libustconsumer/libustconsumer.c

   1 /* Copyright (C) 2009  Pierre-Marc Fournier
   2  *               2010  Alexis Halle
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2.1 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
  17  */
  18
  19 #define _GNU_SOURCE
  20
  21 #include <sys/epoll.h>
  22 #include <sys/shm.h>
  23 #include <sys/types.h>
  24 #include <sys/stat.h>
  25 #include <unistd.h>
  26 #include <pthread.h>
  27 #include <signal.h>
  28
  29 #include <stdlib.h>
  30 #include <stdio.h>
  31 #include <string.h>
  32 #include <errno.h>
  33 #include <assert.h>
  34
  35 #include <ust/ustconsumer.h>
  36 #include "lowlevel.h"
  37 #include "usterr.h"
  38 #include "ustcomm.h"
  39
  40 #define GET_SUBBUF_OK 1
  41 #define GET_SUBBUF_DONE 0
  42 #define GET_SUBBUF_DIED 2
  43
  44 #define PUT_SUBBUF_OK 1
  45 #define PUT_SUBBUF_DIED 0
  46 #define PUT_SUBBUF_PUSHED 2
  47 #define PUT_SUBBUF_DONE 3
  48
  49 #define UNIX_PATH_MAX 108
  50
  51 static int get_subbuffer(struct buffer_info *buf)
  52 {
  53         struct ustcomm_header _send_hdr, *send_hdr;
  54         struct ustcomm_header _recv_hdr, *recv_hdr;
  55         struct ustcomm_buffer_info _send_msg, _recv_msg;
  56         struct ustcomm_buffer_info *send_msg, *recv_msg;
  57         int result;
  58
  59         send_hdr = &_send_hdr;
  60         recv_hdr = &_recv_hdr;
  61         send_msg = &_send_msg;
  62         recv_msg = &_recv_msg;
  63
  64         result = ustcomm_pack_buffer_info(send_hdr, send_msg, buf->trace,
  65                                           buf->channel, buf->channel_cpu);
  66         if (result < 0) {
  67                 return result;
  68         }
  69
  70         send_hdr->command = GET_SUBBUFFER;
  71
  72         result = ustcomm_req(buf->app_sock, send_hdr, (char *)send_msg,
  73                              recv_hdr, (char *)recv_msg);
  74         if ((result < 0 && (errno == ECONNRESET || errno == EPIPE)) ||
  75             result == 0) {
  76                 DBG("app died while being traced");
  77                 return GET_SUBBUF_DIED;
  78         } else if (result < 0) {
  79                 ERR("get_subbuffer: ustcomm_req failed");
  80                 return result;
  81         }
  82
  83         if (!recv_hdr->result) {
  84                 DBG("got subbuffer %s", buf->name);
  85                 buf->consumed_old = recv_msg->consumed_old;
  86                 return GET_SUBBUF_OK;
  87         } else if (recv_hdr->result == -ENODATA) {
  88                 DBG("For buffer %s, the trace was not found. This likely means"
  89                     " it was destroyed by the user.", buf->name);
  90                 return GET_SUBBUF_DIED;
  91         }
  92
  93         DBG("error getting subbuffer %s", buf->name);
  94         return recv_hdr->result;
  95 }
  96
  97 static int put_subbuffer(struct buffer_info *buf)
  98 {
  99         struct ustcomm_header _send_hdr, *send_hdr;
 100         struct ustcomm_header _recv_hdr, *recv_hdr;
 101         struct ustcomm_buffer_info _send_msg, *send_msg;
 102         int result;
 103
 104         send_hdr = &_send_hdr;
 105         recv_hdr = &_recv_hdr;
 106         send_msg = &_send_msg;
 107
 108         result = ustcomm_pack_buffer_info(send_hdr, send_msg, buf->trace,
 109                                           buf->channel, buf->channel_cpu);
 110         if (result < 0) {
 111                 return result;
 112         }
 113
 114         send_hdr->command = PUT_SUBBUFFER;
 115         send_msg->consumed_old = buf->consumed_old;
 116
 117         result = ustcomm_req(buf->app_sock, send_hdr, (char *)send_msg,
 118                              recv_hdr, NULL);
 119         if ((result < 0 && (errno == ECONNRESET || errno == EPIPE)) ||
 120             result == 0) {
 121                 DBG("app died while being traced");
 122                 return PUT_SUBBUF_DIED;
 123         } else if (result < 0) {
 124                 ERR("put_subbuffer: ustcomm_req failed");
 125                 return result;
 126         }
