1 /* 2 * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers 3 * Copyright (c) 1991-1995 by Xerox Corporation. All rights reserved. 4 * Copyright 1996-1999 by Silicon Graphics. All rights reserved. 5 * Copyright 1999 by Hewlett-Packard Company. All rights reserved. 6 * Copyright (C) 2007 Free Software Foundation, Inc 7 * 8 * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED 9 * OR IMPLIED. ANY USE IS AT YOUR OWN RISK. 10 * 11 * Permission is hereby granted to use or copy this program 12 * for any purpose, provided the above notices are retained on all copies. 13 * Permission to modify the code and to distribute modified code is granted, 14 * provided the above notices are retained, and a notice that the code was 15 * modified is included with the above copyright notice. 16 */ 17 18 /* 19 * Note that this defines a large number of tuning hooks, which can 20 * safely be ignored in nearly all cases. For normal use it suffices 21 * to call only GC_MALLOC and perhaps GC_REALLOC. 22 * For better performance, also look at GC_MALLOC_ATOMIC, and 23 * GC_enable_incremental. If you need an action to be performed 24 * immediately before an object is collected, look at GC_register_finalizer. 25 * If you are using Solaris threads, look at the end of this file. 26 * Everything else is best ignored unless you encounter performance 27 * problems. 28 */ 29 30 #ifndef _GC_H 31 32 # define _GC_H 33 34 # include "gc_config_macros.h" 35 36 # ifdef __cplusplus 37 extern "C" { 38 # endif 39 40 41 /* Define word and signed_word to be unsigned and signed types of the */ 42 /* size as char * or void *. There seems to be no way to do this */ 43 /* even semi-portably. The following is probably no better/worse */ 44 /* than almost anything else. */ 45 /* The ANSI standard suggests that size_t and ptr_diff_t might be */ 46 /* better choices. But those had incorrect definitions on some older */ 47 /* systems. Notably "typedef int size_t" is WRONG. */ 48 #ifndef _WIN64 49 typedef unsigned long GC_word; 50 typedef long GC_signed_word; 51 #else 52 /* Win64 isn't really supported yet, but this is the first step. And */ 53 /* it might cause error messages to show up in more plausible places. */ 54 /* This needs basetsd.h, which is included by windows.h. */ 55 typedef unsigned long long GC_word; 56 typedef long long GC_signed_word; 57 #endif 58 59 /* Public read-only variables */ 60 61 GC_API GC_word GC_gc_no;/* Counter incremented per collection. */ 62 /* Includes empty GCs at startup. */ 63 64 GC_API int GC_parallel; /* GC is parallelized for performance on */ 65 /* multiprocessors. Currently set only */ 66 /* implicitly if collector is built with */ 67 /* -DPARALLEL_MARK and if either: */ 68 /* Env variable GC_NPROC is set to > 1, or */ 69 /* GC_NPROC is not set and this is an MP. */ 70 /* If GC_parallel is set, incremental */ 71 /* collection is only partially functional, */ 72 /* and may not be desirable. */ 73 74 75 /* Public R/W variables */ 76 77 GC_API void * (*GC_oom_fn) (size_t bytes_requested); 78 /* When there is insufficient memory to satisfy */ 79 /* an allocation request, we return */ 80 /* (*GC_oom_fn)(). By default this just */ 81 /* returns 0. */ 82 /* If it returns, it must return 0 or a valid */ 83 /* pointer to a previously allocated heap */ 84 /* object. */ 85 86 GC_API int GC_find_leak; 87 /* Do not actually garbage collect, but simply */ 88 /* report inaccessible memory that was not */ 89 /* deallocated with GC_free. Initial value */ 90 /* is determined by FIND_LEAK macro. */ 91 92 GC_API int GC_all_interior_pointers; 93 /* Arrange for pointers to object interiors to */ 94 /* be recognized as valid. May not be changed */ 95 /* after GC initialization. */ 96 /* Initial value is determined by */ 97 /* -DALL_INTERIOR_POINTERS. */ 98 /* Unless DONT_ADD_BYTE_AT_END is defined, this */ 99 /* also affects whether sizes are increased by */ 100 /* at least a byte to allow "off the end" */ 101 /* pointer recognition. */ 102 /* MUST BE 0 or 1. */ 103 104 GC_API int GC_finalize_on_demand; 105 /* If nonzero, finalizers will only be run in */ 106 /* response to an explicit GC_invoke_finalizers */ 107 /* call. The default is determined by whether */ 108 /* the FINALIZE_ON_DEMAND macro is defined */ 109 /* when the collector is built. */ 110 111 GC_API int GC_java_finalization; 112 /* Mark objects reachable from finalizable */ 113 /* objects in a separate postpass. This makes */ 114 /* it a bit safer to use non-topologically- */ 115 /* ordered finalization. Default value is */ 116 /* determined by JAVA_FINALIZATION macro. */ 117 /* Enables register_finalizer_unreachable to */ 118 /* work correctly. */ 119 120 GC_API void (* GC_finalizer_notifier)(void); 121 /* Invoked by the collector when there are */ 122 /* objects to be finalized. Invoked at most */ 123 /* once per GC cycle. Never invoked unless */ 124 /* GC_finalize_on_demand is set. */ 125 /* Typically this will notify a finalization */ 126 /* thread, which will call GC_invoke_finalizers */ 127 /* in response. */ 128 129 GC_API int GC_dont_gc; /* != 0 ==> Dont collect. In versions 6.2a1+, */ 130 /* this overrides explicit GC_gcollect() calls. */ 131 /* Used as a counter, so that nested enabling */ 132 /* and disabling work correctly. Should */ 133 /* normally be updated with GC_enable() and */ 134 /* GC_disable() calls. */ 135 /* Direct assignment to GC_dont_gc is */ 136 /* deprecated. */ 137 138 GC_API int GC_dont_expand; 139 /* Dont expand heap unless explicitly requested */ 140 /* or forced to. */ 141 142 GC_API int GC_use_entire_heap; 143 /* Causes the nonincremental collector to use the */ 144 /* entire heap before collecting. This was the only */ 145 /* option for GC versions < 5.0. This sometimes */ 146 /* results in more large block fragmentation, since */ 147 /* very larg blocks will tend to get broken up */ 148 /* during each GC cycle. It is likely to result in a */ 149 /* larger working set, but lower collection */ 150 /* frequencies, and hence fewer instructions executed */ 151 /* in the collector. */ 152 153 GC_API int GC_full_freq; /* Number of partial collections between */ 154 /* full collections. Matters only if */ 155 /* GC_incremental is set. */ 156 /* Full collections are also triggered if */ 157 /* the collector detects a substantial */ 158 /* increase in the number of in-use heap */ 159 /* blocks. Values in the tens are now */ 160 /* perfectly reasonable, unlike for */ 161 /* earlier GC versions. */ 162 163 GC_API GC_word GC_non_gc_bytes; 164 /* Bytes not considered candidates for collection. */ 165 /* Used only to