dbus-internals.c revision 759fa115c95051eb32f6ed41b3cda1b219fc1aed
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 <fcntl.h> 32#include <stdlib.h> 33 34/** 35 * @defgroup DBusInternals D-Bus internal implementation details 36 * @brief Documentation useful when developing or debugging D-Bus itself. 37 * 38 */ 39 40/** 41 * @defgroup DBusInternalsUtils Utilities and portability 42 * @ingroup DBusInternals 43 * @brief Utility functions (_dbus_assert(), _dbus_warn(), etc.) 44 * @{ 45 */ 46 47/** 48 * @def _dbus_assert 49 * 50 * Aborts with an error message if the condition is false. 51 * 52 * @param condition condition which must be true. 53 */ 54 55/** 56 * @def _dbus_assert_not_reached 57 * 58 * Aborts with an error message if called. 59 * The given explanation will be printed. 60 * 61 * @param explanation explanation of what happened if the code was reached. 62 */ 63 64/** 65 * @def _DBUS_N_ELEMENTS 66 * 67 * Computes the number of elements in a fixed-size array using 68 * sizeof(). 69 * 70 * @param array the array to count elements in. 71 */ 72 73/** 74 * @def _DBUS_POINTER_TO_INT 75 * 76 * Safely casts a void* to an integer; should only be used on void* 77 * that actually contain integers, for example one created with 78 * _DBUS_INT_TO_POINTER. Only guaranteed to preserve 32 bits. 79 * (i.e. it's used to store 32-bit ints in pointers, but 80 * can't be used to store 64-bit pointers in ints.) 81 * 82 * @param pointer pointer to extract an integer from. 83 */ 84/** 85 * @def _DBUS_INT_TO_POINTER 86 * 87 * Safely stuffs an integer into a pointer, to be extracted later with 88 * _DBUS_POINTER_TO_INT. Only guaranteed to preserve 32 bits. 89 * 90 * @param integer the integer to stuff into a pointer. 91 */ 92/** 93 * @def _DBUS_ZERO 94 * 95 * Sets all bits in an object to zero. 96 * 97 * @param object the object to be zeroed. 98 */ 99/** 100 * @def _DBUS_INT16_MIN 101 * 102 * Minimum value of type "int16" 103 */ 104/** 105 * @def _DBUS_INT16_MAX 106 * 107 * Maximum value of type "int16" 108 */ 109/** 110 * @def _DBUS_UINT16_MAX 111 * 112 * Maximum value of type "uint16" 113 */ 114 115/** 116 * @def _DBUS_INT32_MIN 117 * 118 * Minimum value of type "int32" 119 */ 120/** 121 * @def _DBUS_INT32_MAX 122 * 123 * Maximum value of type "int32" 124 */ 125/** 126 * @def _DBUS_UINT32_MAX 127 * 128 * Maximum value of type "uint32" 129 */ 130 131/** 132 * @def _DBUS_INT_MIN 133 * 134 * Minimum value of type "int" 135 */ 136/** 137 * @def _DBUS_INT_MAX 138 * 139 * Maximum value of type "int" 140 */ 141/** 142 * @def _DBUS_UINT_MAX 143 * 144 * Maximum value of type "uint" 145 */ 146 147/** 148 * @typedef DBusForeachFunction 149 * 150 * Used to iterate over each item in a collection, such as 151 * a DBusList. 152 */ 153 154/** 155 * @def _DBUS_LOCK_NAME 156 * 157 * Expands to name of a global lock variable. 158 */ 159 160/** 161 * @def _DBUS_DEFINE_GLOBAL_LOCK 162 * 163 * Defines a global lock variable with the given name. 164 * The lock must be added to the list to initialize 165 * in dbus_threads_init(). 166 */ 167 168/** 169 * @def _DBUS_DECLARE_GLOBAL_LOCK 170 * 171 * Expands to declaration of a global lock defined 172 * with _DBUS_DEFINE_GLOBAL_LOCK. 173 * The lock must be added to the list to initialize 174 * in dbus_threads_init(). 