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 /* 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 listener_arg {
  67 //      int pipe_fd;
  68 //};
  69
  70 struct trctl_msg {
  71         /* size: the size of all the fields except size itself */
  72         uint32_t size;
  73         uint16_t type;
  74         /* Only the necessary part of the payload is transferred. It
  75          * may even be none of it.
  76          */
  77         char payload[94];
  78 };
  79
  80 struct consumer_channel {
  81         int fd;
  82         struct ltt_channel_struct *chan;
  83 };
  84
  85 struct blocked_consumer {
  86         int fd_consumer;
  87         int fd_producer;
  88         int tmp_poll_idx;
  89
  90         /* args to ustcomm_send_reply */
  91         struct ustcomm_server server;
  92         struct ustcomm_source src;
  93
  94         /* args to ltt_do_get_subbuf */
  95         struct rchan_buf *rbuf;
  96         struct ltt_channel_buf_struct *lttbuf;
  97
  98         struct list_head list;
  99 };
 100
 101 static long long make_pidunique(void)
 102 {
 103         s64 retval;
 104         struct timeval tv;
 105
 106         gettimeofday(&tv, NULL);
 107
 108         retval = tv.tv_sec;
 109         retval <<= 32;
 110         retval |= tv.tv_usec;
 111
 112         return retval;
 113 }
 114
 115 static void print_markers(FILE *fp)
 116 {
 117         struct marker_iter iter;
 118
 119         lock_markers();
 120         marker_iter_reset(&iter);
 121         marker_iter_start(&iter);
 122
 123         while(iter.marker) {
 124                 fprintf(fp, "marker: %s/%s %d \"%s\"\n", iter.marker->channel, iter.marker->name, (int)imv_read(iter.marker->state), iter.marker->format);
 125                 marker_iter_next(&iter);
 126         }
 127         unlock_markers();
 128 }
 129
 130 static int init_socket(void);
 131
 132 /* This needs to be called whenever a new thread is created. It notifies
 133  * liburcu of the new thread.
 134  */
 135
 136 void ust_register_thread(void)
 137 {
 138         rcu_register_thread();
 139 }
 140
 141 int fd_notif = -1;
 142 void notif_cb(void)
 143 {
 144         int result;
 145         struct trctl_msg msg;
 146
 147         /* FIXME: fd_notif should probably be protected by a spinlock */
 148
 149         if(fd_notif == -1)
 150                 return;
 151
 152         msg.type = MSG_NOTIF;
 153         msg.size = sizeof(msg.type);
 154
 155         /* FIXME: don't block here */
 156         result = write(fd_notif, &msg, msg.size+sizeof(msg.size));
 157         if(result == -1) {
 158                 PERROR("write");
 159                 return;
 160         }
 161 }
 162
 163 /* Ask the daemon to collect a trace called trace_name and being
 164  * produced by this pid.
 165  *
 166  * The trace must be at least allocated. (It can also be started.)
 167  * This is because _ltt_trace_find is used.
 168  */
 169
 170 static void inform_consumer_daemon(const char *trace_name)
 171 {
 172         int i;
 173         struct ltt_trace_struct *trace;
 174         pid_t pid = getpid();
 175         int result;
 176
 177         ltt_lock_traces();
 178
 179         trace = _ltt_trace_find(trace_name);
 180         if(trace == NULL) {
 181                 WARN("inform_consumer_daemon: could not find trace \"%s\"; it is probably already destroyed", trace_name);
 182                 goto finish;
 183         }
 184
 185         for(i=0; i < trace->nr_channels; i++) {
 186                 result = ustcomm_request_consumer(pid, trace->channels[i].channel_name);
 187                 if(result == -1) {
 188                         WARN("Failed to request collection for channel %s. Is the daemon available?", trace->channels[i].channel_name);
 189                         /* continue even if fail */
 190                 }
 191                 buffers_to_export++;
 192         }
 193
 194         finish:
 195         ltt_unlock_traces();
 196 }
 197
 198 void process_blocked_consumers(void)
 199 {
 200         int n_fds = 0;
 201         struct pollfd *fds;
 202         struct blocked_consumer *bc;
 203         int idx = 0;
 204         char inbuf;
 205         int result;
 206
 207         list_for_each_entry(bc, &blocked_consumers, list) {
 208                 n_fds++;
 209         }
 210
 211         fds = (struct pollfd *) malloc(n_fds * sizeof(struct pollfd));
 212         if(fds == NULL) {
 213                 ERR("malloc returned NULL");
 214                 return;
 215         }
 216
 217         list_for_each_entry(bc, &blocked_consumers, list) {
 218                 fds[idx].fd = bc->fd_producer;
 219                 fds[idx].events = POLLIN;
 220                 bc->tmp_poll_idx = idx;
 221                 idx++;
 222         }
 223
 224         while((result = poll(fds, n_fds, 0)) == -1 && errno == EINTR)
 225                 /* nothing */;
 226         if(result == -1) {
 227                 PERROR("poll");
 228                 return;
 229         }
 230
 231         list_for_each_entry(bc, &blocked_consumers, list) {
 232                 if(fds[bc->tmp_poll_idx].revents) {
 233                         long consumed_old = 0;
 234                         char *reply;
 235
 236                         result = read(bc->fd_producer, &inbuf, 1);
 237                         if(result == -1) {
 238                                 PERROR("read");
 239                                 continue;
 240                         }
 241                         if(result == 0) {
 242                                 DBG("PRODUCER END");
 243
 244                                 close(bc->fd_producer);
 245
 246                                 list_del(&bc->list);
 247
 248                                 result = ustcomm_send_reply(&bc->server, "END", &bc->src);
