Annotation of OpenXM_contrib/gc/gc.h, Revision 1.1.1.3
1.1 maekawa 1: /*
2: * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
3: * Copyright (c) 1991-1995 by Xerox Corporation. All rights reserved.
1.1.1.3 ! maekawa 4: * Copyright 1996-1999 by Silicon Graphics. All rights reserved.
! 5: * Copyright 1999 by Hewlett-Packard Company. All rights reserved.
1.1 maekawa 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: # define __GC
33: # include <stddef.h>
34:
35: #if defined(__CYGWIN32__) && defined(GC_USE_DLL)
36: #include "libgc_globals.h"
37: #endif
38:
1.1.1.3 ! maekawa 39: #if defined(__MINGW32__) && defined(WIN32_THREADS)
! 40: # ifdef GC_BUILD
! 41: # define GC_API __declspec(dllexport)
! 42: # else
! 43: # define GC_API __declspec(dllimport)
! 44: # endif
! 45: #endif
! 46:
1.1 maekawa 47: #if defined(_MSC_VER) && defined(_DLL)
48: # ifdef GC_BUILD
49: # define GC_API __declspec(dllexport)
50: # else
51: # define GC_API __declspec(dllimport)
52: # endif
53: #endif
54:
55: #if defined(__WATCOMC__) && defined(GC_DLL)
56: # ifdef GC_BUILD
57: # define GC_API extern __declspec(dllexport)
58: # else
59: # define GC_API extern __declspec(dllimport)
60: # endif
61: #endif
62:
63: #ifndef GC_API
64: #define GC_API extern
65: #endif
66:
67: # if defined(__STDC__) || defined(__cplusplus)
68: # define GC_PROTO(args) args
69: typedef void * GC_PTR;
1.1.1.2 maekawa 70: # define GC_CONST const
1.1 maekawa 71: # else
72: # define GC_PROTO(args) ()
73: typedef char * GC_PTR;
1.1.1.2 maekawa 74: # define GC_CONST
1.1 maekawa 75: # endif
76:
77: # ifdef __cplusplus
78: extern "C" {
79: # endif
80:
81:
82: /* Define word and signed_word to be unsigned and signed types of the */
83: /* size as char * or void *. There seems to be no way to do this */
84: /* even semi-portably. The following is probably no better/worse */
85: /* than almost anything else. */
86: /* The ANSI standard suggests that size_t and ptr_diff_t might be */
87: /* better choices. But those appear to have incorrect definitions */
88: /* on may systems. Notably "typedef int size_t" seems to be both */
89: /* frequent and WRONG. */
90: typedef unsigned long GC_word;
91: typedef long GC_signed_word;
92:
93: /* Public read-only variables */
94:
95: GC_API GC_word GC_gc_no;/* Counter incremented per collection. */
96: /* Includes empty GCs at startup. */
97:
98:
99: /* Public R/W variables */
100:
101: GC_API GC_PTR (*GC_oom_fn) GC_PROTO((size_t bytes_requested));
102: /* When there is insufficient memory to satisfy */
103: /* an allocation request, we return */
104: /* (*GC_oom_fn)(). By default this just */
105: /* returns 0. */
106: /* If it returns, it must return 0 or a valid */
107: /* pointer to a previously allocated heap */
108: /* object. */
109:
1.1.1.2 maekawa 110: GC_API int GC_find_leak;
111: /* Do not actually garbage collect, but simply */
112: /* report inaccessible memory that was not */
113: /* deallocated with GC_free. Initial value */
114: /* is determined by FIND_LEAK macro. */
115:
1.1 maekawa 116: GC_API int GC_quiet; /* Disable statistics output. Only matters if */
117: /* collector has been compiled with statistics */
118: /* enabled. This involves a performance cost, */
119: /* and is thus not the default. */
120:
1.1.1.2 maekawa 121: GC_API int GC_finalize_on_demand;
122: /* If nonzero, finalizers will only be run in */
123: /* response to an eplit GC_invoke_finalizers */
124: /* call. The default is determined by whether */
125: /* the FINALIZE_ON_DEMAND macro is defined */
126: /* when the collector is built. */
127:
128: GC_API int GC_java_finalization;
129: /* Mark objects reachable from finalizable */
130: /* objects in a separate postpass. This makes */
131: /* it a bit safer to use non-topologically- */
132: /* ordered finalization. Default value is */
133: /* determined by JAVA_FINALIZATION macro. */
134:
1.1 maekawa 135: GC_API int GC_dont_gc; /* Dont collect unless explicitly requested, e.g. */
136: /* because it's not safe. */
137:
138: GC_API int GC_dont_expand;
139: /* Dont expand heap unless explicitly requested */
140: /* or forced to. */
141:
1.1.1.3 ! maekawa 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:
1.1 maekawa 153: GC_API int GC_full_freq; /* Number of partial collections between */
154: /* full collections. Matters only if */
155: /* GC_incremental is set. */
1.1.1.2 maekawa 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. */
1.1 maekawa 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:
167: GC_API GC_word GC_free_space_divisor;
168: /* We try to make sure that we allocate at */
169: /* least N/GC_free_space_divisor bytes between */
170: /* collections, where N is the heap size plus */
171: /* a rough estimate of the root set size. */
172: /* Initially, GC_free_space_divisor = 4. */
173: /* Increasing its value will use less space */
174: /* but more collection time. Decreasing it */
175: /* will appreciably decrease collection time */
176: /* at the expense of space. */
177: /* GC_free_space_divisor = 1 will effectively */
178: /* disable collections. */
179:
180: GC_API GC_word GC_max_retries;
181: /* The maximum number of GCs attempted before */
182: /* reporting out of memory after heap */
183: /* expansion fails. Initially 0. */
184:
185:
186: GC_API char *GC_stackbottom; /* Cool end of user stack. */
187: /* May be set in the client prior to */
188: /* calling any GC_ routines. This */
189: /* avoids some overhead, and */
190: /* potentially some signals that can */
191: /* confuse debuggers. Otherwise the */
192: /* collector attempts to set it */
193: /* automatically. */
194: /* For multithreaded code, this is the */
195: /* cold end of the stack for the */
196: /* primordial thread. */
197:
198: /* Public procedures */
199: /*
200: * general purpose allocation routines, with roughly malloc calling conv.
