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 * 7 * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED 8 * OR IMPLIED. ANY USE IS AT YOUR OWN RISK. 9 * 10 * Permission is hereby granted to use or copy this program 11 * for any purpose, provided the above notices are retained on all copies. 12 * Permission to modify the code and to distribute modified code is granted, 13 * provided the above notices are retained, and a notice that the code was 14 * modified is included with the above copyright notice. 15 */ 16 17 /* 18 * Note that this defines a large number of tuning hooks, which can 19 * safely be ignored in nearly all cases. For normal use it suffices 20 * to call only GC_MALLOC and perhaps GC_REALLOC. 21 * For better performance, also look at GC_MALLOC_ATOMIC, and 22 * GC_enable_incremental. If you need an action to be performed 23 * immediately before an object is collected, look at GC_register_finalizer. 24 * If you are using Solaris threads, look at the end of this file. 25 * Everything else is best ignored unless you encounter performance 26 * problems. 27 */ 28 29 #ifndef _GC_H 30 31 # define _GC_H 32 33 # include "gc_config_macros.h" 34 35 # if defined(__STDC__) || defined(__cplusplus) 36 # define GC_PROTO(args) args 37 typedef void * GC_PTR; 38 # define GC_CONST const 39 # else 40 # define GC_PROTO(args) () 41 typedef char * GC_PTR; 42 # define GC_CONST 43 # endif 44 45 # ifdef __cplusplus 46 extern "C" { 47 # endif 48 49 50 /* Define word and signed_word to be unsigned and signed types of the */ 51 /* size as char * or void *. There seems to be no way to do this */ 52 /* even semi-portably. The following is probably no better/worse */ 53 /* than almost anything else. */ 54 /* The ANSI standard suggests that size_t and ptr_diff_t might be */ 55 /* better choices. But those appear to have incorrect definitions */ 56 /* on may systems. Notably "typedef int size_t" seems to be both */ 57 /* frequent and WRONG. */ 58 typedef unsigned long GC_word; 59 typedef long GC_signed_word; 60 61 /* Public read-only variables */ 62 63 GC_API GC_word GC_gc_no;/* Counter incremented per collection. */ 64 /* Includes empty GCs at startup. */ 65 66 GC_API int GC_parallel; /* GC is parallelized for performance on */ 67 /* multiprocessors. Currently set only */ 68 /* implicitly if collector is built with */ 69 /* -DPARALLEL_MARK and if either: */ 70 /* Env variable GC_NPROC is set to > 1, or */ 71 /* GC_NPROC is not set and this is an MP. */ 72 /* If GC_parallel is set, incremental */ 73 /* collection is only partially functional, */ 74 /* and may not be desirable. */ 75 76 77 /* Public R/W variables */ 78 79 GC_API GC_PTR (*GC_oom_fn) GC_PROTO((size_t bytes_requested)); 80 /* When there is insufficient memory to satisfy */ 81 /* an allocation request, we return */ 82 /* (*GC_oom_fn)(). By default this just */ 83 /* returns 0. */ 84 /* If it returns, it must return 0 or a valid */ 85 /* pointer to a previously allocated heap */ 86 /* object. */ 87 88 GC_API int GC_find_leak; 89 /* Do not actually garbage collect, but simply */ 90 /* report inaccessible memory that was not */ 91 /* deallocated with GC_free. Initial value */ 92 /* is determined by FIND_LEAK macro. */ 93 94 GC_API int GC_all_interior_pointers; 95 /* Arrange for pointers to object interiors to */ 96 /* be recognized as valid. May not be changed */ 97 /* after GC initialization. */ 98 /* Initial value is determined by */ 99 /* -DALL_INTERIOR_POINTERS. */ 100 /* Unless DONT_ADD_BYTE_AT_END is defined, this */ 101 /* also affects whether sizes are increased by */ 102 /* at least a byte to allow "off the end" */ 103 /* pointer recognition. */ 104 /* MUST BE 0 or 1. */ 105 106 GC_API int GC_quiet; /* Disable statistics output. Only matters if */ 107 /* collector has been compiled with statistics */ 108 /* enabled. This involves a performance cost, */ 109 /* and is thus not the default. */ 110 111 GC_API int GC_finalize_on_demand; 112 /* If nonzero, finalizers will only be run in */ 113 /* response to an explicit GC_invoke_finalizers */ 114 /* call. The default is determined by whether */ 115 /* the FINALIZE_ON_DEMAND macro is defined */ 116 /* when the collector is built. */ 117 118 GC_API int GC_java_finalization; 119 /* Mark objects reachable from finalizable */ 120 /* objects in a separate postpass. This makes */ 121 /* it a bit safer to use non-topologically- */ 122 /* ordered finalization. Default value is */ 123 /* determined by JAVA_FINALIZATION macro. */ 124 125 GC_API void (* GC_finalizer_notifier)(); 126 /* Invoked by the collector when there are */ 127 /* objects to be finalized. Invoked at most */ 128 /* once per GC cycle. Never invoked unless */ 129 /* GC_finalize_on_demand is set. */ 130 /* Typically this will notify a finalization */ 131 /* thread, which will call GC_invoke_finalizers */ 132 /* in response. */ 133 134 GC_API int GC_dont_gc; /* != 0 ==> Dont collect. In versions 6.2a1+, */ 135 /* this overrides explicit GC_gcollect() calls. */ 136 /* Used as a counter, so that nested enabling */ 137 /* and disabling work correctly. Should */ 138 /* normally be updated with GC_enable() and */ 139 /* GC_disable() calls. */ 140 /* Direct assignment to GC_dont_gc is */ 141 /* deprecated. */ 142 143 GC_API int GC_dont_expand; 144 /* Dont expand heap unless explicitly requested */ 145 /* or forced to. */ 146 147 GC_API int GC_use_entire_heap; 148 /* Causes the nonincremental collector to use the */ 149 /* entire heap before collecting. This was the only */ 150 /* option for GC versions < 5.0. This sometimes */ 151 /* results in more large block fragmentation, since */ 152 /* very larg blocks will tend to get broken up */ 153 /* during each GC cycle. It is likely to result in a */ 154 /* larger working set, but lower collection */ 155 /* frequencies, and hence fewer instructions executed */ 156 /* in the collector. */ 157 158 GC_API int GC_full_freq; /* Number of partial collections between */ 159 /* full collections. Matters only if */ 160 /* GC_incremental is set. */ 161 /* Full collections are also triggered if */ 162 /* the collector detects a substantial */ 163 /* increase in the number of in-use heap */ 164 /* blocks. Values in the tens are now */ 165 /* perfectly reasonable, unlike for */ 166 /* earlier GC versions. */ 167 168 GC_API GC_word GC_non_gc_bytes; 169 /* Bytes not considered candidates for collection. */ 170 /* Used only to control scheduling of collections. */ 171 /* Updated by GC_malloc_uncollectable and GC_free. */ 172 /* Wizards only. */ 173 174 GC_API int GC_no_dls; 175 /* Don't register dynamic library data segments. */ 176 /* Wizards only. Should be used only if the */ 177 /* application explicitly registers all roots. */ 178 /* In Microsoft Windows environments, this will */ 179 /* usually also prevent registration of the */ 180 /* main data segment as part of the root set. */ 181 182 GC_API GC_word GC_free_space_divisor; 183 /* We try to make sure that we allocate at */ 184 /* least N/GC_free_space_divisor bytes between */ 185 /* collections, where N is the heap size plus */ 186 /* a rough estimate of the root set size. */ 187 /* Initially, GC_free_space_divisor = 4. */ 188 /* Increasing its value will use less space */ 189 /* but more collection time. Decreasing it */ 190 /* will appreciably decrease collection time */ 191 /* at the expense of space. */ 192 /* GC_free_space_divisor = 1 will effectively */ 193 /* disable collections. */ 194 195 GC_API GC_word GC_max_retries; 196 /* The maximum number of GCs attempted before */ 197 /* reporting out of memory after heap */ 198 /* expansion fails. Initially 0. */ 199 200 201 GC_API char *GC_stackbottom; /* Cool end of user stack. */ 202 /* May be set in the client prior to */ 203 /* calling any GC_ routines. This */ 204 /* avoids some overhead, and */ 205 /* potentially some signals that can */ 206 /* confuse debuggers. Otherwise the */ 207 /* collector attempts to set it */ 208 /* automatically. */ 209 /* For multithreaded code, this is the */ 210 /* cold end of the stack for the */ 211 /* primordial thread. */ 212 213 GC_API int GC_dont_precollect; /* Don't collect as part of */ 214 /* initialization. Should be set only */ 215 /* if the client wants a chance to */ 216 /* manually initialize the root set */ 217 /* before the first collection. */ 218 /* Interferes with blacklisting. */ 219 /* Wizards only. */ 220 221 /* Public procedures */ 222 223 /* Initialize the collector. This is only required when using thread-local 224 * allocation, since unlike the regular allocation routines, GC_local_malloc 225 * is not self-initializing. If you use GC_local_malloc you should arrange 226 * to call this somehow (e.g. from a constructor) before doing any allocation. 227 */ 228 GC_API void GC_init GC_PROTO((void)); 229 230 GC_API unsigned long GC_time_limit; 231 /* If incremental collection is enabled, */ 232 /* We try to terminate collections */ 233 /* after this many milliseconds. Not a */ 234 /* hard time bound. Setting this to */ 235 /* GC_TIME_UNLIMITED will essentially */ 236 /* disable incremental collection while */ 237 /* leaving generational collection */ 238 /* enabled. */ 239 # define GC_TIME_UNLIMITED 999999 240 /* Setting GC_time_limit to this value */ 241 /* will disable the "pause time exceeded"*/ 242 /* tests. */ 243 244 /* Public procedures */ 245 246 /* Initialize the collector. This is only required when using thread-local 247 * allocation, since unlike the regular allocation routines, GC_local_malloc 248 * is not self-initializing. If you use GC_local_malloc you should arrange 249 * to call this somehow (e.g. from a constructor) before doing any allocation. 250 */ 251 GC_API void GC_init GC_PROTO((void)); 252 253 /* 254 * general purpose allocation routines, with roughly malloc calling conv. 255 * The atomic versions promise that no relevant pointers are contained 256 * in the object. The nonatomic versions guarantee that the new object 257 * is cleared. GC_malloc_stubborn promises that no changes to the object 258 * will occur after GC_end_stubborn_change has been called on the 259 * result of GC_malloc_stubborn. GC_malloc_uncollectable allocates an object 260 * that is scanned for pointers to collectable objects, but is not itself 261 * collectable. The object is scanned even if it does not appear to 262 * be reachable. GC_malloc_uncollectable and GC_free called on the resulting 263 * object implicitly update GC_non_gc_bytes appropriately. 264 * 265 * Note that the GC_malloc_stubborn support is stubbed out by default 266 * starting in 6.0. GC_malloc_stubborn is an alias for GC_malloc unless 267 * the collector is built with STUBBORN_ALLOC defined. 