libust/tracectl.c

   1 /* Copyright (C) 2009  Pierre-Marc Fournier
   2  *
   3  * This library is free software; you can redistribute it and/or
   4  * modify it under the terms of the GNU Lesser General Public
   5  * License as published by the Free Software Foundation; either
   6  * version 2.1 of the License, or (at your option) any later version.
   7  *
   8  * This library is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * Lesser General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU Lesser General Public
  14  * License along with this library; if not, write to the Free Software
  15  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
  16  */
  17
  18 #define _GNU_SOURCE
  19 #include <stdio.h>
  20 #include <stdint.h>
  21 #include <signal.h>
  22 #include <sys/types.h>
  23 #include <sys/socket.h>
  24 #include <sys/un.h>
  25 #include <sched.h>
  26 #include <fcntl.h>
  27 #include <poll.h>
  28 #include <regex.h>
  29
  30 #include <urcu-bp.h>
  31
  32 #include <ust/marker.h>
  33 #include "tracer.h"
  34 #include "usterr.h"
  35 #include "ustcomm.h"
  36 #include "buffers.h" /* FIXME: remove */
  37 #include "marker-control.h"
  38
  39 //#define USE_CLONE
  40
  41 #define USTSIGNAL SIGIO
  42
  43 #define MAX_MSG_SIZE (100)
  44 #define MSG_NOTIF 1
  45 #define MSG_REGISTER_NOTIF 2
  46
  47 char consumer_stack[10000];
  48
  49 /* This should only be accessed by the constructor, before the creation
  50  * of the listener, and then only by the listener.
  51  */
  52 s64 pidunique = -1LL;
  53
  54 struct list_head blocked_consumers = LIST_HEAD_INIT(blocked_consumers);
  55
  56 static struct ustcomm_app ustcomm_app;
  57
  58 struct tracecmd { /* no padding */
  59         uint32_t size;
  60         uint16_t command;
  61 };
  62
  63 /* volatile because shared between the listener and the main thread */
  64 volatile sig_atomic_t buffers_to_export = 0;
  65
  66 struct trctl_msg {
  67         /* size: the size of all the fields except size itself */
  68         uint32_t size;
  69         uint16_t type;
  70         /* Only the necessary part of the payload is transferred. It
  71          * may even be none of it.
  72          */
  73         char payload[94];
  74 };
  75
  76 struct consumer_channel {
  77         int fd;
  78         struct ltt_channel_struct *chan;
  79 };
  80
  81 struct blocked_consumer {
  82         int fd_consumer;
  83         int fd_producer;
  84         int tmp_poll_idx;
  85
  86         /* args to ustcomm_send_reply */
  87         struct ustcomm_server server;
  88         struct ustcomm_source src;
  89
  90         /* args to ust_buffers_do_get_subbuf */
  91         struct ust_buffer *buf;
  92
  93         struct list_head list;
  94 };
  95
  96 static long long make_pidunique(void)
  97 {
  98         s64 retval;
  99         struct timeval tv;
 100
 101         gettimeofday(&tv, NULL);
 102
 103         retval = tv.tv_sec;
 104         retval <<= 32;
 105         retval |= tv.tv_usec;
 106
 107         return retval;
 108 }
 109
 110 static void print_markers(FILE *fp)
 111 {
 112         struct marker_iter iter;
 113
 114         lock_markers();
 115         marker_iter_reset(&iter);
 116         marker_iter_start(&iter);
 117
 118         while(iter.marker) {
 119                 fprintf(fp, "marker: %s/%s %d \"%s\" %p\n", iter.marker->channel, iter.marker->name, (int)imv_read(iter.marker->state), iter.marker->format, iter.marker->location);
 120                 marker_iter_next(&iter);
 121         }
 122         unlock_markers();
 123 }
 124
 125 static int init_socket(void);
 126
 127 /* This needs to be called whenever a new thread is created. It notifies
 128  * liburcu of the new thread.
 129  */
 130
 131 void ust_register_thread(void)
 132 {
 133         rcu_register_thread();
 134 }
 135
 136 int fd_notif = -1;
 137 void notif_cb(void)
 138 {
 139         int result;
 140         struct trctl_msg msg;
 141
 142         /* FIXME: fd_notif should probably be protected by a spinlock */
 143
 144         if(fd_notif == -1)
 145                 return;
 146
 147         msg.type = MSG_NOTIF;
 148         msg.size = sizeof(msg.type);
 149
 150         /* FIXME: don't block here */
 151         result = write(fd_notif, &msg, msg.size+sizeof(msg.size));
 152         if(result == -1) {
 153                 PERROR("write");
 154                 return;
 155         }
 156 }
 157
 158 /* Ask the daemon to collect a trace called trace_name and being
 159  * produced by this pid.