201: * The atomic versions promise that no relevant pointers are contained
202: * in the object. The nonatomic versions guarantee that the new object
203: * is cleared. GC_malloc_stubborn promises that no changes to the object
204: * will occur after GC_end_stubborn_change has been called on the
205: * result of GC_malloc_stubborn. GC_malloc_uncollectable allocates an object
206: * that is scanned for pointers to collectable objects, but is not itself
207: * collectable. GC_malloc_uncollectable and GC_free called on the resulting
208: * object implicitly update GC_non_gc_bytes appropriately.
209: */
210: GC_API GC_PTR GC_malloc GC_PROTO((size_t size_in_bytes));
211: GC_API GC_PTR GC_malloc_atomic GC_PROTO((size_t size_in_bytes));
212: GC_API GC_PTR GC_malloc_uncollectable GC_PROTO((size_t size_in_bytes));
213: GC_API GC_PTR GC_malloc_stubborn GC_PROTO((size_t size_in_bytes));
214:
215: /* The following is only defined if the library has been suitably */
216: /* compiled: */
217: GC_API GC_PTR GC_malloc_atomic_uncollectable GC_PROTO((size_t size_in_bytes));
218:
219: /* Explicitly deallocate an object. Dangerous if used incorrectly. */
220: /* Requires a pointer to the base of an object. */
221: /* If the argument is stubborn, it should not be changeable when freed. */
222: /* An object should not be enable for finalization when it is */
223: /* explicitly deallocated. */
224: /* GC_free(0) is a no-op, as required by ANSI C for free. */
225: GC_API void GC_free GC_PROTO((GC_PTR object_addr));
226:
227: /*
228: * Stubborn objects may be changed only if the collector is explicitly informed.
229: * The collector is implicitly informed of coming change when such
230: * an object is first allocated. The following routines inform the
231: * collector that an object will no longer be changed, or that it will
232: * once again be changed. Only nonNIL pointer stores into the object
233: * are considered to be changes. The argument to GC_end_stubborn_change
234: * must be exacly the value returned by GC_malloc_stubborn or passed to
235: * GC_change_stubborn. (In the second case it may be an interior pointer
236: * within 512 bytes of the beginning of the objects.)
237: * There is a performance penalty for allowing more than
238: * one stubborn object to be changed at once, but it is acceptable to
239: * do so. The same applies to dropping stubborn objects that are still
240: * changeable.