 127
 128         if (!recv_hdr->result) {
 129                 DBG("put subbuffer %s", buf->name);
 130                 return PUT_SUBBUF_OK;
 131         } else if (recv_hdr->result == -ENODATA) {
 132                 DBG("For buffer %s, the trace was not found. This likely means"
 133                     " it was destroyed by the user.", buf->name);
 134                 return PUT_SUBBUF_DIED;
 135         }
 136
 137         DBG("error getting subbuffer %s", buf->name);
 138         return recv_hdr->result;
 139 }
 140
 141 void decrement_active_buffers(void *arg)
 142 {
 143         struct ustconsumer_instance *instance = arg;
 144         pthread_mutex_lock(&instance->mutex);
 145         instance->active_buffers--;
 146         pthread_mutex_unlock(&instance->mutex);
 147 }
 148
 149 static int get_pidunique(int sock, s64 *pidunique)
 150 {
 151         struct ustcomm_header _send_hdr, *send_hdr;
 152         struct ustcomm_header _recv_hdr, *recv_hdr;
 153         struct ustcomm_pidunique _recv_msg, *recv_msg;
 154         int result;
 155
 156         send_hdr = &_send_hdr;
 157         recv_hdr = &_recv_hdr;
 158         recv_msg = &_recv_msg;
 159
 160         memset(send_hdr, 0, sizeof(*send_hdr));
 161
 162         send_hdr->command = GET_PIDUNIQUE;
 163         result = ustcomm_req(sock, send_hdr, NULL, recv_hdr, (char *)recv_msg);
 164         if (result < 1) {
 165                 return -ENOTCONN;
 166         }
 167         if (recv_hdr->result < 0) {
 168                 ERR("App responded with error: %s", strerror(recv_hdr->result));
 169                 return recv_hdr->result;
 170         }
 171
 172         *pidunique = recv_msg->pidunique;
 173
 174         return 0;
 175 }
 176
 177 static int get_buf_shmid_pipe_fd(int sock, struct buffer_info *buf,
 178                                  int *buf_shmid, int *buf_struct_shmid,
 179                                  int *buf_pipe_fd)
 180 {
 181         struct ustcomm_header _send_hdr, *send_hdr;
 182         struct ustcomm_header _recv_hdr, *recv_hdr;
 183         struct ustcomm_buffer_info _send_msg, *send_msg;
 184         struct ustcomm_buffer_info _recv_msg, *recv_msg;
 185         int result, recv_pipe_fd;
 186
 187         send_hdr = &_send_hdr;
 188         recv_hdr = &_recv_hdr;
 189         send_msg = &_send_msg;
 190         recv_msg = &_recv_msg;
 191
 192         result = ustcomm_pack_buffer_info(send_hdr, send_msg, buf->trace,
 193                                           buf->channel, buf->channel_cpu);
 194         if (result < 0) {
 195                 ERR("Failed to pack buffer info");
 196                 return result;
 197         }
 198
 199         send_hdr->command = GET_BUF_SHMID_PIPE_FD;
 200
 201         result = ustcomm_send(sock, send_hdr, (char *)send_msg);
 202         if (result < 1) {
 203                 ERR("Failed to send request");
 204                 return -ENOTCONN;
 205         }
 206         result = ustcomm_recv_fd(sock, recv_hdr, (char *)recv_msg, &recv_pipe_fd);
 207         if (result < 1) {
 208                 ERR("Failed to receive message and fd");
 209                 return -ENOTCONN;
 210         }
 211         if (recv_hdr->result < 0) {
 212                 ERR("App responded with error %s", strerror(recv_hdr->result));
 213                 return recv_hdr->result;
 214         }
 215
 216         *buf_shmid = recv_msg->buf_shmid;
 217         *buf_struct_shmid = recv_msg->buf_struct_shmid;
 218         *buf_pipe_fd = recv_pipe_fd;
 219
 220         return 0;
 221 }
 222
 223 static int get_subbuf_num_size(int sock, struct buffer_info *buf,
 224                                int *subbuf_num, int *subbuf_size)
 225 {
 226         struct ustcomm_header _send_hdr, *send_hdr;
 227         struct ustcomm_header _recv_hdr, *recv_hdr;
 228         struct ustcomm_channel_info _send_msg, *send_msg;
 229         struct ustcomm_channel_info _recv_msg, *recv_msg;
 230         int result;
 231
 232         send_hdr = &_send_hdr;
 233         recv_hdr = &_recv_hdr;