control scheduling of collections. */ 166 /* Updated by GC_malloc_uncollectable and GC_free. */ 167 /* Wizards only. */ 168 169 GC_API int GC_no_dls; 170 /* Don't register dynamic library data segments. */ 171 /* Wizards only. Should be used only if the */ 172 /* application explicitly registers all roots. */ 173 /* In Microsoft Windows environments, this will */ 174 /* usually also prevent registration of the */ 175 /* main data segment as part of the root set. */ 176 177 GC_API GC_word GC_free_space_divisor; 178 /* We try to make sure that we allocate at */ 179 /* least N/GC_free_space_divisor bytes between */ 180 /* collections, where N is twice the number */ 181 /* of traced bytes, plus the number of untraced */ 182 /* bytes (bytes in "atomic" objects), plus */ 183 /* a rough estimate of the root set size. */ 184 /* N approximates GC tracing work per GC. */ 185 /* Initially, GC_free_space_divisor = 3. */ 186 /* Increasing its value will use less space */ 187 /* but more collection time. Decreasing it */ 188 /* will appreciably decrease collection time */ 189 /* at the expense of space. */ 190 191 GC_API GC_word GC_max_retries; 192 /* The maximum number of GCs attempted before */ 193 /* reporting out of memory after heap */ 194 /* expansion fails. Initially 0. */ 195 196 197 GC_API char *GC_stackbottom; /* Cool end of user stack. */ 198 /* May be set in the client prior to */ 199 /* calling any GC_ routines. This */ 200 /* avoids some overhead, and */ 201 /* potentially some signals that can */ 202 /* confuse debuggers. Otherwise the */ 203 /* collector attempts to set it */ 204 /* automatically. */ 205 /* For multithreaded code, this is the */ 206 /* cold end of the stack for the */ 207 /* primordial thread. */ 208 209 GC_API int GC_dont_precollect; /* Don't collect as part of */ 210 /* initialization. Should be set only */ 211 /* if the client wants a chance to */ 212 /* manually initialize the root set */ 213 /* before the first collection. */ 214 /* Interferes with blacklisting. */ 215 /* Wizards only. */ 216 217 GC_API unsigned long GC_time_limit; 218 /* If incremental collection is enabled, */ 219 /* We try to terminate collections */ 220 /* after this many milliseconds. Not a */ 221 /* hard time bound. Setting this to */ 222 /* GC_TIME_UNLIMITED will essentially */ 223 /* disable incremental collection while */ 224 /* leaving generational collection */ 225 /* enabled. */ 226 # define GC_TIME_UNLIMITED 999999 227 /* Setting GC_time_limit to this value */ 228 /* will disable the "pause time exceeded"*/ 229 /* tests. */ 230 231 /* Public procedures */ 232 233 /* Initialize the collector. This is only required when using thread-local 234 * allocation, since unlike the regular allocation routines, GC_local_malloc 235 * is not self-initializing. If you use GC_local_malloc you should arrange 236 * to call this somehow (e.g. from a constructor) before doing any allocation. 237 * For win32 threads, it needs to be called explicitly. 238 */ 239 GC_API void GC_init(void); 240 241 /* 242 * general purpose allocation routines, with roughly malloc calling conv. 243 * The atomic versions promise that no relevant pointers are contained 244 * in the object. The nonatomic versions guarantee that the new object 245 * is cleared. GC_malloc_stubborn promises that no changes to the object 246 * will occur after GC_end_stubborn_change has been called on the 247 * result of GC_malloc_stubborn. GC_malloc_uncollectable allocates an object 248 * that is scanned for pointers to collectable objects, but is not itself 249 * collectable. The object is scanned even if it does not appear to 250 * be reachable. GC_malloc_uncollectable and GC_free called on the resulting 251 * object implicitly update GC_non_gc_bytes appropriately. 252 * 253 * Note that the GC_malloc_stubborn support is stubbed out by default 254 * starting in 6.0. GC_malloc_stubborn is an alias for GC_malloc unless 255 * the collector is built with STUBBORN_ALLOC defined. 256 */ 257 GC_API void * GC_malloc(size_t size_in_bytes); 258 GC_API void * GC_malloc_atomic(size_t size_in_bytes); 259 GC_API char * GC_strdup (const char *str); 260 GC_API void * GC_malloc_uncollectable(size_t size_in_bytes); 261 GC_API void * GC_malloc_stubborn(size_t size_in_bytes); 262 263 /* The following is only defined if the library has been suitably */ 264 /* compiled: */ 265 GC_API void * GC_malloc_atomic_uncollectable(size_t size_in_bytes); 266 267 /* Explicitly deallocate an object. Dangerous if used incorrectly. */ 268 /* Requires a pointer to the base of an object. */ 269 /* If the argument is stubborn, it should not be changeable when freed. */ 270 /* An object should not be enable for finalization when it is */ 271 /* explicitly deallocated. */ 272 /* GC_free(0) is a no-op, as required by ANSI C for free. */ 273 GC_API void GC_free(void * object_addr); 274 275 /* 276 * Stubborn objects may be changed only if the collector is explicitly informed. 277 * The collector is implicitly informed of coming change when such 278 * an object is first allocated. The following routines inform the 279 * collector that an object will no longer be changed, or that it will 280 * once again be changed. Only nonNIL pointer stores into the object 281 * are considered to be changes. The argument to GC_end_stubborn_change 282 * must be exacly the value returned by GC_malloc_stubborn or passed to 283 * GC_change_stubborn. (In the second case it may be an interior pointer 284 * within 512 bytes of the beginning of the objects.) 285 * There is a performance penalty for allowing more than 286 * one stubborn object to be changed at once, but it is acceptable to 287 * do so. The same applies to dropping stubborn objects that are still 288 * changeable. 