241: */
242: GC_API void GC_change_stubborn GC_PROTO((GC_PTR));
243: GC_API void GC_end_stubborn_change GC_PROTO((GC_PTR));
244:
245: /* Return a pointer to the base (lowest address) of an object given */
246: /* a pointer to a location within the object. */
247: /* Return 0 if displaced_pointer doesn't point to within a valid */
248: /* object. */
249: GC_API GC_PTR GC_base GC_PROTO((GC_PTR displaced_pointer));
250:
251: /* Given a pointer to the base of an object, return its size in bytes. */
252: /* The returned size may be slightly larger than what was originally */
253: /* requested. */
254: GC_API size_t GC_size GC_PROTO((GC_PTR object_addr));
255:
256: /* For compatibility with C library. This is occasionally faster than */
257: /* a malloc followed by a bcopy. But if you rely on that, either here */
258: /* or with the standard C library, your code is broken. In my */
259: /* opinion, it shouldn't have been invented, but now we're stuck. -HB */
260: /* The resulting object has the same kind as the original. */
261: /* If the argument is stubborn, the result will have changes enabled. */
262: /* It is an error to have changes enabled for the original object. */
263: /* Follows ANSI comventions for NULL old_object. */
264: GC_API GC_PTR GC_realloc
265: GC_PROTO((GC_PTR old_object, size_t new_size_in_bytes));
266:
267: /* Explicitly increase the heap size. */
268: /* Returns 0 on failure, 1 on success. */
269: GC_API int GC_expand_hp GC_PROTO((size_t number_of_bytes));
270:
271: /* Limit the heap size to n bytes. Useful when you're debugging, */
272: /* especially on systems that don't handle running out of memory well. */
273: /* n == 0 ==> unbounded. This is the default. */
274: GC_API void GC_set_max_heap_size GC_PROTO((GC_word n));
275:
276: /* Inform the collector that a certain section of statically allocated */
277: /* memory contains no pointers to garbage collected memory. Thus it */
278: /* need not be scanned. This is sometimes important if the application */
279: /* maps large read/write files into the address space, which could be */
280: /* mistaken for dynamic library data segments on some systems. */
281: GC_API void GC_exclude_static_roots GC_PROTO((GC_PTR start, GC_PTR finish));
282:
283: /* Clear the set of root segments. Wizards only. */
284: GC_API void GC_clear_roots GC_PROTO((void));
285:
286: /* Add a root segment. Wizards only. */
287: GC_API void GC_add_roots GC_PROTO((char * low_address,
288: char * high_address_plus_1));
289:
290: /* Add a displacement to the set of those considered valid by the */
291: /* collector. GC_register_displacement(n) means that if p was returned */
292: /* by GC_malloc, then (char *)p + n will be considered to be a valid */
293: /* pointer to n. N must be small and less than the size of p. */
294: /* (All pointers to the interior of objects from the stack are */
295: /* considered valid in any case. This applies to heap objects and */
296: /* static data.) */
297: /* Preferably, this should be called before any other GC procedures. */
298: /* Calling it later adds to the probability of excess memory */
299: /* retention. */
300: /* This is a no-op if the collector was compiled with recognition of */
301: /* arbitrary interior pointers enabled, which is now the default. */
302: GC_API void GC_register_displacement GC_PROTO((GC_word n));
303:
304: /* The following version should be used if any debugging allocation is */
305: /* being done. */
306: GC_API void GC_debug_register_displacement GC_PROTO((GC_word n));
307:
308: /* Explicitly trigger a full, world-stop collection. */
309: GC_API void GC_gcollect GC_PROTO((void));
310:
311: /* Trigger a full world-stopped collection. Abort the collection if */
312: /* and when stop_func returns a nonzero value. Stop_func will be */
313: /* called frequently, and should be reasonably fast. This works even */
314: /* if virtual dirty bits, and hence incremental collection is not */
315: /* available for this architecture. Collections can be aborted faster */
316: /* than normal pause times for incremental collection. However, */
317: /* aborted collections do no useful work; the next collection needs */
318: /* to start from the beginning. */
319: /* Return 0 if the collection was aborted, 1 if it succeeded. */
320: typedef int (* GC_stop_func) GC_PROTO((void));
321: GC_API int GC_try_to_collect GC_PROTO((GC_stop_func stop_func));
322:
323: /* Return the number of bytes in the heap. Excludes collector private */
324: /* data structures. Includes empty blocks and fragmentation loss. */
325: /* Includes some pages that were allocated but never written. */
