dbus-internals.c revision 7f2973c8d1e124f4744af0bee73679607511f3a4
1/* -*- mode: C; c-file-style: "gnu" -*- */ 2/* dbus-internals.c random utility stuff (internal to D-BUS implementation) 3 * 4 * Copyright (C) 2002, 2003 Red Hat, Inc. 5 * 6 * Licensed under the Academic Free License version 2.1 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License as published by 10 * the Free Software Foundation; either version 2 of the License, or 11 * (at your option) any later version. 12 * 13 * This program is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU General Public License for more details. 17 * 18 * You should have received a copy of the GNU General Public License 19 * along with this program; if not, write to the Free Software 20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 21 * 22 */ 23#include "dbus-internals.h" 24#include "dbus-protocol.h" 25#include "dbus-test.h" 26#include <stdio.h> 27#include <stdarg.h> 28#include <string.h> 29#include <sys/types.h> 30#include <errno.h> 31#include <unistd.h> 32#include <fcntl.h> 33#include <stdlib.h> 34 35/** 36 * @defgroup DBusInternals D-BUS internal implementation details 37 * @brief Documentation useful when developing or debugging D-BUS itself. 38 * 39 */ 40 41/** 42 * @defgroup DBusInternalsUtils Utilities and portability 43 * @ingroup DBusInternals 44 * @brief Utility functions (_dbus_assert(), _dbus_warn(), etc.) 45 * @{ 46 */ 47 48/** 49 * @def _dbus_assert 50 * 51 * Aborts with an error message if the condition is false. 52 * 53 * @param condition condition which must be true. 54 */ 55 56/** 57 * @def _dbus_assert_not_reached 58 * 59 * Aborts with an error message if called. 60 * The given explanation will be printed. 61 * 62 * @param explanation explanation of what happened if the code was reached. 63 */ 64 65/** 66 * @def _DBUS_N_ELEMENTS 67 * 68 * Computes the number of elements in a fixed-size array using 69 * sizeof(). 70 * 71 * @param array the array to count elements in. 72 */ 73 74/** 75 * @def _DBUS_POINTER_TO_INT 76 * 77 * Safely casts a void* to an integer; should only be used on void* 78 * that actually contain integers, for example one created with 79 * _DBUS_INT_TO_POINTER. Only guaranteed to preserve 32 bits. 80 * (i.e. it's used to store 32-bit ints in pointers, but 81 * can't be used to store 64-bit pointers in ints.) 82 * 83 * @param pointer pointer to extract an integer from. 84 */ 85/** 86 * @def _DBUS_INT_TO_POINTER 87 * 88 * Safely stuffs an integer into a pointer, to be extracted later with 89 * _DBUS_POINTER_TO_INT. Only guaranteed to preserve 32 bits. 90 * 91 * @param integer the integer to stuff into a pointer. 92 */ 93/** 94 * @def _DBUS_ZERO 95 * 96 * Sets all bits in an object to zero. 97 * 98 * @param object the object to be zeroed. 99 */ 100/** 101 * @def _DBUS_INT16_MIN 102 * 103 * Minimum value of type "int16" 104 */ 105/** 106 * @def _DBUS_INT16_MAX 107 * 108 * Maximum value of type "int16" 109 */ 110/** 111 * @def _DBUS_UINT16_MAX 112 * 113 * Maximum value of type "uint16" 114 */ 115 116/** 117 * @def _DBUS_INT32_MIN 118 * 119 * Minimum value of type "int32" 120 */ 121/** 122 * @def _DBUS_INT32_MAX 123 * 124 * Maximum value of type "int32" 125 */ 126/** 127 * @def _DBUS_UINT32_MAX 128 * 129 * Maximum value of type "uint32" 130 */ 131 132/** 133 * @def _DBUS_INT_MIN 134 * 135 * Minimum value of type "int" 136 */ 137/** 138 * @def _DBUS_INT_MAX 139 * 140 * Maximum value of type "int" 141 */ 142/** 143 * @def _DBUS_UINT_MAX 144 * 145 * Maximum value of type "uint" 146 */ 147 148/** 149 * @typedef DBusForeachFunction 150 * 151 * Used to iterate over each item in a collection, such as 152 * a DBusList. 