| 1 | #include <sys/select.h> |
| 2 | #include <sys/stat.h> |
| 3 | |
| 4 | #include <assert.h> |
| 5 | #include <ctype.h> |
| 6 | #include <errno.h> |
| 7 | #include <fcntl.h> |
| 8 | #include <stdio.h> |
| 9 | #include <stdlib.h> |
| 10 | #include <string.h> |
| 11 | #include <time.h> |
| 12 | #include <unistd.h> |
| 13 | |
| 14 | #include <X11/Xlib.h> |
| 15 | |
| 16 | #include "bsdtimespec.h" |
| 17 | #include "khlib_log.h" |
| 18 | #include "khlib_time.h" |
| 19 | |
| 20 | #define usage(...) { \ |
| 21 | print_usage(); \ |
| 22 | fprintf(stderr, "Error:\n " __VA_ARGS__); \ |
| 23 | exit(EXIT_FAILURE); \ |
| 24 | } |
| 25 | #define ERRMSG "ERROR" |
| 26 | |
| 27 | |
| 28 | static const char errmsg[] = ERRMSG; |
| 29 | static const int errlen = sizeof(ERRMSG) - 1; |
| 30 | |
| 31 | char *argv0; |
| 32 | |
| 33 | /* TODO: Convert slot list to slot array. */ |
| 34 | typedef struct Slot Slot; |
| 35 | struct Slot { |
| 36 | char *in_fifo; |
| 37 | int in_fd; |
| 38 | struct timespec in_last_read; |
| 39 | struct timespec out_ttl; |
| 40 | int out_width; |
| 41 | int out_pos_lo; /* Lowest position on the output buffer. */ |
| 42 | int out_pos_cur; /* Current position on the output buffer. */ |
| 43 | int out_pos_hi; /* Highest position on the output buffer. */ |
| 44 | Slot *next; |
| 45 | }; |
| 46 | |
| 47 | typedef struct Config Config; |
| 48 | struct Config { |
| 49 | double interval; |
| 50 | char * separator; |
| 51 | Slot * slots; |
| 52 | int slot_count; |
| 53 | int total_width; |
| 54 | int output_to_x_root_window; |
| 55 | }; |
| 56 | |
| 57 | enum read_status { |
| 58 | END_OF_FILE, |
| 59 | END_OF_MESSAGE, |
| 60 | RETRY, |
| 61 | FAILURE |
| 62 | }; |
| 63 | |
| 64 | Slot * |
| 65 | slots_rev(Slot *old) |
| 66 | { |
| 67 | Slot *tmp = NULL; |
| 68 | Slot *new = NULL; |
| 69 | |
| 70 | while (old) { |
| 71 | tmp = old->next; |
| 72 | old->next = new; |
| 73 | new = old; |
| 74 | old = tmp; |
| 75 | } |
| 76 | return new; |
| 77 | } |
| 78 | |
| 79 | void |
| 80 | slot_print(Slot *s) |
| 81 | { |
| 82 | khlib_info("Slot " |
| 83 | "{" |
| 84 | " in_fifo = %s," |
| 85 | " in_fd = %d," |
| 86 | " out_width = %d," |
| 87 | " in_last_read = {tv_sec = %ld, tv_nsec = %ld}" |
| 88 | " out_ttl = {tv_sec = %ld, tv_nsec = %ld}," |
| 89 | " out_pos_lo = %d," |
| 90 | " out_pos_cur = %d," |
| 91 | " out_pos_hi = %d," |
| 92 | " next = %p," |
| 93 | " }\n", |
| 94 | s->in_fifo, |
| 95 | s->in_fd, |
| 96 | s->out_width, |
| 97 | s->in_last_read.tv_sec, |
| 98 | s->in_last_read.tv_nsec, |
| 99 | s->out_ttl.tv_sec, |
| 100 | s->out_ttl.tv_nsec, |
| 101 | s->out_pos_lo, |
| 102 | s->out_pos_cur, |
| 103 | s->out_pos_hi, |
| 104 | s->next |
| 105 | ); |
| 106 | } |