326: GC_API size_t GC_get_heap_size GC_PROTO((void));
327:
1.1.1.2 maekawa 328: /* Return a lower bound on the number of free bytes in the heap. */
329: GC_API size_t GC_get_free_bytes GC_PROTO((void));
330:
1.1 maekawa 331: /* Return the number of bytes allocated since the last collection. */
332: GC_API size_t GC_get_bytes_since_gc GC_PROTO((void));
333:
334: /* Enable incremental/generational collection. */
335: /* Not advisable unless dirty bits are */
336: /* available or most heap objects are */
337: /* pointerfree(atomic) or immutable. */
338: /* Don't use in leak finding mode. */
339: /* Ignored if GC_dont_gc is true. */
340: GC_API void GC_enable_incremental GC_PROTO((void));
341:
342: /* Perform some garbage collection work, if appropriate. */
343: /* Return 0 if there is no more work to be done. */
344: /* Typically performs an amount of work corresponding roughly */
345: /* to marking from one page. May do more work if further */
346: /* progress requires it, e.g. if incremental collection is */
347: /* disabled. It is reasonable to call this in a wait loop */
348: /* until it returns 0. */
349: GC_API int GC_collect_a_little GC_PROTO((void));
350:
351: /* Allocate an object of size lb bytes. The client guarantees that */
352: /* as long as the object is live, it will be referenced by a pointer */
353: /* that points to somewhere within the first 256 bytes of the object. */
354: /* (This should normally be declared volatile to prevent the compiler */
355: /* from invalidating this assertion.) This routine is only useful */
356: /* if a large array is being allocated. It reduces the chance of */
357: /* accidentally retaining such an array as a result of scanning an */
358: /* integer that happens to be an address inside the array. (Actually, */
359: /* it reduces the chance of the allocator not finding space for such */
360: /* an array, since it will try hard to avoid introducing such a false */
361: /* reference.) On a SunOS 4.X or MS Windows system this is recommended */
362: /* for arrays likely to be larger than 100K or so. For other systems, */
363: /* or if the collector is not configured to recognize all interior */
364: /* pointers, the threshold is normally much higher. */
365: GC_API GC_PTR GC_malloc_ignore_off_page GC_PROTO((size_t lb));
366: GC_API GC_PTR GC_malloc_atomic_ignore_off_page GC_PROTO((size_t lb));
367:
368: #if defined(__sgi) && !defined(__GNUC__) && _COMPILER_VERSION >= 720
369: # define GC_ADD_CALLER
370: # define GC_RETURN_ADDR (GC_word)__return_address
371: #endif
372:
373: #ifdef GC_ADD_CALLER
374: # define GC_EXTRAS GC_RETURN_ADDR, __FILE__, __LINE__
1.1.1.3 ! maekawa 375: # define GC_EXTRA_PARAMS GC_word ra, GC_CONST char * s, int i
1.1 maekawa 376: #else
377: # define GC_EXTRAS __FILE__, __LINE__
1.1.1.3 ! maekawa 378: # define GC_EXTRA_PARAMS GC_CONST char * s, int i
1.1 maekawa 379: #endif
380:
381: /* Debugging (annotated) allocation. GC_gcollect will check */
382: /* objects allocated in this way for overwrites, etc. */
383: GC_API GC_PTR GC_debug_malloc
384: GC_PROTO((size_t size_in_bytes, GC_EXTRA_PARAMS));
385: GC_API GC_PTR GC_debug_malloc_atomic
386: GC_PROTO((size_t size_in_bytes, GC_EXTRA_PARAMS));
387: GC_API GC_PTR GC_debug_malloc_uncollectable
388: GC_PROTO((size_t size_in_bytes, GC_EXTRA_PARAMS));
389: GC_API GC_PTR GC_debug_malloc_stubborn
390: GC_PROTO((size_t size_in_bytes, GC_EXTRA_PARAMS));
391: GC_API void GC_debug_free GC_PROTO((GC_PTR object_addr));
392: GC_API GC_PTR GC_debug_realloc
393: GC_PROTO((GC_PTR old_object, size_t new_size_in_bytes,
394: GC_EXTRA_PARAMS));
395:
396: GC_API void GC_debug_change_stubborn GC_PROTO((GC_PTR));
397: GC_API void GC_debug_end_stubborn_change GC_PROTO((GC_PTR));
398: # ifdef GC_DEBUG
399: # define GC_MALLOC(sz) GC_debug_malloc(sz, GC_EXTRAS)
400: # define GC_MALLOC_ATOMIC(sz) GC_debug_malloc_atomic(sz, GC_EXTRAS)
401: # define GC_MALLOC_UNCOLLECTABLE(sz) GC_debug_malloc_uncollectable(sz, \
402: GC_EXTRAS)
403: # define GC_REALLOC(old, sz) GC_debug_realloc(old, sz, GC_EXTRAS)
404: # define GC_FREE(p) GC_debug_free(p)
405: # define GC_REGISTER_FINALIZER(p, f, d, of, od) \
406: GC_debug_register_finalizer(p, f, d, of, od)
407: # define GC_REGISTER_FINALIZER_IGNORE_SELF(p, f, d, of, od) \
408: GC_debug_register_finalizer_ignore_self(p, f, d, of, od)
1.1.1.3 ! maekawa 409: # define GC_REGISTER_FINALIZER_NO_ORDER(p, f, d, of, od) \
! 410: GC_debug_register_finalizer_no_order(p, f, d, of, od)
1.1 maekawa 411: # define GC_MALLOC_STUBBORN(sz) GC_debug_malloc_stubborn(sz, GC_EXTRAS);
412: # define GC_CHANGE_STUBBORN(p) GC_debug_change_stubborn(p)
413: # define GC_END_STUBBORN_CHANGE(p) GC_debug_end_stubborn_change(p)