268 */ 269 GC_API GC_PTR GC_malloc GC_PROTO((size_t size_in_bytes)); 270 GC_API GC_PTR GC_malloc_atomic GC_PROTO((size_t size_in_bytes)); 271 GC_API GC_PTR GC_malloc_uncollectable GC_PROTO((size_t size_in_bytes)); 272 GC_API GC_PTR GC_malloc_stubborn GC_PROTO((size_t size_in_bytes)); 273 274 /* The following is only defined if the library has been suitably */ 275 /* compiled: */ 276 GC_API GC_PTR GC_malloc_atomic_uncollectable GC_PROTO((size_t size_in_bytes)); 277 278 /* Explicitly deallocate an object. Dangerous if used incorrectly. */ 279 /* Requires a pointer to the base of an object. */ 280 /* If the argument is stubborn, it should not be changeable when freed. */ 281 /* An object should not be enable for finalization when it is */ 282 /* explicitly deallocated. */ 283 /* GC_free(0) is a no-op, as required by ANSI C for free. */ 284 GC_API void GC_free GC_PROTO((GC_PTR object_addr)); 285 286 /* 287 * Stubborn objects may be changed only if the collector is explicitly informed. 288 * The collector is implicitly informed of coming change when such 289 * an object is first allocated. The following routines inform the 290 * collector that an object will no longer be changed, or that it will 291 * once again be changed. Only nonNIL pointer stores into the object 292 * are considered to be changes. The argument to GC_end_stubborn_change 293 * must be exacly the value returned by GC_malloc_stubborn or passed to 294 * GC_change_stubborn. (In the second case it may be an interior pointer 295 * within 512 bytes of the beginning of the objects.) 296 * There is a performance penalty for allowing more than 297 * one stubborn object to be changed at once, but it is acceptable to 298 * do so. The same applies to dropping stubborn objects that are still 299 * changeable. 300 */ 301 GC_API void GC_change_stubborn GC_PROTO((GC_PTR)); 302 GC_API void GC_end_stubborn_change GC_PROTO((GC_PTR)); 303 304 /* Return a pointer to the base (lowest address) of an object given */ 305 /* a pointer to a location within the object. */ 306 /* I.e. map an interior pointer to the corresponding bas pointer. */ 307 /* Note that with debugging allocation, this returns a pointer to the */ 308 /* actual base of the object, i.e. the debug information, not to */ 309 /* the base of the user object. */ 310 /* Return 0 if displaced_pointer doesn't point to within a valid */ 311 /* object. */ 312 GC_API GC_PTR GC_base GC_PROTO((GC_PTR displaced_pointer)); 313 314 /* Given a pointer to the base of an object, return its size in bytes. */ 315 /* The returned size may be slightly larger than what was originally */ 316 /* requested. */ 317 GC_API size_t GC_size GC_PROTO((GC_PTR object_addr)); 318 319 /* For compatibility with C library. This is occasionally faster than */ 320 /* a malloc followed by a bcopy. But if you rely on that, either here */ 321 /* or with the standard C library, your code is broken. In my */ 322 /* opinion, it shouldn't have been invented, but now we're stuck. -HB */ 323 /* The resulting object has the same kind as the original. */ 324 /* If the argument is stubborn, the result will have changes enabled. */ 325 /* It is an error to have changes enabled for the original object. */ 326 /* Follows ANSI comventions for NULL old_object. */ 327 GC_API GC_PTR GC_realloc 328 GC_PROTO((GC_PTR old_object, size_t new_size_in_bytes)); 329 330 /* Explicitly increase the heap size. */ 331 /* Returns 0 on failure, 1 on success. */ 332 GC_API int GC_expand_hp GC_PROTO((size_t number_of_bytes)); 333 334 /* Limit the heap size to n bytes. Useful when you're debugging, */ 335 /* especially on systems that don't handle running out of memory well. */ 336 /* n == 0 ==> unbounded. This is the default. */ 337 GC_API void GC_set_max_heap_size GC_PROTO((GC_word n)); 338 339 /* Inform the collector that a certain section of statically allocated */ 340 /* memory contains no pointers to garbage collected memory. Thus it */ 341 /* need not be scanned. This is sometimes important if the application */ 342 /* maps large read/write files into the address space, which could be */ 343 /* mistaken for dynamic library data segments on some systems. */ 344 GC_API void GC_exclude_static_roots GC_PROTO((GC_PTR start, GC_PTR finish)); 345 346 /* Clear the set of root segments. Wizards only. */ 347 GC_API void GC_clear_roots GC_PROTO((void)); 348 349 /* Add a root segment. Wizards only. */ 350 GC_API void GC_add_roots GC_PROTO((char * low_address, 351 char * high_address_plus_1)); 352 353 /* Remove a root segment. Wizards only. */ 354 GC_API void GC_remove_roots GC_PROTO((char * low_address, 355 char * high_address_plus_1)); 356 357 /* Add a displacement to the set of those considered valid by the */ 358 /* collector. GC_register_displacement(n) means that if p was returned */ 359 /* by GC_malloc, then (char *)p + n will be considered to be a valid */ 360 /* pointer to p. N must be small and less than the size of p. */ 361 /* (All pointers to the interior of objects from the stack are */ 362 /* considered valid in any case. This applies to heap objects and */ 363 /* static data.) */ 364 /* Preferably, this should be called before any other GC procedures. */ 365 /* Calling it later adds to the probability of excess memory */ 366 /* retention. */ 367 /* This is a no-op if the collector has recognition of */ 368 /* arbitrary interior pointers enabled, which is now the default. */ 369 GC_API void GC_register_displacement GC_PROTO((GC_word n)); 370 371 /* The following version should be used if any debugging allocation is */ 372 /* being done. */ 373 GC_API void GC_debug_register_displacement GC_PROTO((GC_word n)); 374 375 /* Explicitly trigger a full, world-stop collection. */ 376 GC_API void GC_gcollect GC_PROTO((void)); 377 378 /* Trigger a full world-stopped collection. Abort the collection if */ 379 /* and when stop_func returns a