| 107 | |
| 108 | void |
| 109 | slots_print(Slot *head) |
| 110 | { |
| 111 | for (Slot *s = head; s; s = s->next) { |
| 112 | slot_print(s); |
| 113 | } |
| 114 | } |
| 115 | |
| 116 | void |
| 117 | config_print(Config *cfg) |
| 118 | { |
| 119 | khlib_info( |
| 120 | "Config " |
| 121 | "{" |
| 122 | " interval = %f," |
| 123 | " separator = %s," |
| 124 | " slot_count = %d," |
| 125 | " total_width = %d," |
| 126 | " slots = ..." |
| 127 | " }\n", |
| 128 | cfg->interval, |
| 129 | cfg->separator, |
| 130 | cfg->slot_count, |
| 131 | cfg->total_width |
| 132 | ); |
| 133 | slots_print(cfg->slots); |
| 134 | } |
| 135 | |
| 136 | int |
| 137 | is_pos_num(char *str) |
| 138 | { |
| 139 | while (*str != '\0') |
| 140 | if (!isdigit(*(str++))) |
| 141 | return 0; |
| 142 | return 1; |
| 143 | } |
| 144 | |
| 145 | int |
| 146 | is_decimal(char *str) |
| 147 | { |
| 148 | char c; |
| 149 | int seen = 0; |
| 150 | |
| 151 | while ((c = *(str++)) != '\0') |
| 152 | if (!isdigit(c)) { |
| 153 | if (c == '.' && !seen++) |
| 154 | continue; |
| 155 | else |
| 156 | return 0; |
| 157 | } |
| 158 | return 1; |
| 159 | } |
| 160 | |
| 161 | void |
| 162 | print_usage() |
| 163 | { |
| 164 | assert(argv0); |
| 165 | fprintf( |
| 166 | stderr, |
| 167 | "\n" |
| 168 | "Usage: %s [OPTION ...] SPEC [SPEC ...]\n" |
| 169 | "\n" |
| 170 | " SPEC = FILE_PATH DATA_WIDTH DATA_TTL\n" |
| 171 | " FILE_PATH = string\n" |
| 172 | " DATA_WIDTH = int (* (positive) number of characters *)\n" |
| 173 | " DATA_TTL = float (* (positive) number of seconds *)\n" |
| 174 | " OPTION = -i INTERVAL\n" |
| 175 | " | -s SEPARATOR\n" |
| 176 | " | -x (* Output to X root window *)\n" |
| 177 | " | -l LOG_LEVEL\n" |
| 178 | " SEPARATOR = string\n" |
| 179 | " INTERVAL = float (* (positive) number of seconds *)\n" |
| 180 | " LOG_LEVEL = int (* %d through %d *)\n" |
| 181 | "\n", |
| 182 | argv0, |
| 183 | Nothing, |
| 184 | Debug |
| 185 | ); |
| 186 | fprintf( |
| 187 | stderr, |
| 188 | "Example: %s -i 1 /dev/shm/khatus/khatus_sensor_x 4 10\n" |
| 189 | "\n", |
| 190 | argv0 |
| 191 | ); |
| 192 | } |
| 193 | |
| 194 | /* For mutually-recursive calls. */ |
| 195 | void opts_parse_any(Config *, int, char *[], int); |
| 196 | |
| 197 | void |
| 198 | parse_opts_opt_i(Config *cfg, int argc, char *argv[], int i) |
| 199 | { |
| 200 | char *param; |
| 201 | |
| 202 | if (i >= argc) |
| 203 | usage("Option -i parameter is missing.\n"); |
| 204 | param = argv[i++]; |
| 205 | if (!is_decimal(param)) |
| 206 | usage("Option -i parameter is invalid: \"%s\"\n", param); |
| 207 | cfg->interval = atof(param); |
| 208 | opts_parse_any(cfg, argc, argv, i); |
| 209 | } |
| 210 | |
| 211 | void |
