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 /* volatile because shared between the listener and the main thread */
  59 volatile sig_atomic_t buffers_to_export = 0;
  60
  61 //struct listener_arg {
  62 //      int pipe_fd;
  63 //};
  64
  65 struct trctl_msg {
  66         /* size: the size of all the fields except size itself */
  67         uint32_t size;
  68         uint16_t type;
  69         /* Only the necessary part of the payload is transferred. It
  70          * may even be none of it.
  71          */
  72         char payload[94];
  73 };
  74
  75 struct consumer_channel {
  76         int fd;
  77         struct ltt_channel_struct *chan;
  78 };
  79
  80 struct blocked_consumer {
  81         int fd_consumer;
  82         int fd_producer;
  83         int tmp_poll_idx;
  84
  85         /* args to ustcomm_send_reply */
  86         struct ustcomm_server server;
  87         struct ustcomm_source src;
  88
  89         /* args to ltt_do_get_subbuf */
  90         struct rchan_buf *rbuf;
  91         struct ltt_channel_buf_struct *lttbuf;
  92
  93         struct list_head list;
  94 };
  95
  96 static void print_markers(FILE *fp)
  97 {
  98         struct marker_iter iter;
  99
 100         lock_markers();
 101         marker_iter_reset(&iter);
 102         marker_iter_start(&iter);
 103
 104         while(iter.marker) {
 105                 fprintf(fp, "marker: %s_%s %d \"%s\"\n", iter.marker->channel, iter.marker->name, (int)imv_read(iter.marker->state), iter.marker->format);
 106                 marker_iter_next(&iter);
 107         }
 108         unlock_markers();
 109 }
 110
 111 static int init_socket(void);
 112
 113 /* This needs to be called whenever a new thread is created. It notifies
 114  * liburcu of the new thread.
 115  */
 116
 117 void ust_register_thread(void)
 118 {
 119         rcu_register_thread();
 120 }
 121
 122 int fd_notif = -1;
 123 void notif_cb(void)
 124 {
 125         int result;
 126         struct trctl_msg msg;
 127
 128         /* FIXME: fd_notif should probably be protected by a spinlock */
 129
 130         if(fd_notif == -1)
 131                 return;
 132
 133         msg.type = MSG_NOTIF;
 134         msg.size = sizeof(msg.type);
 135
 136         /* FIXME: don't block here */
 137         result = write(fd_notif, &msg, msg.size+sizeof(msg.size));
 138         if(result == -1) {
 139                 PERROR("write");
 140                 return;
 141         }
 142 }
 143
 144 /* Ask the daemon to collect a trace called trace_name and being
 145  * produced by this pid.
 146  *
 147  * The trace must be at least allocated. (It can also be started.)
 148  * This is because _ltt_trace_find is used.
 149  */
 150
 151 static void inform_consumer_daemon(const char *trace_name)
 152 {
 153         int i;
 154         struct ltt_trace_struct *trace;
 155         pid_t pid = getpid();
 156         int result;
 157
 158         ltt_lock_traces();
 159
 160         trace = _ltt_trace_find(trace_name);
 161         if(trace == NULL) {
 162                 WARN("inform_consumer_daemon: could not find trace \"%s\"; it is probably already destroyed", trace_name);
 163                 goto finish;
 164         }
 165
 166         for(i=0; i < trace->nr_channels; i++) {
 167                 result = ustcomm_request_consumer(pid, trace->channels[i].channel_name);
 168                 if(result == -1) {
 169                         WARN("Failed to request collection for channel %s. Is the daemon available?", trace->channels[i].channel_name);
 170                         /* continue even if fail */
 171                 }
 172                 buffers_to_export++;
 173         }
 174
 175         finish:
 176         ltt_unlock_traces();
 177 }
 178
 179 void process_blocked_consumers(void)
 180 {
 181         int n_fds = 0;
 182         struct pollfd *fds;
 183         struct blocked_consumer *bc;
 184         int idx = 0;
 185         char inbuf;
 186         int result;
 187
 188         list_for_each_entry(bc, &blocked_consumers, list) {
 189                 n_fds++;
 190         }
 191
 192         fds = (struct pollfd *) malloc(n_fds * sizeof(struct pollfd));
 193         if(fds == NULL) {
 194                 ERR("malloc returned NULL");
 195                 return;
 196         }
 197
 198         list_for_each_entry(bc, &blocked_consumers, list) {
 199                 fds[idx].fd = bc->fd_producer;
 200                 fds[idx].events = POLLIN;
 201                 bc->tmp_poll_idx = idx;
 202                 idx++;
 203         }
 204
 205         while((result = poll(fds, n_fds, 0)) == -1 && errno == EINTR)
 206                 /* nothing */;
 207         if(result == -1) {
 208                 PERROR("poll");
 209                 return;
 210         }
 211
 212         list_for_each_entry(bc, &blocked_consumers, list) {
 213                 if(fds[bc->tmp_poll_idx].revents) {
 214                         long consumed_old = 0;
 215                         char *reply;
 216
 217                         result = read(bc->fd_producer, &inbuf, 1);
 218                         if(result == -1) {
 219                                 PERROR("read");
 220                                 continue;
 221                         }
 222                         if(result == 0) {
 223                                 DBG("PRODUCER END");