 234         send_msg = &_send_msg;
 235         recv_msg = &_recv_msg;
 236
 237         result = ustcomm_pack_channel_info(send_hdr, send_msg, buf->trace,
 238                                            buf->channel);
 239         if (result < 0) {
 240                 return result;
 241         }
 242
 243         send_hdr->command = GET_SUBBUF_NUM_SIZE;
 244
 245         result = ustcomm_req(sock, send_hdr, (char *)send_msg,
 246                              recv_hdr, (char *)recv_msg);
 247         if (result < 1) {
 248                 return -ENOTCONN;
 249         }
 250
 251         *subbuf_num = recv_msg->subbuf_num;
 252         *subbuf_size = recv_msg->subbuf_size;
 253
 254         return recv_hdr->result;
 255 }
 256
 257
 258 static int notify_buffer_mapped(int sock, struct buffer_info *buf)
 259 {
 260         struct ustcomm_header _send_hdr, *send_hdr;
 261         struct ustcomm_header _recv_hdr, *recv_hdr;
 262         struct ustcomm_buffer_info _send_msg, *send_msg;
 263         int result;
 264
 265         send_hdr = &_send_hdr;
 266         recv_hdr = &_recv_hdr;
 267         send_msg = &_send_msg;
 268
 269         result = ustcomm_pack_buffer_info(send_hdr, send_msg, buf->trace,
 270                                           buf->channel, buf->channel_cpu);
 271         if (result < 0) {
 272                 return result;
 273         }
 274
 275         send_hdr->command = NOTIFY_BUF_MAPPED;
 276
 277         result = ustcomm_req(sock, send_hdr, (char *)send_msg,
 278                              recv_hdr, NULL);
 279         if (result < 1) {
 280                 return -ENOTCONN;
 281         }
 282
 283         return recv_hdr->result;
 284 }
 285
 286
 287 struct buffer_info *connect_buffer(struct ustconsumer_instance *instance, pid_t pid,
 288                                    const char *trace, const char *channel,
 289                                    int channel_cpu)
 290 {
 291         struct buffer_info *buf;
 292         int result;
 293         struct shmid_ds shmds;
 294
 295         buf = (struct buffer_info *) zmalloc(sizeof(struct buffer_info));
 296         if(buf == NULL) {
 297                 ERR("add_buffer: insufficient memory");
 298                 return NULL;
 299         }
 300
 301         buf->trace = strdup(trace);
 302         if (!buf->trace) {
 303                 goto free_buf;
 304         }
 305
 306         buf->channel = strdup(channel);
 307         if (!buf->channel) {
 308                 goto free_buf_trace;
 309         }
 310
 311         result = asprintf(&buf->name, "%s_%d", channel, channel_cpu);
 312         if (result < 0 || buf->name == NULL) {
 313                 goto free_buf_channel;
 314         }
 315
 316         buf->channel_cpu = channel_cpu;
 317         buf->pid = pid;
 318
 319         result = ustcomm_connect_app(buf->pid, &buf->app_sock);
 320         if(result) {
 321                 WARN("unable to connect to process, it probably died before we were able to connect");
 322                 goto free_buf_name;
 323         }
 324
 325         /* get pidunique */
 326         result = get_pidunique(buf->app_sock, &buf->pidunique);
 327         if (result < 0) {
 328                 ERR("Failed to get pidunique");
 329                 goto close_app_sock;
 330         }
 331
 332         /* get shmid and pipe fd */
 333         result = get_buf_shmid_pipe_fd(buf->app_sock, buf, &buf->shmid,
 334                                        &buf->bufstruct_shmid, &buf->pipe_fd);
 335         if (result < 0) {
 336                 ERR("Failed to get buf_shmid and pipe_fd");
 337                 goto close_app_sock;
 338         } else {
 339                 struct stat temp;
 340                 fstat(buf->pipe_fd, &temp);
 341                 if (!S_ISFIFO(temp.st_mode)) {
 342                         ERR("Didn't receive a fifo from the app");
 343                         goto close_app_sock;
 344                 }
 345         }
 346
 347
 348         /* get number of subbufs and subbuf size */