| 212 | parse_opts_opt_s(Config *cfg, int argc, char *argv[], int i) |
| 213 | { |
| 214 | if (i >= argc) |
| 215 | usage("Option -s parameter is missing.\n"); |
| 216 | cfg->separator = calloc((strlen(argv[i]) + 1), sizeof(char)); |
| 217 | strcpy(cfg->separator, argv[i]); |
| 218 | opts_parse_any(cfg, argc, argv, ++i); |
| 219 | } |
| 220 | |
| 221 | void |
| 222 | parse_opts_opt_l(Config *cfg, int argc, char *argv[], int i) |
| 223 | { |
| 224 | char *param; |
| 225 | int log_level; |
| 226 | |
| 227 | if (i >= argc) |
| 228 | usage("Option -l parameter is missing.\n"); |
| 229 | param = argv[i++]; |
| 230 | if (!is_pos_num(param)) |
| 231 | usage("Option -l parameter is invalid: \"%s\"\n", param); |
| 232 | log_level = atoi(param); |
| 233 | if (log_level > Debug) |
| 234 | usage( |
| 235 | "Option -l value (%d) exceeds maximum (%d)\n", |
| 236 | log_level, |
| 237 | Debug |
| 238 | ); |
| 239 | _khlib_log_level = log_level; |
| 240 | opts_parse_any(cfg, argc, argv, i); |
| 241 | } |
| 242 | |
| 243 | void |
| 244 | parse_opts_opt(Config *cfg, int argc, char *argv[], int i) |
| 245 | { |
| 246 | switch (argv[i][1]) { |
| 247 | case 'i': |
| 248 | /* TODO: Generic set_int */ |
| 249 | parse_opts_opt_i(cfg, argc, argv, ++i); |
| 250 | break; |
| 251 | case 's': |
| 252 | /* TODO: Generic set_str */ |
| 253 | parse_opts_opt_s(cfg, argc, argv, ++i); |
| 254 | break; |
| 255 | case 'x': |
| 256 | cfg->output_to_x_root_window = 1; |
| 257 | opts_parse_any(cfg, argc, argv, ++i); |
| 258 | break; |
| 259 | case 'l': |
| 260 | /* TODO: Generic set_int */ |
| 261 | parse_opts_opt_l(cfg, argc, argv, ++i); |
| 262 | break; |
| 263 | default : |
| 264 | usage("Option \"%s\" is invalid\n", argv[i]); |
| 265 | } |
| 266 | } |
| 267 | |
| 268 | void |
| 269 | parse_opts_spec(Config *cfg, int argc, char *argv[], int i) |
| 270 | { |
| 271 | char *n; |
| 272 | char *w; |
| 273 | char *t; |
| 274 | struct timespec in_last_read; |
| 275 | Slot *s; |
| 276 | |
| 277 | if ((i + 3) > argc) |
| 278 | usage( |
| 279 | "[spec] Parameter(s) missing for fifo \"%s\".\n", |
| 280 | argv[i] |
| 281 | ); |
| 282 | |
| 283 | n = argv[i++]; |
| 284 | w = argv[i++]; |
| 285 | t = argv[i++]; |
| 286 | |
| 287 | if (!is_pos_num(w)) |
| 288 | usage("[spec] Invalid width: \"%s\", for fifo \"%s\"\n", w, n); |
| 289 | if (!is_decimal(t)) |
| 290 | usage("[spec] Invalid TTL: \"%s\", for fifo \"%s\"\n", t, n); |
| 291 | |
| 292 | in_last_read.tv_sec = 0; |
| 293 | in_last_read.tv_nsec = 0; |
| 294 | s = calloc(1, sizeof(struct Slot)); |
| 295 | |
| 296 | if (s) { |
| 297 | s->in_fifo = n; |
| 298 | s->in_fd = -1; |
| 299 | s->out_width = atoi(w); |
| 300 | s->out_ttl = khlib_timespec_of_float(atof(t)); |
