Annotation of OpenXM_contrib2/asir2000/gc/alloc.c, Revision 1.1
1.1 ! noro 1: /*
! 2: * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
! 3: * Copyright (c) 1991-1994 by Xerox Corporation. All rights reserved.
! 4: * Copyright (c) 1998 by Silicon Graphics. All rights reserved.
! 5: *
! 6: * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
! 7: * OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
! 8: *
! 9: * Permission is hereby granted to use or copy this program
! 10: * for any purpose, provided the above notices are retained on all copies.
! 11: * Permission to modify the code and to distribute modified code is granted,
! 12: * provided the above notices are retained, and a notice that the code was
! 13: * modified is included with the above copyright notice.
! 14: *
! 15: */
! 16:
! 17:
! 18: # include "gc_priv.h"
! 19:
! 20: # include <stdio.h>
! 21: # ifndef MACOS
! 22: # include <signal.h>
! 23: # include <sys/types.h>
! 24: # endif
! 25:
! 26: void GC_timerstart(),GC_timerstop();
! 27:
! 28: /*
! 29: * Separate free lists are maintained for different sized objects
! 30: * up to MAXOBJSZ.
! 31: * The call GC_allocobj(i,k) ensures that the freelist for
! 32: * kind k objects of size i points to a non-empty
! 33: * free list. It returns a pointer to the first entry on the free list.
! 34: * In a single-threaded world, GC_allocobj may be called to allocate
! 35: * an object of (small) size i as follows:
! 36: *
! 37: * opp = &(GC_objfreelist[i]);
! 38: * if (*opp == 0) GC_allocobj(i, NORMAL);
! 39: * ptr = *opp;
! 40: * *opp = obj_link(ptr);
! 41: *
! 42: * Note that this is very fast if the free list is non-empty; it should
! 43: * only involve the execution of 4 or 5 simple instructions.
! 44: * All composite objects on freelists are cleared, except for
! 45: * their first word.
! 46: */
! 47:
! 48: /*
! 49: * The allocator uses GC_allochblk to allocate large chunks of objects.
! 50: * These chunks all start on addresses which are multiples of
! 51: * HBLKSZ. Each allocated chunk has an associated header,
! 52: * which can be located quickly based on the address of the chunk.
! 53: * (See headers.c for details.)
! 54: * This makes it possible to check quickly whether an
! 55: * arbitrary address corresponds to an object administered by the
! 56: * allocator.
! 57: */
! 58:
! 59: word GC_non_gc_bytes = 0; /* Number of bytes not intended to be collected */
! 60:
! 61: word GC_gc_no = 0;
! 62:
! 63: #ifndef SMALL_CONFIG
! 64: int GC_incremental = 0; /* By default, stop the world. */
! 65: #endif
! 66:
! 67: int GC_full_freq = 4; /* Every 5th collection is a full */
! 68: /* collection. */
! 69:
! 70: char * GC_copyright[] =
! 71: {"Copyright 1988,1989 Hans-J. Boehm and Alan J. Demers ",
! 72: "Copyright (c) 1991-1995 by Xerox Corporation. All rights reserved. ",
! 73: "Copyright (c) 1996-1998 by Silicon Graphics. All rights reserved. ",
! 74: "THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY",
! 75: " EXPRESSED OR IMPLIED. ANY USE IS AT YOUR OWN RISK.",
! 76: "See source code for details." };
! 77:
! 78: # include "version.h"
! 79:
! 80: /* some more variables */
! 81:
! 82: extern signed_word GC_mem_found; /* Number of reclaimed longwords */
! 83: /* after garbage collection */
! 84:
! 85: GC_bool GC_dont_expand = 0;
! 86:
! 87: word GC_free_space_numerator = 1;