289 */ 290 GC_API void GC_change_stubborn(void *); 291 GC_API void GC_end_stubborn_change(void *); 292 293 /* Return a pointer to the base (lowest address) of an object given */ 294 /* a pointer to a location within the object. */ 295 /* I.e. map an interior pointer to the corresponding bas pointer. */ 296 /* Note that with debugging allocation, this returns a pointer to the */ 297 /* actual base of the object, i.e. the debug information, not to */ 298 /* the base of the user object. */ 299 /* Return 0 if displaced_pointer doesn't point to within a valid */ 300 /* object. */ 301 /* Note that a deallocated object in the garbage collected heap */ 302 /* may be considered valid, even if it has been deallocated with */ 303 /* GC_free. */ 304 GC_API void * GC_base(void * displaced_pointer); 305 306 /* Given a pointer to the base of an object, return its size in bytes. */ 307 /* The returned size may be slightly larger than what was originally */ 308 /* requested. */ 309 GC_API size_t GC_size(void * object_addr); 310 311 /* For compatibility with C library. This is occasionally faster than */ 312 /* a malloc followed by a bcopy. But if you rely on that, either here */ 313 /* or with the standard C library, your code is broken. In my */ 314 /* opinion, it shouldn't have been invented, but now we're stuck. -HB */ 315 /* The resulting object has the same kind as the original. */ 316 /* If the argument is stubborn, the result will have changes enabled. */ 317 /* It is an error to have changes enabled for the original object. */ 318 /* Follows ANSI comventions for NULL old_object. */ 319 GC_API void * GC_realloc(void * old_object, size_t new_size_in_bytes); 320 321 /* Explicitly increase the heap size. */ 322 /* Returns 0 on failure, 1 on success. */ 323 GC_API int GC_expand_hp(size_t number_of_bytes); 324 325 /* Limit the heap size to n bytes. Useful when you're debugging, */ 326 /* especially on systems that don't handle running out of memory well. */ 327 /* n == 0 ==> unbounded. This is the default. */ 328 GC_API void GC_set_max_heap_size(GC_word n); 329 330 /* Inform the collector that a certain section of statically allocated */ 331 /* memory contains no pointers to garbage collected memory. Thus it */ 332 /* need not be scanned. This is sometimes important if the application */ 333 /* maps large read/write files into the address space, which could be */ 334 /* mistaken for dynamic library data segments on some systems. */ 335 GC_API void GC_exclude_static_roots(void * low_address, 336 void * high_address_plus_1); 337 338 /* Clear the set of root segments. Wizards only. */ 339 GC_API void GC_clear_roots(void); 340 341 /* Add a root segment. Wizards only. */ 342 GC_API void GC_add_roots(void * low_address, void * high_address_plus_1); 343 344 /* Remove a root segment. Wizards only. */ 345 GC_API void GC_remove_roots(void * low_address, void * high_address_plus_1); 346 347 /* Add a displacement to the set of those considered valid by the */ 348 /* collector. GC_register_displacement(n) means that if p was returned */ 349 /* by GC_malloc, then (char *)p + n will be considered to be a valid */ 350 /* pointer to p. N must be small and less than the size of p. */ 351 /* (All pointers to the interior of objects from the stack are */ 352 /* considered valid in any case. This applies to heap objects and */ 353 /* static data.) */ 354 /* Preferably, this should be called before any other GC procedures. */ 355 /* Calling it later adds to the probability of excess memory */ 356 /* retention. */ 357 /* This is a no-op if the collector has recognition of */ 358 /* arbitrary interior pointers enabled, which is now the default. */ 359 GC_API void GC_register_displacement(size_t n); 360 361 /* The following version should be used if any debugging allocation is */ 362 /* being done. */ 363 GC_API void GC_debug_register_displacement(size_t n); 364 365 /* Explicitly trigger a full, world-stop collection. */ 366 GC_API void GC_gcollect(void); 367 368 /* Trigger a full world-stopped collection. Abort the collection if */ 369 /* and when stop_func returns a nonzero value. Stop_func will be */ 370 /* called frequently, and should be reasonably fast. This works even */ 371 /* if virtual dirty bits, and hence incremental collection is not */ 372 /* available for this architecture. Collections can be aborted faster */ 373 /* than normal pause times for incremental collection. However, */ 374 /* aborted collections do no useful work; the next collection needs */ 375 /* to start from the beginning. */ 376 /* Return 0 if the collection was aborted, 1 if it succeeded. */ 377 typedef int (* GC_stop_func)(void); 378 GC_API int GC_try_to_collect(GC_stop_func stop_func); 379 380 /* Return the number of bytes in the heap. Excludes collector private */ 381 /* data structures. Includes empty blocks and fragmentation loss. */ 382 /* Includes some pages that were allocated but never written. */ 383 GC_API size_t GC_get_heap_size(void); 384 385 /* Return a lower bound on the number of free bytes in the heap. */ 386 GC_API size_t GC_get_free_bytes(void); 387 388 /* Return the number of bytes allocated since the last collection. */ 389 GC_API size_t GC_get_bytes_since_gc(void); 390 391 /* Return the total number of bytes allocated in this process. */ 392 /* Never decreases, except due to wrapping. */ 393 GC_API size_t GC_get_total_bytes(void); 394 395 /* Disable garbage collection. Even GC_gcollect calls will be */ 396 /* ineffective. */ 397 GC_API void GC_disable(void); 398 399 /* Reenable garbage collection. GC_disable() and GC_enable() calls */ 400 /* nest. Garbage collection is enabled if the number of calls to both */ 401 /* both functions is equal. */ 402 GC_API void GC_enable(void); 403 404 /* Enable incremental/generational collection. */ 405 /* Not advisable unless dirty bits are */ 406 /* available or most heap objects are */ 407 /* pointerfree(atomic) or immutable. */ 408 /* Don't use in leak finding mode. */ 409 /* Ignored if GC_dont_gc is true. */ 410 /* Only the generational piece of this is */ 411 /* functional if GC_parallel is TRUE */ 412 /* or if GC_time_limit is GC_TIME_UNLIMITED. */ 413 /* Causes GC_local_gcj_malloc() to revert to */ 414 /* locked allocation. Must be called */ 415 /* before any GC_local_gcj_malloc() calls. */ 416 /* For best performance, should be called as early as possible. */ 417 /* On some platforms, calling it later may have adverse effects.*/ 418 /* Safe to call before GC_INIT(). Includes a GC_init() call. */ 419 GC_API void GC_enable_incremental(void); 420 421 /* Does incremental mode write-protect pages? Returns zero or */ 422 /* more of the following, or'ed together: */ 423 #define GC_PROTECTS_POINTER_HEAP 1 /* May protect non-atomic objs. */ 424 #define GC_PROTECTS_PTRFREE_HEAP 2 425 #define GC_PROTECTS_STATIC_DATA 4 /* Currently never. */ 426 #define GC_PROTECTS_STACK 8 /* Probably impractical. */ 427 428 #define GC_PROTECTS_NONE 0 429 GC_API int GC_incremental_protection_needs(void); 430 431 /* Perform some garbage collection work, if appropriate. */ 432 /* Return 0 if there is no more work to be done. */ 433 /* Typically performs an amount of work corresponding roughly */ 434 /* to marking from one page. May do more work if further */ 435 /* progress requires it, e.g. if incremental collection is */ 436 /* disabled. It is reasonable to call this in a wait loop */ 437 /* until it returns 0. */ 438 GC_API