONE_FS | CLONE_FILES | CLONE_VM | CLONE_SIGHAND | CLONE_THREAD, NULL);
 752         if(result == -1) {
 753                 perror("clone");
 754                 return;
 755         }
 756 #else
 757
 758         pthread_create(&thread, NULL, listener_main, NULL);
 759 #endif
 760
 761         have_listener = 1;
 762 }
 763
 764 /* The signal handler itself. Signals must be setup so there cannot be
 765    nested signals. */
 766
 767 void sighandler(int sig)
 768 {
 769         static char have_listener = 0;
 770         DBG("sighandler");
 771
 772         if(!have_listener) {
 773                 create_listener();
 774                 have_listener = 1;
 775         }
 776 }
 777
 778 /* Called by the app signal handler to chain it to us. */
 779
 780 void chain_signal(void)
 781 {
 782         sighandler(USTSIGNAL);
 783 }
 784
 785 static int init_socket(void)
 786 {
 787         return ustcomm_init_app(getpid(), &ustcomm_app);
 788 }
 789
 790 /* FIXME: reenable this to delete socket file. */
 791
 792 #if 0
 793 static void destroy_socket(void)
 794 {
 795         int result;
 796
 797         if(mysocketfile[0] == '\0')
 798                 return;
 799
 800         result = unlink(mysocketfile);
 801         if(result == -1) {
 802                 PERROR("unlink");
 803         }
 804 }
 805 #endif
 806
 807 static int init_signal_handler(void)
 808 {
 809         /* Attempt to handler SIGIO. If the main program wants to
 810          * handle it, fine, it'll override us. They it'll have to
 811          * use the chaining function.
 812          */
 813
 814         int result;
 815         struct sigaction act;
 816
 817         result = sigemptyset(&act.sa_mask);
 818         if(result == -1) {
 819                 PERROR("sigemptyset");
 820                 return -1;
 821         }
 822
 823         act.sa_handler = sighandler;
 824         act.sa_flags = SA_RESTART;
 825
 826         /* Only defer ourselves. Also, try to restart interrupted
 827          * syscalls to disturb the traced program as little as possible.
 828          */
 829         result = sigaction(SIGIO, &act, NULL);
 830         if(result == -1) {
 831                 PERROR("sigaction");
 832                 return -1;
 833         }
 834
 835         return 0;
 836 }
 837
 838 #define AUTOPROBE_DISABLED      0
 839 #define AUTOPROBE_ENABLE_ALL    1
 840 #define AUTOPROBE_ENABLE_REGEX  2
 841 static int autoprobe_method = AUTOPROBE_DISABLED;
 842 static regex_t autoprobe_regex;
 843
 844 static void auto_probe_connect(struct marker *m)
 845 {
 846         int result;
 847
 848         char* concat_name = NULL;
 849         const char *probe_name = "default";
 850
 851         if(autoprobe_method == AUTOPROBE_DISABLED) {
 852                 return;
 853         }
 854         else if(autoprobe_method == AUTOPROBE_ENABLE_REGEX) {
 855                 result = asprintf(&concat_name, "%s/%s", m->channel, m->name);
 856                 if(result == -1) {
 857                         ERR("auto_probe_connect: asprintf failed (marker %s/%s)",
 858                                 m->channel, m->name);
 859                         return;
 860                 }
 861                 if (regexec(&autoprobe_regex, concat_name, 0, NULL, 0)) {
 862                         free(concat_name);
 863                         return;
 864                 }
 865                 free(concat_name);
 866         }
 867
 868         result = ltt_marker_connect(m->channel, m->name, probe_name);
 869         if(result && result != -EEXIST)
 870                 ERR("ltt_marker_connect (marker = %s/%s, errno = %d)", m->channel, m->name, -result);
 871
 872         DBG("auto connected marker %s %s to probe default", m->channel, m->name);
 873
 874 }
 875
 876 static void __attribute__((constructor(1000))) init()
 877 {
 878         int result;
 879         char* autoprobe_val = NULL;
 880
 881         /* Initialize RCU in case the constructor order is not good. */
 882         urcu_init();
 883
 884         /* It is important to do this before events start to be generated. */
 885         ust_register_thread();
 886
 887         DBG("Tracectl constructor");
 888
 889         /* Must create socket before signal handler to prevent races.