 249                                 if(result < 0) {
 250                                         ERR("ustcomm_send_reply failed");
 251                                         continue;
 252                                 }
 253
 254                                 continue;
 255                         }
 256
 257                         result = ltt_do_get_subbuf(bc->rbuf, bc->lttbuf, &consumed_old);
 258                         if(result == -EAGAIN) {
 259                                 WARN("missed buffer?");
 260                                 continue;
 261                         }
 262                         else if(result < 0) {
 263                                 DBG("ltt_do_get_subbuf: error: %s", strerror(-result));
 264                         }
 265                         asprintf(&reply, "%s %ld", "OK", consumed_old);
 266                         result = ustcomm_send_reply(&bc->server, reply, &bc->src);
 267                         if(result < 0) {
 268                                 ERR("ustcomm_send_reply failed");
 269                                 free(reply);
 270                                 continue;
 271                         }
 272                         free(reply);
 273
 274                         list_del(&bc->list);
 275                 }
 276         }
 277
 278 }
 279
 280 void *listener_main(void *p)
 281 {
 282         int result;
 283
 284         ust_register_thread();
 285
 286         DBG("LISTENER");
 287
 288         for(;;) {
 289                 char trace_name[] = "auto";
 290                 char trace_type[] = "ustrelay";
 291                 char *recvbuf;
 292                 int len;
 293                 struct ustcomm_source src;
 294
 295                 process_blocked_consumers();
 296
 297                 result = ustcomm_app_recv_message(&ustcomm_app, &recvbuf, &src, 5);
 298                 if(result < 0) {
 299                         WARN("error in ustcomm_app_recv_message");
 300                         continue;
 301                 }
 302                 else if(result == 0) {
 303                         /* no message */
 304                         continue;
 305                 }
 306
 307                 DBG("received a message! it's: %s", recvbuf);
 308                 len = strlen(recvbuf);
 309
 310                 if(!strcmp(recvbuf, "print_markers")) {
 311                         print_markers(stderr);
 312                 }
 313                 else if(!strcmp(recvbuf, "list_markers")) {
 314                         char *ptr;
 315                         size_t size;
 316                         FILE *fp;
 317
 318                         fp = open_memstream(&ptr, &size);
 319                         print_markers(fp);
 320                         fclose(fp);
 321
 322                         result = ustcomm_send_reply(&ustcomm_app.server, ptr, &src);
 323
 324                         free(ptr);
 325                 }
 326                 else if(!strcmp(recvbuf, "start")) {
 327                         /* start is an operation that setups the trace, allocates it and starts it */
 328                         result = ltt_trace_setup(trace_name);
 329                         if(result < 0) {
 330                                 ERR("ltt_trace_setup failed");
 331                                 return (void *)1;
 332                         }
 333
 334                         result = ltt_trace_set_type(trace_name, trace_type);
 335                         if(result < 0) {
 336                                 ERR("ltt_trace_set_type failed");
 337                                 return (void *)1;
 338                         }
 339
 340                         result = ltt_trace_alloc(trace_name);
 341                         if(result < 0) {
 342                                 ERR("ltt_trace_alloc failed");
 343                                 return (void *)1;
 344                         }
 345
 346                         inform_consumer_daemon(trace_name);
 347
 348                         result = ltt_trace_start(trace_name);
 349                         if(result < 0) {
 350                                 ERR("ltt_trace_start failed");
 351                                 continue;
 352                         }
 353                 }
 354                 else if(!strcmp(recvbuf, "trace_setup")) {
 355                         DBG("trace setup");
 356
 357                         result = ltt_trace_setup(trace_name);
 358                         if(result < 0) {
 359                                 ERR("ltt_trace_setup failed");
 360                                 return (void *)1;
 361                         }
 362
 363                         result = ltt_trace_set_type(trace_name, trace_type);
 364                         if(result < 0) {
 365                                 ERR("ltt_trace_set_type failed");
 366                                 return (void *)1;
 367                         }
 368                 }
 369                 else if(!strcmp(recvbuf, "trace_alloc")) {
 370                         DBG("trace alloc");
 371
 372                         result = ltt_trace_alloc(trace_name);
 373                         if(result < 0) {
 374                                 ERR("ltt_trace_alloc failed");
 375                                 return (void *)1;
 376                         }
 377                 }
 378                 else if(!strcmp(recvbuf, "trace_start")) {
 379                         DBG("trace start");
 380
 381                         result = ltt_trace_start(trace_name);
 382                         if(result < 0) {
 383                                 ERR("ltt_trace_start failed");
 384                                 continue;