 224
 225                                 close(bc->fd_producer);
 226
 227                                 list_del(&bc->list);
 228
 229                                 result = ustcomm_send_reply(&bc->server, "END", &bc->src);
 230                                 if(result < 0) {
 231                                         ERR("ustcomm_send_reply failed");
 232                                         continue;
 233                                 }
 234
 235                                 continue;
 236                         }
 237
 238                         result = ltt_do_get_subbuf(bc->rbuf, bc->lttbuf, &consumed_old);
 239                         if(result == -EAGAIN) {
 240                                 WARN("missed buffer?");
 241                                 continue;
 242                         }
 243                         else if(result < 0) {
 244                                 DBG("ltt_do_get_subbuf: error: %s", strerror(-result));
 245                         }
 246                         asprintf(&reply, "%s %ld", "OK", consumed_old);
 247                         result = ustcomm_send_reply(&bc->server, reply, &bc->src);
 248                         if(result < 0) {
 249                                 ERR("ustcomm_send_reply failed");
 250                                 free(reply);
 251                                 continue;
 252                         }
 253                         free(reply);
 254
 255                         list_del(&bc->list);
 256                 }
 257         }
 258
 259 }
 260
 261 void *listener_main(void *p)
 262 {
 263         int result;
 264
 265         ust_register_thread();
 266
 267         DBG("LISTENER");
 268
 269         for(;;) {
 270                 char trace_name[] = "auto";
 271                 char trace_type[] = "ustrelay";
 272                 char *recvbuf;
 273                 int len;
 274                 struct ustcomm_source src;
 275
 276                 process_blocked_consumers();
 277
 278                 result = ustcomm_app_recv_message(&ustcomm_app, &recvbuf, &src, 5);
 279                 if(result < 0) {
 280                         WARN("error in ustcomm_app_recv_message");
 281                         continue;
 282                 }
 283                 else if(result == 0) {
 284                         /* no message */
 285                         continue;
 286                 }
 287
 288                 DBG("received a message! it's: %s", recvbuf);
 289                 len = strlen(recvbuf);
 290
 291                 if(!strcmp(recvbuf, "print_markers")) {
 292                         print_markers(stderr);
 293                 }
 294                 else if(!strcmp(recvbuf, "list_markers")) {
 295                         char *ptr;
 296                         size_t size;
 297                         FILE *fp;
 298
 299                         fp = open_memstream(&ptr, &size);
 300                         print_markers(fp);
 301                         fclose(fp);
 302
 303                         result = ustcomm_send_reply(&ustcomm_app.server, ptr, &src);
 304
 305                         free(ptr);
 306                 }
 307                 else if(!strcmp(recvbuf, "start")) {
 308                         /* start is an operation that setups the trace, allocates it and starts it */
 309                         result = ltt_trace_setup(trace_name);
 310                         if(result < 0) {
 311                                 ERR("ltt_trace_setup failed");
 312                                 return (void *)1;
 313                         }
 314
 315                         result = ltt_trace_set_type(trace_name, trace_type);
 316                         if(result < 0) {
 317                                 ERR("ltt_trace_set_type failed");
 318                                 return (void *)1;
 319                         }
 320
 321                         result = ltt_trace_alloc(trace_name);
 322                         if(result < 0) {
 323                                 ERR("ltt_trace_alloc failed");
 324                                 return (void *)1;
 325                         }
 326
 327                         inform_consumer_daemon(trace_name);
 328
 329                         result = ltt_trace_start(trace_name);
 330                         if(result < 0) {
 331                                 ERR("ltt_trace_start failed");
 332                                 continue;
 333                         }
 334                 }
 335                 else if(!strcmp(recvbuf, "trace_setup")) {
 336                         DBG("trace setup");
 337
 338                         result = ltt_trace_setup(trace_name);
 339                         if(result < 0) {
 340                                 ERR("ltt_trace_setup failed");
 341                                 return (void *)1;
 342                         }
 343
 344                         result = ltt_trace_set_type(trace_name, trace_type);
 345                         if(result < 0) {
 346                                 ERR("ltt_trace_set_type failed");
 347                                 return (void *)1;
 348                         }
 349                 }
 350                 else if(!strcmp(recvbuf, "trace_alloc")) {
 351                         DBG("trace alloc");