 349         result = get_subbuf_num_size(buf->app_sock, buf, &buf->n_subbufs,
 350                                      &buf->subbuf_size);
 351         if (result < 0) {
 352                 ERR("Failed to get subbuf number and size");
 353                 goto close_fifo;
 354         }
 355
 356         /* Set subbuffer's information */
 357         buf->subbuf_size_order = get_count_order(buf->subbuf_size);
 358         buf->alloc_size = buf->subbuf_size * buf->n_subbufs;
 359
 360         /* attach memory */
 361         buf->mem = shmat(buf->shmid, NULL, 0);
 362         if(buf->mem == (void *) 0) {
 363                 PERROR("shmat");
 364                 goto close_fifo;
 365         }
 366         DBG("successfully attached buffer memory");
 367
 368         buf->bufstruct_mem = shmat(buf->bufstruct_shmid, NULL, 0);
 369         if(buf->bufstruct_mem == (void *) 0) {
 370                 PERROR("shmat");
 371                 goto shmdt_mem;
 372         }
 373         DBG("successfully attached buffer bufstruct memory");
 374
 375         /* obtain info on the memory segment */
 376         result = shmctl(buf->shmid, IPC_STAT, &shmds);
 377         if(result == -1) {
 378                 PERROR("shmctl");
 379                 goto shmdt_bufstruct_mem;
 380         }
 381         buf->memlen = shmds.shm_segsz;
 382
 383         /* Notify the application that we have mapped the buffer */
 384         result = notify_buffer_mapped(buf->app_sock, buf);
 385         if (result < 0) {
 386                 goto shmdt_bufstruct_mem;
 387         }
 388
 389         if(instance->callbacks->on_open_buffer)
 390                 instance->callbacks->on_open_buffer(instance->callbacks, buf);
 391
 392         pthread_mutex_lock(&instance->mutex);
 393         instance->active_buffers++;
 394         pthread_mutex_unlock(&instance->mutex);
 395
 396         return buf;
 397
 398 shmdt_bufstruct_mem:
 399         shmdt(buf->bufstruct_mem);
 400
 401 shmdt_mem:
 402         shmdt(buf->mem);
 403
 404 close_fifo:
 405         close(buf->pipe_fd);
 406
 407 close_app_sock:
 408         close(buf->app_sock);
 409
 410 free_buf_name:
 411         free(buf->name);
 412
 413 free_buf_channel:
 414         free(buf->channel);
 415
 416 free_buf_trace:
 417         free(buf->trace);
 418
 419 free_buf:
 420         free(buf);
 421         return NULL;
 422 }
 423
 424 static void destroy_buffer(struct ustconsumer_callbacks *callbacks,
 425                         struct buffer_info *buf)
 426 {
 427         int result;
 428
 429         result = close(buf->app_sock);
 430         if(result == -1) {
 431                 WARN("problem calling ustcomm_close_app");
 432         }
 433
 434         result = shmdt(buf->mem);
 435         if(result == -1) {
 436                 PERROR("shmdt");
 437         }
 438
 439         result = shmdt(buf->bufstruct_mem);
 440         if(result == -1) {
 441                 PERROR("shmdt");
 442         }
 443
 444         if(callbacks->on_close_buffer)
 445                 callbacks->on_close_buffer(callbacks, buf);
 446
 447         free(buf);
 448 }
 449
 450 int consumer_loop(struct ustconsumer_instance *instance, struct buffer_info *buf)
 451 {
 452         int result = 0;
 453         int read_result;
 454         char read_buf;
 455
 456         pthread_cleanup_push(decrement_active_buffers, instance);
 457
 458         for(;;) {
 459                 read_result = read(buf->pipe_fd, &read_buf, 1);
 460                 /* get the subbuffer */
 461                 if (read_result == 1) {
 462                         result = get_subbuffer(buf);
 463                         if (result < 0) {
 464                                 ERR("error getting subbuffer");
 465                                 continue;
 466                         } else if (result == GET_SUBBUF_DIED) {
 467                                 finish_consuming_dead_subbuffer(instance->callbacks, buf);
 468                                 break;
 469                         }
 470                 } else if ((read_result == -1 && (errno == ECONNRESET || errno == EPIPE)) ||