 385                         }
 386                 }
 387                 else if(!strcmp(recvbuf, "trace_stop")) {
 388                         DBG("trace stop");
 389
 390                         result = ltt_trace_stop(trace_name);
 391                         if(result < 0) {
 392                                 ERR("ltt_trace_stop failed");
 393                                 return (void *)1;
 394                         }
 395                 }
 396                 else if(!strcmp(recvbuf, "trace_destroy")) {
 397
 398                         DBG("trace destroy");
 399
 400                         result = ltt_trace_destroy(trace_name);
 401                         if(result < 0) {
 402                                 ERR("ltt_trace_destroy failed");
 403                                 return (void *)1;
 404                         }
 405                 }
 406                 else if(nth_token_is(recvbuf, "get_shmid", 0) == 1) {
 407                         struct ltt_trace_struct *trace;
 408                         char trace_name[] = "auto";
 409                         int i;
 410                         char *channel_name;
 411
 412                         DBG("get_shmid");
 413
 414                         channel_name = nth_token(recvbuf, 1);
 415                         if(channel_name == NULL) {
 416                                 ERR("get_shmid: cannot parse channel");
 417                                 goto next_cmd;
 418                         }
 419
 420                         ltt_lock_traces();
 421                         trace = _ltt_trace_find(trace_name);
 422                         ltt_unlock_traces();
 423
 424                         if(trace == NULL) {
 425                                 ERR("cannot find trace!");
 426                                 return (void *)1;
 427                         }
 428
 429                         for(i=0; i<trace->nr_channels; i++) {
 430                                 struct rchan *rchan = trace->channels[i].trans_channel_data;
 431                                 struct rchan_buf *rbuf = rchan->buf;
 432                                 struct ltt_channel_struct *ltt_channel = (struct ltt_channel_struct *)rchan->private_data;
 433
 434                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 435                                         char *reply;
 436
 437                                         DBG("the shmid for the requested channel is %d", rbuf->shmid);
 438                                         DBG("the shmid for its buffer structure is %d", ltt_channel->buf_shmid);
 439                                         asprintf(&reply, "%d %d", rbuf->shmid, ltt_channel->buf_shmid);
 440
 441                                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 442                                         if(result) {
 443                                                 ERR("listener: get_shmid: ustcomm_send_reply failed");
 444                                                 goto next_cmd;
 445                                         }
 446
 447                                         free(reply);
 448
 449                                         break;
 450                                 }
 451                         }
 452
 453                         buffers_to_export--;
 454                 }
 455                 else if(nth_token_is(recvbuf, "get_n_subbufs", 0) == 1) {
 456                         struct ltt_trace_struct *trace;
 457                         char trace_name[] = "auto";
 458                         int i;
 459                         char *channel_name;
 460
 461                         DBG("get_n_subbufs");
 462
 463                         channel_name = nth_token(recvbuf, 1);
 464                         if(channel_name == NULL) {
 465                                 ERR("get_n_subbufs: cannot parse channel");
 466                                 goto next_cmd;
 467                         }
 468
 469                         ltt_lock_traces();
 470                         trace = _ltt_trace_find(trace_name);
 471                         ltt_unlock_traces();
 472
 473                         if(trace == NULL) {
 474                                 ERR("cannot find trace!");
 475                                 return (void *)1;
 476                         }
 477
 478                         for(i=0; i<trace->nr_channels; i++) {
 479                                 struct rchan *rchan = trace->channels[i].trans_channel_data;
 480
 481                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 482                                         char *reply;
 483
 484                                         DBG("the n_subbufs for the requested channel is %zd", rchan->n_subbufs);
 485                                         asprintf(&reply, "%zd", rchan->n_subbufs);
 486
 487                                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 488                                         if(result) {
 489                                                 ERR("listener: get_n_subbufs: ustcomm_send_reply failed");
 490                                                 goto next_cmd;
 491                                         }
 492
 493                                         free(reply);
 494
 495                                         break;
 496                                 }
 497                         }
 498                 }
 499                 else if(nth_token_is(recvbuf, "get_subbuf_size", 0) == 1) {
 500                         struct ltt_trace_struct *trace;
 501                         char trace_name[] = "auto";
 502                         int i;
 503                         char *channel_name;
 504
 505                         DBG("get_subbuf_size");
 506