 352
 353                         result = ltt_trace_alloc(trace_name);
 354                         if(result < 0) {
 355                                 ERR("ltt_trace_alloc failed");
 356                                 return (void *)1;
 357                         }
 358                 }
 359                 else if(!strcmp(recvbuf, "trace_start")) {
 360                         DBG("trace start");
 361
 362                         result = ltt_trace_start(trace_name);
 363                         if(result < 0) {
 364                                 ERR("ltt_trace_start failed");
 365                                 continue;
 366                         }
 367                 }
 368                 else if(!strcmp(recvbuf, "trace_stop")) {
 369                         DBG("trace stop");
 370
 371                         result = ltt_trace_stop(trace_name);
 372                         if(result < 0) {
 373                                 ERR("ltt_trace_stop failed");
 374                                 return (void *)1;
 375                         }
 376                 }
 377                 else if(!strcmp(recvbuf, "trace_destroy")) {
 378
 379                         DBG("trace destroy");
 380
 381                         result = ltt_trace_destroy(trace_name);
 382                         if(result < 0) {
 383                                 ERR("ltt_trace_destroy failed");
 384                                 return (void *)1;
 385                         }
 386                 }
 387                 else if(nth_token_is(recvbuf, "get_shmid", 0) == 1) {
 388                         struct ltt_trace_struct *trace;
 389                         char trace_name[] = "auto";
 390                         int i;
 391                         char *channel_name;
 392
 393                         DBG("get_shmid");
 394
 395                         channel_name = nth_token(recvbuf, 1);
 396                         if(channel_name == NULL) {
 397                                 ERR("get_shmid: cannot parse channel");
 398                                 goto next_cmd;
 399                         }
 400
 401                         ltt_lock_traces();
 402                         trace = _ltt_trace_find(trace_name);
 403                         ltt_unlock_traces();
 404
 405                         if(trace == NULL) {
 406                                 ERR("cannot find trace!");
 407                                 return (void *)1;
 408                         }
 409
 410                         for(i=0; i<trace->nr_channels; i++) {
 411                                 struct rchan *rchan = trace->channels[i].trans_channel_data;
 412                                 struct rchan_buf *rbuf = rchan->buf;
 413                                 struct ltt_channel_struct *ltt_channel = (struct ltt_channel_struct *)rchan->private_data;
 414
 415                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 416                                         char *reply;
 417
 418                                         DBG("the shmid for the requested channel is %d", rbuf->shmid);
 419                                         DBG("the shmid for its buffer structure is %d", ltt_channel->buf_shmid);
 420                                         asprintf(&reply, "%d %d", rbuf->shmid, ltt_channel->buf_shmid);
 421
 422                                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 423                                         if(result) {
 424                                                 ERR("listener: get_shmid: ustcomm_send_reply failed");
 425                                                 goto next_cmd;
 426                                         }
 427
 428                                         free(reply);
 429
 430                                         break;
 431                                 }
 432                         }
 433
 434                         buffers_to_export--;
 435                 }
 436                 else if(nth_token_is(recvbuf, "get_n_subbufs", 0) == 1) {
 437                         struct ltt_trace_struct *trace;
 438                         char trace_name[] = "auto";
 439                         int i;
 440                         char *channel_name;
 441
 442                         DBG("get_n_subbufs");
 443
 444                         channel_name = nth_token(recvbuf, 1);
 445                         if(channel_name == NULL) {
 446                                 ERR("get_n_subbufs: cannot parse channel");
 447                                 goto next_cmd;
 448                         }
 449
 450                         ltt_lock_traces();
 451                         trace = _ltt_trace_find(trace_name);
 452                         ltt_unlock_traces();
 453
 454                         if(trace == NULL) {
 455                                 ERR("cannot find trace!");
 456                                 return (void *)1;
 457                         }
 458
 459                         for(i=0; i<trace->nr_channels; i++) {
 460                                 struct rchan *rchan = trace->channels[i].trans_channel_data;
 461
 462                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 463                                         char *reply;
 464