175 */ 176 177/** 178 * @def _DBUS_LOCK 179 * 180 * Locks a global lock 181 */ 182 183/** 184 * @def _DBUS_UNLOCK 185 * 186 * Unlocks a global lock 187 */ 188 189/** 190 * Fixed "out of memory" error message, just to avoid 191 * making up a different string every time and wasting 192 * space. 193 */ 194const char _dbus_no_memory_message[] = "Not enough memory"; 195 196/** 197 * Prints a warning message to stderr. 198 * 199 * @param format printf-style format string. 200 */ 201void 202_dbus_warn (const char *format, 203 ...) 204{ 205 /* FIXME not portable enough? */ 206 va_list args; 207 208 va_start (args, format); 209 vfprintf (stderr, format, args); 210 va_end (args); 211} 212 213#ifdef DBUS_ENABLE_VERBOSE_MODE 214 215static dbus_bool_t verbose_initted = FALSE; 216 217#define PTHREAD_IN_VERBOSE 0 218#if PTHREAD_IN_VERBOSE 219#include <pthread.h> 220#endif 221 222/** 223 * Prints a warning message to stderr 224 * if the user has enabled verbose mode. 225 * This is the real function implementation, 226 * use _dbus_verbose() macro in code. 227 * 228 * @param format printf-style format string. 229 */ 230void 231_dbus_verbose_real (const char *format, 232 ...) 233{ 234 va_list args; 235 static dbus_bool_t verbose = TRUE; 236 static dbus_bool_t need_pid = TRUE; 237 int len; 238 239 /* things are written a bit oddly here so that 240 * in the non-verbose case we just have the one 241 * conditional and return immediately. 242 */ 243 if (!verbose) 244 return; 245 246 if (!verbose_initted) 247 { 248 const char *p = _dbus_getenv ("DBUS_VERBOSE"); 249 verbose = p != NULL && *p == '1'; 250 verbose_initted = TRUE; 251 if (!verbose) 252 return; 253 } 254 255 /* Print out pid before the line */ 256 if (need_pid) 257 { 258#if PTHREAD_IN_VERBOSE 259 fprintf (stderr, "%lu: 0x%lx: ", _dbus_getpid (), pthread_self ()); 260#else 261 fprintf (stderr, "%lu: ", _dbus_getpid ()); 262#endif 263 } 264 265 266 /* Only print pid again if the next line is a new line */ 267 len = strlen (format); 268 if (format[len-1] == '\n') 269 need_pid = TRUE; 270 else 271 need_pid = FALSE; 272 273 va_start (args, format); 274 vfprintf (stderr, format, args); 275 va_end (args); 276 277 fflush (stderr); 278} 279 280/** 281 * Reinitializes the verbose logging code, used 282 * as a hack in dbus-spawn.c so that a child 283 * process re-reads its pid 284 * 285 */ 286void 287_dbus_verbose_reset_real (void) 288{ 289 verbose_initted = FALSE; 290} 291 292#endif /* DBUS_ENABLE_VERBOSE_MODE */ 293 294/** 295 * Duplicates a string. Result must be freed with 296 * dbus_free(). Returns #NULL if memory allocation fails. 297 * If the string to be duplicated is #NULL, returns #NULL. 298 * 299 * @param str string to duplicate. 300 * @returns newly-allocated copy. 301 */ 302char* 303_dbus_strdup (const char *str) 304{ 305 size_t len; 306 char *copy; 307 308 if (str == NULL) 309 return NULL; 310 311 len = strlen (str); 312 313 copy = dbus_malloc (len + 1); 314 if (copy == NULL) 315 return NULL; 316 317 memcpy (copy, str, len + 1); 318 319 return copy; 320} 321 322/** 323 * Duplicates a block of memory. Returns 324 * #NULL on failure. 325 * 326 * @param mem memory to copy 327 * @param n_bytes number of bytes to copy 328 * @returns the copy 329 */ 330void* 331_dbus_memdup (const void *mem, 332 size_t n_bytes) 333{ 334 void *copy; 335 336 copy = dbus_malloc (n_bytes); 337 if (copy == NULL) 338 return NULL; 339 340 memcpy (copy, mem, n_bytes); 341 342 return copy; 343} 344 345/** 346 * Duplicates a string array. Result may be freed with 347 * dbus_free_string_array(). Returns #NULL if memory allocation fails. 