| 301 | s->in_last_read = in_last_read; |
| 302 | s->out_pos_lo = cfg->total_width; |
| 303 | s->out_pos_cur = s->out_pos_lo; |
| 304 | s->out_pos_hi = s->out_pos_lo + s->out_width - 1; |
| 305 | s->next = cfg->slots; |
| 306 | |
| 307 | cfg->slots = s; |
| 308 | cfg->total_width += s->out_width; |
| 309 | cfg->slot_count++; |
| 310 | } else { |
| 311 | khlib_fatal("[memory] Allocation failure."); |
| 312 | } |
| 313 | opts_parse_any(cfg, argc, argv, i); |
| 314 | } |
| 315 | |
| 316 | void |
| 317 | opts_parse_any(Config *cfg, int argc, char *argv[], int i) |
| 318 | { |
| 319 | if (i < argc) { |
| 320 | switch (argv[i][0]) { |
| 321 | case '-': |
| 322 | parse_opts_opt(cfg, argc, argv, i); |
| 323 | break; |
| 324 | default : |
| 325 | parse_opts_spec(cfg, argc, argv, i); |
| 326 | } |
| 327 | } |
| 328 | } |
| 329 | |
| 330 | void |
| 331 | opts_parse(Config *cfg, int argc, char *argv[]) |
| 332 | { |
| 333 | opts_parse_any(cfg, argc, argv, 1); |
| 334 | cfg->slots = slots_rev(cfg->slots); |
| 335 | } |
| 336 | |
| 337 | void |
| 338 | slot_expire(Slot *s, struct timespec t, char *buf) |
| 339 | { |
| 340 | struct timespec td; |
| 341 | |
| 342 | timespecsub(&t, &(s->in_last_read), &td); |
| 343 | if (timespeccmp(&td, &(s->out_ttl), >=)) { |
| 344 | /* TODO: Maybe configurable expiry character. */ |
| 345 | memset(buf + s->out_pos_lo, '_', s->out_pos_hi - s->out_pos_lo); |
| 346 | khlib_warn("Slot expired: \"%s\"\n", s->in_fifo); |
| 347 | } |
| 348 | } |
| 349 | |
| 350 | void |
| 351 | slot_read_error(Slot *s, char *buf) |
| 352 | { |
| 353 | char *b; |
| 354 | int i; |
| 355 | |
| 356 | b = buf + s->out_pos_lo; |
| 357 | /* Copy as much of the error message as possible. |
| 358 | * EXCLUDING the terminating \0. */ |
| 359 | for (i = 0; i < errlen && i < s->out_width; i++) |
| 360 | b[i] = errmsg[i]; |
| 361 | /* Any remaining positions: */ |
| 362 | for (; i < s->out_width; i++) |
| 363 | b[i] = '_'; |
| 364 | } |
| 365 | |
| 366 | enum read_status |
| 367 | slot_read(Slot *s, struct timespec t, char *buf) |
| 368 | { |
| 369 | char c; /* Character read. */ |
| 370 | int r; /* Remaining unused positions in buffer range. */ |
| 371 | |
| 372 | for (;;) { |
| 373 | switch (read(s->in_fd, &c, 1)) { |
| 374 | case -1: |
| 375 | khlib_error( |
| 376 | "Failed to read: \"%s\". errno: %d, msg: %s\n", |
| 377 | s->in_fifo, |
| 378 | errno, |
| 379 | strerror(errno) |
| 380 | ); |
| 381 | switch (errno) { |
| 382 | case EINTR: |
| 383 | case EAGAIN: |
| 384 | return RETRY; |
| 385 | default: |
| 386 | return FAILURE; |
| 387 | } |
| 388 | case 0: |
| 389 | khlib_debug("%s: End of FILE\n", s->in_fifo); |
| 390 | s->out_pos_cur = s->out_pos_lo; |
| 391 | return END_OF_FILE; |
| 392 | case 1: |
