example-clients/midi_latency_test.c

   1 /*
   2 Copyright (C) 2010 Devin Anderson
   3
   4 This program is free software; you can redistribute it and/or modify
   5 it under the terms of the GNU Lesser General Public License as published by
   6 the Free Software Foundation; either version 2.1 of the License, or
   7 (at your option) any later version.
   8
   9 This program 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
  12 GNU Lesser General Public License for more details.
  13
  14 You should have received a copy of the GNU Lesser General Public License
  15 along with this program; if not, write to the Free Software
  16 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  17
  18 */
  19
  20 /*
  21  * This program is used to measure MIDI latency and jitter.  It writes MIDI
  22  * messages to one port and calculates how long it takes before it reads the
  23  * same MIDI message over another port.  It was written to calculate the
  24  * latency and jitter of hardware and JACK hardware drivers, but might have
  25  * other practical applications.
  26  *
  27  * The latency results of the program include the latency introduced by the
  28  * JACK system.  Because JACK has sample accurate MIDI, the same latency
  29  * imposed on audio is also imposed on MIDI going through the system.  Make
  30  * sure you take this into account before complaining to me or (*especially*)
  31  * other JACK developers about reported MIDI latency.
  32  *
  33  * The jitter results are a little more interesting.  The program attempts to
  34  * calculate 'average jitter' and 'peak jitter', as defined here:
  35  *
  36  *     http://openmuse.org/transport/fidelity.html
  37  *
  38  * It also outputs a jitter plot, which gives you a more specific idea about
  39  * the MIDI jitter for the ports you're testing.  This is useful for catching
  40  * extreme jitter values, and for analyzing the amount of truth in the
  41  * technical specifications for your MIDI interface(s). :)
  42  *
  43  * This program is loosely based on 'alsa-midi-latency-test' in the ALSA test
  44  * suite.
  45  *
  46  * To port this program to non-POSIX platforms, you'll have to include
  47  * implementations for semaphores and command-line argument handling.
  48  */
  49
  50 #include <assert.h>
  51 #include <errno.h>
  52 #include <math.h>
  53 #include <signal.h>
  54 #include <stdio.h>
  55 #include <stdlib.h>
  56 #include <string.h>
  57
  58 #include <getopt.h>
  59
  60 #include <jack/jack.h>
  61 #include <jack/midiport.h>
  62
  63 #ifdef WIN32
  64 #include <windows.h>
  65 #include <unistd.h>
  66 #else
  67 #include <semaphore.h>
  68 #endif
  69
  70 #define ABS(x) (((x) >= 0) ? (x) : (-(x)))
  71
  72 #ifdef WIN32
  73 typedef HANDLE semaphore_t;
  74 #else
  75 typedef sem_t *semaphore_t;
  76 #endif
  77
  78 const char *ERROR_MSG_TIMEOUT = "timed out while waiting for MIDI message";
  79 const char *ERROR_RESERVE = "could not reserve MIDI event on port buffer";
  80 const char *ERROR_SHUTDOWN = "the JACK server has been shutdown";
  81
  82 const char *SOURCE_EVENT_RESERVE = "jack_midi_event_reserve";
  83 const char *SOURCE_PROCESS = "handle_process";
  84 const char *SOURCE_SHUTDOWN = "handle_shutdown";
  85 const char *SOURCE_SIGNAL_SEMAPHORE = "signal_semaphore";
  86 const char *SOURCE_WAIT_SEMAPHORE = "wait_semaphore";
  87
  88 char *alias1;
  89 char *alias2;
  90 jack_client_t *client;
  91 semaphore_t connect_semaphore;
  92 volatile int connections_established;
  93 const char *error_message;
  94 const char *error_source;
  95 jack_nframes_t highest_latency;
  96 jack_time_t highest_latency_time;
  97 jack_latency_range_t in_latency_range;
  98 jack_port_t *in_port;
  99 semaphore_t init_semaphore;
 100 jack_nframes_t last_activity;
 101 jack_time_t last_activity_time;
 102 jack_time_t *latency_time_values;
 103 jack_nframes_t *latency_values;
 104 jack_nframes_t lowest_latency;
 105 jack_time_t lowest_latency_time;
 106 jack_midi_data_t *message_1;
 107 jack_midi_data_t *message_2;
 108 int messages_received;
 109 int messages_sent;
 110 size_t message_size;
 111 jack_latency_range_t out_latency_range;
 112 jack_port_t *out_port;
 113 semaphore_t process_semaphore;
 114 volatile sig_atomic_t process_state;
 115 char *program_name;
 116 jack_port_t *remote_in_port;