int GC_collect_a_little(void); 439 440 /* Allocate an object of size lb bytes. The client guarantees that */ 441 /* as long as the object is live, it will be referenced by a pointer */ 442 /* that points to somewhere within the first 256 bytes of the object. */ 443 /* (This should normally be declared volatile to prevent the compiler */ 444 /* from invalidating this assertion.) This routine is only useful */ 445 /* if a large array is being allocated. It reduces the chance of */ 446 /* accidentally retaining such an array as a result of scanning an */ 447 /* integer that happens to be an address inside the array. (Actually, */ 448 /* it reduces the chance of the allocator not finding space for such */ 449 /* an array, since it will try hard to avoid introducing such a false */ 450 /* reference.) On a SunOS 4.X or MS Windows system this is recommended */ 451 /* for arrays likely to be larger than 100K or so. For other systems, */ 452 /* or if the collector is not configured to recognize all interior */ 453 /* pointers, the threshold is normally much higher. */ 454 GC_API void * GC_malloc_ignore_off_page(size_t lb); 455 GC_API void * GC_malloc_atomic_ignore_off_page(size_t lb); 456 457 #if defined(__sgi) && !defined(__GNUC__) && _COMPILER_VERSION >= 720 458 # define GC_ADD_CALLER 459 # define GC_RETURN_ADDR (GC_word)__return_address 460 #endif 461 462 #if defined(__linux__) || defined(__GLIBC__) 463 # include <features.h> 464 # if (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 1 || __GLIBC__ > 2) \ 465 && !defined(__ia64__) 466 # ifndef GC_HAVE_BUILTIN_BACKTRACE 467 # define GC_HAVE_BUILTIN_BACKTRACE 468 # endif 469 # endif 470 # if defined(__i386__) || defined(__x86_64__) 471 # define GC_CAN_SAVE_CALL_STACKS 472 # endif 473 #endif 474 475 #if defined(_MSC_VER) && _MSC_VER >= 1200 /* version 12.0+ (MSVC 6.0+) */ \ 476 && !defined(_AMD64_) 477 # ifndef GC_HAVE_NO_BUILTIN_BACKTRACE 478 # define GC_HAVE_BUILTIN_BACKTRACE 479 # endif 480 #endif 481 482 #if defined(GC_HAVE_BUILTIN_BACKTRACE) && !defined(GC_CAN_SAVE_CALL_STACKS) 483 # define GC_CAN_SAVE_CALL_STACKS 484 #endif 485 486 #if defined(__sparc__) 487 # define GC_CAN_SAVE_CALL_STACKS 488 #endif 489 490 /* If we're on an a platform on which we can't save call stacks, but */ 491 /* gcc is normally used, we go ahead and define GC_ADD_CALLER. */ 492 /* We make this decision independent of whether gcc is actually being */ 493 /* used, in order to keep the interface consistent, and allow mixing */ 494 /* of compilers. */ 495 /* This may also be desirable if it is possible but expensive to */ 496 /* retrieve the call chain. */ 497 #if (defined(__linux__) || defined(__NetBSD__) || defined(__OpenBSD__) \ 498 || defined(__FreeBSD__) || defined(__DragonFly__)) & !defined(GC_CAN_SAVE_CALL_STACKS) 499 # define GC_ADD_CALLER 500 # if __GNUC__ >= 3 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 95) 501 /* gcc knows how to retrieve return address, but we don't know */ 502 /* how to generate call stacks. */ 503 # define GC_RETURN_ADDR (GC_word)__builtin_return_address(0) 504 # else 505 /* Just pass 0 for gcc compatibility. */ 506 # define GC_RETURN_ADDR 0 507 # endif 508 #endif 509 510 #ifdef GC_ADD_CALLER 511 # define GC_EXTRAS GC_RETURN_ADDR, __FILE__, __LINE__ 512 # define GC_EXTRA_PARAMS GC_word ra, const char * s, int i 513 #else 514 # define GC_EXTRAS __FILE__, __LINE__ 515 # define GC_EXTRA_PARAMS const char * s, int i 516 #endif 517 518 /* Debugging (annotated) allocation. GC_gcollect will check */ 519 /* objects allocated in this way for overwrites, etc. */ 520 GC_API void * GC_debug_malloc(size_t size_in_bytes, GC_EXTRA_PARAMS); 521 GC_API void * GC_debug_malloc_atomic(size_t size_in_bytes, GC_EXTRA_PARAMS); 522 GC_API char * GC_debug_strdup(const char *str, GC_EXTRA_PARAMS); 523 GC_API void * GC_debug_malloc_uncollectable 524 (size_t size_in_bytes, GC_EXTRA_PARAMS); 525 GC_API void * GC_debug_malloc_stubborn 526 (size_t size_in_bytes, GC_EXTRA_PARAMS); 527 GC_API void * GC_debug_malloc_ignore_off_page 528 (size_t size_in_bytes, GC_EXTRA_PARAMS); 529 GC_API void * GC_debug_malloc_atomic_ignore_off_page 530 (size_t size_in_bytes, GC_EXTRA_PARAMS); 531 GC_API void GC_debug_free (void * object_addr); 532 GC_API void * GC_debug_realloc 533 (void * old_object, size_t new_size_in_bytes, GC_EXTRA_PARAMS); 534 GC_API void GC_debug_change_stubborn(void *); 535 GC_API void GC_debug_end_stubborn_change(void *); 536 537 /* Routines that allocate objects with debug information (like the */ 538 /* above), but just fill in dummy file and line number information. */ 539 /* Thus they can serve as drop-in malloc/realloc replacements. This */ 540 /* can be useful for two reasons: */ 541 /* 1) It allows the collector to be built with DBG_HDRS_ALL defined */ 542 /* even if some allocation calls come from 3rd party libraries */ 543 /* that can't be recompiled. */ 544 /* 2) On some platforms, the file and line information is redundant, */ 545 /* since it can be reconstructed from a stack trace. On such */ 546 /* platforms it may be more convenient not to recompile, e.g. for */ 547 /* leak detection. This can be accomplished by instructing the */ 548 /* linker to replace malloc/realloc with these. */ 549 GC_API void * GC_debug_malloc_replacement (size_t size_in_bytes); 550 GC_API void * GC_debug_realloc_replacement 551 (void * object_addr, size_t size_in_bytes); 552 553 # ifdef GC_DEBUG 554 # define GC_MALLOC(sz) GC_debug_malloc(sz, GC_EXTRAS) 555 # define GC_MALLOC_ATOMIC(sz) GC_debug_malloc_atomic(sz, GC_EXTRAS) 556 # define GC_STRDUP(s) GC_debug_strdup((s), GC_EXTRAS) 557 # define GC_MALLOC_UNCOLLECTABLE(sz) \ 558 GC_debug_malloc_uncollectable(sz, GC_EXTRAS) 559 # define GC_MALLOC_IGNORE_OFF_PAGE(sz) \ 560 GC_debug_malloc_ignore_off_page(sz, GC_EXTRAS) 561 # define GC_MALLOC_ATOMIC_IGNORE_OFF_PAGE(sz) \ 562 GC_debug_malloc_atomic_ignore_off_page(sz, GC_EXTRAS) 563 # define GC_REALLOC(old, sz) GC_debug_realloc(old, sz, GC_EXTRAS) 564 # define GC_FREE(p) GC_debug_free(p) 565 # define GC_REGISTER_FINALIZER(p, f, d, of, od) \ 566 GC_debug_register_finalizer(p, f, d, of, od) 567 # define GC_REGISTER_FINALIZER_IGNORE_SELF(p, f, d, of, od) \ 568 GC_debug_register_finalizer_ignore_self(p, f, d, of, od) 569 # define GC_REGISTER_FINALIZER_NO_ORDER(p, f, d, of, od) \ 570 GC_debug_register_finalizer_no_order(p, f, d, of, od) 571 # define GC_REGISTER_FINALIZER_UNREACHABLE(p, f, d, of, od) \ 572 GC_debug_register_finalizer_unreachable(p, f, d, of, od) 573 # define GC_MALLOC_STUBBORN(sz) GC_debug_malloc_stubborn(sz, GC_EXTRAS); 574 # define