 507                         channel_name = nth_token(recvbuf, 1);
 508                         if(channel_name == NULL) {
 509                                 ERR("get_subbuf_size: cannot parse channel");
 510                                 goto next_cmd;
 511                         }
 512
 513                         ltt_lock_traces();
 514                         trace = _ltt_trace_find(trace_name);
 515                         ltt_unlock_traces();
 516
 517                         if(trace == NULL) {
 518                                 ERR("cannot find trace!");
 519                                 return (void *)1;
 520                         }
 521
 522                         for(i=0; i<trace->nr_channels; i++) {
 523                                 struct rchan *rchan = trace->channels[i].trans_channel_data;
 524
 525                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 526                                         char *reply;
 527
 528                                         DBG("the subbuf_size for the requested channel is %zd", rchan->subbuf_size);
 529                                         asprintf(&reply, "%zd", rchan->subbuf_size);
 530
 531                                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 532                                         if(result) {
 533                                                 ERR("listener: get_subbuf_size: ustcomm_send_reply failed");
 534                                                 goto next_cmd;
 535                                         }
 536
 537                                         free(reply);
 538
 539                                         break;
 540                                 }
 541                         }
 542                 }
 543                 else if(nth_token_is(recvbuf, "load_probe_lib", 0) == 1) {
 544                         char *libfile;
 545
 546                         libfile = nth_token(recvbuf, 1);
 547
 548                         DBG("load_probe_lib loading %s", libfile);
 549                 }
 550                 else if(nth_token_is(recvbuf, "get_subbuffer", 0) == 1) {
 551                         struct ltt_trace_struct *trace;
 552                         char trace_name[] = "auto";
 553                         int i;
 554                         char *channel_name;
 555
 556                         DBG("get_subbuf");
 557
 558                         channel_name = nth_token(recvbuf, 1);
 559                         if(channel_name == NULL) {
 560                                 ERR("get_subbuf: cannot parse channel");
 561                                 goto next_cmd;
 562                         }
 563
 564                         ltt_lock_traces();
 565                         trace = _ltt_trace_find(trace_name);
 566                         ltt_unlock_traces();
 567
 568                         if(trace == NULL) {
 569                                 ERR("cannot find trace!");
 570                                 return (void *)1;
 571                         }
 572
 573                         for(i=0; i<trace->nr_channels; i++) {
 574                                 struct rchan *rchan = trace->channels[i].trans_channel_data;
 575
 576                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 577                                         struct rchan_buf *rbuf = rchan->buf;
 578                                         struct ltt_channel_buf_struct *lttbuf = trace->channels[i].buf;
 579                                         struct blocked_consumer *bc;
 580
 581                                         bc = (struct blocked_consumer *) malloc(sizeof(struct blocked_consumer));
 582                                         if(bc == NULL) {
 583                                                 ERR("malloc returned NULL");
 584                                                 goto next_cmd;
 585                                         }
 586                                         bc->fd_consumer = src.fd;
 587                                         bc->fd_producer = lttbuf->data_ready_fd_read;
 588                                         bc->rbuf = rbuf;
 589                                         bc->lttbuf = lttbuf;
 590                                         bc->src = src;
 591                                         bc->server = ustcomm_app.server;
 592
 593                                         list_add(&bc->list, &blocked_consumers);
 594
 595                                         break;
 596                                 }
 597                         }
 598                 }
 599                 else if(nth_token_is(recvbuf, "put_subbuffer", 0) == 1) {
 600                         struct ltt_trace_struct *trace;
 601                         char trace_name[] = "auto";
 602                         int i;
 603                         char *channel_name;
 604                         long consumed_old;
 605                         char *consumed_old_str;
 606                         char *endptr;
 607
 608                         DBG("put_subbuf");
 609
 610                         channel_name = strdup_malloc(nth_token(recvbuf, 1));
 611                         if(channel_name == NULL) {
 612                                 ERR("put_subbuf_size: cannot parse channel");
 613                                 goto next_cmd;
 614                         }
 615
 616                         consumed_old_str = strdup_malloc(nth_token(recvbuf, 2));
 617                         if(consumed_old_str == NULL) {
 618                                 ERR("put_subbuf: cannot parse consumed_old");
 619                                 goto next_cmd;
 620                         }
 621                         consumed_old = strtol(consumed_old_str, &endptr, 10);