 890          */
 891         result = init_socket();
 892         if(result == -1) {
 893                 ERR("init_socket error");
 894                 return;
 895         }
 896         result = init_signal_handler();
 897         if(result == -1) {
 898                 ERR("init_signal_handler error");
 899                 return;
 900         }
 901
 902         autoprobe_val = getenv("UST_AUTOPROBE");
 903         if(autoprobe_val) {
 904                 struct marker_iter iter;
 905
 906                 DBG("Autoprobe enabled.");
 907
 908                 /* Ensure markers are initialized */
 909                 //init_markers();
 910
 911                 /* Ensure marker control is initialized, for the probe */
 912                 init_marker_control();
 913
 914                 /* first, set the callback that will connect the
 915                  * probe on new markers
 916                  */
 917                 if(autoprobe_val[0] == '/') {
 918                         result = regcomp(&autoprobe_regex, autoprobe_val+1, 0);
 919                         if (result) {
 920                                 char regexerr[150];
 921
 922                                 regerror(result, &autoprobe_regex, regexerr, sizeof(regexerr));
 923                                 ERR("cannot parse regex %s (%s), will ignore UST_AUTOPROBE", autoprobe_val, regexerr);
 924                                 /* don't crash the application just for this */
 925                         }
 926                         else {
 927                                 autoprobe_method = AUTOPROBE_ENABLE_REGEX;
 928                         }
 929                 }
 930                 else {
 931                         /* just enable all instrumentation */
 932                         autoprobe_method = AUTOPROBE_ENABLE_ALL;
 933                 }
 934
 935                 marker_set_new_marker_cb(auto_probe_connect);
 936
 937                 /* Now, connect the probes that were already registered. */
 938                 marker_iter_reset(&iter);
 939                 marker_iter_start(&iter);
 940
 941                 DBG("now iterating on markers already registered");
 942                 while(iter.marker) {
 943                         DBG("now iterating on marker %s", iter.marker->name);
 944                         auto_probe_connect(iter.marker);
 945                         marker_iter_next(&iter);
 946                 }
 947         }
 948
 949         if(getenv("UST_TRACE")) {
 950                 char trace_name[] = "auto";
 951                 char trace_type[] = "ustrelay";
 952
 953                 DBG("starting early tracing");
 954
 955                 /* Ensure marker control is initialized */
 956                 init_marker_control();
 957
 958                 /* Ensure relay is initialized */
 959                 init_ustrelay_transport();
 960
 961                 /* Ensure markers are initialized */
 962                 init_markers();
 963
 964                 /* In case. */
 965                 ltt_channels_register("ust");
 966
 967                 result = ltt_trace_setup(trace_name);
 968                 if(result < 0) {
 969                         ERR("ltt_trace_setup failed");
 970                         return;
 971                 }
 972
 973                 result = ltt_trace_set_type(trace_name, trace_type);
 974                 if(result < 0) {
 975                         ERR("ltt_trace_set_type failed");
 976                         return;
 977                 }
 978
 979                 result = ltt_trace_alloc(trace_name);
 980                 if(result < 0) {
 981                         ERR("ltt_trace_alloc failed");
 982                         return;
 983                 }
 984
 985                 inform_consumer_daemon(trace_name);
 986
 987                 result = ltt_trace_start(trace_name);
 988                 if(result < 0) {
 989                         ERR("ltt_trace_start failed");
 990                         return;
 991                 }
 992         }
 993
 994
 995         return;
 996
 997         /* should decrementally destroy stuff if error */