| 393 | /* TODO: Consider making msg term char a CLI option */ |
| 394 | if (c == '\n' || c == '\0') { |
| 395 | r = s->out_pos_hi - s->out_pos_cur; |
| 396 | if (r > 0) |
| 397 | memset(buf + s->out_pos_cur, ' ', r); |
| 398 | s->out_pos_cur = s->out_pos_lo; |
| 399 | s->in_last_read = t; |
| 400 | return END_OF_MESSAGE; |
| 401 | } else { |
| 402 | if (s->out_pos_cur <= s->out_pos_hi) |
| 403 | buf[s->out_pos_cur++] = c; |
| 404 | /* Drop beyond available range. */ |
| 405 | /* |
| 406 | * TODO Define max after which we stop reading. |
| 407 | * To ensure that a rogue large message |
| 408 | * doesn't trap us here. |
| 409 | */ |
| 410 | } |
| 411 | break; |
| 412 | default: |
| 413 | assert(0); |
| 414 | } |
| 415 | } |
| 416 | } |
| 417 | |
| 418 | void |
| 419 | slots_read(Config *cfg, struct timespec *ti, char *buf) |
| 420 | { |
| 421 | fd_set fds; |
| 422 | int maxfd = -1; |
| 423 | int ready = 0; |
| 424 | struct stat st; |
| 425 | struct timespec t; |
| 426 | Slot *s; |
| 427 | |
| 428 | FD_ZERO(&fds); |
| 429 | for (s = cfg->slots; s; s = s->next) { |
| 430 | /* TODO: Create the FIFO if it doesn't already exist. */ |
| 431 | if (lstat(s->in_fifo, &st) < 0) { |
| 432 | khlib_error( |
| 433 | "Cannot stat \"%s\". Error: %s\n", |
| 434 | s->in_fifo, |
| 435 | strerror(errno) |
| 436 | ); |
| 437 | slot_read_error(s, buf); |
| 438 | continue; |
| 439 | } |
| 440 | if (!(st.st_mode & S_IFIFO)) { |
| 441 | khlib_error("\"%s\" is not a FIFO\n", s->in_fifo); |
| 442 | slot_read_error(s, buf); |
| 443 | continue; |
| 444 | } |
| 445 | if (s->in_fd < 0) { |
| 446 | khlib_debug( |
| 447 | "%s: closed. opening. in_fd: %d\n", |
| 448 | s->in_fifo, |
| 449 | s->in_fd |
| 450 | ); |
| 451 | s->in_fd = open(s->in_fifo, O_RDONLY | O_NONBLOCK); |
| 452 | } else { |
| 453 | khlib_debug( |
| 454 | "%s: already openned. in_fd: %d\n", |
| 455 | s->in_fifo, |
| 456 | s->in_fd |
| 457 | ); |
| 458 | } |
| 459 | if (s->in_fd == -1) { |
| 460 | /* TODO Consider backing off retries for failed slots */ |
| 461 | khlib_error("Failed to open \"%s\"\n", s->in_fifo); |
| 462 | slot_read_error(s, buf); |
| 463 | continue; |
| 464 | } |
| 465 | khlib_debug("%s: open. in_fd: %d\n", s->in_fifo, s->in_fd); |
| 466 | if (s->in_fd > maxfd) |
| 467 | maxfd = s->in_fd; |
| 468 | FD_SET(s->in_fd, &fds); |
| 469 | } |
| 470 | khlib_debug("selecting...\n"); |
| 471 | ready = pselect(maxfd + 1, &fds, NULL, NULL, ti, NULL); |
| 472 | khlib_debug("ready: %d\n", ready); |
| 473 | clock_gettime(CLOCK_MONOTONIC, &t); |
| 474 | if (ready == -1) { |
| 475 | switch (errno) { |
| 476 | case EINTR: |
| 477 | khlib_error( |
| 478 | "pselect temp failure: %d, errno: %d, msg: %s\n", |
| 479 | ready, |