 465                                         DBG("the n_subbufs for the requested channel is %zd", rchan->n_subbufs);
 466                                         asprintf(&reply, "%zd", rchan->n_subbufs);
 467
 468                                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 469                                         if(result) {
 470                                                 ERR("listener: get_n_subbufs: ustcomm_send_reply failed");
 471                                                 goto next_cmd;
 472                                         }
 473
 474                                         free(reply);
 475
 476                                         break;
 477                                 }
 478                         }
 479                 }
 480                 else if(nth_token_is(recvbuf, "get_subbuf_size", 0) == 1) {
 481                         struct ltt_trace_struct *trace;
 482                         char trace_name[] = "auto";
 483                         int i;
 484                         char *channel_name;
 485
 486                         DBG("get_subbuf_size");
 487
 488                         channel_name = nth_token(recvbuf, 1);
 489                         if(channel_name == NULL) {
 490                                 ERR("get_subbuf_size: cannot parse channel");
 491                                 goto next_cmd;
 492                         }
 493
 494                         ltt_lock_traces();
 495                         trace = _ltt_trace_find(trace_name);
 496                         ltt_unlock_traces();
 497
 498                         if(trace == NULL) {
 499                                 ERR("cannot find trace!");
 500                                 return (void *)1;
 501                         }
 502
 503                         for(i=0; i<trace->nr_channels; i++) {
 504                                 struct rchan *rchan = trace->channels[i].trans_channel_data;
 505
 506                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 507                                         char *reply;
 508
 509                                         DBG("the subbuf_size for the requested channel is %zd", rchan->subbuf_size);
 510                                         asprintf(&reply, "%zd", rchan->subbuf_size);
 511
 512                                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 513                                         if(result) {
 514                                                 ERR("listener: get_subbuf_size: ustcomm_send_reply failed");
 515                                                 goto next_cmd;
 516                                         }
 517
 518                                         free(reply);
 519
 520                                         break;
 521                                 }
 522                         }
 523                 }
 524                 else if(nth_token_is(recvbuf, "load_probe_lib", 0) == 1) {
 525                         char *libfile;
 526
 527                         libfile = nth_token(recvbuf, 1);
 528
 529                         DBG("load_probe_lib loading %s", libfile);
 530                 }
 531                 else if(nth_token_is(recvbuf, "get_subbuffer", 0) == 1) {
 532                         struct ltt_trace_struct *trace;
 533                         char trace_name[] = "auto";
 534                         int i;
 535                         char *channel_name;
 536
 537                         DBG("get_subbuf");
 538
 539                         channel_name = nth_token(recvbuf, 1);
 540                         if(channel_name == NULL) {
 541                                 ERR("get_subbuf: cannot parse channel");
 542                                 goto next_cmd;
 543                         }
 544
 545                         ltt_lock_traces();
 546                         trace = _ltt_trace_find(trace_name);
 547                         ltt_unlock_traces();
 548
 549                         if(trace == NULL) {
 550                                 ERR("cannot find trace!");
 551                                 return (void *)1;
 552                         }
 553
 554                         for(i=0; i<trace->nr_channels; i++) {
 555                                 struct rchan *rchan = trace->channels[i].trans_channel_data;
 556
 557                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 558                                         struct rchan_buf *rbuf = rchan->buf;
 559                                         struct ltt_channel_buf_struct *lttbuf = trace->channels[i].buf;
 560                                         struct blocked_consumer *bc;
 561
 562                                         bc = (struct blocked_consumer *) malloc(sizeof(struct blocked_consumer));
 563                                         if(bc == NULL) {
 564                                                 ERR("malloc returned NULL");
 565                                                 goto next_cmd;
 566                                         }
 567                                         bc->fd_consumer = src.fd;
 568                                         bc->fd_producer = lttbuf->data_ready_fd_read;
 569                                         bc->rbuf = rbuf;
 570                                         bc->lttbuf = lttbuf;