414: # define GC_GENERAL_REGISTER_DISAPPEARING_LINK(link, obj) \
415: GC_general_register_disappearing_link(link, GC_base(obj))
416: # define GC_REGISTER_DISPLACEMENT(n) GC_debug_register_displacement(n)
417: # else
418: # define GC_MALLOC(sz) GC_malloc(sz)
419: # define GC_MALLOC_ATOMIC(sz) GC_malloc_atomic(sz)
420: # define GC_MALLOC_UNCOLLECTABLE(sz) GC_malloc_uncollectable(sz)
421: # define GC_REALLOC(old, sz) GC_realloc(old, sz)
422: # define GC_FREE(p) GC_free(p)
423: # define GC_REGISTER_FINALIZER(p, f, d, of, od) \
424: GC_register_finalizer(p, f, d, of, od)
425: # define GC_REGISTER_FINALIZER_IGNORE_SELF(p, f, d, of, od) \
426: GC_register_finalizer_ignore_self(p, f, d, of, od)
1.1.1.3 ! maekawa 427: # define GC_REGISTER_FINALIZER_NO_ORDER(p, f, d, of, od) \
! 428: GC_register_finalizer_no_order(p, f, d, of, od)
1.1 maekawa 429: # define GC_MALLOC_STUBBORN(sz) GC_malloc_stubborn(sz)
430: # define GC_CHANGE_STUBBORN(p) GC_change_stubborn(p)
431: # define GC_END_STUBBORN_CHANGE(p) GC_end_stubborn_change(p)
432: # define GC_GENERAL_REGISTER_DISAPPEARING_LINK(link, obj) \
433: GC_general_register_disappearing_link(link, obj)
434: # define GC_REGISTER_DISPLACEMENT(n) GC_register_displacement(n)
435: # endif
436: /* The following are included because they are often convenient, and */
437: /* reduce the chance for a misspecifed size argument. But calls may */
438: /* expand to something syntactically incorrect if t is a complicated */
439: /* type expression. */
440: # define GC_NEW(t) (t *)GC_MALLOC(sizeof (t))
441: # define GC_NEW_ATOMIC(t) (t *)GC_MALLOC_ATOMIC(sizeof (t))
442: # define GC_NEW_STUBBORN(t) (t *)GC_MALLOC_STUBBORN(sizeof (t))
443: # define GC_NEW_UNCOLLECTABLE(t) (t *)GC_MALLOC_UNCOLLECTABLE(sizeof (t))
444:
445: /* Finalization. Some of these primitives are grossly unsafe. */
446: /* The idea is to make them both cheap, and sufficient to build */
447: /* a safer layer, closer to PCedar finalization. */
448: /* The interface represents my conclusions from a long discussion */
449: /* with Alan Demers, Dan Greene, Carl Hauser, Barry Hayes, */
450: /* Christian Jacobi, and Russ Atkinson. It's not perfect, and */
451: /* probably nobody else agrees with it. Hans-J. Boehm 3/13/92 */
452: typedef void (*GC_finalization_proc)
453: GC_PROTO((GC_PTR obj, GC_PTR client_data));
454:
455: GC_API void GC_register_finalizer
456: GC_PROTO((GC_PTR obj, GC_finalization_proc fn, GC_PTR cd,
457: GC_finalization_proc *ofn, GC_PTR *ocd));
458: GC_API void GC_debug_register_finalizer
459: GC_PROTO((GC_PTR obj, GC_finalization_proc fn, GC_PTR cd,
460: GC_finalization_proc *ofn, GC_PTR *ocd));
461: /* When obj is no longer accessible, invoke */
462: /* (*fn)(obj, cd). If a and b are inaccessible, and */
463: /* a points to b (after disappearing links have been */
464: /* made to disappear), then only a will be */
465: /* finalized. (If this does not create any new */
466: /* pointers to b, then b will be finalized after the */
467: /* next collection.) Any finalizable object that */
468: /* is reachable from itself by following one or more */
469: /* pointers will not be finalized (or collected). */
470: /* Thus cycles involving finalizable objects should */
471: /* be avoided, or broken by disappearing links. */
472: /* All but the last finalizer registered for an object */
473: /* is ignored. */
474: /* Finalization may be removed by passing 0 as fn. */
475: /* Finalizers are implicitly unregistered just before */
476: /* they are invoked. */
477: /* The old finalizer and client data are stored in */
478: /* *ofn and *ocd. */
479: /* Fn is never invoked on an accessible object, */
480: /* provided hidden pointers are converted to real */
481: /* pointers only if the allocation lock is held, and */
482: /* such conversions are not performed by finalization */
483: /* routines. */
484: /* If GC_register_finalizer is aborted as a result of */
485: /* a signal, the object may be left with no */
486: /* finalization, even if neither the old nor new */
487: /* finalizer were NULL. */
488: /* Obj should be the nonNULL starting address of an */
489: /* object allocated by GC_malloc or friends. */
490: /* Note that any garbage collectable object referenced */
491: /* by cd will be considered accessible until the */
492: /* finalizer is invoked. */
493:
494: /* Another versions of the above follow. It ignores */
495: /* self-cycles, i.e. pointers from a finalizable object to */
496: /* itself. There is a stylistic argument that this is wrong, */
497: /* but it's unavoidable for C++, since the compiler may */