 117 jack_port_t *remote_out_port;
 118 size_t samples;
 119 const char *target_in_port_name;
 120 const char *target_out_port_name;
 121 int timeout;
 122 jack_nframes_t total_latency;
 123 jack_time_t total_latency_time;
 124 int unexpected_messages;
 125 int xrun_count;
 126
 127 #ifdef WIN32
 128 char semaphore_error_msg[1024];
 129 #endif
 130
 131 static void
 132 output_error(const char *source, const char *message);
 133
 134 static void
 135 output_usage(void);
 136
 137 static void
 138 set_process_error(const char *source, const char *message);
 139
 140 static int
 141 signal_semaphore(semaphore_t semaphore);
 142
 143 static jack_port_t *
 144 update_connection(jack_port_t *remote_port, int connected,
 145                   jack_port_t *local_port, jack_port_t *current_port,
 146                   const char *target_name);
 147
 148 static int
 149 wait_semaphore(semaphore_t semaphore, int block);
 150
 151 static semaphore_t
 152 create_semaphore(int id)
 153 {
 154     semaphore_t semaphore;
 155
 156 #ifdef WIN32
 157     semaphore = CreateSemaphore(NULL, 0, 2, NULL);
 158 #elif defined (__APPLE__)
 159     char name[128];
 160     sprintf(name, "midi_sem_%d", id);
 161     semaphore = sem_open(name, O_CREAT, 0777, 0);
 162     if (semaphore == (sem_t *) SEM_FAILED) {
 163         semaphore = NULL;
 164     }
 165 #else
 166     semaphore = malloc(sizeof(semaphore_t));
 167     if (semaphore != NULL) {
 168         if (sem_init(semaphore, 0, 0)) {
 169             free(semaphore);
 170             semaphore = NULL;
 171         }
 172     }
 173 #endif
 174
 175     return semaphore;
 176 }
 177
 178 static void
 179 destroy_semaphore(semaphore_t semaphore, int id)
 180 {
 181
 182 #ifdef WIN32
 183     CloseHandle(semaphore);
 184 #else
 185     sem_destroy(semaphore);
 186 #ifdef __APPLE__
 187     {
 188         char name[128];
 189         sprintf(name, "midi_sem_%d", id);
 190         sem_close(semaphore);
 191         sem_unlink(name);
 192     }
 193 #else
 194     free(semaphore);
 195 #endif
 196 #endif
 197
 198 }
 199
 200 static void
 201 die(const char *source, const char *error_message)
 202 {
 203     output_error(source, error_message);
 204     output_usage();
 205     exit(EXIT_FAILURE);
 206 }
 207
 208 static const char *
 209 get_semaphore_error(void)
 210 {
 211
 212 #ifdef WIN32
 213     DWORD error = GetLastError();
 214     if (! FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM, NULL, error,
 215                         MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
 216                         semaphore_error_msg, 1024, NULL)) {
 217         snprintf(semaphore_error_msg, 1023, "Unknown OS error code '%ld'",
 218                 error);
 219     }
 220     return semaphore_error_msg;
 221 #else
 222     return strerror(errno);
 223 #endif
 224
 225 }
 226
 227 static void
 228 handle_info(const char *message)
 229 {
 230     /* Suppress info */
 231 }
 232
 233 static void
 234 handle_port_connection_change(jack_port_id_t port_id_1,
 235                               jack_port_id_t port_id_2, int connected,
 236                               void *arg)
 237 {
 238     jack_port_t *port_1;
 239     jack_port_t *port_2;
 240     if ((remote_in_port != NULL) && (remote_out_port != NULL)) {
 241         return;
 242     }
 243     port_1 = jack_port_by_id(client, port_id_1);
 244     port_2 = jack_port_by_id(client, port_id_2);
 245
 246     /* The 'update_connection' call is not RT-safe.  It calls
 247        'jack_port_get_connections' and 'jack_free'.  This might be a problem
 248        with JACK 1, as this callback runs in the process thread in JACK 1. */
 249
 250     if (port_1 == in_port) {
 251         remote_in_port = update_connection(port_2, connected, in_port,
 252                                            remote_in_port,
 253                                            target_in_port_name);
 254     } else if (port_2 == in_port) {
 255         remote_in_port = update_connection(port_1, connected, in_port,
 256                                            remote_in_port,
 257                                            target_in_port_name);
 258     } else if (port_1 == out_port) {
 259         remote_out_port = update_connection(port_2, connected, out_port,
 260                                             remote_out_port,