348 * If the array to be duplicated is #NULL, returns #NULL. 349 * 350 * @param array array to duplicate. 351 * @returns newly-allocated copy. 352 */ 353char** 354_dbus_dup_string_array (const char **array) 355{ 356 int len; 357 int i; 358 char **copy; 359 360 if (array == NULL) 361 return NULL; 362 363 for (len = 0; array[len] != NULL; ++len) 364 ; 365 366 copy = dbus_new0 (char*, len + 1); 367 if (copy == NULL) 368 return NULL; 369 370 i = 0; 371 while (i < len) 372 { 373 copy[i] = _dbus_strdup (array[i]); 374 if (copy[i] == NULL) 375 { 376 dbus_free_string_array (copy); 377 return NULL; 378 } 379 380 ++i; 381 } 382 383 return copy; 384} 385 386/** 387 * Checks whether a string array contains the given string. 388 * 389 * @param array array to search. 390 * @param str string to look for 391 * @returns #TRUE if array contains string 392 */ 393dbus_bool_t 394_dbus_string_array_contains (const char **array, 395 const char *str) 396{ 397 int i; 398 399 i = 0; 400 while (array[i] != NULL) 401 { 402 if (strcmp (array[i], str) == 0) 403 return TRUE; 404 ++i; 405 } 406 407 return FALSE; 408} 409 410#ifdef DBUS_BUILD_TESTS 411/** 412 * Returns a string describing the given name. 413 * 414 * @param header_field the field to describe 415 * @returns a constant string describing the field 416 */ 417const char * 418_dbus_header_field_to_string (int header_field) 419{ 420 switch (header_field) 421 { 422 case DBUS_HEADER_FIELD_INVALID: 423 return "invalid"; 424 case DBUS_HEADER_FIELD_PATH: 425 return "path"; 426 case DBUS_HEADER_FIELD_INTERFACE: 427 return "interface"; 428 case DBUS_HEADER_FIELD_MEMBER: 429 return "member"; 430 case DBUS_HEADER_FIELD_ERROR_NAME: 431 return "error-name"; 432 case DBUS_HEADER_FIELD_REPLY_SERIAL: 433 return "reply-serial"; 434 case DBUS_HEADER_FIELD_DESTINATION: 435 return "destination"; 436 case DBUS_HEADER_FIELD_SENDER: 437 return "sender"; 438 case DBUS_HEADER_FIELD_SIGNATURE: 439 return "signature"; 440 default: 441 return "unknown"; 442 } 443} 444#endif /* DBUS_BUILD_TESTS */ 445 446#ifndef DBUS_DISABLE_CHECKS 447/** String used in _dbus_return_if_fail macro */ 448const char _dbus_return_if_fail_warning_format[] = 449"%lu: arguments to %s() were incorrect, assertion \"%s\" failed in file %s line %d.\n" 450"This is normally a bug in some application using the D-Bus library.\n"; 451#endif 452 453#ifndef DBUS_DISABLE_ASSERT 454/** 455 * Internals of _dbus_assert(); it's a function 456 * rather than a macro with the inline code so 457 * that the assertion failure blocks don't show up 458 * in test suite coverage, and to shrink code size. 459 * 460 * @param condition TRUE if assertion succeeded 461 * @param condition_text condition as a string 462 * @param file file the assertion is in 463 * @param line line the assertion is in 464 * @param func function the assertion is in 465 */ 466void 467_dbus_real_assert (dbus_bool_t condition, 468 const char *condition_text, 469 const char *file, 470 int line, 471 const char *func) 472{ 473 if (_DBUS_UNLIKELY (!condition)) 474 { 475 _dbus_warn ("%lu: assertion failed \"%s\" file \"%s\" line %d function %s\n", 476 _dbus_getpid (), condition_text, file, line, func); 477 _dbus_abort (); 478 } 479} 480 481/** 482 * Internals of _dbus_assert_not_reached(); it's a function 483 * rather than a macro with the inline code so 484 * that the assertion failure blocks don't show up 485 * in test suite coverage, and to shrink code size. 486 * 487 * @param explanation what was reached that shouldn't have been 488 * @param file file the assertion is in 489 * @param line line the assertion is in 490 */ 491void 492_dbus_real_assert_not_reached (const char *explanation, 493 const char *file, 494 int line) 495{ 496 _dbus_warn ("File \"%s\" line %d process %lu should not have been reached: %s\n", 497 file, line, _dbus_getpid (), explanation); 498 _dbus_abort (); 499} 500#endif /* DBUS_DISABLE_ASSERT */ 501 502#ifdef DBUS_BUILD_TESTS 503static dbus_bool_t 504run_failing_each_malloc (int n_mallocs, 505 const char *description, 506 DBusTestMemoryFunction func, 507 void *data) 508{ 509 n_mallocs += 10; /* fudge factor to ensure reallocs etc. are covered */ 510 511 while (n_mallocs >= 0) 512 { 513 _dbus_set_fail_alloc_counter (n_mallocs); 514 515 _dbus_verbose ("\n===\n%s: (will fail malloc %d with %d failures)\n===\n", 516 description, n_mallocs, 517 _dbus_get_fail_alloc_failures ()); 518 519 if (!(* func) (data)) 520 return FALSE; 521 522 n_mallocs -= 1; 523 } 524 525 _dbus_set_fail_alloc_counter (_DBUS_INT_MAX); 526 527 return TRUE; 528} 529 530/** 531 * Tests how well the given function responds to out-of-memory 532 * situations. Calls the function repeatedly, failing a different 533 * call to malloc() each time. If the function ever returns #FALSE, 534 * the test fails. The function should return #TRUE whenever something 535 * valid (such as returning an error, or succeeding) occurs, and #FALSE 536 * if it gets confused in some way. 537 * 538 * @param description description of the test used in verbose output 539 * @param func function to call 540 * @param data data to pass to function 541 * @returns #TRUE if the function never returns FALSE 542 */ 543dbus_bool_t 544_dbus_test_oom_handling (const char *description, 545 DBusTestMemoryFunction func, 546 void *data) 547{ 548 int approx_mallocs; 549 const char *setting; 550 int max_failures_to_try; 551 int i; 552 553 /* Run once to see about how many mallocs are involved */ 554 555 _dbus_set_fail_alloc_counter (_DBUS_INT_MAX); 556 557 _dbus_verbose ("Running once to count mallocs\n"); 558 559 if (!(* func) (data)) 560 return FALSE; 561 562 approx_mallocs = _DBUS_INT_MAX - _dbus_get_fail_alloc_counter (); 563 564 _dbus_verbose ("\n=================\n%s: about %d mallocs total\n=================\n", 565 description, approx_mallocs); 566 567 setting = _dbus_getenv ("DBUS_TEST_MALLOC_FAILURES"); 568 if (setting != NULL) 569 { 570 DBusString str; 571 long v; 572 _dbus_string_init_const (&str, setting); 573 v = 4; 574 if (!_dbus_string_parse_int (&str, 0, &v, NULL)) 575 _dbus_warn ("couldn't parse '%s' as integer\n", setting); 576 max_failures_to_try = v; 577 } 578 else 579 { 580 max_failures_to_try = 4; 581 } 582 583 i = setting ? max_failures_to_try - 1 : 1; 584 while (i < max_failures_to_try) 585 { 586 _dbus_set_fail_alloc_failures (i); 587 if (!run_failing_each_malloc (approx_mallocs, description, func, data)) 588 return FALSE; 589 ++i; 590 } 591 592 _dbus_verbose ("\n=================\n%s: all iterations passed\n=================\n", 593 description); 594 595 return TRUE; 596} 597#endif /* DBUS_BUILD_TESTS */ 598 599/** @} */ 600