GC_CHANGE_STUBBORN(p) GC_debug_change_stubborn(p) 575 # define GC_END_STUBBORN_CHANGE(p) GC_debug_end_stubborn_change(p) 576 # define GC_GENERAL_REGISTER_DISAPPEARING_LINK(link, obj) \ 577 GC_general_register_disappearing_link(link, GC_base(obj)) 578 # define GC_REGISTER_DISPLACEMENT(n) GC_debug_register_displacement(n) 579 # else 580 # define GC_MALLOC(sz) GC_malloc(sz) 581 # define GC_MALLOC_ATOMIC(sz) GC_malloc_atomic(sz) 582 # define GC_STRDUP(s) GC_strdup(s) 583 # define GC_MALLOC_UNCOLLECTABLE(sz) GC_malloc_uncollectable(sz) 584 # define GC_MALLOC_IGNORE_OFF_PAGE(sz) \ 585 GC_malloc_ignore_off_page(sz) 586 # define GC_MALLOC_ATOMIC_IGNORE_OFF_PAGE(sz) \ 587 GC_malloc_atomic_ignore_off_page(sz) 588 # define GC_REALLOC(old, sz) GC_realloc(old, sz) 589 # define GC_FREE(p) GC_free(p) 590 # define GC_REGISTER_FINALIZER(p, f, d, of, od) \ 591 GC_register_finalizer(p, f, d, of, od) 592 # define GC_REGISTER_FINALIZER_IGNORE_SELF(p, f, d, of, od) \ 593 GC_register_finalizer_ignore_self(p, f, d, of, od) 594 # define GC_REGISTER_FINALIZER_NO_ORDER(p, f, d, of, od) \ 595 GC_register_finalizer_no_order(p, f, d, of, od) 596 # define GC_REGISTER_FINALIZER_UNREACHABLE(p, f, d, of, od) \ 597 GC_register_finalizer_unreachable(p, f, d, of, od) 598 # define GC_MALLOC_STUBBORN(sz) GC_malloc_stubborn(sz) 599 # define GC_CHANGE_STUBBORN(p) GC_change_stubborn(p) 600 # define GC_END_STUBBORN_CHANGE(p) GC_end_stubborn_change(p) 601 # define GC_GENERAL_REGISTER_DISAPPEARING_LINK(link, obj) \ 602 GC_general_register_disappearing_link(link, obj) 603 # define GC_REGISTER_DISPLACEMENT(n) GC_register_displacement(n) 604 # endif 605 /* The following are included because they are often convenient, and */ 606 /* reduce the chance for a misspecifed size argument. But calls may */ 607 /* expand to something syntactically incorrect if t is a complicated */ 608 /* type expression. */ 609 # define GC_NEW(t) (t *)GC_MALLOC(sizeof (t)) 610 # define GC_NEW_ATOMIC(t) (t *)GC_MALLOC_ATOMIC(sizeof (t)) 611 # define GC_NEW_STUBBORN(t) (t *)GC_MALLOC_STUBBORN(sizeof (t)) 612 # define GC_NEW_UNCOLLECTABLE(t) (t *)GC_MALLOC_UNCOLLECTABLE(sizeof (t)) 613 614 /* Finalization. Some of these primitives are grossly unsafe. */ 615 /* The idea is to make them both cheap, and sufficient to build */ 616 /* a safer layer, closer to Modula-3, Java, or PCedar finalization. */ 617 /* The interface represents my conclusions from a long discussion */ 618 /* with Alan Demers, Dan Greene, Carl Hauser, Barry Hayes, */ 619 /* Christian Jacobi, and Russ Atkinson. It's not perfect, and */ 620 /* probably nobody else agrees with it. Hans-J. Boehm 3/13/92 */ 621 typedef void (*GC_finalization_proc) (void * obj, void * client_data); 622 623 GC_API void GC_register_finalizer(void * obj, GC_finalization_proc fn, 624 void * cd, GC_finalization_proc *ofn, 625 void * *ocd); 626 GC_API void GC_debug_register_finalizer 627 (void * obj, GC_finalization_proc fn, void * cd, 628 GC_finalization_proc *ofn, void * *ocd); 629 /* When obj is no longer accessible, invoke */ 630 /* (*fn)(obj, cd). If a and b are inaccessible, and */ 631 /* a points to b (after disappearing links have been */ 632 /* made to disappear), then only a will be */ 633 /* finalized. (If this does not create any new */ 634 /* pointers to b, then b will be finalized after the */ 635 /* next collection.) Any finalizable object that */ 636 /* is reachable from itself by following one or more */ 637 /* pointers will not be finalized (or collected). */ 638 /* Thus cycles involving finalizable objects should */ 639 /* be avoided, or broken by disappearing links. */ 640 /* All but the last finalizer registered for an object */ 641 /* is ignored. */ 642 /* Finalization may be removed by passing 0 as fn. */ 643 /* Finalizers are implicitly unregistered just before */ 644 /* they are invoked. */ 645 /* The old finalizer and client data are stored in */ 646 /* *ofn and *ocd. */ 647 /* Fn is never invoked on an accessible object, */ 648 /* provided hidden pointers are converted to real */ 649 /* pointers only if the allocation lock is held, and */ 650 /* such conversions are not performed by finalization */ 651 /* routines. */ 652 /* If GC_register_finalizer is aborted as a result of */ 653 /* a signal, the object may be left with no */ 654 /* finalization, even if neither the old nor new */ 655 /* finalizer were NULL. */ 656 /* Obj should be the nonNULL starting address of an */ 657 /* object allocated by GC_malloc or friends. */ 658 /* Note that any garbage collectable object referenced */ 659 /* by cd will be considered accessible until the */ 660 /* finalizer is invoked. */ 661 662 /* Another versions of the above follow. It ignores */ 663 /* self-cycles, i.e. pointers from a finalizable object to */ 664 /* itself. There is a stylistic argument that this is wrong, */ 665 /* but it's unavoidable for C++, since the compiler may */ 666 /* silently introduce these. It's also benign in that specific */ 667 /* case. And it helps if finalizable objects are split to */ 668 /* avoid cycles. */ 669 /* Note that cd will still be viewed as accessible, even if it */ 670 /* refers to the object itself. */ 671 GC_API void GC_register_finalizer_ignore_self 672 (void * obj, GC_finalization_proc fn, void * cd, 673 GC_finalization_proc *ofn, void * *ocd); 674 GC_API void GC_debug_register_finalizer_ignore_self 675 (void * obj, GC_finalization_proc fn, void * cd, 676 GC_finalization_proc *ofn, void * *ocd); 677 678 /* Another version of the above. It ignores all cycles. */ 679 /* It should probably only be used by Java implementations. */ 680 /* Note that cd will still be viewed as accessible, even if it */ 681 /* refers to the object itself. */ 682 GC_API void GC_register_finalizer_no_order 683 (void * obj, GC_finalization_proc fn, void * cd, 684 GC_finalization_proc *ofn, void * *ocd); 685 GC_API void GC_debug_register_finalizer_no_order 686 (void * obj, GC_finalization_proc fn, void * cd, 687 GC_finalization_proc *ofn, void * *ocd); 688 689 /* This is a special finalizer that is useful when an object's */ 690 /* finalizer must be run when the object is known to be no */ 691 /* longer reachable, not even from other finalizable objects. */ 692 /* It behaves like "normal" finalization, except that the */ 693 /* finalizer is not run while the object is reachable from */ 694 /* other objects specifying unordered finalization. */ 695 /* Effectively it allows an object referenced, possibly */ 696 /* indirectly, from an unordered finalizable object to override */ 697 /* the unordered finalization request. */ 698 /* This can be