| 480 | errno, |
| 481 | strerror(errno) |
| 482 | ); |
| 483 | /* TODO: Reconsider what to do here. */ |
| 484 | return; |
| 485 | default: |
| 486 | khlib_fatal( |
| 487 | "pselect failed: %d, errno: %d, msg: %s\n", |
| 488 | ready, |
| 489 | errno, |
| 490 | strerror(errno) |
| 491 | ); |
| 492 | } |
| 493 | } |
| 494 | /* At-least-once ensures that expiries are still checked on timeouts. */ |
| 495 | do { |
| 496 | for (s = cfg->slots; s; s = s->next) { |
| 497 | if (FD_ISSET(s->in_fd, &fds)) { |
| 498 | khlib_debug("reading: %s\n", s->in_fifo); |
| 499 | switch (slot_read(s, t, buf)) { |
| 500 | /* |
| 501 | * ### MESSAGE LOSS ### |
| 502 | * is introduced by closing at EOM in addition |
| 503 | * to EOF, since there may be unread messages |
| 504 | * remaining in the pipe. However, |
| 505 | * |
| 506 | * ### INTER-MESSAGE PUSHBACK ### |
| 507 | * is also gained, since pipes block at the |
| 508 | * "open" call. |
| 509 | * |
| 510 | * This is an acceptable trade-off because we |
| 511 | * are a stateless reporter of a _most-recent_ |
| 512 | * status, not a stateful accumulator. |
| 513 | */ |
| 514 | case END_OF_MESSAGE: |
| 515 | case END_OF_FILE: |
| 516 | case FAILURE: |
| 517 | close(s->in_fd); |
| 518 | s->in_fd = -1; |
| 519 | ready--; |
| 520 | break; |
| 521 | case RETRY: |
| 522 | break; |
| 523 | default: |
| 524 | assert(0); |
| 525 | } |
| 526 | } else { |
| 527 | slot_expire(s, t, buf); |
| 528 | } |
| 529 | } |
| 530 | } while (ready); |
| 531 | assert(ready == 0); |
| 532 | } |
| 533 | |
| 534 | int |
| 535 | main(int argc, char *argv[]) |
| 536 | { |
| 537 | Config cfg = { |
| 538 | .interval = 1.0, |
| 539 | .separator = "|", |
| 540 | .slots = NULL, |
| 541 | .slot_count = 0, |
| 542 | .total_width = 0, |
| 543 | .output_to_x_root_window = 0, |
| 544 | }; |
| 545 | |
| 546 | int width = 0; |
| 547 | int nslots = 0; |
| 548 | int seplen = 0; |
| 549 | int prefix = 0; |
| 550 | int errors = 0; |
| 551 | char *buf; |
| 552 | Display *d = NULL; |
| 553 | struct stat st; |
| 554 | struct timespec |
| 555 | t0, /* time stamp. before reading slots */ |
| 556 | t1, /* time stamp. after reading slots */ |
| 557 | ti, /* time interval desired (t1 - t0) */ |
| 558 | td, /* time interval measured (t1 - t0) */ |
| 559 | tc; /* time interval correction (ti - td) when td < ti */ |
| 560 | Slot *s; |
| 561 | |
| 562 | argv0 = argv[0]; |
| 563 | |
| 564 | opts_parse(&cfg, argc, argv); |
| 565 | khlib_debug("argv0 = %s\n", argv0); |
| 566 | config_print(&cfg); |
| 567 | |
| 568 | ti = khlib_timespec_of_float(cfg.interval); |
| 569 | |
| 570 | if (cfg.slots == NULL) |
| 571 | usage("No slot specs were given!\n"); |
| 572 | |
| 573 | /* 1st pass to check file existence and type */ |