 160  *
 161  * The trace must be at least allocated. (It can also be started.)
 162  * This is because _ltt_trace_find is used.
 163  */
 164
 165 static void inform_consumer_daemon(const char *trace_name)
 166 {
 167         int i;
 168         struct ltt_trace_struct *trace;
 169         pid_t pid = getpid();
 170         int result;
 171
 172         ltt_lock_traces();
 173
 174         trace = _ltt_trace_find(trace_name);
 175         if(trace == NULL) {
 176                 WARN("inform_consumer_daemon: could not find trace \"%s\"; it is probably already destroyed", trace_name);
 177                 goto finish;
 178         }
 179
 180         for(i=0; i < trace->nr_channels; i++) {
 181                 result = ustcomm_request_consumer(pid, trace->channels[i].channel_name);
 182                 if(result == -1) {
 183                         WARN("Failed to request collection for channel %s. Is the daemon available?", trace->channels[i].channel_name);
 184                         /* continue even if fail */
 185                 }
 186                 buffers_to_export++;
 187         }
 188
 189         finish:
 190         ltt_unlock_traces();
 191 }
 192
 193 void process_blocked_consumers(void)
 194 {
 195         int n_fds = 0;
 196         struct pollfd *fds;
 197         struct blocked_consumer *bc;
 198         int idx = 0;
 199         char inbuf;
 200         int result;
 201
 202         list_for_each_entry(bc, &blocked_consumers, list) {
 203                 n_fds++;
 204         }
 205
 206         fds = (struct pollfd *) malloc(n_fds * sizeof(struct pollfd));
 207         if(fds == NULL) {
 208                 ERR("malloc returned NULL");
 209                 return;
 210         }
 211
 212         list_for_each_entry(bc, &blocked_consumers, list) {
 213                 fds[idx].fd = bc->fd_producer;
 214                 fds[idx].events = POLLIN;
 215                 bc->tmp_poll_idx = idx;
 216                 idx++;
 217         }
 218
 219         while((result = poll(fds, n_fds, 0)) == -1 && errno == EINTR)
 220                 /* nothing */;
 221         if(result == -1) {
 222                 PERROR("poll");
 223                 return;
 224         }
 225
 226         list_for_each_entry(bc, &blocked_consumers, list) {
 227                 if(fds[bc->tmp_poll_idx].revents) {
 228                         long consumed_old = 0;
 229                         char *reply;
 230
 231                         result = read(bc->fd_producer, &inbuf, 1);
 232                         if(result == -1) {
 233                                 PERROR("read");
 234                                 continue;
 235                         }
 236                         if(result == 0) {
 237                                 DBG("PRODUCER END");
 238
 239                                 close(bc->fd_producer);
 240
 241                                 list_del(&bc->list);
 242
 243                                 result = ustcomm_send_reply(&bc->server, "END", &bc->src);
 244                                 if(result < 0) {
 245                                         ERR("ustcomm_send_reply failed");
 246                                         continue;
 247                                 }
 248
 249                                 continue;
 250                         }
 251
 252                         result = ust_buffers_do_get_subbuf(bc->buf, &consumed_old);
 253                         if(result == -EAGAIN) {
 254                                 WARN("missed buffer?");
 255                                 continue;
 256                         }
 257                         else if(result < 0) {
 258                                 DBG("ust_buffers_do_get_subbuf: error: %s", strerror(-result));
 259                         }
 260                         asprintf(&reply, "%s %ld", "OK", consumed_old);
 261                         result = ustcomm_send_reply(&bc->server, reply, &bc->src);
 262                         if(result < 0) {
 263                                 ERR("ustcomm_send_reply failed");
 264                                 free(reply);
 265                                 continue;
 266                         }
 267                         free(reply);
 268
 269                         list_del(&bc->list);
 270                 }
 271         }
 272
 273 }
 274
 275 void *listener_main(void *p)
 276 {
 277         int result;
 278
 279         ust_register_thread();
 280
 281         DBG("LISTENER");
 282
 283         for(;;) {
 284                 char trace_name[] = "auto";
 285                 char trace_type[] = "ustrelay";
 286                 char *recvbuf;
 287                 int len;
 288                 struct ustcomm_source src;
 289
 290                 process_blocked_consumers();
 291
 292                 result = ustcomm_app_recv_message(&ustcomm_app, &recvbuf, &src, 5);
 293                 if(result < 0) {
 294                         WARN("error in ustcomm_app_recv_message");
 295                         continue;
 296                 }
 297                 else if(result == 0) {
 298                         /* no message */
 299                         continue;
 300                 }
 301
 302                 DBG("received a message! it's: %s", recvbuf);
 303                 len = strlen(recvbuf);
 304
 305                 if(!strcmp(recvbuf, "print_markers")) {
 306                         print_markers(stderr);
 307                 }
 308                 else if(!strcmp(recvbuf, "list_markers")) {
 309                         char *ptr;
 310                         size_t size;
 311                         FILE *fp;
 312
 313                         fp = open_memstream(&ptr, &size);
 314                         print_markers(fp);
 315                         fclose(fp);
 316
 317                         result = ustcomm_send_reply(&ustcomm_app.server, ptr, &src);
 318
 319                         free(ptr);