 261                                             target_out_port_name);
 262     } else if (port_2 == out_port) {
 263         remote_out_port = update_connection(port_1, connected, out_port,
 264                                             remote_out_port,
 265                                             target_out_port_name);
 266     }
 267     if ((remote_in_port != NULL) && (remote_out_port != NULL)) {
 268         connections_established = 1;
 269         if (! signal_semaphore(connect_semaphore)) {
 270             /* Sigh ... */
 271             die("post_semaphore", get_semaphore_error());
 272         }
 273         if (! signal_semaphore(init_semaphore)) {
 274             /* Sigh ... */
 275             die("post_semaphore", get_semaphore_error());
 276         }
 277     }
 278 }
 279
 280 static int
 281 handle_process(jack_nframes_t frames, void *arg)
 282 {
 283     jack_midi_data_t *buffer;
 284     jack_midi_event_t event;
 285     jack_nframes_t event_count;
 286     jack_nframes_t event_time;
 287     jack_nframes_t frame;
 288     size_t i;
 289     jack_nframes_t last_frame_time;
 290     jack_midi_data_t *message;
 291     jack_time_t microseconds;
 292     void *port_buffer;
 293     jack_time_t time;
 294     jack_midi_clear_buffer(jack_port_get_buffer(out_port, frames));
 295     switch (process_state) {
 296
 297     case 0:
 298         /* State: initializing */
 299         switch (wait_semaphore(init_semaphore, 0)) {
 300         case -1:
 301             set_process_error(SOURCE_WAIT_SEMAPHORE, get_semaphore_error());
 302             /* Fallthrough on purpose */
 303         case 0:
 304             return 0;
 305         }
 306         highest_latency = 0;
 307         lowest_latency = 0;
 308         messages_received = 0;
 309         messages_sent = 0;
 310         process_state = 1;
 311         total_latency = 0;
 312         total_latency_time = 0;
 313         unexpected_messages = 0;
 314         xrun_count = 0;
 315         jack_port_get_latency_range(remote_in_port, JackCaptureLatency,
 316                                     &in_latency_range);
 317         jack_port_get_latency_range(remote_out_port, JackPlaybackLatency,
 318                                     &out_latency_range);
 319         goto send_message;
 320
 321     case 1:
 322         /* State: processing */
 323         port_buffer = jack_port_get_buffer(in_port, frames);
 324         event_count = jack_midi_get_event_count(port_buffer);
 325         last_frame_time = jack_last_frame_time(client);
 326         for (i = 0; i < event_count; i++) {
 327             jack_midi_event_get(&event, port_buffer, i);
 328             message = (messages_received % 2) ? message_2 : message_1;
 329             if ((event.size == message_size) &&
 330                 (! memcmp(message, event.buffer,
 331                           message_size * sizeof(jack_midi_data_t)))) {
 332                 goto found_message;
 333             }
 334             unexpected_messages++;
 335         }
 336         microseconds = jack_frames_to_time(client, last_frame_time) -
 337             last_activity_time;
 338         if ((microseconds / 1000000) >= timeout) {
 339             set_process_error(SOURCE_PROCESS, ERROR_MSG_TIMEOUT);
 340         }
 341         break;
 342     found_message:
 343         event_time = last_frame_time + event.time;
 344         frame = event_time - last_activity;
 345         time = jack_frames_to_time(client, event_time) - last_activity_time;
 346         if ((! highest_latency) || (frame > highest_latency)) {
 347             highest_latency = frame;
 348             highest_latency_time = time;
 349         }
 350         if ((! lowest_latency) || (frame < lowest_latency)) {
 351             lowest_latency = frame;
 352             lowest_latency_time = time;
 353         }
 354         latency_time_values[messages_received] = time;
 355         latency_values[messages_received] = frame;
 356         total_latency += frame;
 357         total_latency_time += time;
 358         messages_received++;
 359         if (messages_received == samples) {
 360             process_state = 2;
 361             if (! signal_semaphore(process_semaphore)) {
 362                 /* Sigh ... */
 363                 die(SOURCE_SIGNAL_SEMAPHORE, get_semaphore_error());