 471                            result == 0) {
 472                         DBG("App died while being traced");
 473                         finish_consuming_dead_subbuffer(instance->callbacks, buf);
 474                         break;
 475                 }
 476
 477                 if(instance->callbacks->on_read_subbuffer)
 478                         instance->callbacks->on_read_subbuffer(instance->callbacks, buf);
 479
 480                 /* put the subbuffer */
 481                 result = put_subbuffer(buf);
 482                 if(result == -1) {
 483                         ERR("unknown error putting subbuffer (channel=%s)", buf->name);
 484                         break;
 485                 }
 486                 else if(result == PUT_SUBBUF_PUSHED) {
 487                         ERR("Buffer overflow (channel=%s), reader pushed. This channel will not be usable passed this point.", buf->name);
 488                         break;
 489                 }
 490                 else if(result == PUT_SUBBUF_DIED) {
 491                         DBG("application died while putting subbuffer");
 492                         /* Skip the first subbuffer. We are not sure it is trustable
 493                          * because the put_subbuffer() did not complete.
 494                          */
 495                         /* TODO: check on_put_error return value */
 496                         if(instance->callbacks->on_put_error)
 497                                 instance->callbacks->on_put_error(instance->callbacks, buf);
 498
 499                         finish_consuming_dead_subbuffer(instance->callbacks, buf);
 500                         break;
 501                 }
 502                 else if(result == PUT_SUBBUF_DONE) {
 503                         /* Done with this subbuffer */
 504                         /* FIXME: add a case where this branch is used? Upon
 505                          * normal trace termination, at put_subbuf time, a
 506                          * special last-subbuffer code could be returned by
 507                          * the listener.
 508                          */
 509                         break;
 510                 }
 511                 else if(result == PUT_SUBBUF_OK) {
 512                 }
 513         }
 514
 515         DBG("thread for buffer %s is stopping", buf->name);
 516
 517         /* FIXME: destroy, unalloc... */
 518
 519         pthread_cleanup_pop(1);
 520
 521         return 0;
 522 }
 523
 524 struct consumer_thread_args {
 525         pid_t pid;
 526         const char *trace;
 527         const char *channel;
 528         int channel_cpu;
 529         struct ustconsumer_instance *instance;
 530 };
 531
 532 void *consumer_thread(void *arg)
 533 {
 534         struct buffer_info *buf;
 535         struct consumer_thread_args *args = (struct consumer_thread_args *) arg;
 536         int result;
 537         sigset_t sigset;
 538
 539         if(args->instance->callbacks->on_new_thread)
 540                 args->instance->callbacks->on_new_thread(args->instance->callbacks);
 541
 542         /* Block signals that should be handled by the main thread. */
 543         result = sigemptyset(&sigset);
 544         if(result == -1) {
 545                 PERROR("sigemptyset");
 546                 goto end;
 547         }
 548         result = sigaddset(&sigset, SIGTERM);
 549         if(result == -1) {
 550                 PERROR("sigaddset");
 551                 goto end;
 552         }
 553         result = sigaddset(&sigset, SIGINT);
 554         if(result == -1) {
 555                 PERROR("sigaddset");
 556                 goto end;
 557         }
 558         result = sigprocmask(SIG_BLOCK, &sigset, NULL);
 559         if(result == -1) {
 560                 PERROR("sigprocmask");
 561                 goto end;
 562         }
 563
 564         buf = connect_buffer(args->instance, args->pid, args->trace,
 565                              args->channel, args->channel_cpu);
 566         if(buf == NULL) {