used in combination with finalizer_no_order so */ 699 /* as to release resources that must not be released while an */ 700 /* object can still be brought back to life by other */ 701 /* finalizers. */ 702 /* Only works if GC_java_finalization is set. Probably only */ 703 /* of interest when implementing a language that requires */ 704 /* unordered finalization (e.g. Java, C#). */ 705 GC_API void GC_register_finalizer_unreachable 706 (void * obj, GC_finalization_proc fn, void * cd, 707 GC_finalization_proc *ofn, void * *ocd); 708 GC_API void GC_debug_register_finalizer_unreachable 709 (void * obj, GC_finalization_proc fn, void * cd, 710 GC_finalization_proc *ofn, void * *ocd); 711 712 /* The following routine may be used to break cycles between */ 713 /* finalizable objects, thus causing cyclic finalizable */ 714 /* objects to be finalized in the correct order. Standard */ 715 /* use involves calling GC_register_disappearing_link(&p), */ 716 /* where p is a pointer that is not followed by finalization */ 717 /* code, and should not be considered in determining */ 718 /* finalization order. */ 719 GC_API int GC_register_disappearing_link(void * * link ); 720 /* Link should point to a field of a heap allocated */ 721 /* object obj. *link will be cleared when obj is */ 722 /* found to be inaccessible. This happens BEFORE any */ 723 /* finalization code is invoked, and BEFORE any */ 724 /* decisions about finalization order are made. */ 725 /* This is useful in telling the finalizer that */ 726 /* some pointers are not essential for proper */ 727 /* finalization. This may avoid finalization cycles. */ 728 /* Note that obj may be resurrected by another */ 729 /* finalizer, and thus the clearing of *link may */ 730 /* be visible to non-finalization code. */ 731 /* There's an argument that an arbitrary action should */ 732 /* be allowed here, instead of just clearing a pointer. */ 733 /* But this causes problems if that action alters, or */ 734 /* examines connectivity. */ 735 /* Returns 1 if link was already registered, 0 */ 736 /* otherwise. */ 737 /* Only exists for backward compatibility. See below: */ 738 739 GC_API int GC_general_register_disappearing_link (void * * link, void * obj); 740 /* A slight generalization of the above. *link is */ 741 /* cleared when obj first becomes inaccessible. This */ 742 /* can be used to implement weak pointers easily and */ 743 /* safely. Typically link will point to a location */ 744 /* holding a disguised pointer to obj. (A pointer */ 745 /* inside an "atomic" object is effectively */ 746 /* disguised.) In this way soft */ 747 /* pointers are broken before any object */ 748 /* reachable from them are finalized. Each link */ 749 /* May be registered only once, i.e. with one obj */ 750 /* value. This was added after a long email discussion */ 751 /* with John Ellis. */ 752 /* Obj must be a pointer to the first word of an object */ 753 /* we allocated. It is unsafe to explicitly deallocate */ 754 /* the object containing link. Explicitly deallocating */ 755 /* obj may or may not cause link to eventually be */ 756 /* cleared. */ 757 /* This can be used to implement certain types of */ 758 /* weak pointers. Note however that this generally */ 759 /* requires that thje allocation lock is held (see */ 760 /* GC_call_with_allock_lock() below) when the disguised */ 761 /* pointer is accessed. Otherwise a strong pointer */ 762 /* could be recreated between the time the collector */ 763 /* decides to reclaim the object and the link is */ 764 /* cleared. */ 765 766 GC_API int GC_unregister_disappearing_link (void * * link); 767 /* Returns 0 if link was not actually registered. */ 768 /* Undoes a registration by either of the above two */ 769 /* routines. */ 770 771 /* Returns !=0 if GC_invoke_finalizers has something to do. */ 772 GC_API int GC_should_invoke_finalizers(void); 773 774 GC_API int GC_invoke_finalizers(void); 775 /* Run finalizers for all objects that are ready to */ 776 /* be finalized. Return the number of finalizers */ 777 /* that were run. Normally this is also called */ 778 /* implicitly during some allocations. If */ 779 /* GC-finalize_on_demand is nonzero, it must be called */ 780 /* explicitly. */ 781 782 /* Explicitly tell the collector that an object is reachable */ 783 /* at a particular program point. This prevents the argument */ 784 /* pointer from being optimized away, even it is otherwise no */ 785 /* longer needed. It should have no visible effect in the */ 786 /* absence of finalizers or disappearing links. But it may be */ 787 /* needed to prevent finalizers from running while the */ 788 /* associated external resource is still in use. */ 789 /* The function is sometimes called keep_alive in other */ 790 /* settings. */ 791 # if defined(__GNUC__) && !defined(__INTEL_COMPILER) 792 # define GC_reachable_here(ptr) \ 793 __asm__ volatile(" " : : "X"(ptr) : "memory"); 794 # else 795 GC_API void GC_noop1(GC_word x); 796 # define GC_reachable_here(ptr) GC_noop1((GC_word)(ptr)); 797 #endif 798 799 /* GC_set_warn_proc can be used to redirect or filter warning messages. */ 800 /* p may not be a NULL pointer. */ 801 typedef void (*GC_warn_proc) (char *msg, GC_word arg); 802 GC_API GC_warn_proc GC_set_warn_proc(GC_warn_proc p); 803 /* Returns old warning procedure. */ 804 805 GC_API GC_word GC_set_free_space_divisor(GC_word value); 806 /* Set free_space_divisor. See above for definition. */ 807 /* Returns old value. */ 808 809 /* The following is intended to be used by a higher level */ 810 /* (e.g. Java-like) finalization facility. It is expected */ 811 /* that finalization code will arrange for hidden pointers to */ 812 /* disappear. Otherwise objects can be accessed after they */ 813 /* have been collected. */ 814 /* Note that putting pointers in atomic objects or in */ 815 /* nonpointer slots of "typed" objects is equivalent to */ 816 /* disguising them in this way, and may have other advantages. */ 817 # if defined(I_HIDE_POINTERS) || defined(GC_I_HIDE_POINTERS) 818 typedef GC_word GC_hidden_pointer; 819 # define HIDE_POINTER(p) (~(GC_hidden_pointer)(p)) 820 # define REVEAL_POINTER(p) ((void *)(HIDE_POINTER(p))) 821 /* Converting a hidden pointer to a real pointer requires verifying */ 822 /* that the object still exists. This involves acquiring the */ 823 /* allocator lock to avoid a race with the collector. */ 824 # endif /* I_HIDE_POINTERS */ 825 826 typedef void * (*GC_fn_type) (void * client_data); 827 GC_API void * GC_call_with_alloc_lock (GC_fn_type fn, void * client_data); 828 829 /* These routines are intended to explicitly