! 88: word GC_free_space_divisor = 3;
! 89:
! 90: extern GC_bool GC_collection_in_progress();
! 91: /* Collection is in progress, or was abandoned. */
! 92:
! 93: int GC_never_stop_func GC_PROTO((void)) { return(0); }
! 94:
! 95: CLOCK_TYPE GC_start_time; /* Time at which we stopped world. */
! 96: /* used only in GC_timeout_stop_func. */
! 97:
! 98: int GC_n_attempts = 0; /* Number of attempts at finishing */
! 99: /* collection within TIME_LIMIT */
! 100:
! 101: #ifdef SMALL_CONFIG
! 102: # define GC_timeout_stop_func GC_never_stop_func
! 103: #else
! 104: int GC_timeout_stop_func GC_PROTO((void))
! 105: {
! 106: CLOCK_TYPE current_time;
! 107: static unsigned count = 0;
! 108: unsigned long time_diff;
! 109:
! 110: if ((count++ & 3) != 0) return(0);
! 111: GET_TIME(current_time);
! 112: time_diff = MS_TIME_DIFF(current_time,GC_start_time);
! 113: if (time_diff >= TIME_LIMIT) {
! 114: # ifdef PRINTSTATS
! 115: GC_printf0("Abandoning stopped marking after ");
! 116: GC_printf1("%lu msecs", (unsigned long)time_diff);
! 117: GC_printf1("(attempt %d)\n", (unsigned long) GC_n_attempts);
! 118: # endif
! 119: return(1);
! 120: }
! 121: return(0);
! 122: }
! 123: #endif /* !SMALL_CONFIG */
! 124:
! 125: /* Return the minimum number of words that must be allocated between */
! 126: /* collections to amortize the collection cost. */
! 127: static word min_words_allocd()
! 128: {
! 129: # ifdef THREADS
! 130: /* We punt, for now. */
! 131: register signed_word stack_size = 10000;
! 132: # else
! 133: int dummy;
! 134: register signed_word stack_size = (ptr_t)(&dummy) - GC_stackbottom;
! 135: # endif
! 136: word total_root_size; /* includes double stack size, */
! 137: /* since the stack is expensive */
! 138: /* to scan. */
! 139: word scan_size; /* Estimate of memory to be scanned */
! 140: /* during normal GC. */
! 141:
! 142: if (stack_size < 0) stack_size = -stack_size;
! 143: total_root_size = 2 * stack_size + GC_root_size;
! 144: scan_size = BYTES_TO_WORDS(GC_heapsize - GC_large_free_bytes
! 145: + (GC_large_free_bytes >> 2)
! 146: /* use a bit more of large empty heap */
! 147: + total_root_size);
! 148: if (GC_incremental) {
! 149: return (scan_size*GC_free_space_numerator) / (2 * GC_free_space_divisor);
! 150: } else {
! 151: return (scan_size*GC_free_space_numerator) / GC_free_space_divisor;
! 152: }
! 153: }
! 154:
! 155: /* Return the number of words allocated, adjusted for explicit storage */
! 156: /* management, etc.. This number is used in deciding when to trigger */
! 157: /* collections. */
! 158: word GC_adj_words_allocd()
! 159: {
! 160: register signed_word result;
! 161: register signed_word expl_managed =
! 162: BYTES_TO_WORDS((long)GC_non_gc_bytes
! 163: - (long)GC_non_gc_bytes_at_gc);
! 164:
! 165: /* Don't count what was explicitly freed, or newly allocated for */
! 166: /* explicit management. Note that deallocating an explicitly */
! 167: /* managed object should not alter result, assuming the client */
! 168: /* is playing by the rules. */
! 169: result = (signed_word)GC_words_allocd
! 170: - (signed_word)GC_mem_freed - expl_managed;
! 171: if (result > (signed_word)GC_words_allocd) {
! 172: result = GC_words_allocd;
! 173: /* probably client bug or unfortunate scheduling */
! 174: }
! 175: result += GC_words_finalized;
! 176: /* We count objects enqueued for finalization as though they */