 622                         if(*endptr != '\0') {
 623                                 ERR("put_subbuf: invalid value for consumed_old");
 624                                 goto next_cmd;
 625                         }
 626
 627                         ltt_lock_traces();
 628                         trace = _ltt_trace_find(trace_name);
 629                         ltt_unlock_traces();
 630
 631                         if(trace == NULL) {
 632                                 ERR("cannot find trace!");
 633                                 return (void *)1;
 634                         }
 635
 636                         for(i=0; i<trace->nr_channels; i++) {
 637                                 struct rchan *rchan = trace->channels[i].trans_channel_data;
 638
 639                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 640                                         struct rchan_buf *rbuf = rchan->buf;
 641                                         struct ltt_channel_buf_struct *lttbuf = trace->channels[i].buf;
 642                                         char *reply;
 643                                         long consumed_old=0;
 644
 645                                         result = ltt_do_put_subbuf(rbuf, lttbuf, consumed_old);
 646                                         if(result < 0) {
 647                                                 WARN("ltt_do_put_subbuf: error (subbuf=%s)", channel_name);
 648                                                 asprintf(&reply, "%s", "ERROR");
 649                                         }
 650                                         else {
 651                                                 DBG("ltt_do_put_subbuf: success (subbuf=%s)", channel_name);
 652                                                 asprintf(&reply, "%s", "OK");
 653                                         }
 654
 655                                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 656                                         if(result) {
 657                                                 ERR("listener: put_subbuf: ustcomm_send_reply failed");
 658                                                 goto next_cmd;
 659                                         }
 660
 661                                         free(reply);
 662
 663                                         break;
 664                                 }
 665                         }
 666
 667                         free(channel_name);
 668                         free(consumed_old_str);
 669                 }
 670                 else if(nth_token_is(recvbuf, "enable_marker", 0) == 1) {
 671                         char *channel_slash_name = nth_token(recvbuf, 1);
 672                         char channel_name[256]="";
 673                         char marker_name[256]="";
 674
 675                         result = sscanf(channel_slash_name, "%255[^/]/%255s", channel_name, marker_name);
 676
 677                         if(channel_name == NULL || marker_name == NULL) {
 678                                 WARN("invalid marker name");
 679                                 goto next_cmd;
 680                         }
 681                         printf("%s %s\n", channel_name, marker_name);
 682
 683                         result = ltt_marker_connect(channel_name, marker_name, "default");
 684                         if(result < 0) {
 685                                 WARN("could not enable marker; channel=%s, name=%s", channel_name, marker_name);
 686                         }
 687                 }
 688                 else if(nth_token_is(recvbuf, "disable_marker", 0) == 1) {
 689                         char *channel_slash_name = nth_token(recvbuf, 1);
 690                         char *marker_name;
 691                         char *channel_name;
 692
 693                         result = sscanf(channel_slash_name, "%a[^/]/%as", &channel_name, &marker_name);
 694
 695                         if(marker_name == NULL) {
 696                         }
 697                         printf("%s %s\n", channel_name, marker_name);
 698
 699                         result = ltt_marker_disconnect(channel_name, marker_name, "default");
 700                         if(result < 0) {
 701                                 WARN("could not disable marker; channel=%s, name=%s", channel_name, marker_name);
 702                         }
 703                 }
 704                 else if(nth_token_is(recvbuf, "get_pidunique", 0) == 1) {
 705                         char *reply;
 706
 707                         asprintf(&reply, "%lld", pidunique);
 708
 709                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 710                         if(result) {
 711                                 ERR("listener: get_pidunique: ustcomm_send_reply failed");
 712                                 goto next_cmd;
 713                         }
 714
 715                         free(reply);
 716                 }
 717 //              else if(nth_token_is(recvbuf, "get_notifications", 0) == 1) {
 718 //                      struct ltt_trace_struct *trace;
 719 //                      char trace_name[] = "auto";
 720 //                      int i;
 721 //                      char *channel_name;
 722 //
 723 //                      DBG("get_notifications");
 724 //
 725 //                      channel_name = strdup_malloc(nth_token(recvbuf, 1));
 726 //                      if(channel_name == NULL) {
 727 //                              ERR("put_subbuf_size: cannot parse channel");
 728 //                              goto next_cmd;
 729 //                      }
 730 //
 731 //                      ltt_lock_traces();
 732 //                      trace = _ltt_trace_find(trace_name);