notify the collector */ 830 /* of new threads. Often this is unnecessary because thread creation */ 831 /* is implicitly intercepted by the collector, using header-file */ 832 /* defines, or linker-based interception. In the long run the intent */ 833 /* is to always make redundant registration safe. In the short run, */ 834 /* this is being implemented a platform at a time. */ 835 /* The interface is complicated by the fact that we probably will not */ 836 /* ever be able to automatically determine the stack base for thread */ 837 /* stacks on all platforms. */ 838 839 /* Structure representing the base of a thread stack. On most */ 840 /* platforms this contains just a single address. */ 841 struct GC_stack_base { 842 void * mem_base; /* Base of memory stack. */ 843 # if defined(__ia64) || defined(__ia64__) 844 void * reg_base; /* Base of separate register stack. */ 845 # endif 846 }; 847 848 typedef void * (*GC_stack_base_func)(struct GC_stack_base *sb, void *arg); 849 850 /* Call a function with a stack base structure corresponding to */ 851 /* somewhere in the GC_call_with_stack_base frame. This often can */ 852 /* be used to provide a sufficiently accurate stack base. And we */ 853 /* implement it everywhere. */ 854 void * GC_call_with_stack_base(GC_stack_base_func fn, void *arg); 855 856 /* Register the current thread, with the indicated stack base, as */ 857 /* a new thread whose stack(s) should be traced by the GC. If a */ 858 /* platform does not implicitly do so, this must be called before a */ 859 /* thread can allocate garbage collected memory, or assign pointers */ 860 /* to the garbage collected heap. Once registered, a thread will be */ 861 /* stopped during garbage collections. */ 862 /* Return codes: */ 863 #define GC_SUCCESS 0 864 #define GC_DUPLICATE 1 /* Was already registered. */ 865 #define GC_NO_THREADS 2 /* No thread support in GC. */ 866 #define GC_UNIMPLEMENTED 3 /* Not yet implemented on this platform. */ 867 int GC_register_my_thread(struct GC_stack_base *); 868 869 /* Unregister the current thread. The thread may no longer allocate */ 870 /* garbage collected memory or manipulate pointers to the */ 871 /* garbage collected heap after making this call. */ 872 /* Specifically, if it wants to return or otherwise communicate a */ 873 /* pointer to the garbage-collected heap to another thread, it must */ 874 /* do this before calling GC_unregister_my_thread, most probably */ 875 /* by saving it in a global data structure. */ 876 int GC_unregister_my_thread(void); 877 878 /* Attempt to fill in the GC_stack_base structure with the stack base */ 879 /* for this thread. This appears to be required to implement anything */ 880 /* like the JNI AttachCurrentThread in an environment in which new */ 881 /* threads are not automatically registered with the collector. */ 882 /* It is also unfortunately hard to implement well on many platforms. */ 883 /* Returns GC_SUCCESS or GC_UNIMPLEMENTED. */ 884 int GC_get_stack_base(struct GC_stack_base *); 885 886 /* The following routines are primarily intended for use with a */ 887 /* preprocessor which inserts calls to check C pointer arithmetic. */ 888 /* They indicate failure by invoking the corresponding _print_proc. */ 889 890 /* Check that p and q point to the same object. */ 891 /* Fail conspicuously if they don't. */ 892 /* Returns the first argument. */ 893 /* Succeeds if neither p nor q points to the heap. */ 894 /* May succeed if both p and q point to between heap objects. */ 895 GC_API void * GC_same_obj (void * p, void * q); 896 897 /* Checked pointer pre- and post- increment operations. Note that */ 898 /* the second argument is in units of bytes, not multiples of the */ 899 /* object size. This should either be invoked from a macro, or the */ 900 /* call should be automatically generated. */ 901 GC_API void * GC_pre_incr (void * *p, size_t how_much); 902 GC_API void * GC_post_incr (void * *p, size_t how_much); 903 904 /* Check that p is visible */ 905 /* to the collector as a possibly pointer containing location. */ 906 /* If it isn't fail conspicuously. */ 907 /* Returns the argument in all cases. May erroneously succeed */ 908 /* in hard cases. (This is intended for debugging use with */ 909 /* untyped allocations. The idea is that it should be possible, though */ 910 /* slow, to add such a call to all indirect pointer stores.) */ 911 /* Currently useless for multithreaded worlds. */ 912 GC_API void * GC_is_visible (void * p); 913 914 /* Check that if p is a pointer to a heap page, then it points to */ 915 /* a valid displacement within a heap object. */ 916 /* Fail conspicuously if this property does not hold. */ 917 /* Uninteresting with GC_all_interior_pointers. */ 918 /* Always returns its argument. */ 919 GC_API void * GC_is_valid_displacement (void * p); 920 921 /* Explicitly dump the GC state. This is most often called from the */ 922 /* debugger, or by setting the GC_DUMP_REGULARLY environment variable, */ 923 /* but it may be useful to call it from client code during debugging. */ 924 void GC_dump(void); 925 926 /* Safer, but slow, pointer addition. Probably useful mainly with */ 927 /* a preprocessor. Useful only for heap pointers. */ 928 #ifdef GC_DEBUG 929 # define GC_PTR_ADD3(x, n, type_of_result) \ 930 ((type_of_result)GC_same_obj((x)+(n), (x))) 931 # define GC_PRE_INCR3(x, n, type_of_result) \ 932 ((type_of_result)GC_pre_incr(&(x), (n)*sizeof(*x)) 933 # define GC_POST_INCR2(x, type_of_result) \ 934 ((type_of_result)GC_post_incr(&(x), sizeof(*x)) 935 # ifdef __GNUC__ 936 # define GC_PTR_ADD(x, n) \ 937 GC_PTR_ADD3(x, n, typeof(x)) 938 # define GC_PRE_INCR(x, n) \ 939 GC_PRE_INCR3(x, n, typeof(x)) 940 # define GC_POST_INCR(x, n) \ 941 GC_POST_INCR3(x, typeof(x)) 942 # else 943 /* We can't do this right without typeof, which ANSI */ 944 /* decided was not sufficiently useful. Repeatedly */ 945 /* mentioning the arguments seems too dangerous to be */ 946 /* useful. So does not casting the result. */ 947 # define GC_PTR_ADD(x, n) ((x)+(n)) 948 # endif 949 #else /* !GC_DEBUG */ 950 # define GC_PTR_ADD3(x, n, type_of_result) ((x)+(n)) 951 # define GC_PTR_ADD(x, n) ((x)+(n)) 952 # define GC_PRE_INCR3(x, n, type_of_result) ((x) += (n)) 953 # define GC_PRE_INCR(x, n) ((x) += (n)) 954 # define GC_POST_INCR2(x, n, type_of_result) ((x)++) 955 # define GC_POST_INCR(x, n) ((x)++) 956 #endif 957 958 /* Safer assignment of a pointer to a nonstack location. */ 959 #ifdef GC_DEBUG 960 # define GC_PTR_STORE(p, q) \ 961 (*(void **)GC_is_visible(p) = GC_is_valid_displacement(q)) 962 #else /* !GC_DEBUG */ 963 # define GC_PTR_STORE(p, q) *((p) = (q)) 964 #endif 965 966 /* Functions called to report pointer checking errors */ 967 GC_API void (*GC_same_obj_print_proc) (void * p, void * q); 968 969 GC_API void (*GC_is_valid_displacement_print_proc) (void * p); 970 971 GC_API void (*GC_is_visible_print_proc) (void * p); 972 973 974 /* For pthread support, we generally need to intercept a number of */ 975 /* thread library calls. We do that here by macro defining them. */ 976 977 #if !defined(GC_USE_LD_WRAP) && \ 978 (defined(GC_PTHREADS) || defined(GC_SOLARIS_THREADS)) 979 # include "gc_pthread_redirects.h" 980 #endif 981 982 # if defined(PCR) || defined(GC_SOLARIS_THREADS) || \ 983 defined(GC_PTHREADS) || defined(GC_WIN32_THREADS) 984 /* Any flavor of threads. */ 985 /* This returns a list of objects, linked through their first */ 986 /* word. Its use can greatly reduce lock contention problems, since */ 987 /* the allocation lock can be acquired and released many fewer times. */ 988 /* It is used internally by gc_local_alloc.h, which provides a simpler */ 989 /* programming interface on Linux. */ 990 void * GC_malloc_many(size_t lb); 991 #define GC_NEXT(p) (*(void * *)(p)) /* Retrieve the next element */ 992 /* in returned list. */ 993 extern void GC_thr_init(void); /* Needed for Solaris/X86 ?? */ 994 995 #endif /* THREADS */ 996 997 /* Register a callback to control the scanning of dynamic libraries. 998 When the GC scans the static data of a dynamic library, it will 999 first call a user-supplied routine with filename of the library and 1000 the address and length of the memory region. This routine should 1001 return nonzero if that region should be scanned. */ 1002 GC_API void 1003 GC_register_has_static_roots_callback 1004 (int (*callback)(const char *, void *, size_t)); 1005 1006 1007 #if defined(GC_WIN32_THREADS) && !defined(__CYGWIN32__) \ 1008 && !defined(__CYGWIN__) \ 1009 && !defined(GC_PTHREADS) 1010 1011 #ifdef __cplusplus 1012 } /* Including windows.h in an extern "C" context no longer works. */ 1013 #endif 1014 1015 # include <windows.h> 1016 1017 #ifdef __cplusplus 1018 extern "C" { 1019 #endif 1020 /* 1021 * All threads must be created using GC_CreateThread or GC_beginthreadex, 1022 * or must explicitly call GC_register_my_thread, 1023 * so that they will be recorded in the thread table. 1024 * For backwards compatibility, it is possible to build the GC 1025 * with GC_DLL defined, and to call GC_use_DllMain(). 1026 * This implicitly registers all created threads, but appears to be 1027 * less robust. 1028 * 1029 * Currently the collector expects all threads to fall through and 1030 * terminate normally, or call GC_endthreadex() or GC_ExitThread, 1031 * so that the thread is properly unregistered. (An explicit call 1032 * to GC_unregister_my_thread() should also work, but risks unregistering 1033 * the thread twice.) 1034 */ 1035 GC_API HANDLE WINAPI GC_CreateThread( 1036 LPSECURITY_ATTRIBUTES lpThreadAttributes, 1037 DWORD dwStackSize, LPTHREAD_START_ROUTINE lpStartAddress, 1038 LPVOID lpParameter, DWORD dwCreationFlags, LPDWORD lpThreadId ); 1039 1040 1041 GC_API uintptr_t GC_beginthreadex( 1042 void *security, unsigned stack_size, 1043 unsigned ( __stdcall *start_address )( void * ), 1044 void *arglist, unsigned initflag, unsigned *thrdaddr); 1045 1046 GC_API void GC_endthreadex(unsigned retval); 1047 1048 GC_API void WINAPI GC_ExitThread(DWORD dwExitCode); 1049 1050 # if defined(_WIN32_WCE) 1051 /* 1052 * win32_threads.c implements the real WinMain, which will start a new thread 1053 * to call GC_WinMain after initializing the garbage collector. 1054 */ 1055 GC_API int WINAPI GC_WinMain( 1056 HINSTANCE hInstance, 1057 HINSTANCE hPrevInstance, 1058 LPWSTR lpCmdLine, 1059 int nCmdShow ); 1060 # ifndef GC_BUILD 1061 # define WinMain GC_WinMain 1062 # endif 1063 # endif /* defined(_WIN32_WCE) */ 1064 1065 /* 1066 * Use implicit thread registration via DllMain. 1067 */ 1068 GC_API void GC_use_DllMain(void); 1069 1070 # define CreateThread GC_CreateThread 1071 # define ExitThread GC_ExitThread 1072 # define _beginthreadex GC_beginthreadex 1073 # define _endthreadex GC_endthreadex 1074 # define _beginthread { > "Please use _beginthreadex instead of _beginthread" < } 1075 1076 #endif /* defined(GC_WIN32_THREADS) && !cygwin */ 1077 1078 /* 1079 * Fully portable code should call GC_INIT() from the main program 1080 * before making any other GC_ calls. On most platforms this is a 1081 * no-op and the collector self-initializes. But a number of platforms 1082 * make that too hard. 1083 * A GC_INIT call is required if the collector is built with THREAD_LOCAL_ALLOC 1084 * defined and the initial allocation call is not to GC_malloc(). 1085 */ 1086 #if defined(__CYGWIN32__) || defined (_AIX) 1087 /* 1088 * Similarly gnu-win32 DLLs need explicit initialization from 1089 * the main program, as does AIX. 1090 */ 1091 # ifdef __CYGWIN32__ 1092 extern int _data_start__[]; 1093 extern int _data_end__[]; 1094 extern int _bss_start__[]; 1095 extern int _bss_end__[]; 1096 # define GC_MAX(x,y) ((x) > (y) ? (x) : (y)) 1097 # define GC_MIN(x,y) ((x) < (y) ? (x) : (y)) 1098 # define GC_DATASTART ((void *) GC_MIN(_data_start__, _bss_start__)) 1099 # define GC_DATAEND ((void *) GC_MAX(_data_end__, _bss_end__)) 1100 # if defined(GC_DLL) 1101 # define GC_INIT() { GC_add_roots(GC_DATASTART, GC_DATAEND); \ 1102 GC_gcollect(); /* For blacklisting. */} 1103 # else 1104 /* Main program init not required */ 1105 # define GC_INIT() { GC_init(); } 1106 # endif 1107 # endif 1108 # if defined(_AIX) 1109 extern int _data[], _end[]; 1110 # define GC_DATASTART ((void *)((ulong)_data)) 1111 # define GC_DATAEND ((void *)((ulong)_end)) 1112 # define GC_INIT() { GC_add_roots(GC_DATASTART, GC_DATAEND); } 1113 # endif 1114 #else 1115 # define GC_INIT() { GC_init(); } 1116 #endif 1117 1118 #if !defined(_WIN32_WCE) \ 1119 && ((defined(_MSDOS) || defined(_MSC_VER)) && (_M_IX86 >= 300) \ 1120 || defined(_WIN32) && !defined(__CYGWIN32__) && !defined(__CYGWIN__)) 1121 /* win32S may not free all resources on process exit. */ 1122 /* This explicitly deallocates the heap. */ 1123 GC_API void GC_win32_free_heap (); 1124 #endif 1125 1126 #if ( defined(_AMIGA) && !defined(GC_AMIGA_MAKINGLIB) ) 1127 /* Allocation really goes through GC_amiga_allocwrapper_do */ 1128 # include "gc_amiga_redirects.h" 1129 #endif 1130 1131 #if defined(GC_REDIRECT_TO_LOCAL) && !defined(GC_LOCAL_ALLOC_H) 1132 # include "gc_local_alloc.h" 1133 #endif 1134 1135 #ifdef __cplusplus 1136 } /* end of extern "C" */ 1137 #endif 1138 1139 #endif /* _GC_H */ 1140