 567                 ERR("failed to connect to buffer");
 568                 goto end;
 569         }
 570
 571         consumer_loop(args->instance, buf);
 572
 573         destroy_buffer(args->instance->callbacks, buf);
 574
 575         end:
 576
 577         if(args->instance->callbacks->on_close_thread)
 578                 args->instance->callbacks->on_close_thread(args->instance->callbacks);
 579
 580         free((void *)args->channel);
 581         free(args);
 582         return NULL;
 583 }
 584
 585 int start_consuming_buffer(struct ustconsumer_instance *instance, pid_t pid,
 586                            const char *trace, const char *channel,
 587                            int channel_cpu)
 588 {
 589         pthread_t thr;
 590         struct consumer_thread_args *args;
 591         int result;
 592
 593         DBG("beginning of start_consuming_buffer: args: pid %d bufname %s_%d", pid, channel,
 594             channel_cpu);
 595
 596         args = (struct consumer_thread_args *) zmalloc(sizeof(struct consumer_thread_args));
 597         if (!args) {
 598                 return -ENOMEM;
 599         }
 600
 601         args->pid = pid;
 602         args->trace = strdup(trace);
 603         args->channel = strdup(channel);
 604         args->channel_cpu = channel_cpu;
 605         args->instance = instance;
 606         DBG("beginning2 of start_consuming_buffer: args: pid %d trace %s"
 607             " bufname %s_%d", args->pid, args->trace, args->channel, args->channel_cpu);
 608
 609         result = pthread_create(&thr, NULL, consumer_thread, args);
 610         if(result == -1) {
 611                 ERR("pthread_create failed");
 612                 return -1;
 613         }
 614         result = pthread_detach(thr);
 615         if(result == -1) {
 616                 ERR("pthread_detach failed");
 617                 return -1;
 618         }
 619         DBG("end of start_consuming_buffer: args: pid %d trace %s "
 620             "bufname %s_%d", args->pid, args->channel, args->trace, args->channel_cpu);
 621
 622         return 0;
 623 }
 624 static void process_client_cmd(int sock, struct ustcomm_header *req_header,
 625                                char *recvbuf, struct ustconsumer_instance *instance)
 626 {
 627         int result;
 628         struct ustcomm_header _res_header = {0};
 629         struct ustcomm_header *res_header = &_res_header;
 630         struct ustcomm_buffer_info *buf_inf;
 631
 632         DBG("Processing client command");
 633
 634         switch (req_header->command) {
 635         case CONSUME_BUFFER:
 636
 637                 buf_inf = (struct ustcomm_buffer_info *)recvbuf;
 638                 result = ustcomm_unpack_buffer_info(buf_inf);
 639                 if (result < 0) {
 640                         ERR("Couldn't unpack buffer info");
 641                         return;
 642                 }
 643
 644                 DBG("Going to consume trace %s buffer %s_%d in process %d",
 645                     buf_inf->trace, buf_inf->channel, buf_inf->ch_cpu,
 646                     buf_inf->pid);
 647                 result = start_consuming_buffer(instance, buf_inf->pid,
 648                                                 buf_inf->trace,
 649                                                 buf_inf->channel,
 650                                                 buf_inf->ch_cpu);
 651                 if (result < 0) {
 652                         ERR("error in add_buffer");
 653                         return;
 654                 }
 655
 656                 res_header->result = 0;
 657                 break;
 658         case EXIT:
 659                 res_header->result = 0;
 660                 /* Only there to force poll to return */
 661                 break;
 662         default:
 663                 res_header->result = -EINVAL;
 664                 WARN("unknown command: %d", req_header->command);
 665         }
 666
 667         if (ustcomm_send(sock, res_header, NULL) <= 0) {
 668                 ERR("couldn't send command response");