 733 //                      ltt_unlock_traces();
 734 //
 735 //                      if(trace == NULL) {
 736 //                              ERR("cannot find trace!");
 737 //                              return (void *)1;
 738 //                      }
 739 //
 740 //                      for(i=0; i<trace->nr_channels; i++) {
 741 //                              struct rchan *rchan = trace->channels[i].trans_channel_data;
 742 //                              int fd;
 743 //
 744 //                              if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 745 //                                      struct rchan_buf *rbuf = rchan->buf;
 746 //                                      struct ltt_channel_buf_struct *lttbuf = trace->channels[i].buf;
 747 //
 748 //                                      result = fd = ustcomm_app_detach_client(&ustcomm_app, &src);
 749 //                                      if(result == -1) {
 750 //                                              ERR("ustcomm_app_detach_client failed");
 751 //                                              goto next_cmd;
 752 //                                      }
 753 //
 754 //                                      lttbuf->wake_consumer_arg = (void *) fd;
 755 //
 756 //                                      smp_wmb();
 757 //
 758 //                                      lttbuf->call_wake_consumer = 1;
 759 //
 760 //                                      break;
 761 //                              }
 762 //                      }
 763 //
 764 //                      free(channel_name);
 765 //              }
 766                 else {
 767                         ERR("unable to parse message: %s", recvbuf);
 768                 }
 769
 770         next_cmd:
 771                 free(recvbuf);
 772         }
 773 }
 774
 775 volatile sig_atomic_t have_listener = 0;
 776
 777 void create_listener(void)
 778 {
 779 #ifdef USE_CLONE
 780         static char listener_stack[16384];
 781 #else
 782         pthread_t thread;
 783 #endif
 784
 785         if(have_listener)
 786                 return;
 787
 788 #ifdef USE_CLONE
 789         result = clone(listener_main, listener_stack+sizeof(listener_stack)-1, CLONE_FS | CLONE_FILES | CLONE_VM | CLONE_SIGHAND | CLONE_THREAD, NULL);
 790         if(result == -1) {
 791                 perror("clone");
 792                 return;
 793         }
 794 #else
 795
 796         pthread_create(&thread, NULL, listener_main, NULL);
 797 #endif
 798
 799         have_listener = 1;
 800 }
 801
 802 /* The signal handler itself. Signals must be setup so there cannot be
 803    nested signals. */
 804
 805 void sighandler(int sig)
 806 {
 807         DBG("sighandler");
 808
 809         if(!have_listener) {
 810                 create_listener();
 811         }
 812 }
 813
 814 /* Called by the app signal handler to chain it to us. */
 815
 816 void chain_signal(void)
 817 {
 818         sighandler(USTSIGNAL);
 819 }
 820
 821 static int init_socket(void)
 822 {
 823         return ustcomm_init_app(getpid(), &ustcomm_app);
 824 }
 825
 826 static int init_signal_handler(void)
 827 {
 828         /* Attempt to handler SIGIO. If the main program wants to
 829          * handle it, fine, it'll override us. They it'll have to
 830          * use the chaining function.
 831          */
 832
 833         int result;
 834         struct sigaction act;
 835
 836         result = sigemptyset(&act.sa_mask);
 837         if(result == -1) {
 838                 PERROR("sigemptyset");
 839                 return -1;
 840         }
 841
 842         act.sa_handler = sighandler;
 843         act.sa_flags = SA_RESTART;
 844
 845         /* Only defer ourselves. Also, try to restart interrupted
 846          * syscalls to disturb the traced program as little as possible.
 847          */
 848         result = sigaction(SIGIO, &act, NULL);
 849         if(result == -1) {
 850                 PERROR("sigaction");
 851                 return -1;
 852         }
 853
 854         return 0;
 855 }
 856
 857 #define AUTOPROBE_DISABLED      0
 858 #define AUTOPROBE_ENABLE_ALL    1
 859 #define AUTOPROBE_ENABLE_REGEX  2
 860 static int autoprobe_method = AUTOPROBE_DISABLED;
 861 static regex_t autoprobe_regex;
 862
 863 static void auto_probe_connect(struct marker *m)
 864 {
 865         int result;
 866
 867         char* concat_name = NULL;
 868         const char *probe_name = "default";
 869
 870         if(autoprobe_method == AUTOPROBE_DISABLED) {
 871                 return;
 872         }
 873         else if(autoprobe_method == AUTOPROBE_ENABLE_REGEX) {
 874                 result = asprintf(&concat_name, "%s/%s", m->channel, m->name);
 875                 if(result == -1) {
 876                         ERR("auto_probe_connect: asprintf failed (marker %s/%s)",
 877                                 m->channel, m->name);
 878                         return;
 879                 }
 880                 if (regexec(&autoprobe_regex, concat_name, 0, NULL, 0)) {
 881                         free(concat_name);
 882                         return;
 883                 }
 884                 free(concat_name);
 885         }
 886
 887         result = ltt_marker_connect(m->channel, m->name, probe_name);
 888         if(result && result != -EEXIST)
 889                 ERR("ltt_marker_connect (marker = %s/%s, errno = %d)", m->channel, m->name, -result);
 890
 891         DBG("auto connected marker %s %s to probe default", m->channel, m->name);
 892
 893 }
 894
 895 static void __attribute__((constructor(1000))) init()
 896 {
 897         int result;
 898         char* autoprobe_val = NULL;
 899
 900         /* Assign the pidunique, to be able to differentiate the processes with same
 901          * pid, (before and after an exec).