! 177: /* had been reallocated this round. Finalization is user */
! 178: /* visible progress. And if we don't count this, we have */
! 179: /* stability problems for programs that finalize all objects. */
! 180: result += GC_words_wasted;
! 181: /* This doesn't reflect useful work. But if there is lots of */
! 182: /* new fragmentation, the same is probably true of the heap, */
! 183: /* and the collection will be correspondingly cheaper. */
! 184: if (result < (signed_word)(GC_words_allocd >> 3)) {
! 185: /* Always count at least 1/8 of the allocations. We don't want */
! 186: /* to collect too infrequently, since that would inhibit */
! 187: /* coalescing of free storage blocks. */
! 188: /* This also makes us partially robust against client bugs. */
! 189: return(GC_words_allocd >> 3);
! 190: } else {
! 191: return(result);
! 192: }
! 193: }
! 194:
! 195:
! 196: /* Clear up a few frames worth of garbage left at the top of the stack. */
! 197: /* This is used to prevent us from accidentally treating garbade left */
! 198: /* on the stack by other parts of the collector as roots. This */
! 199: /* differs from the code in misc.c, which actually tries to keep the */
! 200: /* stack clear of long-lived, client-generated garbage. */
! 201: void GC_clear_a_few_frames()
! 202: {
! 203: # define NWORDS 64
! 204: word frames[NWORDS];
! 205: register int i;
! 206:
! 207: for (i = 0; i < NWORDS; i++) frames[i] = 0;
! 208: }
! 209:
! 210: /* Have we allocated enough to amortize a collection? */
! 211: GC_bool GC_should_collect()
! 212: {
! 213: return(GC_adj_words_allocd() >= min_words_allocd());
! 214: }
! 215:
! 216: void GC_notify_full_gc()
! 217: {
! 218: if (GC_start_call_back != (void (*)())0) {
! 219: (*GC_start_call_back)();
! 220: }
! 221: }
! 222:
! 223: /*
! 224: * Initiate a garbage collection if appropriate.
! 225: * Choose judiciously
! 226: * between partial, full, and stop-world collections.
! 227: * Assumes lock held, signals disabled.
! 228: */
! 229: void GC_maybe_gc()
! 230: {
! 231: static int n_partial_gcs = 0;
! 232: GC_bool is_full_gc = FALSE;
! 233:
! 234: if (GC_should_collect()) {
! 235: if (!GC_incremental) {
! 236: GC_notify_full_gc();
! 237: GC_gcollect_inner();
! 238: n_partial_gcs = 0;
! 239: return;
! 240: } else if (n_partial_gcs >= GC_full_freq) {
! 241: # ifdef PRINTSTATS
! 242: GC_printf2(
! 243: "***>Full mark for collection %lu after %ld allocd bytes\n",
! 244: (unsigned long) GC_gc_no+1,
! 245: (long)WORDS_TO_BYTES(GC_words_allocd));
! 246: # endif
! 247: GC_promote_black_lists();
! 248: (void)GC_reclaim_all((GC_stop_func)0, TRUE);
! 249: GC_clear_marks();
! 250: n_partial_gcs = 0;
! 251: GC_notify_full_gc();
! 252: is_full_gc = TRUE;
! 253: } else {
! 254: n_partial_gcs++;
! 255: }
! 256: /* We try to mark with the world stopped. */
! 257: /* If we run out of time, this turns into */
! 258: /* incremental marking. */
! 259: GET_TIME(GC_start_time);
! 260: if (GC_stopped_mark(GC_timeout_stop_func)) {
! 261: # ifdef SAVE_CALL_CHAIN
! 262: GC_save_callers(GC_last_stack);
! 263: # endif
! 264: GC_finish_collection();
! 265: } else {
! 266: if (!is_full_gc) {
! 267: /* Count this as the first attempt */
! 268: GC_n_attempts++;
! 269: }
! 270: }
! 271: }
! 272: }
! 273:
! 274:
! 275: /*
! 276: * Stop the world garbage collection. Assumes lock held, signals disabled.