498: /* silently introduce these. It's also benign in that specific */
499: /* case. */
500: GC_API void GC_register_finalizer_ignore_self
501: GC_PROTO((GC_PTR obj, GC_finalization_proc fn, GC_PTR cd,
502: GC_finalization_proc *ofn, GC_PTR *ocd));
503: GC_API void GC_debug_register_finalizer_ignore_self
504: GC_PROTO((GC_PTR obj, GC_finalization_proc fn, GC_PTR cd,
505: GC_finalization_proc *ofn, GC_PTR *ocd));
506:
1.1.1.3 ! maekawa 507: /* Another version of the above. It ignores all cycles. */
! 508: /* It should probably only be used by Java implementations. */
! 509: GC_API void GC_register_finalizer_no_order
! 510: GC_PROTO((GC_PTR obj, GC_finalization_proc fn, GC_PTR cd,
! 511: GC_finalization_proc *ofn, GC_PTR *ocd));
! 512: GC_API void GC_debug_register_finalizer_no_order
! 513: GC_PROTO((GC_PTR obj, GC_finalization_proc fn, GC_PTR cd,
! 514: GC_finalization_proc *ofn, GC_PTR *ocd));
! 515:
! 516:
1.1 maekawa 517: /* The following routine may be used to break cycles between */
518: /* finalizable objects, thus causing cyclic finalizable */
519: /* objects to be finalized in the correct order. Standard */
520: /* use involves calling GC_register_disappearing_link(&p), */
521: /* where p is a pointer that is not followed by finalization */
522: /* code, and should not be considered in determining */
523: /* finalization order. */
524: GC_API int GC_register_disappearing_link GC_PROTO((GC_PTR * /* link */));
525: /* Link should point to a field of a heap allocated */
526: /* object obj. *link will be cleared when obj is */
527: /* found to be inaccessible. This happens BEFORE any */
528: /* finalization code is invoked, and BEFORE any */
529: /* decisions about finalization order are made. */
530: /* This is useful in telling the finalizer that */
531: /* some pointers are not essential for proper */
532: /* finalization. This may avoid finalization cycles. */
533: /* Note that obj may be resurrected by another */
534: /* finalizer, and thus the clearing of *link may */
535: /* be visible to non-finalization code. */
536: /* There's an argument that an arbitrary action should */
537: /* be allowed here, instead of just clearing a pointer. */
538: /* But this causes problems if that action alters, or */
539: /* examines connectivity. */
540: /* Returns 1 if link was already registered, 0 */
541: /* otherwise. */
542: /* Only exists for backward compatibility. See below: */
543:
544: GC_API int GC_general_register_disappearing_link
545: GC_PROTO((GC_PTR * /* link */, GC_PTR obj));
546: /* A slight generalization of the above. *link is */
547: /* cleared when obj first becomes inaccessible. This */
548: /* can be used to implement weak pointers easily and */
549: /* safely. Typically link will point to a location */
550: /* holding a disguised pointer to obj. (A pointer */
551: /* inside an "atomic" object is effectively */
552: /* disguised.) In this way soft */
553: /* pointers are broken before any object */
554: /* reachable from them are finalized. Each link */
555: /* May be registered only once, i.e. with one obj */
556: /* value. This was added after a long email discussion */
557: /* with John Ellis. */
558: /* Obj must be a pointer to the first word of an object */
559: /* we allocated. It is unsafe to explicitly deallocate */
560: /* the object containing link. Explicitly deallocating */
561: /* obj may or may not cause link to eventually be */
562: /* cleared. */
563: GC_API int GC_unregister_disappearing_link GC_PROTO((GC_PTR * /* link */));
564: /* Returns 0 if link was not actually registered. */
565: /* Undoes a registration by either of the above two */
566: /* routines. */
567:
568: /* Auxiliary fns to make finalization work correctly with displaced */
569: /* pointers introduced by the debugging allocators. */
570: GC_API GC_PTR GC_make_closure GC_PROTO((GC_finalization_proc fn, GC_PTR data));
571: GC_API void GC_debug_invoke_finalizer GC_PROTO((GC_PTR obj, GC_PTR data));
572:
1.1.1.3 ! maekawa 573: /* Returns !=0 if GC_invoke_finalizers has something to do. */
! 574: GC_API int GC_should_invoke_finalizers GC_PROTO((void));
! 575:
1.1 maekawa 576: GC_API int GC_invoke_finalizers GC_PROTO((void));
577: /* Run finalizers for all objects that are ready to */
578: /* be finalized. Return the number of finalizers */
579: /* that were run. Normally this is also called */
580: /* implicitly during some allocations. If */
1.1.1.2 maekawa 581: /* GC-finalize_on_demand is nonzero, it must be called */
1.1 maekawa 582: /* explicitly. */
583:
584: /* GC_set_warn_proc can be used to redirect or filter warning messages. */
585: /* p may not be a NULL pointer. */