 364             }
 365             break;
 366         }
 367     send_message:
 368         frame = (jack_nframes_t) ((((double) rand()) / RAND_MAX) * frames);
 369         if (frame >= frames) {
 370             frame = frames - 1;
 371         }
 372         port_buffer = jack_port_get_buffer(out_port, frames);
 373         buffer = jack_midi_event_reserve(port_buffer, frame, message_size);
 374         if (buffer == NULL) {
 375             set_process_error(SOURCE_EVENT_RESERVE, ERROR_RESERVE);
 376             break;
 377         }
 378         message = (messages_sent % 2) ? message_2 : message_1;
 379         memcpy(buffer, message, message_size * sizeof(jack_midi_data_t));
 380         last_activity = jack_last_frame_time(client) + frame;
 381         last_activity_time = jack_frames_to_time(client, last_activity);
 382         messages_sent++;
 383
 384     case 2:
 385         /* State: finished - do nothing */
 386     case -1:
 387         /* State: error - do nothing */
 388     case -2:
 389         /* State: signalled - do nothing */
 390         ;
 391     }
 392     return 0;
 393 }
 394
 395 static void
 396 handle_shutdown(void *arg)
 397 {
 398     set_process_error(SOURCE_SHUTDOWN, ERROR_SHUTDOWN);
 399 }
 400
 401 static void
 402 handle_signal(int sig)
 403 {
 404     process_state = -2;
 405     if (! signal_semaphore(connect_semaphore)) {
 406         /* Sigh ... */
 407         die(SOURCE_SIGNAL_SEMAPHORE, get_semaphore_error());
 408     }
 409     if (! signal_semaphore(process_semaphore)) {
 410         /* Sigh ... */
 411         die(SOURCE_SIGNAL_SEMAPHORE, get_semaphore_error());
 412     }
 413 }
 414
 415 static int
 416 handle_xrun(void *arg)
 417 {
 418     xrun_count++;
 419     return 0;
 420 }
 421
 422 static void
 423 output_error(const char *source, const char *message)
 424 {
 425     fprintf(stderr, "%s: %s: %s\n", program_name, source, message);
 426 }
 427
 428 static void
 429 output_usage(void)
 430 {
 431     fprintf(stderr, "Usage: %s [options] [out-port-name in-port-name]\n\n"
 432             "\t-h, --help              print program usage\n"
 433             "\t-m, --message-size=size set size of MIDI messages to send "
 434             "(default: 3)\n"
 435             "\t-s, --samples=n         number of MIDI messages to send "
 436             "(default: 1024)\n"
 437             "\t-t, --timeout=seconds   message timeout (default: 5)\n\n",
 438             program_name);
 439 }
 440
 441 static unsigned long
 442 parse_positive_number_arg(char *s, char *name)
 443 {
 444     char *end_ptr;
 445     unsigned long result;
 446     errno = 0;
 447     result = strtoul(s, &end_ptr, 10);
 448     if (errno) {
 449         die(name, strerror(errno));
 450     }
 451     if (*s == '\0') {
 452         die(name, "argument value cannot be empty");
 453     }
 454     if (*end_ptr != '\0') {
 455         die(name, "invalid value");
 456     }
 457     if (! result) {
 458         die(name, "must be a positive number");
 459     }
 460     return result;
 461 }
 462
 463 static int
 464 register_signal_handler(void (*func)(int))
 465 {
 466
 467 #ifdef WIN32
 468     if (signal(SIGABRT, func) == SIG_ERR) {
 469         return 0;
 470     }
 471 #else
 472     if (signal(SIGQUIT, func) == SIG_ERR) {
 473         return 0;
 474     }
 475     if (signal(SIGHUP, func) == SIG_ERR) {
 476         return 0;
 477     }
 478 #endif
 479
 480     if (signal(SIGINT, func) == SIG_ERR) {
 481         return 0;
 482     }
 483     if (signal(SIGTERM, func) == SIG_ERR) {
 484         return 0;
 485     }
 486     return 1;
 487 }
 488
 489 static void
 490 set_process_error(const char *source, const char *message)
 491 {
 492     error_source = source;
 493     error_message = message;
 494     process_state = -1;
 495     if (! signal_semaphore(process_semaphore)) {
 496         /* Sigh ... */
 497         output_error(source, message);
 498         die(SOURCE_SIGNAL_SEMAPHORE, get_semaphore_error());
 499     }
 500 }
 501
 502 static int
 503 signal_semaphore(semaphore_t semaphore)
 504 {
 505
 506 #ifdef WIN32
 507     return ReleaseSemaphore(semaphore, 1, NULL);
 508 #else
 509     return ! sem_post(semaphore);
 510 #endif
 511
 512 }
 513
 514 static jack_port_t *
 515 update_connection(jack_port_t *remote_port, int connected,