! 277: * If stop_func is not GC_never_stop_func, then abort if stop_func returns TRUE.
! 278: */
! 279: GC_bool GC_try_to_collect_inner(stop_func)
! 280: GC_stop_func stop_func;
! 281: {
! 282: if (GC_incremental && GC_collection_in_progress()) {
! 283: # ifdef PRINTSTATS
! 284: GC_printf0(
! 285: "GC_try_to_collect_inner: finishing collection in progress\n");
! 286: # endif /* PRINTSTATS */
! 287: /* Just finish collection already in progress. */
! 288: while(GC_collection_in_progress()) {
! 289: if (stop_func()) return(FALSE);
! 290: GC_collect_a_little_inner(1);
! 291: }
! 292: }
! 293: # ifdef PRINTSTATS
! 294: GC_printf2(
! 295: "Initiating full world-stop collection %lu after %ld allocd bytes\n",
! 296: (unsigned long) GC_gc_no+1,
! 297: (long)WORDS_TO_BYTES(GC_words_allocd));
! 298: # endif
! 299: GC_promote_black_lists();
! 300: /* Make sure all blocks have been reclaimed, so sweep routines */
! 301: /* don't see cleared mark bits. */
! 302: /* If we're guaranteed to finish, then this is unnecessary. */
! 303: if (stop_func != GC_never_stop_func
! 304: && !GC_reclaim_all(stop_func, FALSE)) {
! 305: /* Aborted. So far everything is still consistent. */
! 306: return(FALSE);
! 307: }
! 308: GC_invalidate_mark_state(); /* Flush mark stack. */
! 309: GC_clear_marks();
! 310: # ifdef SAVE_CALL_CHAIN
! 311: GC_save_callers(GC_last_stack);
! 312: # endif
! 313: if (!GC_stopped_mark(stop_func)) {
! 314: if (!GC_incremental) {
! 315: /* We're partially done and have no way to complete or use */
! 316: /* current work. Reestablish invariants as cheaply as */
! 317: /* possible. */
! 318: GC_invalidate_mark_state();
! 319: GC_unpromote_black_lists();
! 320: } /* else we claim the world is already still consistent. We'll */
! 321: /* finish incrementally. */
! 322: return(FALSE);
! 323: }
! 324: GC_finish_collection();
! 325: return(TRUE);
! 326: }
! 327:
! 328:
! 329:
! 330: /*
! 331: * Perform n units of garbage collection work. A unit is intended to touch
! 332: * roughly GC_RATE pages. Every once in a while, we do more than that.
! 333: * This needa to be a fairly large number with our current incremental
! 334: * GC strategy, since otherwise we allocate too much during GC, and the
! 335: * cleanup gets expensive.
! 336: */
! 337: # define GC_RATE 10
! 338: # define MAX_PRIOR_ATTEMPTS 1
! 339: /* Maximum number of prior attempts at world stop marking */
! 340: /* A value of 1 means that we finish the seconf time, no matter */
! 341: /* how long it takes. Doesn't count the initial root scan */
! 342: /* for a full GC. */
! 343:
! 344: int GC_deficit = 0; /* The number of extra calls to GC_mark_some */
! 345: /* that we have made. */
! 346:
! 347: void GC_collect_a_little_inner(n)
! 348: int n;
! 349: {
! 350: register int i;
! 351:
! 352: if (GC_incremental && GC_collection_in_progress()) {
! 353: for (i = GC_deficit; i < GC_RATE*n; i++) {
! 354: if (GC_mark_some((ptr_t)0)) {
! 355: /* Need to finish a collection */
! 356: # ifdef SAVE_CALL_CHAIN
! 357: GC_save_callers(GC_last_stack);
! 358: # endif
! 359: if (GC_n_attempts < MAX_PRIOR_ATTEMPTS) {
! 360: GET_TIME(GC_start_time);
! 361: if (!GC_stopped_mark(GC_timeout_stop_func)) {
! 362: GC_n_attempts++;
! 363: break;
! 364: }
! 365: } else {
! 366: (void)GC_stopped_mark(GC_never_stop_func);
! 367: }
! 368: GC_finish_collection();
! 369: break;
! 370: }
! 371: }
! 372: if (GC_deficit > 0) GC_deficit -= GC_RATE*n;
! 373: if (GC_deficit < 0) GC_deficit = 0;
! 374: } else {
! 375: GC_maybe_gc();
! 376: }
! 377: }
! 378:
! 379: int GC_collect_a_little GC_PROTO(())
! 380: {
! 381: int result;
! 382: DCL_LOCK_STATE;
! 383:
! 384: DISABLE_SIGNALS();
! 385: LOCK();
! 386: GC_collect_a_little_inner(1);
! 387: result = (int)GC_collection_in_progress();
! 388: UNLOCK();
! 389: ENABLE_SIGNALS();
! 390: return(result);
! 391: }
! 392:
! 393: /*
! 394: * Assumes lock is held, signals are disabled.