586: typedef void (*GC_warn_proc) GC_PROTO((char *msg, GC_word arg));
587: GC_API GC_warn_proc GC_set_warn_proc GC_PROTO((GC_warn_proc p));
588: /* Returns old warning procedure. */
589:
590: /* The following is intended to be used by a higher level */
591: /* (e.g. cedar-like) finalization facility. It is expected */
592: /* that finalization code will arrange for hidden pointers to */
593: /* disappear. Otherwise objects can be accessed after they */
594: /* have been collected. */
595: /* Note that putting pointers in atomic objects or in */
596: /* nonpointer slots of "typed" objects is equivalent to */
597: /* disguising them in this way, and may have other advantages. */
598: # if defined(I_HIDE_POINTERS) || defined(GC_I_HIDE_POINTERS)
599: typedef GC_word GC_hidden_pointer;
600: # define HIDE_POINTER(p) (~(GC_hidden_pointer)(p))
601: # define REVEAL_POINTER(p) ((GC_PTR)(HIDE_POINTER(p)))
602: /* Converting a hidden pointer to a real pointer requires verifying */
603: /* that the object still exists. This involves acquiring the */
604: /* allocator lock to avoid a race with the collector. */
605: # endif /* I_HIDE_POINTERS */
606:
607: typedef GC_PTR (*GC_fn_type) GC_PROTO((GC_PTR client_data));
608: GC_API GC_PTR GC_call_with_alloc_lock
609: GC_PROTO((GC_fn_type fn, GC_PTR client_data));
610:
611: /* Check that p and q point to the same object. */
612: /* Fail conspicuously if they don't. */
613: /* Returns the first argument. */
614: /* Succeeds if neither p nor q points to the heap. */
615: /* May succeed if both p and q point to between heap objects. */
616: GC_API GC_PTR GC_same_obj GC_PROTO((GC_PTR p, GC_PTR q));
617:
618: /* Checked pointer pre- and post- increment operations. Note that */
619: /* the second argument is in units of bytes, not multiples of the */
620: /* object size. This should either be invoked from a macro, or the */
621: /* call should be automatically generated. */
622: GC_API GC_PTR GC_pre_incr GC_PROTO((GC_PTR *p, size_t how_much));
623: GC_API GC_PTR GC_post_incr GC_PROTO((GC_PTR *p, size_t how_much));
624:
625: /* Check that p is visible */
626: /* to the collector as a possibly pointer containing location. */
627: /* If it isn't fail conspicuously. */
628: /* Returns the argument in all cases. May erroneously succeed */
629: /* in hard cases. (This is intended for debugging use with */
630: /* untyped allocations. The idea is that it should be possible, though */
631: /* slow, to add such a call to all indirect pointer stores.) */
632: /* Currently useless for multithreaded worlds. */
633: GC_API GC_PTR GC_is_visible GC_PROTO((GC_PTR p));
634:
635: /* Check that if p is a pointer to a heap page, then it points to */
636: /* a valid displacement within a heap object. */
637: /* Fail conspicuously if this property does not hold. */
638: /* Uninteresting with ALL_INTERIOR_POINTERS. */
639: /* Always returns its argument. */
640: GC_API GC_PTR GC_is_valid_displacement GC_PROTO((GC_PTR p));
641:
642: /* Safer, but slow, pointer addition. Probably useful mainly with */
643: /* a preprocessor. Useful only for heap pointers. */
644: #ifdef GC_DEBUG
645: # define GC_PTR_ADD3(x, n, type_of_result) \
646: ((type_of_result)GC_same_obj((x)+(n), (x)))
647: # define GC_PRE_INCR3(x, n, type_of_result) \
648: ((type_of_result)GC_pre_incr(&(x), (n)*sizeof(*x))
649: # define GC_POST_INCR2(x, type_of_result) \
650: ((type_of_result)GC_post_incr(&(x), sizeof(*x))
651: # ifdef __GNUC__
652: # define GC_PTR_ADD(x, n) \
653: GC_PTR_ADD3(x, n, typeof(x))
654: # define GC_PRE_INCR(x, n) \
655: GC_PRE_INCR3(x, n, typeof(x))
656: # define GC_POST_INCR(x, n) \
657: GC_POST_INCR3(x, typeof(x))
658: # else
659: /* We can't do this right without typeof, which ANSI */
660: /* decided was not sufficiently useful. Repeatedly */
661: /* mentioning the arguments seems too dangerous to be */
662: /* useful. So does not casting the result. */
663: # define GC_PTR_ADD(x, n) ((x)+(n))
664: # endif
665: #else /* !GC_DEBUG */
666: # define GC_PTR_ADD3(x, n, type_of_result) ((x)+(n))
667: # define GC_PTR_ADD(x, n) ((x)+(n))
668: # define GC_PRE_INCR3(x, n, type_of_result) ((x) += (n))
669: # define GC_PRE_INCR(x, n) ((x) += (n))
670: # define GC_POST_INCR2(x, n, type_of_result) ((x)++)
671: # define GC_POST_INCR(x, n) ((x)++)
672: #endif
673:
674: /* Safer assignment of a pointer to a nonstack location. */
675: #ifdef GC_DEBUG
676: # ifdef __STDC__
677: # define GC_PTR_STORE(p, q) \
678: (*(void **)GC_is_visible(p) = GC_is_valid_displacement(q))
679: # else
680: # define GC_PTR_STORE(p, q) \
681: (*(char **)GC_is_visible(p) = GC_is_valid_displacement(q))
682: # endif
683: #else /* !GC_DEBUG */