 571                                         bc->src = src;
 572                                         bc->server = ustcomm_app.server;
 573
 574                                         list_add(&bc->list, &blocked_consumers);
 575
 576                                         break;
 577                                 }
 578                         }
 579                 }
 580                 else if(nth_token_is(recvbuf, "put_subbuffer", 0) == 1) {
 581                         struct ltt_trace_struct *trace;
 582                         char trace_name[] = "auto";
 583                         int i;
 584                         char *channel_name;
 585                         long consumed_old;
 586                         char *consumed_old_str;
 587                         char *endptr;
 588
 589                         DBG("put_subbuf");
 590
 591                         channel_name = strdup_malloc(nth_token(recvbuf, 1));
 592                         if(channel_name == NULL) {
 593                                 ERR("put_subbuf_size: cannot parse channel");
 594                                 goto next_cmd;
 595                         }
 596
 597                         consumed_old_str = strdup_malloc(nth_token(recvbuf, 2));
 598                         if(consumed_old_str == NULL) {
 599                                 ERR("put_subbuf: cannot parse consumed_old");
 600                                 goto next_cmd;
 601                         }
 602                         consumed_old = strtol(consumed_old_str, &endptr, 10);
 603                         if(*endptr != '\0') {
 604                                 ERR("put_subbuf: invalid value for consumed_old");
 605                                 goto next_cmd;
 606                         }
 607
 608                         ltt_lock_traces();
 609                         trace = _ltt_trace_find(trace_name);
 610                         ltt_unlock_traces();
 611
 612                         if(trace == NULL) {
 613                                 ERR("cannot find trace!");
 614                                 return (void *)1;
 615                         }
 616
 617                         for(i=0; i<trace->nr_channels; i++) {
 618                                 struct rchan *rchan = trace->channels[i].trans_channel_data;
 619
 620                                 if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 621                                         struct rchan_buf *rbuf = rchan->buf;
 622                                         struct ltt_channel_buf_struct *lttbuf = trace->channels[i].buf;
 623                                         char *reply;
 624                                         long consumed_old=0;
 625
 626                                         result = ltt_do_put_subbuf(rbuf, lttbuf, consumed_old);
 627                                         if(result < 0) {
 628                                                 WARN("ltt_do_put_subbuf: error (subbuf=%s)", channel_name);
 629                                                 asprintf(&reply, "%s", "ERROR");
 630                                         }
 631                                         else {
 632                                                 DBG("ltt_do_put_subbuf: success (subbuf=%s)", channel_name);
 633                                                 asprintf(&reply, "%s", "OK");
 634                                         }
 635
 636                                         result = ustcomm_send_reply(&ustcomm_app.server, reply, &src);
 637                                         if(result) {
 638                                                 ERR("listener: put_subbuf: ustcomm_send_reply failed");
 639                                                 goto next_cmd;
 640                                         }
 641
 642                                         free(reply);
 643
 644                                         break;
 645                                 }
 646                         }
 647
 648                         free(channel_name);
 649                         free(consumed_old_str);
 650                 }
 651                 else if(nth_token_is(recvbuf, "enable_marker", 0) == 1) {
 652                         char *channel_slash_name = nth_token(recvbuf, 1);
 653                         char channel_name[256]="";
 654                         char marker_name[256]="";
 655
 656                         result = sscanf(channel_slash_name, "%255[^/]/%255s", channel_name, marker_name);
 657
 658                         if(channel_name == NULL || marker_name == NULL) {
 659                                 WARN("invalid marker name");
 660                                 goto next_cmd;
 661                         }
 662                         printf("%s %s\n", channel_name, marker_name);
 663
 664                         result = ltt_marker_connect(channel_name, marker_name, "default");
 665                         if(result < 0) {
 666                                 WARN("could not enable marker; channel=%s, name=%s", channel_name, marker_name);
 667                         }
 668                 }
 669                 else if(nth_token_is(recvbuf, "disable_marker", 0) == 1) {
 670                         char *channel_slash_name = nth_token(recvbuf, 1);