nonzero value. Stop_func will be */ 380 /* called frequently, and should be reasonably fast. This works even */ 381 /* if virtual dirty bits, and hence incremental collection is not */ 382 /* available for this architecture. Collections can be aborted faster */ 383 /* than normal pause times for incremental collection. However, */ 384 /* aborted collections do no useful work; the next collection needs */ 385 /* to start from the beginning. */ 386 /* Return 0 if the collection was aborted, 1 if it succeeded. */ 387 typedef int (* GC_stop_func) GC_PROTO((void)); 388 GC_API int GC_try_to_collect GC_PROTO((GC_stop_func stop_func)); 389 390 /* Return the number of bytes in the heap. Excludes collector private */ 391 /* data structures. Includes empty blocks and fragmentation loss. */ 392 /* Includes some pages that were allocated but never written. */ 393 GC_API size_t GC_get_heap_size GC_PROTO((void)); 394 395 /* Return a lower bound on the number of free bytes in the heap. */ 396 GC_API size_t GC_get_free_bytes GC_PROTO((void)); 397 398 /* Return the number of bytes allocated since the last collection. */ 399 GC_API size_t GC_get_bytes_since_gc GC_PROTO((void)); 400 401 /* Return the total number of bytes allocated in this process. */ 402 /* Never decreases, except due to wrapping. */ 403 GC_API size_t GC_get_total_bytes GC_PROTO((void)); 404 405 /* Disable garbage collection. Even GC_gcollect calls will be */ 406 /* ineffective. */ 407 GC_API void GC_disable GC_PROTO((void)); 408 409 /* Reenable garbage collection. GC_disable() and GC_enable() calls */ 410 /* nest. Garbage collection is enabled if the number of calls to both */ 411 /* both functions is equal. */ 412 GC_API void GC_enable GC_PROTO((void)); 413 414 /* Enable incremental/generational collection. */ 415 /* Not advisable unless dirty bits are */ 416 /* available or most heap objects are */ 417 /* pointerfree(atomic) or immutable. */ 418 /* Don't use in leak finding mode. */ 419 /* Ignored if GC_dont_gc is true. */ 420 /* Only the generational piece of this is */ 421 /* functional if GC_parallel is TRUE */ 422 /* or if GC_time_limit is GC_TIME_UNLIMITED. */ 423 /* Causes GC_local_gcj_malloc() to revert to */ 424 /* locked allocation. Must be called */ 425 /* before any GC_local_gcj_malloc() calls. */ 426 GC_API void GC_enable_incremental GC_PROTO((void)); 427 428 /* Does incremental mode write-protect pages? Returns zero or */ 429 /* more of the following, or'ed together: */ 430 #define GC_PROTECTS_POINTER_HEAP 1 /* May protect non-atomic objs. */ 431 #define GC_PROTECTS_PTRFREE_HEAP 2 432 #define GC_PROTECTS_STATIC_DATA 4 /* Curently never. */ 433 #define GC_PROTECTS_STACK 8 /* Probably impractical. */ 434 435 #define GC_PROTECTS_NONE 0 436 GC_API int GC_incremental_protection_needs GC_PROTO((void)); 437 438 /* Perform some garbage collection work, if appropriate. */ 439 /* Return 0 if there is no more work to be done. */ 440 /* Typically performs an amount of work corresponding roughly */ 441 /* to marking from one page. May do more work if further */ 442 /* progress requires it, e.g. if incremental collection is */ 443 /* disabled. It is reasonable to call this in a wait loop */ 444 /* until it returns 0. */ 445 GC_API int GC_collect_a_little GC_PROTO((void)); 446 447 /* Allocate an object of size lb bytes. The client guarantees that */ 448 /* as long as the object is live, it will be referenced by a pointer */ 449 /* that points to somewhere within the first 256 bytes of the object. */ 450 /* (This should normally be declared volatile to prevent the compiler */ 451 /* from invalidating this assertion.) This routine is only useful */ 452 /* if a large array is being allocated. It reduces the chance of */ 453 /* accidentally retaining such an array as a result of scanning an */ 454 /* integer that happens to be an address inside the array. (Actually, */ 455 /* it reduces the chance of the allocator not finding space for such */ 456 /* an array, since it will try hard to avoid introducing such a false */ 457 /* reference.) On a SunOS 4.X or MS Windows system this is recommended */ 458 /* for arrays likely to be larger than 100K or so. For other systems, */ 459 /* or if the collector is not configured to recognize all interior */ 460 /* pointers, the threshold is normally much higher. */ 461 GC_API GC_PTR GC_malloc_ignore_off_page GC_PROTO((size_t lb)); 462 GC_API GC_PTR GC_malloc_atomic_ignore_off_page GC_PROTO((size_t lb)); 463 464 #if defined(__sgi) && !defined(__GNUC__) && _COMPILER_VERSION >= 720 465 # define GC_ADD_CALLER 466 # define GC_RETURN_ADDR (GC_word)__return_address 467 #endif 468 469 #ifdef __linux__ 470 # include <features.h> 471 # if (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 1 || __GLIBC__ > 2) \ 472 && !defined(__ia64__) 473 # define GC_HAVE_BUILTIN_BACKTRACE 474 # define GC_CAN_SAVE_CALL_STACKS 475 # endif 476 # if defined(__i386__) || defined(__x86_64__) 477 # define GC_CAN_SAVE_CALL_STACKS 478 # endif 479 #endif 480 481 #if defined(__sparc__) 482 # define GC_CAN_SAVE_CALL_STACKS 483 #endif 484 485 /* If we're on an a platform on which we can't save call stacks, but */ 486 /* gcc is normally used, we go ahead and define GC_ADD_CALLER. */ 487 /* We make this decision independent of whether gcc is actually being */ 488 /* used, in order to keep the interface consistent, and allow mixing */ 489 /* of compilers. */ 490 /* This may also be desirable if it is possible but expensive to */ 491 /* retrieve the call chain. */ 492 #if (defined(__linux__) || defined(__NetBSD__) || defined(__OpenBSD__) \ 493 || defined(__FreeBSD__)) & !defined(GC_CAN_SAVE_CALL_STACKS) 494 # define GC_ADD_CALLER 495 # if __GNUC__ >= 3 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 95) 496 /* gcc knows how to retrieve return address, but we don't know */ 497 /* how to generate call stacks. */ 498 # define GC_RETURN_ADDR (GC_word)__builtin_return_address(0) 499 # else 500 /* Just pass 0 for gcc compatibility. */ 501 # define GC_RETURN_ADDR 0 502 # endif 503 #endif 504 505 #ifdef GC_ADD_CALLER 506 # define GC_EXTRAS GC_RETURN_ADDR, __FILE__, __LINE__ 507 # define GC_EXTRA_PARAMS GC_word ra, GC_CONST char * s, int i 508 #else 509 # define GC_EXTRAS __FILE__, __LINE__ 510 # define GC_EXTRA_PARAMS GC_CONST char * s, int i 511 #endif 512 513 /* Debugging (annotated) allocation. GC_gcollect will check */ 514 /* objects allocated in this way for overwrites, etc. */ 515 GC_API GC_PTR GC_debug_malloc 516 GC_PROTO((size_t size_in_bytes, GC_EXTRA_PARAMS)); 517 GC_API GC_PTR GC_debug_malloc_atomic 518 GC_PROTO((size_t size_in_bytes, GC_EXTRA_PARAMS)); 519 GC_API GC_PTR GC_debug_malloc_uncollectable 520 GC_PROTO((size_t size_in_bytes, GC_EXTRA_PARAMS)); 521 GC_API GC_PTR GC_debug_malloc_stubborn 522 GC_PROTO((size_t size_in_bytes, GC_EXTRA_PARAMS)); 523 GC_API GC_PTR GC_debug_malloc_ignore_off_page 524 GC_PROTO((size_t size_in_bytes, GC_EXTRA_PARAMS)); 525 GC_API GC_PTR GC_debug_malloc_atomic_ignore_off_page 526 GC_PROTO((size_t size_in_bytes, GC_EXTRA_PARAMS)); 527 GC_API void GC_debug_free GC_PROTO((GC_PTR object_addr)); 528 GC_API GC_PTR GC_debug_realloc 529 GC_PROTO((GC_PTR old_object, size_t new_size_in_bytes, 530 GC_EXTRA_PARAMS)); 531 GC_API void GC_debug_change_stubborn GC_PROTO((GC_PTR)); 532 GC_API void GC_debug_end_stubborn_change GC_PROTO((GC_PTR)); 533 534 /* Routines that allocate objects with debug information (like the */ 535 /* above), but just fill in dummy file and line number information. */ 536 /* Thus they can serve as drop-in malloc/realloc replacements. This */ 537 /* can be useful for two reasons: */ 538 /* 1) It allows the collector to be built with DBG_HDRS_ALL defined */ 539 /* even if some allocation calls come from 3rd party libraries */ 540 /* that can't be recompiled. */ 541 /* 2) On some platforms, the file and line information is redundant, */ 542 /* since it can be reconstructed from a stack trace. On such */ 543 /* platforms it may be more convenient not to recompile, e.g. for */ 544 /* leak detection. This can be accomplished by instructing the */ 545 /* linker to replace malloc/realloc with these. */ 546 GC_API GC_PTR GC_debug_malloc_replacement GC_PROTO((size_t size_in_bytes)); 547 GC_API GC_PTR GC_debug_realloc_replacement 548 GC_PROTO((GC_PTR object_addr, size_t size_in_bytes)); 549 550 # ifdef GC_DEBUG 551 # define GC_MALLOC(sz) GC_debug_malloc(sz, GC_EXTRAS) 552 # define GC_MALLOC_ATOMIC(sz) GC_debug_malloc_atomic(sz, GC_EXTRAS) 553 # define GC_MALLOC_UNCOLLECTABLE(sz) \ 554 GC_debug_malloc_uncollectable(sz, GC_EXTRAS) 555 # define GC_MALLOC_IGNORE_OFF_PAGE(sz) \ 556 GC_debug_malloc_ignore_off_page(sz, GC_EXTRAS) 557 # define GC_MALLOC_ATOMIC_IGNORE_OFF_PAGE(sz) \ 558 GC_debug_malloc_atomic_ignore_off_page(sz, GC_EXTRAS) 559 # define GC_REALLOC(old, sz) GC_debug_realloc(old, sz, GC_EXTRAS) 560 # define GC_FREE(p) GC_debug_free(p) 561 # define GC_REGISTER_FINALIZER(p, f, d, of, od) \ 562 GC_debug_register_finalizer(p, f, d, of, od) 563 # define GC_REGISTER_FINALIZER_IGNORE_SELF(p, f, d, of, od) \ 564 GC_debug_register_finalizer_ignore_self(p, f, d, of, od) 565 # define GC_REGISTER_FINALIZER_NO_ORDER(p, f, d, of, od) \ 566 GC_debug_register_finalizer_no_order(p, f, d, of, od) 567 # define GC_MALLOC_STUBBORN(sz) GC_debug_malloc_stubborn(sz, GC_EXTRAS); 568 # define GC_CHANGE_STUBBORN(p) GC_debug_change_stubborn(p) 569 # define GC_END_STUBBORN_CHANGE(p) GC_debug_end_stubborn_change(p) 570 # define GC_GENERAL_REGISTER_DISAPPEARING_LINK(link, obj) \ 571 GC_general_register_disappearing_link(link, GC_base(obj)) 572 # define GC_REGISTER_DISPLACEMENT(n) GC_debug_register_displacement(n) 573 # else 574 # define GC_MALLOC(sz) GC_malloc(sz) 575 # define GC_MALLOC_ATOMIC(sz) GC_malloc_atomic(sz) 576 # define GC_MALLOC_UNCOLLECTABLE(sz) GC_malloc_uncollectable(sz) 577 # define GC_MALLOC_IGNORE_OFF_PAGE(sz) \ 578 GC_malloc_ignore_off_page(sz) 579 # define GC_MALLOC_ATOMIC_IGNORE_OFF_PAGE(sz) \ 580 GC_malloc_atomic_ignore_off_page(sz) 581 # define GC_REALLOC(old, sz) GC_realloc(old, sz) 582 # define GC_FREE(p) GC_free(p) 583 # define GC_REGISTER_FINALIZER(p, f, d, of, od) \ 584 GC_register_finalizer(p, f, d, of, od) 585 # define GC_REGISTER_FINALIZER_IGNORE_SELF(p, f, d, of, od) \ 586 GC_register_finalizer_ignore_self(p, f, d, of, od) 587 # define GC_REGISTER_FINALIZER_NO_ORDER(p, f, d, of, od) \ 588 GC_register_finalizer_no_order(p, f, d, of, od) 589 # define GC_MALLOC_STUBBORN(sz) GC_malloc_stubborn(sz) 590 # define GC_CHANGE_STUBBORN(p) GC_change_stubborn(p) 591 # define GC_END_STUBBORN_CHANGE(p) GC_end_stubborn_change(p) 592 # define GC_GENERAL_REGISTER_DISAPPEARING_LINK(link, obj) \ 593 GC_general_register_disappearing_link(link, obj) 594 # define GC_REGISTER_DISPLACEMENT(n) GC_register_displacement(n) 595 # endif 596 /* The following are included because they are often convenient, and */ 597 /* reduce the chance for a misspecifed size argument. But calls may */ 598 /* expand to something syntactically incorrect if t is a complicated */ 599 /* type expression. */ 