 516                   jack_port_t *local_port, jack_port_t *current_port,
 517                   const char *target_name)
 518 {
 519     if (connected) {
 520         if (current_port) {
 521             return current_port;
 522         }
 523         if (target_name) {
 524             char *aliases[2];
 525             if (! strcmp(target_name, jack_port_name(remote_port))) {
 526                 return remote_port;
 527             }
 528             aliases[0] = alias1;
 529             aliases[1] = alias2;
 530             switch (jack_port_get_aliases(remote_port, aliases)) {
 531             case -1:
 532                 /* Sigh ... */
 533                 die("jack_port_get_aliases", "Failed to get port aliases");
 534             case 2:
 535                 if (! strcmp(target_name, alias2)) {
 536                     return remote_port;
 537                 }
 538                 /* Fallthrough on purpose */
 539             case 1:
 540                 if (! strcmp(target_name, alias1)) {
 541                     return remote_port;
 542                 }
 543                 /* Fallthrough on purpose */
 544             case 0:
 545                 return NULL;
 546             }
 547             /* This shouldn't happen. */
 548             assert(0);
 549         }
 550         return remote_port;
 551     }
 552     if (! strcmp(jack_port_name(remote_port), jack_port_name(current_port))) {
 553         const char **port_names;
 554         if (target_name) {
 555             return NULL;
 556         }
 557         port_names = jack_port_get_connections(local_port);
 558         if (port_names == NULL) {
 559             return NULL;
 560         }
 561
 562         /* If a connected port is disconnected and other ports are still
 563            connected, then we take the first port name in the array and use it
 564            as our remote port.  It's a dumb implementation. */
 565         current_port = jack_port_by_name(client, port_names[0]);
 566         jack_free(port_names);
 567         if (current_port == NULL) {
 568             /* Sigh */
 569             die("jack_port_by_name", "failed to get port by name");
 570         }
 571     }
 572     return current_port;
 573 }
 574
 575 static int
 576 wait_semaphore(semaphore_t semaphore, int block)
 577 {
 578
 579 #ifdef WIN32
 580     DWORD result = WaitForSingleObject(semaphore, block ? INFINITE : 0);
 581     switch (result) {
 582     case WAIT_OBJECT_0:
 583         return 1;
 584     case WAIT_TIMEOUT:
 585         return 0;
 586     }
 587     return -1;
 588 #else
 589     if (block) {
 590         while (sem_wait(semaphore)) {
 591             if (errno != EINTR) {
 592                 return -1;
 593             }
 594         }
 595     } else {
 596         while (sem_trywait(semaphore)) {
 597             switch (errno) {
 598             case EAGAIN:
 599                 return 0;
 600             case EINTR:
 601                 continue;
 602             default:
 603                 return -1;
 604             }
 605         }
 606     }
 607     return 1;
 608 #endif
 609
 610 }
 611
 612 int
 613 main(int argc, char **argv)
 614 {
 615     int jitter_plot[101];
 616     int latency_plot[101];
 617     int long_index = 0;
 618     struct option long_options[] = {
 619         {"help", 0, NULL, 'h'},
 620         {"message-size", 1, NULL, 'm'},
 621         {"samples", 1, NULL, 's'},
 622         {"timeout", 1, NULL, 't'}
 623     };
 624     size_t name_arg_count;
 625     size_t name_size;
 626     char *option_string = "hm:s:t:";
 627     int show_usage = 0;
 628     connections_established = 0;
 629     error_message = NULL;
 630     message_size = 3;
 631     program_name = argv[0];
 632     remote_in_port = 0;
 633     remote_out_port = 0;
 634     samples = 1024;
 635     timeout = 5;
 636
 637     for (;;) {
 638         char c = getopt_long(argc, argv, option_string, long_options,
 639                              &long_index);
 640         switch (c) {
 641         case 'h':
 642             show_usage = 1;
 643             break;
 644         case 'm':
 645             message_size = parse_positive_number_arg(optarg, "message-size");
 646             break;
 647         case 's':
 648             samples = parse_positive_number_arg(optarg, "samples");
 649             break;