 671                         char *marker_name;
 672                         char *channel_name;
 673
 674                         result = sscanf(channel_slash_name, "%a[^/]/%as", &channel_name, &marker_name);
 675
 676                         if(marker_name == NULL) {
 677                         }
 678                         printf("%s %s\n", channel_name, marker_name);
 679
 680                         result = ltt_marker_disconnect(channel_name, marker_name, "default");
 681                         if(result < 0) {
 682                                 WARN("could not disable marker; channel=%s, name=%s", channel_name, marker_name);
 683                         }
 684                 }
 685 //              else if(nth_token_is(recvbuf, "get_notifications", 0) == 1) {
 686 //                      struct ltt_trace_struct *trace;
 687 //                      char trace_name[] = "auto";
 688 //                      int i;
 689 //                      char *channel_name;
 690 //
 691 //                      DBG("get_notifications");
 692 //
 693 //                      channel_name = strdup_malloc(nth_token(recvbuf, 1));
 694 //                      if(channel_name == NULL) {
 695 //                              ERR("put_subbuf_size: cannot parse channel");
 696 //                              goto next_cmd;
 697 //                      }
 698 //
 699 //                      ltt_lock_traces();
 700 //                      trace = _ltt_trace_find(trace_name);
 701 //                      ltt_unlock_traces();
 702 //
 703 //                      if(trace == NULL) {
 704 //                              ERR("cannot find trace!");
 705 //                              return (void *)1;
 706 //                      }
 707 //
 708 //                      for(i=0; i<trace->nr_channels; i++) {
 709 //                              struct rchan *rchan = trace->channels[i].trans_channel_data;
 710 //                              int fd;
 711 //
 712 //                              if(!strcmp(trace->channels[i].channel_name, channel_name)) {
 713 //                                      struct rchan_buf *rbuf = rchan->buf;
 714 //                                      struct ltt_channel_buf_struct *lttbuf = trace->channels[i].buf;
 715 //
 716 //                                      result = fd = ustcomm_app_detach_client(&ustcomm_app, &src);
 717 //                                      if(result == -1) {
 718 //                                              ERR("ustcomm_app_detach_client failed");
 719 //                                              goto next_cmd;
 720 //                                      }
 721 //
 722 //                                      lttbuf->wake_consumer_arg = (void *) fd;
 723 //
 724 //                                      smp_wmb();
 725 //
 726 //                                      lttbuf->call_wake_consumer = 1;
 727 //
 728 //                                      break;
 729 //                              }
 730 //                      }
 731 //
 732 //                      free(channel_name);
 733 //              }
 734                 else {
 735                         ERR("unable to parse message: %s", recvbuf);
 736                 }
 737
 738         next_cmd:
 739                 free(recvbuf);
 740         }
 741 }
 742
 743 int have_listener = 0;
 744
 745 void create_listener(void)
 746 {
 747 #ifdef USE_CLONE
 748         static char listener_stack[16384];
 749 #else
 750         pthread_t thread;
 751 #endif
 752
 753         if(have_listener)
 754                 return;
 755
 756 #ifdef USE_CLONE
 757         result = clone(listener_main, listener_stack+sizeof(listener_stack)-1, CLONE_FS | CLONE_FILES | CLONE_VM | CLONE_SIGHAND | CLONE_THREAD, NULL);
 758         if(result == -1) {
 759                 perror("clone");
 760                 return;
 761         }
 762 #else
 763
 764         pthread_create(&thread, NULL, listener_main, NULL);
 765 #endif
 766
 767         have_listener = 1;
 768 }
 769
 770 /* The signal handler itself. Signals must be setup so there cannot be
 771    nested signals. */
 772
 773 void sighandler(int sig)
 774 {
 775         static char have_listener = 0;
 776         DBG("sighandler");
 777
 778         if(!have_listener) {
 779                 create_listener();
 780                 have_listener = 1;
 781         }
 782 }
 783
 784 /* Called by the app signal handler to chain it to us. */
 785
 786 void chain_signal(void)
 787 {
 788         sighandler(USTSIGNAL);
 789 }
 790
 791 static int init_socket(void)
 792 {
 793         return ustcomm_init_app(getpid(), &ustcomm_app);
 794 }
 795
 796 static int init_signal_handler(void)
 797 {
 798         /* Attempt to handler SIGIO. If the main program wants to
 799          * handle it, fine, it'll override us. They it'll have to
 800          * use the chaining function.
 801          */
 802
 803         int result;
 804         struct sigaction act;
 805
 806         result = sigemptyset(&act.sa_mask);
 807         if(result == -1) {
 808                 PERROR("sigemptyset");
 809                 return -1;
 810         }
 811
 812         act.sa_handler = sighandler;
 813         act.sa_flags = SA_RESTART;
 814
 815         /* Only defer ourselves. Also, try to restart interrupted
 816          * syscalls to disturb the traced program as little as possible.