153 */ 154 155/** 156 * @def _DBUS_LOCK_NAME 157 * 158 * Expands to name of a global lock variable. 159 */ 160 161/** 162 * @def _DBUS_DEFINE_GLOBAL_LOCK 163 * 164 * Defines a global lock variable with the given name. 165 * The lock must be added to the list to initialize 166 * in dbus_threads_init(). 167 */ 168 169/** 170 * @def _DBUS_DECLARE_GLOBAL_LOCK 171 * 172 * Expands to declaration of a global lock defined 173 * with _DBUS_DEFINE_GLOBAL_LOCK. 174 * The lock must be added to the list to initialize 175 * in dbus_threads_init(). 176 */ 177 178/** 179 * @def _DBUS_LOCK 180 * 181 * Locks a global lock 182 */ 183 184/** 185 * @def _DBUS_UNLOCK 186 * 187 * Unlocks a global lock 188 */ 189 190/** 191 * Fixed "out of memory" error message, just to avoid 192 * making up a different string every time and wasting 193 * space. 194 */ 195const char _dbus_no_memory_message[] = "Not enough memory"; 196 197/** 198 * Prints a warning message to stderr. 199 * 200 * @param format printf-style format string. 201 */ 202void 203_dbus_warn (const char *format, 204 ...) 205{ 206 /* FIXME not portable enough? */ 207 va_list args; 208 209 va_start (args, format); 210 vfprintf (stderr, format, args); 211 va_end (args); 212} 213 214#ifdef DBUS_ENABLE_VERBOSE_MODE 215 216static dbus_bool_t verbose_initted = FALSE; 217 218#include <pthread.h> 219/** 220 * Prints a warning message to stderr 221 * if the user has enabled verbose mode. 222 * This is the real function implementation, 223 * use _dbus_verbose() macro in code. 224 * 225 * @param format printf-style format string. 226 */ 227void 228_dbus_verbose_real (const char *format, 229 ...) 230{ 231 va_list args; 232 static dbus_bool_t verbose = TRUE; 233 static dbus_bool_t need_pid = TRUE; 234 int len; 235 236 /* things are written a bit oddly here so that 237 * in the non-verbose case we just have the one 238 * conditional and return immediately. 239 */ 240 if (!verbose) 241 return; 242 243 if (!verbose_initted) 244 { 245 verbose = _dbus_getenv ("DBUS_VERBOSE") != NULL; 246 verbose_initted = TRUE; 247 if (!verbose) 248 return; 249 } 250 251 /* Print out pid before the line */ 252 if (need_pid) 253 fprintf (stderr, "%lu: 0x%lx: ", _dbus_getpid (), pthread_self ()); 254 255 /* Only print pid again if the next line is a new line */ 256 len = strlen (format); 257 if (format[len-1] == '\n') 258 need_pid = TRUE; 259 else 260 need_pid = FALSE; 261 262 va_start (args, format); 263 vfprintf (stderr, format, args); 264 va_end (args); 265 266 fflush (stderr); 267} 268 269/** 270 * Reinitializes the verbose logging code, used 271 * as a hack in dbus-spawn.c so that a child 272 * process re-reads its pid 273 * 274 */ 275void 276_dbus_verbose_reset_real (void) 277{ 278 verbose_initted = FALSE; 279} 280 281#endif /* DBUS_ENABLE_VERBOSE_MODE */ 282 283/** 284 * Duplicates a string. Result must be freed with 285 * dbus_free(). Returns #NULL if memory allocation fails. 286 * If the string to be duplicated is #NULL, returns #NULL. 287 * 288 * @param str string to duplicate. 289 * @returns newly-allocated copy. 290 */ 291char* 292_dbus_strdup (const char *str) 293{ 294 size_t len; 295 char *copy; 296 297 if (str == NULL) 298 return NULL; 299 300 len = strlen (str); 301 302 copy = dbus_malloc (len + 1); 303 if (copy == NULL) 304 return NULL; 305 306 memcpy (copy, str, len + 1); 307 308 return copy; 309} 310 311/** 312 * Duplicates a block of memory. Returns 313 * #NULL on failure. 