| 574 | for (s = cfg.slots; s; s = s->next) { |
| 575 | if (lstat(s->in_fifo, &st) < 0) { |
| 576 | khlib_error( |
| 577 | "Cannot stat \"%s\". Error: %s\n", |
| 578 | s->in_fifo, |
| 579 | strerror(errno) |
| 580 | ); |
| 581 | errors++; |
| 582 | continue; |
| 583 | } |
| 584 | if (!(st.st_mode & S_IFIFO)) { |
| 585 | khlib_error("\"%s\" is not a FIFO\n", s->in_fifo); |
| 586 | errors++; |
| 587 | continue; |
| 588 | } |
| 589 | } |
| 590 | if (errors) |
| 591 | khlib_fatal( |
| 592 | "Encountered errors with given file paths. See log.\n" |
| 593 | ); |
| 594 | |
| 595 | width = cfg.total_width; |
| 596 | seplen = strlen(cfg.separator); |
| 597 | |
| 598 | /* 2nd pass to make space for separators */ |
| 599 | for (s = cfg.slots; s; s = s->next) { |
| 600 | s->out_pos_lo += prefix; |
| 601 | s->out_pos_hi += prefix; |
| 602 | s->out_pos_cur = s->out_pos_lo; |
| 603 | prefix += seplen; |
| 604 | nslots++; |
| 605 | } |
| 606 | width += (seplen * (nslots - 1)); |
| 607 | buf = calloc(1, width + 1); |
| 608 | if (buf == NULL) |
| 609 | khlib_fatal( |
| 610 | "[memory] Failed to allocate buffer of %d bytes", |
| 611 | width |
| 612 | ); |
| 613 | memset(buf, ' ', width); |
| 614 | buf[width] = '\0'; |
| 615 | /* 3rd pass to set the separators */ |
| 616 | for (s = cfg.slots; s; s = s->next) { |
| 617 | if (s->out_pos_lo) { /* Skip the first, left-most */ |
| 618 | /* Copying only seplen ensures we omit the '\0' byte. */ |
| 619 | strncpy( |
| 620 | buf + (s->out_pos_lo - seplen), |
| 621 | cfg.separator, |
| 622 | seplen |
| 623 | ); |
| 624 | } |
| 625 | } |
| 626 | |
| 627 | if (cfg.output_to_x_root_window && !(d = XOpenDisplay(NULL))) |
| 628 | khlib_fatal("XOpenDisplay failed with: %p\n", d); |
| 629 | /* TODO: Handle signals */ |
| 630 | for (;;) { |
| 631 | clock_gettime(CLOCK_MONOTONIC, &t0); // FIXME: check errors |
| 632 | slots_read(&cfg, &ti, buf); |
| 633 | if (cfg.output_to_x_root_window) { |
| 634 | if (XStoreName(d, DefaultRootWindow(d), buf) < 0) |
| 635 | khlib_fatal("XStoreName failed.\n"); |
| 636 | XFlush(d); |
| 637 | } else { |
| 638 | puts(buf); |
| 639 | fflush(stdout); |
| 640 | } |
| 641 | clock_gettime(CLOCK_MONOTONIC, &t1); // FIXME: check errors |
| 642 | timespecsub(&t1, &t0, &td); |
| 643 | khlib_debug( |
| 644 | "td {tv_sec = %ld, tv_nsec = %ld}\n", |
| 645 | td.tv_sec, |
| 646 | td.tv_nsec |
| 647 | ); |
| 648 | if (timespeccmp(&td, &ti, <)) { |
| 649 | /* |
| 650 | * Pushback on data producers by refusing to read the |
| 651 | * pipe more frequently than the interval. |
| 652 | */ |
| 653 | timespecsub(&ti, &td, &tc); |
| 654 | khlib_sleep(&tc); |
| 655 | } |
| 656 | } |
| 657 | return EXIT_SUCCESS; |
| 658 | } |