 320                 }
 321                 else if(!strcmp(recvbuf, "start")) {
 322                         /* start is an operation that setups the trace, allocates it and starts it */
 323                         result = ltt_trace_setup(trace_name);
 324                         if(result < 0) {
 325                                 ERR("ltt_trace_setup failed");
 326                                 return (void *)1;
 327                         }
 328
 329                         result = ltt_trace_set_type(trace_name, trace_type);
 330                         if(result < 0) {
 331                                 ERR("ltt_trace_set_type failed");
 332                                 return (void *)1;
 333                         }
 334
 335                         result = ltt_trace_alloc(trace_name);
 336                         if(result < 0) {
 337                                 ERR("ltt_trace_alloc failed");
 338                                 return (void *)1;
 339                         }
 340
 341                         inform_consumer_daemon(trace_name);
 342
 343                         result = ltt_trace_start(trace_name);
 344                         if(result < 0) {
 345                                 ERR("ltt_trace_start failed");
 346                                 continue;
 347                         }
 348                 }
 349                 else if(!strcmp(recvbuf, "trace_setup")) {
 350                         DBG("trace setup");
 351
 352                         result = ltt_trace_setup(trace_name);
 353                         if(result < 0) {
 354                                 ERR("ltt_trace_setup failed");
 355                                 return (void *)1;
 356                         }
 357
 358                         result = ltt_trace_set_type(trace_name, trace_type);
 359                         if(result < 0) {
 360                                 ERR("ltt_trace_set_type failed");
 361                                 return (void *)1;
 362                         }
 363                 }
 364                 else if(!strcmp(recvbuf, "trace_alloc")) {
 365                         DBG("trace alloc");
 366
 367                         result = ltt_trace_alloc(trace_name);
 368                         if(result < 0) {
 369                                 ERR("ltt_trace_alloc failed");
 370                                 return (void *)1;
 371                         }
 372                 }
 373                 else if(!strcmp(recvbuf, "trace_start")) {
 374                         DBG("trace start");
 375
 376                         result = ltt_trace_start(trace_name);
 377                         if(result < 0) {
 378                                 ERR("ltt_trace_start failed");
 379                                 continue;
 380                         }
 381                 }
 382                 else if(!strcmp(recvbuf, "trace_stop")) {
 383                         DBG("trace stop");
 384
 385                         result = ltt_trace_stop(trace_name);
 386                         if(result < 0) {
 387                                 ERR("ltt_trace_stop failed");
 388                                 return (void *)1;
 389                         }
 390                 }
 391                 else if(!strcmp(recvbuf, "trace_destroy")) {
 392
 393                         DBG("trace destroy");
 394
 395                         result = ltt_trace_destroy(trace_name);
 396                         if(result < 0) {
 397                                 ERR("ltt_trace_destroy failed");
 398                                 return (void *)1;
 399                         }
 400                 }
 401                 else if(nth_token_is(recvbuf, "get_shmid", 0) == 1) {
 402                         struct ltt_trace_struct *trace;
 403                         char trace_name[] = "auto";
 404                         int i;
 405                         char *channel_name;
 406
 407                         DBG("get_shmid");
 408
 409                         channel_name = nth_token(recvbuf, 1);
 410                         if(channel_name == NULL) {
 411                                 ERR("get_shmid: 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 ust_channel *channel = &trace->channels[i];
 426                                 struct ust_buffer *buf = channel->buf;
 427
 428                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 429                                         char *reply;
 430
 431                                         DBG("the shmid for the requested channel is %d", buf->shmid);
 432                                         DBG("the shmid for its buffer structure is %d", channel->buf_shmid);
 433                                         asprintf(&reply, "%d %d", buf->shmid, channel->buf_shmid);
 434
 435                                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 436                                         if(result) {
 437                                                 ERR("listener: get_shmid: ustcomm_send_reply failed");
 438                                                 goto next_cmd;
 439                                         }
 440
 441                                         free(reply);
 442
 443                                         break;
 444                                 }
 445                         }
 446
 447                         buffers_to_export--;
 448                 }
 449                 else if(nth_token_is(recvbuf, "get_n_subbufs", 0) == 1) {
 450                         struct ltt_trace_struct *trace;
 451                         char trace_name[] = "auto";
 452                         int i;
 453                         char *channel_name;
 454
 455                         DBG("get_n_subbufs");
 456
 457                         channel_name = nth_token(recvbuf, 1);
 458                         if(channel_name == NULL) {