 902          */
 903         pidunique = make_pidunique();
 904
 905         /* Initialize RCU in case the constructor order is not good. */
 906         urcu_init();
 907
 908         /* It is important to do this before events start to be generated. */
 909         ust_register_thread();
 910
 911         DBG("Tracectl constructor");
 912
 913         /* Must create socket before signal handler to prevent races.
 914          */
 915         result = init_socket();
 916         if(result == -1) {
 917                 ERR("init_socket error");
 918                 return;
 919         }
 920         result = init_signal_handler();
 921         if(result == -1) {
 922                 ERR("init_signal_handler error");
 923                 return;
 924         }
 925
 926         autoprobe_val = getenv("UST_AUTOPROBE");
 927         if(autoprobe_val) {
 928                 struct marker_iter iter;
 929
 930                 DBG("Autoprobe enabled.");
 931
 932                 /* Ensure markers are initialized */
 933                 //init_markers();
 934
 935                 /* Ensure marker control is initialized, for the probe */
 936                 init_marker_control();
 937
 938                 /* first, set the callback that will connect the
 939                  * probe on new markers
 940                  */
 941                 if(autoprobe_val[0] == '/') {
 942                         result = regcomp(&autoprobe_regex, autoprobe_val+1, 0);
 943                         if (result) {
 944                                 char regexerr[150];
 945
 946                                 regerror(result, &autoprobe_regex, regexerr, sizeof(regexerr));
 947                                 ERR("cannot parse regex %s (%s), will ignore UST_AUTOPROBE", autoprobe_val, regexerr);
 948                                 /* don't crash the application just for this */
 949                         }
 950                         else {
 951                                 autoprobe_method = AUTOPROBE_ENABLE_REGEX;
 952                         }
 953                 }
 954                 else {
 955                         /* just enable all instrumentation */
 956                         autoprobe_method = AUTOPROBE_ENABLE_ALL;
 957                 }
 958
 959                 marker_set_new_marker_cb(auto_probe_connect);
 960
 961                 /* Now, connect the probes that were already registered. */
 962                 marker_iter_reset(&iter);
 963                 marker_iter_start(&iter);
 964
 965                 DBG("now iterating on markers already registered");
 966                 while(iter.marker) {
 967                         DBG("now iterating on marker %s", iter.marker->name);
 968                         auto_probe_connect(iter.marker);
 969                         marker_iter_next(&iter);
 970                 }
 971         }
 972
 973         if(getenv("UST_TRACE")) {
 974                 char trace_name[] = "auto";
 975                 char trace_type[] = "ustrelay";
 976
 977                 DBG("starting early tracing");
 978
 979                 /* Ensure marker control is initialized */
 980                 init_marker_control();
 981
 982                 /* Ensure relay is initialized */
 983                 init_ustrelay_transport();
 984
 985                 /* Ensure markers are initialized */
 986                 init_markers();
 987
 988                 /* In case. */
 989                 ltt_channels_register("ust");
 990
 991                 result = ltt_trace_setup(trace_name);
 992                 if(result < 0) {
 993                         ERR("ltt_trace_setup failed");
 994                         return;
 995                 }
 996
 997                 result = ltt_trace_set_type(trace_name, trace_type);
 998                 if(result < 0) {
 999                         ERR("ltt_trace_set_type failed");
1000                         return;
1001                 }
1002
1003                 result = ltt_trace_alloc(trace_name);
1004                 if(result < 0) {
1005                         ERR("ltt_trace_alloc failed");
1006                         return;
1007                 }
1008
1009                 result = ltt_trace_start(trace_name);
1010                 if(result < 0) {
1011                         ERR("ltt_trace_start failed");
1012                         return;
1013                 }
1014
1015                 /* Do this after the trace is started in order to avoid creating confusion
1016                  * if the trace fails to start. */
1017                 inform_consumer_daemon(trace_name);
1018         }
1019
1020
1021         return;
1022
1023         /* should decrementally destroy stuff if error */
1024
1025 }
1026
1027 /* This is only called if we terminate normally, not with an unhandled signal,
1028  * so we cannot rely on it. However, for now, LTTV requires that the header of
1029  * the last sub-buffer contain a valid end time for the trace. This is done
1030  * automatically only when the trace is properly stopped.