 650         case 't':
 651             timeout = parse_positive_number_arg(optarg, "timeout");
 652             break;
 653         default:
 654             {
 655                 char *s = "'- '";
 656                 s[2] = c;
 657                 die(s, "invalid switch");
 658             }
 659         case -1:
 660             if (show_usage) {
 661                 output_usage();
 662                 exit(EXIT_SUCCESS);
 663             }
 664             goto parse_port_names;
 665         case 1:
 666             /* end of switch :) */
 667             ;
 668         }
 669     }
 670  parse_port_names:
 671     name_arg_count = argc - optind;
 672     switch (name_arg_count) {
 673     case 2:
 674         target_in_port_name = argv[optind + 1];
 675         target_out_port_name = argv[optind];
 676         break;
 677     case 0:
 678         target_in_port_name = 0;
 679         target_out_port_name = 0;
 680         break;
 681     default:
 682         output_usage();
 683         return EXIT_FAILURE;
 684     }
 685     name_size = jack_port_name_size();
 686     alias1 = malloc(name_size * sizeof(char));
 687     if (alias1 == NULL) {
 688         error_message = strerror(errno);
 689         error_source = "malloc";
 690         goto show_error;
 691     }
 692     alias2 = malloc(name_size * sizeof(char));
 693     if (alias2 == NULL) {
 694         error_message = strerror(errno);
 695         error_source = "malloc";
 696         goto free_alias1;
 697     }
 698     latency_values = malloc(sizeof(jack_nframes_t) * samples);
 699     if (latency_values == NULL) {
 700         error_message = strerror(errno);
 701         error_source = "malloc";
 702         goto free_alias2;
 703     }
 704     latency_time_values = malloc(sizeof(jack_time_t) * samples);
 705     if (latency_time_values == NULL) {
 706         error_message = strerror(errno);
 707         error_source = "malloc";
 708         goto free_latency_values;
 709     }
 710     message_1 = malloc(message_size * sizeof(jack_midi_data_t));
 711     if (message_1 == NULL) {
 712         error_message = strerror(errno);
 713         error_source = "malloc";
 714         goto free_latency_time_values;
 715     }
 716     message_2 = malloc(message_size * sizeof(jack_midi_data_t));
 717     if (message_2 == NULL) {
 718         error_message = strerror(errno);
 719         error_source = "malloc";
 720         goto free_message_1;
 721     }
 722     switch (message_size) {
 723     case 1:
 724         message_1[0] = 0xf6;
 725         message_2[0] = 0xfe;
 726         break;
 727     case 2:
 728         message_1[0] = 0xc0;
 729         message_1[1] = 0x00;
 730         message_2[0] = 0xd0;
 731         message_2[1] = 0x7f;
 732         break;
 733     case 3:
 734         message_1[0] = 0x80;
 735         message_1[1] = 0x00;
 736         message_1[2] = 0x00;
 737         message_2[0] = 0x90;
 738         message_2[1] = 0x7f;
 739         message_2[2] = 0x7f;
 740         break;
 741     default:
 742         message_1[0] = 0xf0;
 743         memset(message_1 + 1, 0,
 744                (message_size - 2) * sizeof(jack_midi_data_t));
 745         message_1[message_size - 1] = 0xf7;
 746         message_2[0] = 0xf0;
 747         memset(message_2 + 1, 0x7f,
 748                (message_size - 2) * sizeof(jack_midi_data_t));
 749         message_2[message_size - 1] = 0xf7;
 750     }
 751     client = jack_client_open(program_name, JackNullOption, NULL);
 752     if (client == NULL) {
 753         error_message = "failed to open JACK client";
 754         error_source = "jack_client_open";
 755         goto free_message_2;
 756     }
 757     in_port = jack_port_register(client, "in", JACK_DEFAULT_MIDI_TYPE,
 758                                  JackPortIsInput, 0);
 759     if (in_port == NULL) {
 760         error_message = "failed to register MIDI-in port";
 761         error_source = "jack_port_register";
 762         goto close_client;
 763     }
 764     out_port = jack_port_register(client, "out", JACK_DEFAULT_MIDI_TYPE,
 765                                   JackPortIsOutput, 0);
 766     if (out_port == NULL) {
 767         error_message = "failed to register MIDI-out port";
 768         error_source = "jack_port_register";
 769         goto unregister_in_port;
 770     }