 669         }
 670 }
 671
 672 #define MAX_EVENTS 10
 673
 674 int ustconsumer_start_instance(struct ustconsumer_instance *instance)
 675 {
 676         struct ustcomm_header recv_hdr;
 677         char recv_buf[USTCOMM_BUFFER_SIZE];
 678         struct ustcomm_sock *epoll_sock;
 679         struct epoll_event events[MAX_EVENTS];
 680         struct sockaddr addr;
 681         int result, epoll_fd, accept_fd, nfds, i, addr_size, timeout;
 682
 683         if(!instance->is_init) {
 684                 ERR("libustconsumer instance not initialized");
 685                 return 1;
 686         }
 687         epoll_fd = instance->epoll_fd;
 688
 689         timeout = -1;
 690
 691         /* app loop */
 692         for(;;) {
 693                 nfds = epoll_wait(epoll_fd, events, MAX_EVENTS, timeout);
 694                 if (nfds == -1 && errno == EINTR) {
 695                         /* Caught signal */
 696                 } else if (nfds == -1) {
 697                         PERROR("ustconsumer_start_instance: epoll_wait failed");
 698                         continue;
 699                 }
 700
 701                 for (i = 0; i < nfds; ++i) {
 702                         epoll_sock = (struct ustcomm_sock *)events[i].data.ptr;
 703                         if (epoll_sock == instance->listen_sock) {
 704                                 addr_size = sizeof(struct sockaddr);
 705                                 accept_fd = accept(epoll_sock->fd,
 706                                                    &addr,
 707                                                    (socklen_t *)&addr_size);
 708                                 if (accept_fd == -1) {
 709                                         PERROR("ustconsumer_start_instance: "
 710                                                "accept failed");
 711                                         continue;
 712                                 }
 713                                 ustcomm_init_sock(accept_fd, epoll_fd,
 714                                                  &instance->connections);
 715                         } else {
 716                                 result = ustcomm_recv(epoll_sock->fd, &recv_hdr,
 717                                                       recv_buf);
 718                                 if (result < 1) {
 719                                         ustcomm_del_sock(epoll_sock, 0);
 720                                 } else {
 721                                         process_client_cmd(epoll_sock->fd,
 722                                                            &recv_hdr, recv_buf,
 723                                                            instance);
 724                                 }
 725
 726                         }
 727                 }
 728
 729                 if (instance->quit_program) {
 730                         pthread_mutex_lock(&instance->mutex);
 731                         if(instance->active_buffers == 0) {
 732                                 pthread_mutex_unlock(&instance->mutex);
 733                                 break;
 734                         }
 735                         pthread_mutex_unlock(&instance->mutex);
 736                         timeout = 100;
 737                 }
 738         }
 739
 740         if(instance->callbacks->on_trace_end)
 741                 instance->callbacks->on_trace_end(instance);
 742
 743         ustconsumer_delete_instance(instance);
 744
 745         return 0;
 746 }
 747
 748 /* FIXME: threads and connections !? */
 749 void ustconsumer_delete_instance(struct ustconsumer_instance *instance)
 750 {
 751         if (instance->is_init) {
 752                 ustcomm_del_named_sock(instance->listen_sock, 0);
 753                 close(instance->epoll_fd);
 754         }
 755
 756         pthread_mutex_destroy(&instance->mutex);
 757         free(instance->sock_path);
 758         free(instance);
 759 }
 760
 761 /* FIXME: Do something about the fixed path length, maybe get rid
 762  * of the whole concept and use a pipe?