! 395: * We stop the world.
! 396: * If stop_func() ever returns TRUE, we may fail and return FALSE.
! 397: * Increment GC_gc_no if we succeed.
! 398: */
! 399: GC_bool GC_stopped_mark(stop_func)
! 400: GC_stop_func stop_func;
! 401: {
! 402: register int i;
! 403: int dummy;
! 404: # ifdef PRINTSTATS
! 405: CLOCK_TYPE start_time, current_time;
! 406: # endif
! 407:
! 408: STOP_WORLD();
! 409: GC_timerstart();
! 410: # ifdef PRINTSTATS
! 411: GET_TIME(start_time);
! 412: GC_printf1("--> Marking for collection %lu ",
! 413: (unsigned long) GC_gc_no + 1);
! 414: GC_printf2("after %lu allocd bytes + %lu wasted bytes\n",
! 415: (unsigned long) WORDS_TO_BYTES(GC_words_allocd),
! 416: (unsigned long) WORDS_TO_BYTES(GC_words_wasted));
! 417: # endif
! 418:
! 419: /* Mark from all roots. */
! 420: /* Minimize junk left in my registers and on the stack */
! 421: GC_clear_a_few_frames();
! 422: GC_noop(0,0,0,0,0,0);
! 423: GC_initiate_gc();
! 424: for(i = 0;;i++) {
! 425: if ((*stop_func)()) {
! 426: # ifdef PRINTSTATS
! 427: GC_printf0("Abandoned stopped marking after ");
! 428: GC_printf1("%lu iterations\n",
! 429: (unsigned long)i);
! 430: # endif
! 431: GC_timerstop();
! 432: GC_deficit = i; /* Give the mutator a chance. */
! 433: START_WORLD();
! 434: return(FALSE);
! 435: }
! 436: if (GC_mark_some((ptr_t)(&dummy))) break;
! 437: }
! 438:
! 439: GC_gc_no++;
! 440: # ifdef PRINTSTATS
! 441: GC_printf2("Collection %lu reclaimed %ld bytes",
! 442: (unsigned long) GC_gc_no - 1,
! 443: (long)WORDS_TO_BYTES(GC_mem_found));
! 444: GC_printf1(" ---> heapsize = %lu bytes\n",
! 445: (unsigned long) GC_heapsize);
! 446: /* Printf arguments may be pushed in funny places. Clear the */
! 447: /* space. */
! 448: GC_printf0("");
! 449: # endif
! 450:
! 451: /* Check all debugged objects for consistency */
! 452: if (GC_debugging_started) {
! 453: (*GC_check_heap)();
! 454: }
! 455:
! 456: # ifdef PRINTTIMES
! 457: GET_TIME(current_time);
! 458: GC_printf1("World-stopped marking took %lu msecs\n",
! 459: MS_TIME_DIFF(current_time,start_time));
! 460: # endif
! 461: GC_timerstop();
! 462: START_WORLD();
! 463: return(TRUE);
! 464: }
! 465:
! 466:
! 467: /* Finish up a collection. Assumes lock is held, signals are disabled, */
! 468: /* but the world is otherwise running. */
! 469: void GC_finish_collection()
! 470: {
! 471: # ifdef PRINTTIMES
! 472: CLOCK_TYPE start_time;
! 473: CLOCK_TYPE finalize_time;
! 474: CLOCK_TYPE done_time;
! 475:
! 476: GET_TIME(start_time);