 771     if (jack_set_process_callback(client, handle_process, NULL)) {
 772         error_message = "failed to set process callback";
 773         error_source = "jack_set_process_callback";
 774         goto unregister_out_port;
 775     }
 776     if (jack_set_xrun_callback(client, handle_xrun, NULL)) {
 777         error_message = "failed to set xrun callback";
 778         error_source = "jack_set_xrun_callback";
 779         goto unregister_out_port;
 780     }
 781     if (jack_set_port_connect_callback(client, handle_port_connection_change,
 782                                        NULL)) {
 783         error_message = "failed to set port connection callback";
 784         error_source = "jack_set_port_connect_callback";
 785         goto unregister_out_port;
 786     }
 787     jack_on_shutdown(client, handle_shutdown, NULL);
 788     jack_set_info_function(handle_info);
 789     process_state = 0;
 790
 791     connect_semaphore = create_semaphore(0);
 792     if (connect_semaphore == NULL) {
 793         error_message = get_semaphore_error();
 794         error_source = "create_semaphore";
 795         goto unregister_out_port;
 796     }
 797     init_semaphore = create_semaphore(1);
 798     if (init_semaphore == NULL) {
 799         error_message = get_semaphore_error();
 800         error_source = "create_semaphore";
 801         goto destroy_connect_semaphore;;
 802     }
 803     process_semaphore = create_semaphore(2);
 804     if (process_semaphore == NULL) {
 805         error_message = get_semaphore_error();
 806         error_source = "create_semaphore";
 807         goto destroy_init_semaphore;
 808     }
 809     if (jack_activate(client)) {
 810         error_message = "could not activate client";
 811         error_source = "jack_activate";
 812         goto destroy_process_semaphore;
 813     }
 814     if (name_arg_count) {
 815         if (jack_connect(client, jack_port_name(out_port),
 816                          target_out_port_name)) {
 817             error_message = "could not connect MIDI out port";
 818             error_source = "jack_connect";
 819             goto deactivate_client;
 820         }
 821         if (jack_connect(client, target_in_port_name,
 822                          jack_port_name(in_port))) {
 823             error_message = "could not connect MIDI in port";
 824             error_source = "jack_connect";
 825             goto deactivate_client;
 826         }
 827     }
 828     if (! register_signal_handler(handle_signal)) {
 829         error_message = strerror(errno);
 830         error_source = "register_signal_handler";
 831         goto deactivate_client;
 832     }
 833     printf("Waiting for connections ...\n");
 834     if (wait_semaphore(connect_semaphore, 1) == -1) {
 835         error_message = get_semaphore_error();
 836         error_source = "wait_semaphore";
 837         goto deactivate_client;
 838     }
 839     if (connections_established) {
 840         printf("Waiting for test completion ...\n\n");
 841         if (wait_semaphore(process_semaphore, 1) == -1) {
 842             error_message = get_semaphore_error();
 843             error_source = "wait_semaphore";
 844             goto deactivate_client;
 845         }
 846     }
 847     if (! register_signal_handler(SIG_DFL)) {
 848         error_message = strerror(errno);
 849         error_source = "register_signal_handler";
 850         goto deactivate_client;
 851     }
 852     if (process_state == 2) {
 853         double average_latency = ((double) total_latency) / samples;
 854         double average_latency_time = total_latency_time / samples;
 855         size_t i;
 856         double latency_plot_offset =
 857             floor(((double) lowest_latency_time) / 100.0) / 10.0;
 858         double sample_rate = (double) jack_get_sample_rate(client);
 859         jack_nframes_t total_jitter = 0;
 860         jack_time_t total_jitter_time = 0;
 861         for (i = 0; i <= 100; i++) {
 862             jitter_plot[i] = 0;
 863             latency_plot[i] = 0;
 864         }
 865         for (i = 0; i < samples; i++) {
 866             double latency_time_value = (double) latency_time_values[i];
 867             double latency_plot_time =
 868                 (latency_time_value / 1000.0) - latency_plot_offset;
 869             double jitter_time = ABS(average_latency_time -