600 # define GC_NEW(t) (t *)GC_MALLOC(sizeof (t)) 601 # define GC_NEW_ATOMIC(t) (t *)GC_MALLOC_ATOMIC(sizeof (t)) 602 # define GC_NEW_STUBBORN(t) (t *)GC_MALLOC_STUBBORN(sizeof (t)) 603 # define GC_NEW_UNCOLLECTABLE(t) (t *)GC_MALLOC_UNCOLLECTABLE(sizeof (t)) 604 605 /* Finalization. Some of these primitives are grossly unsafe. */ 606 /* The idea is to make them both cheap, and sufficient to build */ 607 /* a safer layer, closer to PCedar finalization. */ 608 /* The interface represents my conclusions from a long discussion */ 609 /* with Alan Demers, Dan Greene, Carl Hauser, Barry Hayes, */ 610 /* Christian Jacobi, and Russ Atkinson. It's not perfect, and */ 611 /* probably nobody else agrees with it. Hans-J. Boehm 3/13/92 */ 612 typedef void (*GC_finalization_proc) 613 GC_PROTO((GC_PTR obj, GC_PTR client_data)); 614 615 GC_API void GC_register_finalizer 616 GC_PROTO((GC_PTR obj, GC_finalization_proc fn, GC_PTR cd, 617 GC_finalization_proc *ofn, GC_PTR *ocd)); 618 GC_API void GC_debug_register_finalizer 619 GC_PROTO((GC_PTR obj, GC_finalization_proc fn, GC_PTR cd, 620 GC_finalization_proc *ofn, GC_PTR *ocd)); 621 /* When obj is no longer accessible, invoke */ 622 /* (*fn)(obj, cd). If a and b are inaccessible, and */ 623 /* a points to b (after disappearing links have been */ 624 /* made to disappear), then only a will be */ 625 /* finalized. (If this does not create any new */ 626 /* pointers to b, then b will be finalized after the */ 627 /* next collection.) Any finalizable object that */ 628 /* is reachable from itself by following one or more */ 629 /* pointers will not be finalized (or collected). */ 630 /* Thus cycles involving finalizable objects should */ 631 /* be avoided, or broken by disappearing links. */ 632 /* All but the last finalizer registered for an object */ 633 /* is ignored. */ 634 /* Finalization may be removed by passing 0 as fn. */ 635 /* Finalizers are implicitly unregistered just before */ 636 /* they are invoked. */ 637 /* The old finalizer and client data are stored in */ 638 /* *ofn and *ocd. */ 639 /* Fn is never invoked on an accessible object, */ 640 /* provided hidden pointers are converted to real */ 641 /* pointers only if the allocation lock is held, and */ 642 /* such conversions are not performed by finalization */ 643 /* routines. */ 644 /* If GC_register_finalizer is aborted as a result of */ 645 /* a signal, the object may be left with no */ 646 /* finalization, even if neither the old nor new */ 647 /* finalizer were NULL. */ 648 /* Obj should be the nonNULL starting address of an */ 649 /* object allocated by GC_malloc or friends. */ 650 /* Note that any garbage collectable object referenced */ 651 /* by cd will be considered accessible until the */ 652 /* finalizer is invoked. */ 653 654 /* Another versions of the above follow. It ignores */ 655 /* self-cycles, i.e. pointers from a finalizable object to */ 656 /* itself. There is a stylistic argument that this is wrong, */ 657 /* but it's unavoidable for C++, since the compiler may */ 658 /* silently introduce these. It's also benign in that specific */ 659 /* case. And it helps if finalizable objects are split to */ 660 /* avoid cycles. */ 661 /* Note that cd will still be viewed as accessible, even if it */ 662 /* refers to the object itself. */ 663 GC_API void GC_register_finalizer_ignore_self 664 GC_PROTO((GC_PTR obj, GC_finalization_proc fn, GC_PTR cd, 665 GC_finalization_proc *ofn, GC_PTR *ocd)); 666 GC_API void GC_debug_register_finalizer_ignore_self 667 GC_PROTO((GC_PTR obj, GC_finalization_proc fn, GC_PTR cd, 668 GC_finalization_proc *ofn, GC_PTR *ocd)); 669 670 /* Another version of the above. It ignores all cycles. */ 671 /* It should probably only be used by Java implementations. */ 672 /* Note that cd will still be viewed as accessible, even if it */ 673 /* refers to the object itself. */ 674 GC_API void GC_register_finalizer_no_order 675 GC_PROTO((GC_PTR obj, GC_finalization_proc fn, GC_PTR cd, 676 GC_finalization_proc *ofn, GC_PTR *ocd)); 677 GC_API void GC_debug_register_finalizer_no_order 678 GC_PROTO((GC_PTR obj, GC_finalization_proc fn, GC_PTR cd, 679 GC_finalization_proc *ofn, GC_PTR *ocd)); 680 681 682 /* The following routine may be used to break cycles between */ 683 /* finalizable objects, thus causing cyclic finalizable */ 684 /* objects to be finalized in the correct order. Standard */ 685 /* use involves calling GC_register_disappearing_link(&p), */ 686 /* where p is a pointer that is not followed by finalization */ 687 /* code, and should not be considered in determining */ 688 /* finalization order. */ 689 GC_API int GC_register_disappearing_link GC_PROTO((GC_PTR * /* link */)); 690 /* Link should point to a field of a heap allocated */ 691 /* object obj. *link will be cleared when obj is */ 692 /* found to be inaccessible. This happens BEFORE any */ 693 /* finalization code is invoked, and BEFORE any */ 694 /* decisions about finalization order are made. */ 695 /* This is useful in telling the finalizer that */ 696 /* some pointers are not essential for proper */ 697 /* finalization. This may avoid finalization cycles. */ 698 /* Note that obj may be resurrected by another */ 699 /* finalizer, and thus the clearing of *link may */ 700 /* be visible to non-finalization code. */ 701 /* There's an argument that an arbitrary action should */ 702 /* be allowed here, instead of just clearing a pointer. */ 703 /* But this causes problems if that action alters, or */ 704 /* examines connectivity. */ 705 /* Returns 1 if link was already registered, 0 */ 706 /* otherwise. */ 707 /* Only exists for backward compatibility. See below: */ 708 709 GC_API int GC_general_register_disappearing_link 710 GC_PROTO((GC_PTR * /* link */, GC_PTR obj)); 711 /* A slight generalization of the above. *link is */ 712 /* cleared when obj first becomes inaccessible. This */ 713 /* can be used to implement weak pointers easily and */ 714 /* safely. Typically link will point to a location */ 715 /* holding a disguised pointer to obj. (A pointer */ 716 /* inside an "atomic" object is effectively */ 717 /* disguised.) In this way soft */ 718 /* pointers are broken before any object */ 719 /* reachable from them are finalized. Each link */ 720 /* May be registered only once, i.e. with one obj */ 721 /* value. This was added after a long email discussion */ 722 /* with John Ellis. */ 723 /* Obj must be a pointer to the first word of an object */ 724 /* we allocated. It is unsafe to explicitly deallocate */ 725 /* the object containing link. Explicitly deallocating */ 726 /* obj may or may not cause link to eventually be */ 727 /* cleared. */ 728 GC_API int GC_unregister_disappearing_link GC_PROTO((GC_PTR * /* link */)); 729 /* Returns 0 if link was not actually registered. */ 730 /* Undoes a registration by either of the above two */ 731 /* routines. */ 732 733 /* Returns !=0 if GC_invoke_finalizers has something to do. */ 734 GC_API int GC_should_invoke_finalizers GC_PROTO((void)); 735 736 GC_API int GC_invoke_finalizers GC_PROTO((void)); 737 /* Run finalizers for all objects that are ready to */ 738 /* be finalized. Return the number of finalizers */ 739 /* that were run. Normally this is also called */ 740 /* implicitly during some allocations. If */ 741 /* GC-finalize_on_demand is nonzero, it must be called */ 742 /* explicitly. */ 743 744 /* GC_set_warn_proc can be used to redirect or filter warning messages. */ 745 /* p may not be a NULL pointer. */ 746 typedef void (*GC_warn_proc) GC_PROTO((char *msg, GC_word arg)); 747 GC_API GC_warn_proc GC_set_warn_proc GC_PROTO((GC_warn_proc p)); 748 /* Returns old warning procedure. */ 749 750 GC_API GC_word GC_set_free_space_divisor GC_PROTO((GC_word value)); 751 /* Set free_space_divisor. See above for definition. */ 752 /* Returns old value. */ 753 754 /* The following is intended to be used by a higher level */ 755 /* (e.g. Java-like) finalization facility. It is expected */ 756 /* that finalization code will arrange for hidden pointers to */ 757 /* disappear. Otherwise objects can be accessed after they */ 758 /* have been collected. */ 759 /* Note that putting pointers in atomic objects or in */ 760 /* nonpointer slots of "typed" objects is equivalent to */ 761 /* disguising them in this way, and may have other advantages. */ 762 # if defined(I_HIDE_POINTERS) || defined(GC_I_HIDE_POINTERS) 763 typedef GC_word GC_hidden_pointer; 764 # define HIDE_POINTER(p) (~(GC_hidden_pointer)(p)) 765 # define REVEAL_POINTER(p) ((GC_PTR)(HIDE_POINTER(p))) 766 /* Converting a hidden pointer to a real pointer requires verifying */ 767 /* that the object still exists. This involves acquiring the */ 768 /* allocator lock to avoid a race with the collector. */ 769 # endif /* I_HIDE_POINTERS */ 770 771 typedef GC_PTR (*GC_fn_type) GC_PROTO((GC_PTR client_data)); 772 GC_API GC_PTR GC_call_with_alloc_lock 773 GC_PROTO((GC_fn_type fn, GC_PTR client_data)); 774 775 /* The following routines are primarily intended for use with a */ 776 /* preprocessor which inserts calls to check C pointer arithmetic. */ 777 778 /* Check that p and q point to the same object. */ 779 /* Fail conspicuously if they don't. */ 780 /* Returns the first argument. */ 781 /* Succeeds if neither p nor q points to the heap. */ 782 /* May succeed if both p and q point to between heap objects. */ 783 GC_API GC_PTR GC_same_obj GC_PROTO((GC_PTR p, GC_PTR q)); 784 785 /* Checked pointer pre- and post- increment operations. Note that */ 786 /* the second argument is in units of bytes, not multiples of the */ 787 /* object size. This should either be invoked from a macro, or the */ 788 /* call should be automatically generated. */ 789 GC_API GC_PTR GC_pre_incr GC_PROTO((GC_PTR *p, size_t how_much)); 790 GC_API GC_PTR GC_post_incr GC_PROTO((GC_PTR *p, size_t how_much)); 791 792 /* Check that p is visible */ 793 /* to the collector as a possibly pointer containing location. */ 794 /* If it isn't fail conspicuously. */ 795 /* Returns the argument in all cases. May erroneously succeed */ 796 /* in hard cases. (This is intended for debugging use with */ 797 /* untyped allocations. The idea is that it should be possible, though */ 798 /* slow, to add such a call to all indirect pointer stores.) */ 799 /* Currently useless for multithreaded worlds. */ 800 GC_API GC_PTR GC_is_visible GC_PROTO((GC_PTR p)); 801 802 /* Check that if p is a pointer to a heap page, then it points to */ 803 /* a valid displacement within a heap object. */ 804 /* Fail conspicuously if this property does not hold. */ 805 /* Uninteresting with GC_all_interior_pointers. */ 806 /* Always returns its argument. */ 807 GC_API GC_PTR GC_is_valid_displacement GC_PROTO((GC_PTR p)); 808 809 /* Safer, but slow, pointer addition. Probably useful mainly with */ 810 /* a preprocessor. Useful only for heap pointers. */ 811 #ifdef GC_DEBUG 812 # define GC_PTR_ADD3(x, n, type_of_result) \ 813 ((type_of_result)GC_same_obj((x)+(n), (x))) 814 # define GC_PRE_INCR3(x, n, type_of_result) \ 815 ((type_of_result)GC_pre_incr(&(x), (n)*sizeof(*x)) 