! 477: finalize_time = start_time;
! 478: # endif
! 479: GC_timerstart();
! 480:
! 481: # ifdef GATHERSTATS
! 482: GC_mem_found = 0;
! 483: # endif
! 484: # ifdef FIND_LEAK
! 485: /* Mark all objects on the free list. All objects should be */
! 486: /* marked when we're done. */
! 487: {
! 488: register word size; /* current object size */
! 489: register ptr_t p; /* pointer to current object */
! 490: register struct hblk * h; /* pointer to block containing *p */
! 491: register hdr * hhdr;
! 492: register int word_no; /* "index" of *p in *q */
! 493: int kind;
! 494:
! 495: for (kind = 0; kind < GC_n_kinds; kind++) {
! 496: for (size = 1; size <= MAXOBJSZ; size++) {
! 497: for (p= GC_obj_kinds[kind].ok_freelist[size];
! 498: p != 0; p=obj_link(p)){
! 499: h = HBLKPTR(p);
! 500: hhdr = HDR(h);
! 501: word_no = (((word *)p) - ((word *)h));
! 502: set_mark_bit_from_hdr(hhdr, word_no);
! 503: }
! 504: }
! 505: }
! 506: }
! 507: /* Check that everything is marked */
! 508: GC_start_reclaim(TRUE);
! 509: # else
! 510:
! 511: GC_finalize();
! 512: # ifdef STUBBORN_ALLOC
! 513: GC_clean_changing_list();
! 514: # endif
! 515:
! 516: # ifdef PRINTTIMES
! 517: GET_TIME(finalize_time);
! 518: # endif
! 519:
! 520: /* Clear free list mark bits, in case they got accidentally marked */
! 521: /* Note: HBLKPTR(p) == pointer to head of block containing *p */
! 522: /* Also subtract memory remaining from GC_mem_found count. */
! 523: /* Note that composite objects on free list are cleared. */
! 524: /* Thus accidentally marking a free list is not a problem; only */
! 525: /* objects on the list itself will be marked, and that's fixed here. */
! 526: {
! 527: register word size; /* current object size */
! 528: register ptr_t p; /* pointer to current object */
! 529: register struct hblk * h; /* pointer to block containing *p */
! 530: register hdr * hhdr;
! 531: register int word_no; /* "index" of *p in *q */
! 532: int kind;
! 533:
! 534: for (kind = 0; kind < GC_n_kinds; kind++) {
! 535: for (size = 1; size <= MAXOBJSZ; size++) {
! 536: for (p= GC_obj_kinds[kind].ok_freelist[size];
! 537: p != 0; p=obj_link(p)){
! 538: h = HBLKPTR(p);
! 539: hhdr = HDR(h);
! 540: word_no = (((word *)p) - ((word *)h));
! 541: clear_mark_bit_from_hdr(hhdr, word_no);
! 542: # ifdef GATHERSTATS
! 543: GC_mem_found -= size;
! 544: # endif
! 545: }
! 546: }
! 547: }
! 548: }
! 549:
! 550:
! 551: # ifdef PRINTSTATS
! 552: GC_printf1("Bytes recovered before sweep - f.l. count = %ld\n",