 459                                 ERR("get_n_subbufs: cannot parse channel");
 460                                 goto next_cmd;
 461                         }
 462
 463                         ltt_lock_traces();
 464                         trace = _ltt_trace_find(trace_name);
 465                         ltt_unlock_traces();
 466
 467                         if(trace == NULL) {
 468                                 ERR("cannot find trace!");
 469                                 return (void *)1;
 470                         }
 471
 472                         for(i=0; i<trace->nr_channels; i++) {
 473                                 struct ust_channel *channel = &trace->channels[i];
 474
 475                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 476                                         char *reply;
 477
 478                                         DBG("the n_subbufs for the requested channel is %d", channel->subbuf_cnt);
 479                                         asprintf(&reply, "%d", channel->subbuf_cnt);
 480
 481                                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 482                                         if(result) {
 483                                                 ERR("listener: get_n_subbufs: ustcomm_send_reply failed");
 484                                                 goto next_cmd;
 485                                         }
 486
 487                                         free(reply);
 488
 489                                         break;
 490                                 }
 491                         }
 492                 }
 493                 else if(nth_token_is(recvbuf, "get_subbuf_size", 0) == 1) {
 494                         struct ltt_trace_struct *trace;
 495                         char trace_name[] = "auto";
 496                         int i;
 497                         char *channel_name;
 498
 499                         DBG("get_subbuf_size");
 500
 501                         channel_name = nth_token(recvbuf, 1);
 502                         if(channel_name == NULL) {
 503                                 ERR("get_subbuf_size: cannot parse channel");
 504                                 goto next_cmd;
 505                         }
 506
 507                         ltt_lock_traces();
 508                         trace = _ltt_trace_find(trace_name);
 509                         ltt_unlock_traces();
 510
 511                         if(trace == NULL) {
 512                                 ERR("cannot find trace!");
 513                                 return (void *)1;
 514                         }
 515
 516                         for(i=0; i<trace->nr_channels; i++) {
 517                                 struct ust_channel *channel = &trace->channels[i];
 518
 519                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 520                                         char *reply;
 521
 522                                         DBG("the subbuf_size for the requested channel is %zd", channel->subbuf_size);
 523                                         asprintf(&reply, "%zd", channel->subbuf_size);
 524
 525                                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 526                                         if(result) {
 527                                                 ERR("listener: get_subbuf_size: ustcomm_send_reply failed");
 528                                                 goto next_cmd;
 529                                         }
 530
 531                                         free(reply);
 532
 533                                         break;
 534                                 }
 535                         }
 536                 }
 537                 else if(nth_token_is(recvbuf, "load_probe_lib", 0) == 1) {
 538                         char *libfile;
 539
 540                         libfile = nth_token(recvbuf, 1);
 541
 542                         DBG("load_probe_lib loading %s", libfile);
 543                 }
 544                 else if(nth_token_is(recvbuf, "get_subbuffer", 0) == 1) {
 545                         struct ltt_trace_struct *trace;
 546                         char trace_name[] = "auto";
 547                         int i;
 548                         char *channel_name;
 549
 550                         DBG("get_subbuf");
 551
 552                         channel_name = nth_token(recvbuf, 1);
 553                         if(channel_name == NULL) {
 554                                 ERR("get_subbuf: cannot parse channel");
 555                                 goto next_cmd;
 556                         }
 557
 558                         ltt_lock_traces();
 559                         trace = _ltt_trace_find(trace_name);
 560                         ltt_unlock_traces();
 561
 562                         if(trace == NULL) {
 563                                 ERR("cannot find trace!");
 564                                 return (void *)1;
 565                         }
 566
 567                         for(i=0; i<trace->nr_channels; i++) {
 568                                 struct ust_channel *channel = &trace->channels[i];
 569
 570                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 571                                         struct ust_buffer *buf = channel->buf;
 572                                         struct blocked_consumer *bc;
 573
 574                                         bc = (struct blocked_consumer *) malloc(sizeof(struct blocked_consumer));
 575                                         if(bc == NULL) {
 576                                                 ERR("malloc returned NULL");
 577                                                 goto next_cmd;
 578                                         }
 579                                         bc->fd_consumer = src.fd;