1031  *
1032  * If the traced program crashed, it is always possible to manually add the
1033  * right value in the header, or to open the trace in text mode.
1034  *
1035  * FIXME: Fix LTTV so it doesn't need this.
1036  */
1037
1038 static void destroy_traces(void)
1039 {
1040         int result;
1041
1042         /* if trace running, finish it */
1043
1044         DBG("destructor stopping traces");
1045
1046         result = ltt_trace_stop("auto");
1047         if(result == -1) {
1048                 ERR("ltt_trace_stop error");
1049         }
1050
1051         result = ltt_trace_destroy("auto");
1052         if(result == -1) {
1053                 ERR("ltt_trace_destroy error");
1054         }
1055 }
1056
1057 static int trace_recording(void)
1058 {
1059         int retval = 0;
1060         struct ltt_trace_struct *trace;
1061
1062         ltt_lock_traces();
1063
1064         list_for_each_entry(trace, &ltt_traces.head, list) {
1065                 if(trace->active) {
1066                         retval = 1;
1067                         break;
1068                 }
1069         }
1070
1071         ltt_unlock_traces();
1072
1073         return retval;
1074 }
1075
1076 #if 0
1077 static int have_consumer(void)
1078 {
1079         return !list_empty(&blocked_consumers);
1080 }
1081 #endif
1082
1083 int restarting_usleep(useconds_t usecs)
1084 {
1085         struct timespec tv;
1086         int result;
1087
1088         tv.tv_sec = 0;
1089         tv.tv_nsec = usecs * 1000;
1090
1091         do {
1092                 result = nanosleep(&tv, &tv);
1093         } while(result == -1 && errno == EINTR);
1094
1095         return result;
1096 }
1097
1098 /* This destructor keeps the process alive for a few seconds in order
1099  * to leave time to ustd to connect to its buffers. This is necessary
1100  * for programs whose execution is very short. It is also useful in all
1101  * programs when tracing is started close to the end of the program
1102  * execution.
1103  *
1104  * FIXME: For now, this only works for the first trace created in a
1105  * process.
1106  */
1107
1108 static void __attribute__((destructor)) keepalive()
1109 {
1110         if(trace_recording() && buffers_to_export) {
1111                 int total = 0;
1112                 DBG("Keeping process alive for consumer daemon...");
1113                 while(buffers_to_export) {
1114                         const int interv = 200000;
1115                         restarting_usleep(interv);
1116                         total += interv;
1117
1118                         if(total >= 3000000) {
1119                                 WARN("non-consumed buffers remaining after wait limit; not waiting anymore");
1120                                 break;
1121                         }
1122                 }
1123                 DBG("Finally dying...");
1124         }
1125
1126         destroy_traces();
1127
1128         ustcomm_fini_app(&ustcomm_app);
1129 }
1130
1131 void ust_potential_exec(void)
1132 {
1133         trace_mark(ust, potential_exec, MARK_NOARGS);
1134
1135         keepalive();
1136 }
1137
1138 /* Notify ust that there was a fork. This needs to be called inside
1139  * the new process, anytime a process whose memory is not shared with
1140  * the parent is created. If this function is not called, the events
1141  * of the new process will not be collected.
1142  */
1143
1144 void ust_fork(void)
1145 {
1146         struct blocked_consumer *bc;
1147         struct blocked_consumer *deletable_bc = NULL;
1148         int result;
1149
1150         DBG("ust: forking");
1151         ltt_trace_stop("auto");
1152         ltt_trace_destroy("auto");
1153         /* Delete all active connections */
1154         ustcomm_close_all_connections(&ustcomm_app.server);
1155
1156         /* Delete all blocked consumers */
1157         list_for_each_entry(bc, &blocked_consumers, list) {
1158                 close(bc->fd_producer);
1159                 close(bc->fd_consumer);
1160                 free(deletable_bc);
1161                 deletable_bc = bc;
1162                 list_del(&bc->list);
1163         }
1164
1165         have_listener = 0;
1166         create_listener();
1167         init_socket();
1168         ltt_trace_setup("auto");
1169         result = ltt_trace_set_type("auto", "ustrelay");
1170         if(result < 0) {
1171                 ERR("ltt_trace_set_type failed");
1172                 return;
1173         }
1174
1175         ltt_trace_alloc("auto");
1176         ltt_trace_start("auto");
1177         inform_consumer_daemon("auto");
1178 }
1179