684: # define GC_PTR_STORE(p, q) *((p) = (q))
685: #endif
686:
687: /* Fynctions called to report pointer checking errors */
688: GC_API void (*GC_same_obj_print_proc) GC_PROTO((GC_PTR p, GC_PTR q));
689:
690: GC_API void (*GC_is_valid_displacement_print_proc)
691: GC_PROTO((GC_PTR p));
692:
693: GC_API void (*GC_is_visible_print_proc)
694: GC_PROTO((GC_PTR p));
695:
696: #if defined(_SOLARIS_PTHREADS) && !defined(SOLARIS_THREADS)
697: # define SOLARIS_THREADS
698: #endif
699:
700: #ifdef SOLARIS_THREADS
701: /* We need to intercept calls to many of the threads primitives, so */
702: /* that we can locate thread stacks and stop the world. */
703: /* Note also that the collector cannot see thread specific data. */
704: /* Thread specific data should generally consist of pointers to */
705: /* uncollectable objects, which are deallocated using the destructor */
706: /* facility in thr_keycreate. */
707: # include <thread.h>
708: # include <signal.h>
709: int GC_thr_create(void *stack_base, size_t stack_size,
710: void *(*start_routine)(void *), void *arg, long flags,
711: thread_t *new_thread);
712: int GC_thr_join(thread_t wait_for, thread_t *departed, void **status);
713: int GC_thr_suspend(thread_t target_thread);
714: int GC_thr_continue(thread_t target_thread);
715: void * GC_dlopen(const char *path, int mode);
716:
717: # ifdef _SOLARIS_PTHREADS
718: # include <pthread.h>
719: extern int GC_pthread_create(pthread_t *new_thread,
720: const pthread_attr_t *attr,
721: void * (*thread_execp)(void *), void *arg);
722: extern int GC_pthread_join(pthread_t wait_for, void **status);
723:
724: # undef thread_t
725:
726: # define pthread_join GC_pthread_join
727: # define pthread_create GC_pthread_create
728: #endif
729:
730: # define thr_create GC_thr_create
731: # define thr_join GC_thr_join
732: # define thr_suspend GC_thr_suspend
733: # define thr_continue GC_thr_continue
734: # define dlopen GC_dlopen
735:
736: # endif /* SOLARIS_THREADS */
737:
738:
1.1.1.3 ! maekawa 739: #if !defined(USE_LD_WRAP) && \
! 740: (defined(IRIX_THREADS) || defined(LINUX_THREADS) || defined(HPUX_THREADS))
1.1 maekawa 741: /* We treat these similarly. */
742: # include <pthread.h>
743: # include <signal.h>
744:
745: int GC_pthread_create(pthread_t *new_thread,
746: const pthread_attr_t *attr,
747: void *(*start_routine)(void *), void *arg);
748: int GC_pthread_sigmask(int how, const sigset_t *set, sigset_t *oset);
749: int GC_pthread_join(pthread_t thread, void **retval);
750:
751: # define pthread_create GC_pthread_create
752: # define pthread_sigmask GC_pthread_sigmask
753: # define pthread_join GC_pthread_join
1.1.1.3 ! maekawa 754: # define dlopen GC_dlopen
1.1 maekawa 755:
1.1.1.3 ! maekawa 756: #endif /* xxxxx_THREADS */
1.1 maekawa 757:
758: # if defined(PCR) || defined(SOLARIS_THREADS) || defined(WIN32_THREADS) || \
759: defined(IRIX_THREADS) || defined(LINUX_THREADS) || \
1.1.1.2 maekawa 760: defined(IRIX_JDK_THREADS) || defined(HPUX_THREADS)
1.1 maekawa 761: /* Any flavor of threads except SRC_M3. */
762: /* This returns a list of objects, linked through their first */
763: /* word. Its use can greatly reduce lock contention problems, since */
764: /* the allocation lock can be acquired and released many fewer times. */
1.1.1.2 maekawa 765: /* lb must be large enough to hold the pointer field. */
1.1 maekawa 766: GC_PTR GC_malloc_many(size_t lb);
767: #define GC_NEXT(p) (*(GC_PTR *)(p)) /* Retrieve the next element */
768: /* in returned list. */
769: extern void GC_thr_init(); /* Needed for Solaris/X86 */
770:
771: #endif /* THREADS && !SRC_M3 */
772:
773: /*
774: * If you are planning on putting
775: * the collector in a SunOS 5 dynamic library, you need to call GC_INIT()
776: * from the statically loaded program section.
777: * This circumvents a Solaris 2.X (X<=4) linker bug.
778: */
779: #if defined(sparc) || defined(__sparc)
780: # define GC_INIT() { extern end, etext; \
781: GC_noop(&end, &etext); }
782: #else
783: # if defined(__CYGWIN32__) && defined(GC_USE_DLL)
784: /*
785: * Similarly gnu-win32 DLLs need explicit initialization
786: */
787: # define GC_INIT() { GC_add_roots(DATASTART, DATAEND); }
788: # else
789: # define GC_INIT()
790: # endif
791: #endif
792:
793: #if (defined(_MSDOS) || defined(_MSC_VER)) && (_M_IX86 >= 300) \
794: || defined(_WIN32)
795: /* win32S may not free all resources on process exit. */
796: /* This explicitly deallocates the heap. */
797: GC_API void GC_win32_free_heap ();
798: #endif
799:
800: #ifdef __cplusplus
801: } /* end of extern "C" */
802: #endif
803:
804: #endif /* _GC_H */
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