 580                                         bc->fd_producer = buf->data_ready_fd_read;
 581                                         bc->buf = buf;
 582                                         bc->src = src;
 583                                         bc->server = ustcomm_app.server;
 584
 585                                         list_add(&bc->list, &blocked_consumers);
 586
 587                                         break;
 588                                 }
 589                         }
 590                 }
 591                 else if(nth_token_is(recvbuf, "put_subbuffer", 0) == 1) {
 592                         struct ltt_trace_struct *trace;
 593                         char trace_name[] = "auto";
 594                         int i;
 595                         char *channel_name;
 596                         long consumed_old;
 597                         char *consumed_old_str;
 598                         char *endptr;
 599
 600                         DBG("put_subbuf");
 601
 602                         channel_name = strdup_malloc(nth_token(recvbuf, 1));
 603                         if(channel_name == NULL) {
 604                                 ERR("put_subbuf_size: cannot parse channel");
 605                                 goto next_cmd;
 606                         }
 607
 608                         consumed_old_str = strdup_malloc(nth_token(recvbuf, 2));
 609                         if(consumed_old_str == NULL) {
 610                                 ERR("put_subbuf: cannot parse consumed_old");
 611                                 goto next_cmd;
 612                         }
 613                         consumed_old = strtol(consumed_old_str, &endptr, 10);
 614                         if(*endptr != '\0') {
 615                                 ERR("put_subbuf: invalid value for consumed_old");
 616                                 goto next_cmd;
 617                         }
 618
 619                         ltt_lock_traces();
 620                         trace = _ltt_trace_find(trace_name);
 621                         ltt_unlock_traces();
 622
 623                         if(trace == NULL) {
 624                                 ERR("cannot find trace!");
 625                                 return (void *)1;
 626                         }
 627
 628                         for(i=0; i<trace->nr_channels; i++) {
 629                                 struct ust_channel *channel = &trace->channels[i];
 630
 631                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 632                                         struct ust_buffer *buf = channel->buf;
 633                                         char *reply;
 634                                         long consumed_old=0;
 635
 636                                         result = ust_buffers_do_put_subbuf(buf, consumed_old);
 637                                         if(result < 0) {
 638                                                 WARN("ust_buffers_do_put_subbuf: error (subbuf=%s)", channel_name);
 639                                                 asprintf(&reply, "%s", "ERROR");
 640                                         }
 641                                         else {
 642                                                 DBG("ust_buffers_do_put_subbuf: success (subbuf=%s)", channel_name);
 643                                                 asprintf(&reply, "%s", "OK");
 644                                         }
 645
 646                                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 647                                         if(result) {
 648                                                 ERR("listener: put_subbuf: ustcomm_send_reply failed");
 649                                                 goto next_cmd;
 650                                         }
 651
 652                                         free(reply);
 653
 654                                         break;
 655                                 }
 656                         }
 657
 658                         free(channel_name);
 659                         free(consumed_old_str);
 660                 }
 661                 else if(nth_token_is(recvbuf, "enable_marker", 0) == 1) {
 662                         char *channel_slash_name = nth_token(recvbuf, 1);
 663                         char channel_name[256]="";
 664                         char marker_name[256]="";
 665
 666                         result = sscanf(channel_slash_name, "%255[^/]/%255s", channel_name, marker_name);
 667
 668                         if(channel_name == NULL || marker_name == NULL) {
 669                                 WARN("invalid marker name");
 670                                 goto next_cmd;
 671                         }
 672                         printf("%s %s\n", channel_name, marker_name);
 673
 674                         result = ltt_marker_connect(channel_name, marker_name, "default");
 675                         if(result < 0) {
 676                                 WARN("could not enable marker; channel=%s, name=%s", channel_name, marker_name);
 677                         }
 678                 }
 679                 else if(nth_token_is(recvbuf, "disable_marker", 0) == 1) {
 680                         char *channel_slash_name = nth_token(recvbuf, 1);
 681                         char *marker_name;
 682                         char *channel_name;
 683
 684                         result = sscanf(channel_slash_name, "%a[^/]/%as", &channel_name, &marker_name);
 685
 686                         if(marker_name == NULL) {
 687                         }
 688                         printf("%s %s\n", channel_name, marker_name);
 689
 690                         result = ltt_marker_disconnect(channel_name, marker_name, "default");
 691                         if(result < 0) {
 692                                 WARN("could not disable marker; channel=%s, name=%s", channel_name, marker_name);