 998
 999 }
1000
1001 /* This is only called if we terminate normally, not with an unhandled signal,
1002  * so we cannot rely on it. */
1003
1004 /* This destructor probably isn't needed, because ustd can do crash recovery. */
1005 #if 0
1006 static void __attribute__((destructor)) fini()
1007 {
1008         int result;
1009
1010         /* if trace running, finish it */
1011
1012         DBG("destructor stopping traces");
1013
1014         result = ltt_trace_stop("auto");
1015         if(result == -1) {
1016                 ERR("ltt_trace_stop error");
1017         }
1018
1019         result = ltt_trace_destroy("auto");
1020         if(result == -1) {
1021                 ERR("ltt_trace_destroy error");
1022         }
1023
1024         destroy_socket();
1025 }
1026 #endif
1027
1028 #if 0
1029 static int trace_recording(void)
1030 {
1031         int retval = 0;
1032         struct ltt_trace_struct *trace;
1033
1034         ltt_lock_traces();
1035
1036         list_for_each_entry(trace, &ltt_traces.head, list) {
1037                 if(trace->active) {
1038                         retval = 1;
1039                         break;
1040                 }
1041         }
1042
1043         ltt_unlock_traces();
1044
1045         return retval;
1046 }
1047
1048 static int have_consumer(void)
1049 {
1050         return !list_empty(&blocked_consumers);
1051 }
1052
1053 /* This destructor keeps the process alive for a few seconds in order
1054  * to leave time to ustd to consume its buffers.
1055  */
1056
1057 int restarting_sleep(int secs)
1058 {
1059         struct timespec tv;
1060         int result;
1061
1062         tv.tv_sec = secs;
1063         tv.tv_nsec = 0;
1064
1065         do {
1066                 result = nanosleep(&tv, &tv);
1067         } while(result == -1 && errno == EINTR);
1068
1069         return result;
1070 }
1071
1072 static void __attribute__((destructor)) keepalive()
1073 {
1074 //      struct ustcomm_ustd ustd;
1075 //      int result;
1076 //      sigset_t sigset;
1077 //
1078 //      result = sigemptyset(&sigset);
1079 //      if(result == -1) {
1080 //              perror("sigemptyset");
1081 //              return;
1082 //      }
1083 //      result = sigaddset(&sigset, SIGIO);
1084 //      if(result == -1) {
1085 //              perror("sigaddset");
1086 //              return;
1087 //      }
1088 //      result = sigprocmask(SIG_BLOCK, &sigset, NULL);
1089 //      if(result == -1) {
1090 //              perror("sigprocmask");
1091 //              return;
1092 //      }
1093 //
1094 //      if(trace_recording()) {
1095 //              if(!have_consumer()) {
1096 //                      /* Request listener creation. We've blocked SIGIO's in
1097 //                       * order to not interrupt sleep(), so we will miss the
1098 //                       * one sent by the daemon and therefore won't create
1099 //                       * the listener automatically.
1100 //                       */
1101 //                      create_listener();
1102 //
1103                         printf("Keeping process alive for consumer daemon...\n");
1104                         restarting_sleep(3);
1105                         printf("Finally dying...\n");
1106 //              }
1107 //      }
1108 //
1109 //      result = sigprocmask(SIG_UNBLOCK, &sigset, NULL);
1110 //      if(result == -1) {
1111 //              perror("sigprocmask");
1112 //              return;
1113 //      }
1114 }
1115 #endif
1116
1117 /* Notify ust that there was a fork. This needs to be called inside
1118  * the new process, anytime a process whose memory is not shared with
1119  * the parent is created. If this function is not called, the events
1120  * of the new process will not be collected.
1121  */
1122
1123 void ust_fork(void)
1124 {
1125         DBG("ust: forking");
1126         ltt_trace_stop("auto");
1127         ltt_trace_destroy("auto");
1128         ltt_trace_alloc("auto");
1129         ltt_trace_start("auto");
1130         init_socket();
1131         have_listener = 0;
1132         create_listener();
1133         inform_consumer_daemon("auto");
1134 }
1135