314 * 315 * @param mem memory to copy 316 * @param n_bytes number of bytes to copy 317 * @returns the copy 318 */ 319void* 320_dbus_memdup (const void *mem, 321 size_t n_bytes) 322{ 323 void *copy; 324 325 copy = dbus_malloc (n_bytes); 326 if (copy == NULL) 327 return NULL; 328 329 memcpy (copy, mem, n_bytes); 330 331 return copy; 332} 333 334/** 335 * Duplicates a string array. Result may be freed with 336 * dbus_free_string_array(). Returns #NULL if memory allocation fails. 337 * If the array to be duplicated is #NULL, returns #NULL. 338 * 339 * @param array array to duplicate. 340 * @returns newly-allocated copy. 341 */ 342char** 343_dbus_dup_string_array (const char **array) 344{ 345 int len; 346 int i; 347 char **copy; 348 349 if (array == NULL) 350 return NULL; 351 352 for (len = 0; array[len] != NULL; ++len) 353 ; 354 355 copy = dbus_new0 (char*, len + 1); 356 if (copy == NULL) 357 return NULL; 358 359 i = 0; 360 while (i < len) 361 { 362 copy[i] = _dbus_strdup (array[i]); 363 if (copy[i] == NULL) 364 { 365 dbus_free_string_array (copy); 366 return NULL; 367 } 368 369 ++i; 370 } 371 372 return copy; 373} 374 375/** 376 * Checks whether a string array contains the given string. 377 * 378 * @param array array to search. 379 * @param str string to look for 380 * @returns #TRUE if array contains string 381 */ 382dbus_bool_t 383_dbus_string_array_contains (const char **array, 384 const char *str) 385{ 386 int i; 387 388 i = 0; 389 while (array[i] != NULL) 390 { 391 if (strcmp (array[i], str) == 0) 392 return TRUE; 393 ++i; 394 } 395 396 return FALSE; 397} 398 399#ifdef DBUS_BUILD_TESTS 400/** 401 * Returns a string describing the given name. 402 * 403 * @param header_field the field to describe 404 * @returns a constant string describing the field 405 */ 406const char * 407_dbus_header_field_to_string (int header_field) 408{ 409 switch (header_field) 410 { 411 case DBUS_HEADER_FIELD_INVALID: 412 return "invalid"; 413 case DBUS_HEADER_FIELD_PATH: 414 return "path"; 415 case DBUS_HEADER_FIELD_INTERFACE: 416 return "interface"; 417 case DBUS_HEADER_FIELD_MEMBER: 418 return "member"; 419 case DBUS_HEADER_FIELD_ERROR_NAME: 420 return "error-name"; 421 case DBUS_HEADER_FIELD_REPLY_SERIAL: 422 return "reply-serial"; 423 case DBUS_HEADER_FIELD_DESTINATION: 424 return "destination"; 425 case DBUS_HEADER_FIELD_SENDER: 426 return "sender"; 427 case DBUS_HEADER_FIELD_SIGNATURE: 428 return "signature"; 429 default: 430 return "unknown"; 431 } 432} 433#endif /* DBUS_BUILD_TESTS */ 434 435#ifndef DBUS_DISABLE_CHECKS 436/** String used in _dbus_return_if_fail macro */ 437const char _dbus_return_if_fail_warning_format[] = 438"%lu: arguments to %s() were incorrect, assertion \"%s\" failed in file %s line %d.\n" 439"This is normally a bug in some application using the D-BUS library.\n"; 440#endif 441 442#ifndef DBUS_DISABLE_ASSERT 443/** 444 * Internals of _dbus_assert(); it's a function 445 * rather than a macro with the inline code so 446 * that the assertion failure blocks don't show up 447 * in test suite coverage, and to shrink code size. 448 * 449 * @param condition TRUE if assertion succeeded 450 * @param condition_text condition as a string 451 * @param file file the assertion is in 452 * @param line line the assertion is in 453 * @param func function the assertion is in 454 */ 455void 456_dbus_real_assert (dbus_bool_t condition, 457 const char *condition_text, 458 const char *file, 459 int line, 460 const char *func) 461{ 462 if (_DBUS_UNLIKELY (!condition)) 463 { 464 _dbus_warn ("%lu: assertion failed \"%s\" file \"%s\" line %d function %s\n", 465 _dbus_getpid (), condition_text, file, line, func); 466 _dbus_abort (); 467 } 468} 469 470/** 471 * Internals of _dbus_assert_not_reached(); it's a function 472 * rather than a macro with the inline code so 473 * that the assertion failure blocks don't show up 474 * in test suite coverage, and to shrink code size. 475 * 476 * @param explanation what was reached that shouldn't have been 477 * @param file file the assertion is in 478 * @param line line the assertion is in 479 */ 480void 481_dbus_real_assert_not_reached (const char *explanation, 482 const char *file, 483 int line) 484{ 485 _dbus_warn ("File \"%s\" line %d process %lu should not have been reached: %s\n", 486 file, line, _dbus_getpid (), explanation); 487 _dbus_abort (); 488} 489#endif /* DBUS_DISABLE_ASSERT */ 490 491#ifdef DBUS_BUILD_TESTS 492static dbus_bool_t 493run_failing_each_malloc (int n_mallocs, 494 const char *description, 495 DBusTestMemoryFunction func, 496 void *data) 497{ 498 n_mallocs += 10; /* fudge factor to ensure reallocs etc. are covered */ 499 500 while (n_mallocs >= 0) 501 { 502 _dbus_set_fail_alloc_counter (n_mallocs); 503 504 _dbus_verbose ("\n===\n%s: (will fail malloc %d with %d failures)\n===\n", 505 description, n_mallocs, 506 _dbus_get_fail_alloc_failures ()); 507 508 if (!(* func) (data)) 509 return FALSE; 510 511 n_mallocs -= 1; 512 } 513 514 _dbus_set_fail_alloc_counter (_DBUS_INT_MAX); 515 516 return TRUE; 517} 518 519/** 520 * Tests how well the given function responds to out-of-memory 521 * situations. Calls the function repeatedly, failing a different 522 * call to malloc() each time. If the function ever returns #FALSE, 523 * the test fails. The function should return #TRUE whenever something 524 * valid (such as returning an error, or succeeding) occurs, and #FALSE 525 * if it gets confused in some way. 526 * 527 * @param description description of the test used in verbose output 528 * @param func function to call 529 * @param data data to pass to function 530 * @returns #TRUE if the function never returns FALSE 531 */ 532dbus_bool_t 533_dbus_test_oom_handling (const char *description, 534 DBusTestMemoryFunction func, 535 void *data) 536{ 537 int approx_mallocs; 538 const char *setting; 539 int max_failures_to_try; 540 int i; 541 542 /* Run once to see about how many mallocs are involved */ 543 544 _dbus_set_fail_alloc_counter (_DBUS_INT_MAX); 545 546 _dbus_verbose ("Running once to count mallocs\n"); 547 548 if (!(* func) (data)) 549 return FALSE; 550 551 approx_mallocs = _DBUS_INT_MAX - _dbus_get_fail_alloc_counter (); 552 553 _dbus_verbose ("\n=================\n%s: about %d mallocs total\n=================\n", 554 description, approx_mallocs); 555 556 setting = _dbus_getenv ("DBUS_TEST_MALLOC_FAILURES"); 557 if (setting != NULL) 558 { 559 DBusString str; 560 long v; 561 _dbus_string_init_const (&str, setting); 562 v = 4; 563 if (!_dbus_string_parse_int (&str, 0, &v, NULL)) 564 _dbus_warn ("couldn't parse '%s' as integer\n", setting); 565 max_failures_to_try = v; 566 } 567 else 568 { 569 max_failures_to_try = 4; 570 } 571 572 i = setting ? max_failures_to_try - 1 : 1; 573 while (i < max_failures_to_try) 574 { 575 _dbus_set_fail_alloc_failures (i); 576 if (!run_failing_each_malloc (approx_mallocs, description, func, data)) 577 return FALSE; 578 ++i; 579 } 580 581 _dbus_verbose ("\n=================\n%s: all iterations passed\n=================\n", 582 description); 583 584 return TRUE; 585} 586#endif /* DBUS_BUILD_TESTS */ 587 588/** @} */ 589