816 # define GC_POST_INCR2(x, type_of_result) \ 817 ((type_of_result)GC_post_incr(&(x), sizeof(*x)) 818 # ifdef __GNUC__ 819 # define GC_PTR_ADD(x, n) \ 820 GC_PTR_ADD3(x, n, typeof(x)) 821 # define GC_PRE_INCR(x, n) \ 822 GC_PRE_INCR3(x, n, typeof(x)) 823 # define GC_POST_INCR(x, n) \ 824 GC_POST_INCR3(x, typeof(x)) 825 # else 826 /* We can't do this right without typeof, which ANSI */ 827 /* decided was not sufficiently useful. Repeatedly */ 828 /* mentioning the arguments seems too dangerous to be */ 829 /* useful. So does not casting the result. */ 830 # define GC_PTR_ADD(x, n) ((x)+(n)) 831 # endif 832 #else /* !GC_DEBUG */ 833 # define GC_PTR_ADD3(x, n, type_of_result) ((x)+(n)) 834 # define GC_PTR_ADD(x, n) ((x)+(n)) 835 # define GC_PRE_INCR3(x, n, type_of_result) ((x) += (n)) 836 # define GC_PRE_INCR(x, n) ((x) += (n)) 837 # define GC_POST_INCR2(x, n, type_of_result) ((x)++) 838 # define GC_POST_INCR(x, n) ((x)++) 839 #endif 840 841 /* Safer assignment of a pointer to a nonstack location. */ 842 #ifdef GC_DEBUG 843 # ifdef __STDC__ 844 # define GC_PTR_STORE(p, q) \ 845 (*(void **)GC_is_visible(p) = GC_is_valid_displacement(q)) 846 # else 847 # define GC_PTR_STORE(p, q) \ 848 (*(char **)GC_is_visible(p) = GC_is_valid_displacement(q)) 849 # endif 850 #else /* !GC_DEBUG */ 851 # define GC_PTR_STORE(p, q) *((p) = (q)) 852 #endif 853 854 /* Fynctions called to report pointer checking errors */ 855 GC_API void (*GC_same_obj_print_proc) GC_PROTO((GC_PTR p, GC_PTR q)); 856 857 GC_API void (*GC_is_valid_displacement_print_proc) 858 GC_PROTO((GC_PTR p)); 859 860 GC_API void (*GC_is_visible_print_proc) 861 GC_PROTO((GC_PTR p)); 862 863 864 /* For pthread support, we generally need to intercept a number of */ 865 /* thread library calls. We do that here by macro defining them. */ 866 867 #if !defined(GC_USE_LD_WRAP) && \ 868 (defined(GC_PTHREADS) || defined(GC_SOLARIS_THREADS)) 869 # include "gc_pthread_redirects.h" 870 #endif 871 872 # if defined(PCR) || defined(GC_SOLARIS_THREADS) || \ 873 defined(GC_PTHREADS) || defined(GC_WIN32_THREADS) 874 /* Any flavor of threads except SRC_M3. */ 875 /* This returns a list of objects, linked through their first */ 876 /* word. Its use can greatly reduce lock contention problems, since */ 877 /* the allocation lock can be acquired and released many fewer times. */ 878 /* lb must be large enough to hold the pointer field. */ 879 /* It is used internally by gc_local_alloc.h, which provides a simpler */ 880 /* programming interface on Linux. */ 881 GC_PTR GC_malloc_many(size_t lb); 882 #define GC_NEXT(p) (*(GC_PTR *)(p)) /* Retrieve the next element */ 883 /* in returned list. */ 884 extern void GC_thr_init(); /* Needed for Solaris/X86 */ 885 886 #endif /* THREADS && !SRC_M3 */ 887 888 #if defined(GC_WIN32_THREADS) && !defined(__CYGWIN32__) && !defined(__CYGWIN__) 889 # include <windows.h> 890 891 /* 892 * All threads must be created using GC_CreateThread, so that they will be 893 * recorded in the thread table. For backwards compatibility, this is not 894 * technically true if the GC is built as a dynamic library, since it can 895 * and does then use DllMain to keep track of thread creations. But new code 896 * should be built to call GC_CreateThread. 897 */ 898 GC_API HANDLE WINAPI GC_CreateThread( 899 LPSECURITY_ATTRIBUTES lpThreadAttributes, 900 DWORD dwStackSize, LPTHREAD_START_ROUTINE lpStartAddress, 901 LPVOID lpParameter, DWORD dwCreationFlags, LPDWORD lpThreadId ); 902 903 # if defined(_WIN32_WCE) 904 /* 905 * win32_threads.c implements the real WinMain, which will start a new thread 906 * to call GC_WinMain after initializing the garbage collector. 907 */ 908 int WINAPI GC_WinMain( 909 HINSTANCE hInstance, 910 HINSTANCE hPrevInstance, 911 LPWSTR lpCmdLine, 912 int nCmdShow ); 913 914 # ifndef GC_BUILD 915 # define WinMain GC_WinMain 916 # define CreateThread GC_CreateThread 917 # endif 918 # endif /* defined(_WIN32_WCE) */ 919 920 #endif /* defined(GC_WIN32_THREADS) && !cygwin */ 921 922 /* 923 * If you are planning on putting 924 * the collector in a SunOS 5 dynamic library, you need to call GC_INIT() 925 * from the statically loaded program section. 926 * This circumvents a Solaris 2.X (X<=4) linker bug. 927 */ 928 #if defined(sparc) || defined(__sparc) 929 # define GC_INIT() { extern end, etext; \ 930 GC_noop(&end, &etext); } 931 #else 932 # if defined(__CYGWIN32__) && defined(GC_DLL) || defined (_AIX) 933 /* 934 * Similarly gnu-win32 DLLs need explicit initialization from 935 * the main program, as does AIX. 936 */ 937 # define GC_INIT() { GC_add_roots(DATASTART, DATAEND); } 938 # else 939 # if defined(__APPLE__) && defined(__MACH__) 940 # define GC_INIT() { GC_init(); } 941 # else 942 # define GC_INIT() 943 # endif 944 # endif 945 #endif 946 947 #if !defined(_WIN32_WCE) \ 948 && ((defined(_MSDOS) || defined(_MSC_VER)) && (_M_IX86 >= 300) \ 949 || defined(_WIN32) && !defined(__CYGWIN32__) && !defined(__CYGWIN__)) 950 /* win32S may not free all resources on process exit. */ 951 /* This explicitly deallocates the heap. */ 952 GC_API void GC_win32_free_heap (); 953 #endif 954 955 #if ( defined(_AMIGA) && !defined(GC_AMIGA_MAKINGLIB) ) 956 /* Allocation really goes through GC_amiga_allocwrapper_do */ 957 # include "gc_amiga_redirects.h" 958 #endif 959 960 #if defined(GC_REDIRECT_TO_LOCAL) && !defined(GC_LOCAL_ALLOC_H) 961 # include "gc_local_alloc.h" 962 #endif 963 964 #ifdef __cplusplus 965 } /* end of extern "C" */ 966 #endif 967 968 #endif /* _GC_H */ 969