! 553: (long)WORDS_TO_BYTES(GC_mem_found));
! 554: # endif
! 555:
! 556: /* Reconstruct free lists to contain everything not marked */
! 557: GC_start_reclaim(FALSE);
! 558:
! 559: # endif /* !FIND_LEAK */
! 560:
! 561: # ifdef PRINTSTATS
! 562: GC_printf2(
! 563: "Immediately reclaimed %ld bytes in heap of size %lu bytes",
! 564: (long)WORDS_TO_BYTES(GC_mem_found),
! 565: (unsigned long)GC_heapsize);
! 566: # ifdef USE_MUNMAP
! 567: GC_printf1("(%lu unmapped)", GC_unmapped_bytes);
! 568: # endif
! 569: GC_printf2(
! 570: "\n%lu (atomic) + %lu (composite) collectable bytes in use\n",
! 571: (unsigned long)WORDS_TO_BYTES(GC_atomic_in_use),
! 572: (unsigned long)WORDS_TO_BYTES(GC_composite_in_use));
! 573: # endif
! 574:
! 575: GC_n_attempts = 0;
! 576: /* Reset or increment counters for next cycle */
! 577: GC_words_allocd_before_gc += GC_words_allocd;
! 578: GC_non_gc_bytes_at_gc = GC_non_gc_bytes;
! 579: GC_words_allocd = 0;
! 580: GC_words_wasted = 0;
! 581: GC_mem_freed = 0;
! 582:
! 583: # ifdef USE_MUNMAP
! 584: GC_unmap_old();
! 585: # endif
! 586: # ifdef PRINTTIMES
! 587: GET_TIME(done_time);
! 588: GC_printf2("Finalize + initiate sweep took %lu + %lu msecs\n",
! 589: MS_TIME_DIFF(finalize_time,start_time),
! 590: MS_TIME_DIFF(done_time,finalize_time));
! 591: # endif
! 592: GC_timerstop();
! 593: }
! 594:
! 595: /* Externally callable routine to invoke full, stop-world collection */
! 596: # if defined(__STDC__) || defined(__cplusplus)
! 597: int GC_try_to_collect(GC_stop_func stop_func)
! 598: # else
! 599: int GC_try_to_collect(stop_func)
! 600: GC_stop_func stop_func;
! 601: # endif
! 602: {
! 603: int result;
! 604: DCL_LOCK_STATE;
! 605:
! 606: GC_INVOKE_FINALIZERS();
! 607: DISABLE_SIGNALS();
! 608: LOCK();
! 609: ENTER_GC();
! 610: if (!GC_is_initialized) GC_init_inner();
! 611: /* Minimize junk left in my registers */
! 612: GC_noop(0,0,0,0,0,0);
! 613: result = (int)GC_try_to_collect_inner(stop_func);
! 614: EXIT_GC();
! 615: UNLOCK();
! 616: ENABLE_SIGNALS();
! 617: if(result) GC_INVOKE_FINALIZERS();
! 618: return(result);
! 619: }
! 620:
! 621: void GC_gcollect GC_PROTO(())
! 622: {
! 623: GC_notify_full_gc();
! 624: (void)GC_try_to_collect(GC_never_stop_func);
! 625: }
! 626:
! 627: word GC_n_heap_sects = 0; /* Number of sections currently in heap. */
! 628:
! 629: /*
! 630: * Use the chunk of memory starting at p of size bytes as part of the heap.
! 631: * Assumes p is HBLKSIZE aligned, and bytes is a multiple of HBLKSIZE.