 870                                      latency_time_value);
 871             if (latency_plot_time >= 10.0) {
 872                 (latency_plot[100])++;
 873             } else {
 874                 (latency_plot[(int) (latency_plot_time * 10.0)])++;
 875             }
 876             if (jitter_time >= 10000.0) {
 877                 (jitter_plot[100])++;
 878             } else {
 879                 (jitter_plot[(int) (jitter_time / 100.0)])++;
 880             }
 881             total_jitter += ABS(average_latency -
 882                                 ((double) latency_values[i]));
 883             total_jitter_time += jitter_time;
 884         }
 885         printf("Reported out-port latency: %.2f-%.2f ms (%u-%u frames)\n"
 886                "Reported in-port latency: %.2f-%.2f ms (%u-%u frames)\n"
 887                "Average latency: %.2f ms (%.2f frames)\n"
 888                "Lowest latency: %.2f ms (%u frames)\n"
 889                "Highest latency: %.2f ms (%u frames)\n"
 890                "Peak MIDI jitter: %.2f ms (%u frames)\n"
 891                "Average MIDI jitter: %.2f ms (%.2f frames)\n",
 892                (out_latency_range.min / sample_rate) * 1000.0,
 893                (out_latency_range.max / sample_rate) * 1000.0,
 894                out_latency_range.min, out_latency_range.max,
 895                (in_latency_range.min / sample_rate) * 1000.0,
 896                (in_latency_range.max / sample_rate) * 1000.0,
 897                in_latency_range.min, in_latency_range.max,
 898                average_latency_time / 1000.0, average_latency,
 899                lowest_latency_time / 1000.0, lowest_latency,
 900                highest_latency_time / 1000.0, highest_latency,
 901                (highest_latency_time - lowest_latency_time) / 1000.0,
 902                highest_latency - lowest_latency,
 903                (total_jitter_time / 1000.0) / samples,
 904                ((double) total_jitter) / samples);
 905         printf("\nJitter Plot:\n");
 906         for (i = 0; i < 100; i++) {
 907             if (jitter_plot[i]) {
 908                 printf("%.1f - %.1f ms: %d\n", ((float) i) / 10.0,
 909                        ((float) (i + 1)) / 10.0, jitter_plot[i]);
 910             }
 911         }
 912         if (jitter_plot[100]) {
 913             printf("     > 10 ms: %d\n", jitter_plot[100]);
 914         }
 915         printf("\nLatency Plot:\n");
 916         for (i = 0; i < 100; i++) {
 917             if (latency_plot[i]) {
 918                 printf("%.1f - %.1f ms: %d\n",
 919                        latency_plot_offset + (((float) i) / 10.0),
 920                        latency_plot_offset + (((float) (i + 1)) / 10.0),
 921                        latency_plot[i]);
 922             }
 923         }
 924         if (latency_plot[100]) {
 925             printf("     > %.1f ms: %d\n", latency_plot_offset + 10.0,
 926                    latency_plot[100]);
 927         }
 928     }
 929  deactivate_client:
 930     jack_deactivate(client);
 931     printf("\nMessages sent: %d\nMessages received: %d\n", messages_sent,
 932            messages_received);
 933     if (unexpected_messages) {
 934         printf("Unexpected messages received: %d\n", unexpected_messages);
 935     }
 936     if (xrun_count) {
 937         printf("Xruns: %d\n", xrun_count);
 938     }
 939  destroy_process_semaphore:
 940     destroy_semaphore(process_semaphore, 2);
 941  destroy_init_semaphore:
 942     destroy_semaphore(init_semaphore, 1);
 943  destroy_connect_semaphore:
 944     destroy_semaphore(connect_semaphore, 0);
 945  unregister_out_port:
 946     jack_port_unregister(client, out_port);
 947  unregister_in_port:
 948     jack_port_unregister(client, in_port);
 949  close_client:
 950     jack_client_close(client);
 951  free_message_2:
 952     free(message_2);
 953  free_message_1:
 954     free(message_1);
 955  free_latency_time_values:
 956     free(latency_time_values);
 957  free_latency_values:
 958     free(latency_values);
 959  free_alias2:
 960     free(alias2);
 961  free_alias1:
 962     free(alias1);
 963     if (error_message != NULL) {
 964     show_error:
 965         output_error(error_source, error_message);
 966         exit(EXIT_FAILURE);
 967     }
 968     return EXIT_SUCCESS;
 969 }