 693                         }
 694                 }
 695                 else if(nth_token_is(recvbuf, "get_pidunique", 0) == 1) {
 696                         char *reply;
 697
 698                         asprintf(&reply, "%lld", pidunique);
 699
 700                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 701                         if(result) {
 702                                 ERR("listener: get_pidunique: ustcomm_send_reply failed");
 703                                 goto next_cmd;
 704                         }
 705
 706                         free(reply);
 707                 }
 708 //              else if(nth_token_is(recvbuf, "get_notifications", 0) == 1) {
 709 //                      struct ltt_trace_struct *trace;
 710 //                      char trace_name[] = "auto";
 711 //                      int i;
 712 //                      char *channel_name;
 713 //
 714 //                      DBG("get_notifications");
 715 //
 716 //                      channel_name = strdup_malloc(nth_token(recvbuf, 1));
 717 //                      if(channel_name == NULL) {
 718 //                              ERR("put_subbuf_size: cannot parse channel");
 719 //                              goto next_cmd;
 720 //                      }
 721 //
 722 //                      ltt_lock_traces();
 723 //                      trace = _ltt_trace_find(trace_name);
 724 //                      ltt_unlock_traces();
 725 //
 726 //                      if(trace == NULL) {
 727 //                              ERR("cannot find trace!");
 728 //                              return (void *)1;
 729 //                      }
 730 //
 731 //                      for(i=0; i<trace->nr_channels; i++) {
 732 //                              struct rchan *rchan = trace->channels[i].trans_channel_data;
 733 //                              int fd;
 734 //
 735 //                              if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 736 //                                      struct rchan_buf *rbuf = rchan->buf;
 737 //                                      struct ltt_channel_buf_struct *lttbuf = trace->channels[i].buf;
 738 //
 739 //                                      result = fd = ustcomm_app_detach_client(&ustcomm_app, &src);
 740 //                                      if(result == -1) {
 741 //                                              ERR("ustcomm_app_detach_client failed");
 742 //                                              goto next_cmd;
 743 //                                      }
 744 //
 745 //                                      lttbuf->wake_consumer_arg = (void *) fd;
 746 //
 747 //                                      smp_wmb();
 748 //
 749 //                                      lttbuf->call_wake_consumer = 1;
 750 //
 751 //                                      break;
 752 //                              }
 753 //                      }
 754 //
 755 //                      free(channel_name);
 756 //              }
 757                 else {
 758                         ERR("unable to parse message: %s", recvbuf);
 759                 }
 760
 761         next_cmd:
 762                 free(recvbuf);
 763         }
 764 }
 765
 766 volatile sig_atomic_t have_listener = 0;
 767
 768 void create_listener(void)
 769 {
 770 #ifdef USE_CLONE
 771         static char listener_stack[16384];
 772         int result;
 773 #else
 774         pthread_t thread;
 775 #endif
 776
 777         if(have_listener) {
 778                 WARN("not creating listener because we already had one");
 779                 return;
 780         }
 781
 782 #ifdef USE_CLONE
 783         result = clone((int (*)(void *)) listener_main, listener_stack+sizeof(listener_stack)-1, CLONE_FS | CLONE_FILES | CLONE_VM | CLONE_SIGHAND | CLONE_THREAD, NULL);
 784         if(result == -1) {
 785                 perror("clone");
 786                 return;
 787         }
 788 #else
 789
 790         pthread_create(&thread, NULL, listener_main, NULL);
 791 #endif
 792
 793         have_listener = 1;
 794 }
 795
 796 static int init_socket(void)
 797 {
 798         return ustcomm_init_app(getpid(), &ustcomm_app);
 799 }
 800
 801 #define AUTOPROBE_DISABLED      0
 802 #define AUTOPROBE_ENABLE_ALL    1
 803 #define AUTOPROBE_ENABLE_REGEX  2
 804 static int autoprobe_method = AUTOPROBE_DISABLED;
 805 static regex_t autoprobe_regex;
 806
 807 static void auto_probe_connect(struct marker *m)
 808 {
 809         int result;
 810
 811         char* concat_name = NULL;
 812         const char *probe_name = "default";
 813
 814         if(autoprobe_method == AUTOPROBE_DISABLED) {
 815                 return;
 816         }
 817         else if(autoprobe_method == AUTOPROBE_ENABLE_REGEX) {
 818                 result = asprintf(&concat_name, "%s/%s", m->channel, m->name);
 819                 if(result == -1) {
 820                         ERR("auto_probe_connect: asprintf failed (marker %s/%s)",
 821                                 m->channel, m->name);
 822                         return;
 823                 }
 824                 if (regexec(&autoprobe_regex, concat_name, 0, NULL, 0)) {
 825                         free(concat_name);
 826                         return;
 827                 }
 828                 free(concat_name);
 829         }
 830
 831         result = ltt_marker_connect(m->channel, m->name, probe_name);
 832         if(result && result != -EEXIST)
 833                 ERR("ltt_marker_connect (marker = %s/%s, errno = %d)", m->channel, m->name, -result);
 834
 835         DBG("auto connected marker %s (addr: %p) %s to probe default", m->channel, m, m->name);
 836
 837 }
 838
 839 static void __attribute__((constructor)) init()
 840 {
 841         int result;
 842         char* autoprobe_val = NULL;
 843
 844         /* Assign the pidunique, to be able to differentiate the processes with same
 845          * pid, (before and after an exec).