 817          */
 818         result = sigaction(SIGIO, &act, NULL);
 819         if(result == -1) {
 820                 PERROR("sigaction");
 821                 return -1;
 822         }
 823
 824         return 0;
 825 }
 826
 827 #define AUTOPROBE_DISABLED      0
 828 #define AUTOPROBE_ENABLE_ALL    1
 829 #define AUTOPROBE_ENABLE_REGEX  2
 830 static int autoprobe_method = AUTOPROBE_DISABLED;
 831 static regex_t autoprobe_regex;
 832
 833 static void auto_probe_connect(struct marker *m)
 834 {
 835         int result;
 836
 837         char* concat_name = NULL;
 838         const char *probe_name = "default";
 839
 840         if(autoprobe_method == AUTOPROBE_DISABLED) {
 841                 return;
 842         }
 843         else if(autoprobe_method == AUTOPROBE_ENABLE_REGEX) {
 844                 result = asprintf(&concat_name, "%s/%s", m->channel, m->name);
 845                 if(result == -1) {
 846                         ERR("auto_probe_connect: asprintf failed (marker %s/%s)",
 847                                 m->channel, m->name);
 848                         return;
 849                 }
 850                 if (regexec(&autoprobe_regex, concat_name, 0, NULL, 0)) {
 851                         free(concat_name);
 852                         return;
 853                 }
 854                 free(concat_name);
 855         }
 856
 857         result = ltt_marker_connect(m->channel, m->name, probe_name);
 858         if(result && result != -EEXIST)
 859                 ERR("ltt_marker_connect (marker = %s/%s, errno = %d)", m->channel, m->name, -result);
 860
 861         DBG("auto connected marker %s %s to probe default", m->channel, m->name);
 862
 863 }
 864
 865 static void __attribute__((constructor(1000))) init()
 866 {
 867         int result;
 868         char* autoprobe_val = NULL;
 869
 870         /* Initialize RCU in case the constructor order is not good. */
 871         urcu_init();
 872
 873         /* It is important to do this before events start to be generated. */
 874         ust_register_thread();
 875
 876         DBG("Tracectl constructor");
 877
 878         /* Must create socket before signal handler to prevent races.
 879          */
 880         result = init_socket();
 881         if(result == -1) {
 882                 ERR("init_socket error");
 883                 return;
 884         }
 885         result = init_signal_handler();
 886         if(result == -1) {
 887                 ERR("init_signal_handler error");
 888                 return;
 889         }
 890
 891         autoprobe_val = getenv("UST_AUTOPROBE");
 892         if(autoprobe_val) {
 893                 struct marker_iter iter;
 894
 895                 DBG("Autoprobe enabled.");
 896
 897                 /* Ensure markers are initialized */
 898                 //init_markers();
 899
 900                 /* Ensure marker control is initialized, for the probe */
 901                 init_marker_control();
 902
 903                 /* first, set the callback that will connect the
 904                  * probe on new markers
 905                  */
 906                 if(autoprobe_val[0] == '/') {
 907                         result = regcomp(&autoprobe_regex, autoprobe_val+1, 0);
 908                         if (result) {
 909                                 char regexerr[150];
 910
 911                                 regerror(result, &autoprobe_regex, regexerr, sizeof(regexerr));
 912                                 ERR("cannot parse regex %s (%s), will ignore UST_AUTOPROBE", autoprobe_val, regexerr);
 913                                 /* don't crash the application just for this */
 914                         }
 915                         else {
 916                                 autoprobe_method = AUTOPROBE_ENABLE_REGEX;
 917                         }
 918                 }
 919                 else {
 920                         /* just enable all instrumentation */
 921                         autoprobe_method = AUTOPROBE_ENABLE_ALL;
 922                 }
 923
 924                 marker_set_new_marker_cb(auto_probe_connect);
 925
 926                 /* Now, connect the probes that were already registered. */
 927                 marker_iter_reset(&iter);
 928                 marker_iter_start(&iter);
 929
 930                 DBG("now iterating on markers already registered");
 931                 while(iter.marker) {
 932                         DBG("now iterating on marker %s", iter.marker->name);
 933                         auto_probe_connect(iter.marker);
 934                         marker_iter_next(&iter);
 935                 }
 936         }
 937
 938         if(getenv("UST_TRACE")) {
 939                 char trace_name[] = "auto";
 940                 char trace_type[] = "ustrelay";
 941
 942                 DBG("starting early tracing");
 943
 944                 /* Ensure marker control is initialized */
 945                 init_marker_control();
 946
 947                 /* Ensure relay is initialized */
 948                 init_ustrelay_transport();
 949
 950                 /* Ensure markers are initialized */
 951                 init_markers();
 952
 953                 /* In case. */
 954                 ltt_channels_register("ust");
 955
 956                 result = ltt_trace_setup(trace_name);