 763  */
 764 int ustconsumer_stop_instance(struct ustconsumer_instance *instance, int send_msg)
 765 {
 766         int result;
 767         int fd;
 768         int bytes = 0;
 769
 770         char msg[] = "exit";
 771
 772         instance->quit_program = 1;
 773
 774         if(!send_msg)
 775                 return 0;
 776
 777         /* Send a message through the socket to force poll to return */
 778
 779         struct sockaddr_un addr;
 780
 781         result = fd = socket(PF_UNIX, SOCK_STREAM, 0);
 782         if(result == -1) {
 783                 PERROR("socket");
 784                 return 1;
 785         }
 786
 787         addr.sun_family = AF_UNIX;
 788
 789         strncpy(addr.sun_path, instance->sock_path, UNIX_PATH_MAX);
 790         addr.sun_path[UNIX_PATH_MAX-1] = '\0';
 791
 792         result = connect(fd, (struct sockaddr *)&addr, sizeof(addr));
 793         if(result == -1) {
 794                 PERROR("connect");
 795         }
 796
 797         while(bytes != sizeof(msg))
 798                 bytes += send(fd, msg, sizeof(msg), 0);
 799
 800         close(fd);
 801
 802         return 0;
 803 }
 804
 805 struct ustconsumer_instance
 806 *ustconsumer_new_instance(struct ustconsumer_callbacks *callbacks,
 807                       char *sock_path)
 808 {
 809         struct ustconsumer_instance *instance =
 810                 zmalloc(sizeof(struct ustconsumer_instance));
 811         if(!instance) {
 812                 return NULL;
 813         }
 814
 815         instance->callbacks = callbacks;
 816         instance->quit_program = 0;
 817         instance->is_init = 0;
 818         instance->active_buffers = 0;
 819         pthread_mutex_init(&instance->mutex, NULL);
 820
 821         if (sock_path) {
 822                 instance->sock_path = strdup(sock_path);
 823         } else {
 824                 instance->sock_path = NULL;
 825         }
 826
 827         return instance;
 828 }
 829
 830 static int init_ustconsumer_socket(struct ustconsumer_instance *instance)
 831 {
 832         char *name;
 833
 834         if (instance->sock_path) {
 835                 if (asprintf(&name, "%s", instance->sock_path) < 0) {
 836                         ERR("ustcomm_init_ustconsumer : asprintf failed (sock_path %s)",
 837                             instance->sock_path);
 838                         return -1;
 839                 }
 840         } else {
 841                 int result;
 842
 843                 /* Only check if socket dir exists if we are using the default directory */
 844                 result = ensure_dir_exists(SOCK_DIR);
 845                 if (result == -1) {
 846                         ERR("Unable to create socket directory %s", SOCK_DIR);
 847                         return -1;
 848                 }
 849
 850                 if (asprintf(&name, "%s/%s", SOCK_DIR, "ustconsumer") < 0) {
 851                         ERR("ustcomm_init_ustconsumer : asprintf failed (%s/ustconsumer)",
 852                             SOCK_DIR);
 853                         return -1;
 854                 }
 855         }
 856
 857         /* Set up epoll */
 858         instance->epoll_fd = epoll_create(MAX_EVENTS);
 859         if (instance->epoll_fd == -1) {
 860                 ERR("epoll_create failed, start instance bailing");
 861                 goto free_name;
 862         }
 863
 864         /* Create the named socket */
 865         instance->listen_sock = ustcomm_init_named_socket(name,
 866                                                           instance->epoll_fd);
 867         if(!instance->listen_sock) {
 868                 ERR("error initializing named socket at %s", name);
 869                 goto close_epoll;
 870         }
 871
 872         CDS_INIT_LIST_HEAD(&instance->connections);
 873
 874         free(name);
 875
 876         return 0;
 877
 878 close_epoll:
 879         close(instance->epoll_fd);
 880 free_name:
 881         free(name);
 882
 883         return -1;
 884 }
 885
 886 int ustconsumer_init_instance(struct ustconsumer_instance *instance)
 887 {
 888         int result;
 889         result = init_ustconsumer_socket(instance);
 890         if(result == -1) {
 891                 ERR("failed to initialize socket");
 892                 return 1;
 893         }
 894         instance->is_init = 1;
 895         return 0;
 896 }
 897