 846          */
 847         pidunique = make_pidunique();
 848
 849         /* Initialize RCU in case the constructor order is not good. */
 850         urcu_init();
 851
 852         /* It is important to do this before events start to be generated. */
 853         ust_register_thread();
 854
 855         DBG("Tracectl constructor");
 856
 857         /* Must create socket before signal handler to prevent races.
 858          */
 859         result = init_socket();
 860         if(result == -1) {
 861                 ERR("init_socket error");
 862                 return;
 863         }
 864
 865         create_listener();
 866
 867         autoprobe_val = getenv("UST_AUTOPROBE");
 868         if(autoprobe_val) {
 869                 struct marker_iter iter;
 870
 871                 DBG("Autoprobe enabled.");
 872
 873                 /* Ensure markers are initialized */
 874                 //init_markers();
 875
 876                 /* Ensure marker control is initialized, for the probe */
 877                 init_marker_control();
 878
 879                 /* first, set the callback that will connect the
 880                  * probe on new markers
 881                  */
 882                 if(autoprobe_val[0] == '/') {
 883                         result = regcomp(&autoprobe_regex, autoprobe_val+1, 0);
 884                         if (result) {
 885                                 char regexerr[150];
 886
 887                                 regerror(result, &autoprobe_regex, regexerr, sizeof(regexerr));
 888                                 ERR("cannot parse regex %s (%s), will ignore UST_AUTOPROBE", autoprobe_val, regexerr);
 889                                 /* don't crash the application just for this */
 890                         }
 891                         else {
 892                                 autoprobe_method = AUTOPROBE_ENABLE_REGEX;
 893                         }
 894                 }
 895                 else {
 896                         /* just enable all instrumentation */
 897                         autoprobe_method = AUTOPROBE_ENABLE_ALL;
 898                 }
 899
 900                 marker_set_new_marker_cb(auto_probe_connect);
 901
 902                 /* Now, connect the probes that were already registered. */
 903                 marker_iter_reset(&iter);
 904                 marker_iter_start(&iter);
 905
 906                 DBG("now iterating on markers already registered");
 907                 while(iter.marker) {
 908                         DBG("now iterating on marker %s", iter.marker->name);
 909                         auto_probe_connect(iter.marker);
 910                         marker_iter_next(&iter);
 911                 }
 912         }
 913
 914         if(getenv("UST_TRACE")) {
 915                 char trace_name[] = "auto";
 916                 char trace_type[] = "ustrelay";
 917
 918                 DBG("starting early tracing");
 919
 920                 /* Ensure marker control is initialized */
 921                 init_marker_control();
 922
 923                 /* Ensure relay is initialized */
 924                 init_ustrelay_transport();
 925
 926                 /* Ensure markers are initialized */
 927                 init_markers();
 928
 929                 /* In case. */
 930                 ltt_channels_register("ust");
 931
 932                 result = ltt_trace_setup(trace_name);
 933                 if(result < 0) {
 934                         ERR("ltt_trace_setup failed");
 935                         return;
 936                 }
 937
 938                 result = ltt_trace_set_type(trace_name, trace_type);
 939                 if(result < 0) {
 940                         ERR("ltt_trace_set_type failed");
 941                         return;
 942                 }
 943
 944                 result = ltt_trace_alloc(trace_name);
 945                 if(result < 0) {
 946                         ERR("ltt_trace_alloc failed");
 947                         return;
 948                 }
 949
 950                 result = ltt_trace_start(trace_name);
 951                 if(result < 0) {
 952                         ERR("ltt_trace_start failed");
 953                         return;
 954                 }
 955
 956                 /* Do this after the trace is started in order to avoid creating confusion
 957                  * if the trace fails to start. */
 958                 inform_consumer_daemon(trace_name);
 959         }
 960
 961
 962         return;
 963
 964         /* should decrementally destroy stuff if error */
 965
 966 }
 967
 968 /* This is only called if we terminate normally, not with an unhandled signal,
 969  * so we cannot rely on it. However, for now, LTTV requires that the header of
 970  * the last sub-buffer contain a valid end time for the trace. This is done
 971  * automatically only when the trace is properly stopped.