 957                 if(result < 0) {
 958                         ERR("ltt_trace_setup failed");
 959                         return;
 960                 }
 961
 962                 result = ltt_trace_set_type(trace_name, trace_type);
 963                 if(result < 0) {
 964                         ERR("ltt_trace_set_type failed");
 965                         return;
 966                 }
 967
 968                 result = ltt_trace_alloc(trace_name);
 969                 if(result < 0) {
 970                         ERR("ltt_trace_alloc failed");
 971                         return;
 972                 }
 973
 974                 inform_consumer_daemon(trace_name);
 975
 976                 result = ltt_trace_start(trace_name);
 977                 if(result < 0) {
 978                         ERR("ltt_trace_start failed");
 979                         return;
 980                 }
 981         }
 982
 983
 984         return;
 985
 986         /* should decrementally destroy stuff if error */
 987
 988 }
 989
 990 /* This is only called if we terminate normally, not with an unhandled signal,
 991  * so we cannot rely on it. */
 992
 993 /* This destructor probably isn't needed, because ustd can do crash recovery. */
 994 #if 0
 995 static void __attribute__((destructor)) fini()
 996 {
 997 //      int result;
 998
 999         /* if trace running, finish it */
1000
1001 //      DBG("destructor stopping traces");
1002
1003 //      result = ltt_trace_stop("auto");
1004 //      if(result == -1) {
1005 //              ERR("ltt_trace_stop error");
1006 //      }
1007 //
1008 //      result = ltt_trace_destroy("auto");
1009 //      if(result == -1) {
1010 //              ERR("ltt_trace_destroy error");
1011 //      }
1012 //
1013 //      destroy_socket();
1014 }
1015 #endif
1016
1017 static int trace_recording(void)
1018 {
1019         int retval = 0;
1020         struct ltt_trace_struct *trace;
1021
1022         ltt_lock_traces();
1023
1024         list_for_each_entry(trace, &ltt_traces.head, list) {
1025                 if(trace->active) {
1026                         retval = 1;
1027                         break;
1028                 }
1029         }
1030
1031         ltt_unlock_traces();
1032
1033         return retval;
1034 }
1035
1036 #if 0
1037 static int have_consumer(void)
1038 {
1039         return !list_empty(&blocked_consumers);
1040 }
1041 #endif
1042
1043 int restarting_usleep(useconds_t usecs)
1044 {
1045         struct timespec tv;
1046         int result;
1047
1048         tv.tv_sec = 0;
1049         tv.tv_nsec = usecs * 1000;
1050
1051         do {
1052                 result = nanosleep(&tv, &tv);
1053         } while(result == -1 && errno == EINTR);
1054
1055         return result;
1056 }
1057
1058 /* This destructor keeps the process alive for a few seconds in order
1059  * to leave time to ustd to connect to its buffers. This is necessary
1060  * for programs whose execution is very short. It is also useful in all
1061  * programs when tracing is started close to the end of the program
1062  * execution.
1063  *
1064  * FIXME: For now, this only works for the first trace created in a
1065  * process.
1066  */
1067
1068 static void __attribute__((destructor)) keepalive()
1069 {
1070         if(trace_recording() && buffers_to_export) {
1071                 int total = 0;
1072                 DBG("Keeping process alive for consumer daemon...");
1073                 while(buffers_to_export) {
1074                         const int interv = 200000;
1075                         restarting_usleep(interv);
1076                         total += interv;
1077
1078                         if(total >= 3000000) {
1079                                 WARN("non-consumed buffers remaining after wait limit; not waiting anymore");
1080                                 break;
1081                         }
1082                 }
1083                 DBG("Finally dying...");
1084         }
1085 }
1086
1087 /* Notify ust that there was a fork. This needs to be called inside
1088  * the new process, anytime a process whose memory is not shared with
1089  * the parent is created. If this function is not called, the events
1090  * of the new process will not be collected.
1091  */
1092
1093 void ust_fork(void)
1094 {
1095         struct blocked_consumer *bc;
1096         struct blocked_consumer *deletable_bc = NULL;
1097         int result;
1098
1099         DBG("ust: forking");
1100         ltt_trace_stop("auto");
1101         ltt_trace_destroy("auto");
1102         /* Delete all active connections */
1103         ustcomm_close_all_connections(&ustcomm_app.server);
1104
1105         /* Delete all blocked consumers */
1106         list_for_each_entry(bc, &blocked_consumers, list) {
1107                 free(deletable_bc);
1108                 deletable_bc = bc;
1109                 list_del(&bc->list);
1110         }
1111
1112         have_listener = 0;
1113         create_listener();
1114         init_socket();
1115         ltt_trace_setup("auto");
1116         result = ltt_trace_set_type("auto", "ustrelay");
1117         if(result < 0) {
1118                 ERR("ltt_trace_set_type failed");
1119                 return (void *)1;
1120         }
1121
1122         ltt_trace_alloc("auto");
1123         ltt_trace_start("auto");
1124         inform_consumer_daemon("auto");
1125 }
1126