 972  *
 973  * If the traced program crashed, it is always possible to manually add the
 974  * right value in the header, or to open the trace in text mode.
 975  *
 976  * FIXME: Fix LTTV so it doesn't need this.
 977  */
 978
 979 static void destroy_traces(void)
 980 {
 981         int result;
 982
 983         /* if trace running, finish it */
 984
 985         DBG("destructor stopping traces");
 986
 987         result = ltt_trace_stop("auto");
 988         if(result == -1) {
 989                 ERR("ltt_trace_stop error");
 990         }
 991
 992         result = ltt_trace_destroy("auto");
 993         if(result == -1) {
 994                 ERR("ltt_trace_destroy error");
 995         }
 996 }
 997
 998 static int trace_recording(void)
 999 {
1000         int retval = 0;
1001         struct ltt_trace_struct *trace;
1002
1003         ltt_lock_traces();
1004
1005         list_for_each_entry(trace, &ltt_traces.head, list) {
1006                 if(trace->active) {
1007                         retval = 1;
1008                         break;
1009                 }
1010         }
1011
1012         ltt_unlock_traces();
1013
1014         return retval;
1015 }
1016
1017 #if 0
1018 static int have_consumer(void)
1019 {
1020         return !list_empty(&blocked_consumers);
1021 }
1022 #endif
1023
1024 int restarting_usleep(useconds_t usecs)
1025 {
1026         struct timespec tv;
1027         int result;
1028
1029         tv.tv_sec = 0;
1030         tv.tv_nsec = usecs * 1000;
1031
1032         do {
1033                 result = nanosleep(&tv, &tv);
1034         } while(result == -1 && errno == EINTR);
1035
1036         return result;
1037 }
1038
1039 /* This destructor keeps the process alive for a few seconds in order
1040  * to leave time to ustd to connect to its buffers. This is necessary
1041  * for programs whose execution is very short. It is also useful in all
1042  * programs when tracing is started close to the end of the program
1043  * execution.
1044  *
1045  * FIXME: For now, this only works for the first trace created in a
1046  * process.
1047  */
1048
1049 static void __attribute__((destructor)) keepalive()
1050 {
1051         if(trace_recording() && buffers_to_export) {
1052                 int total = 0;
1053                 DBG("Keeping process alive for consumer daemon...");
1054                 while(buffers_to_export) {
1055                         const int interv = 200000;
1056                         restarting_usleep(interv);
1057                         total += interv;
1058
1059                         if(total >= 3000000) {
1060                                 WARN("non-consumed buffers remaining after wait limit; not waiting anymore");
1061                                 break;
1062                         }
1063                 }
1064                 DBG("Finally dying...");
1065         }
1066
1067         destroy_traces();
1068
1069         ustcomm_fini_app(&ustcomm_app);
1070 }
1071
1072 void ust_potential_exec(void)
1073 {
1074         trace_mark(ust, potential_exec, MARK_NOARGS);
1075
1076         DBG("test");
1077
1078         keepalive();
1079 }
1080
1081 /* Notify ust that there was a fork. This needs to be called inside
1082  * the new process, anytime a process whose memory is not shared with
1083  * the parent is created. If this function is not called, the events
1084  * of the new process will not be collected.
1085  */
1086
1087 void ust_fork(void)
1088 {
1089         struct blocked_consumer *bc;
1090         struct blocked_consumer *deletable_bc = NULL;
1091         int result;
1092
1093         DBG("ust: forking");
1094         ltt_trace_stop("auto");
1095         ltt_trace_destroy("auto");
1096         /* Delete all active connections */
1097         ustcomm_close_all_connections(&ustcomm_app.server);
1098
1099         /* Delete all blocked consumers */
1100         list_for_each_entry(bc, &blocked_consumers, list) {
1101                 close(bc->fd_producer);
1102                 close(bc->fd_consumer);
1103                 free(deletable_bc);
1104                 deletable_bc = bc;
1105                 list_del(&bc->list);
1106         }
1107
1108         have_listener = 0;
1109         create_listener();
1110         init_socket();
1111         ltt_trace_setup("auto");
1112         result = ltt_trace_set_type("auto", "ustrelay");
1113         if(result < 0) {
1114                 ERR("ltt_trace_set_type failed");
1115                 return;
1116         }
1117
1118         ltt_trace_alloc("auto");
1119         ltt_trace_start("auto");
1120         inform_consumer_daemon("auto");
1121 }
1122