! 632: */
! 633: void GC_add_to_heap(p, bytes)
! 634: struct hblk *p;
! 635: word bytes;
! 636: {
! 637: word words;
! 638: hdr * phdr;
! 639:
! 640: if (GC_n_heap_sects >= MAX_HEAP_SECTS) {
! 641: ABORT("Too many heap sections: Increase MAXHINCR or MAX_HEAP_SECTS");
! 642: }
! 643: if (!GC_install_header(p)) {
! 644: /* This is extremely unlikely. Can't add it. This will */
! 645: /* almost certainly result in a 0 return from the allocator, */
! 646: /* which is entirely appropriate. */
! 647: return;
! 648: }
! 649: GC_heap_sects[GC_n_heap_sects].hs_start = (ptr_t)p;
! 650: GC_heap_sects[GC_n_heap_sects].hs_bytes = bytes;
! 651: GC_n_heap_sects++;
! 652: words = BYTES_TO_WORDS(bytes - HDR_BYTES);
! 653: phdr = HDR(p);
! 654: phdr -> hb_sz = words;
! 655: phdr -> hb_map = (char *)1; /* A value != GC_invalid_map */
! 656: phdr -> hb_flags = 0;
! 657: GC_freehblk(p);
! 658: GC_heapsize += bytes;
! 659: if ((ptr_t)p <= GC_least_plausible_heap_addr
! 660: || GC_least_plausible_heap_addr == 0) {
! 661: GC_least_plausible_heap_addr = (ptr_t)p - sizeof(word);
! 662: /* Making it a little smaller than necessary prevents */
! 663: /* us from getting a false hit from the variable */
! 664: /* itself. There's some unintentional reflection */
! 665: /* here. */
! 666: }
! 667: if ((ptr_t)p + bytes >= GC_greatest_plausible_heap_addr) {
! 668: GC_greatest_plausible_heap_addr = (ptr_t)p + bytes;
! 669: }
! 670: }
! 671:
! 672: #ifdef PRESERVE_LAST
! 673:
! 674: GC_bool GC_protect_last_block = FALSE;
! 675:
! 676: GC_bool GC_in_last_heap_sect(p)
! 677: ptr_t p;
! 678: {
! 679: struct HeapSect * last_heap_sect;
! 680: ptr_t start;
! 681: ptr_t end;
! 682:
! 683: if (!GC_protect_last_block) return FALSE;
! 684: last_heap_sect = &(GC_heap_sects[GC_n_heap_sects-1]);
! 685: start = last_heap_sect -> hs_start;
! 686: if (p < start) return FALSE;
! 687: end = start + last_heap_sect -> hs_bytes;
! 688: if (p >= end) return FALSE;
! 689: return TRUE;
! 690: }
! 691: #endif
! 692:
! 693: # if !defined(NO_DEBUGGING)
! 694: void GC_print_heap_sects()
! 695: {
! 696: register unsigned i;
! 697:
! 698: GC_printf1("Total heap size: %lu\n", (unsigned long) GC_heapsize);
! 699: for (i = 0; i < GC_n_heap_sects; i++) {
! 700: unsigned long start = (unsigned long) GC_heap_sects[i].hs_start;
! 701: unsigned long len = (unsigned long) GC_heap_sects[i].hs_bytes;
! 702: struct hblk *h;
! 703: unsigned nbl = 0;
! 704:
! 705: GC_printf3("Section %ld from 0x%lx to 0x%lx ", (unsigned long)i,
! 706: start, (unsigned long)(start + len));
! 707: for (h = (struct hblk *)start; h < (struct hblk *)(start + len); h++) {
! 708: if (GC_is_black_listed(h, HBLKSIZE)) nbl++;
! 709: }
! 710: GC_printf2("%lu/%lu blacklisted\n", (unsigned long)nbl,
! 711: (unsigned long)(len/HBLKSIZE));
! 712: }
! 713: }
! 714: # endif
! 715:
! 716: ptr_t GC_least_plausible_heap_addr = (ptr_t)ONES;
! 717: ptr_t GC_greatest_plausible_heap_addr = 0;
! 718:
! 719: ptr_t GC_max(x,y)
! 720: ptr_t x, y;
! 721: {
! 722: return(x > y? x : y);
! 723: }
! 724:
! 725: ptr_t GC_min(x,y)
! 726: ptr_t x, y;
! 727: {
! 728: return(x < y? x : y);
! 729: }
! 730:
! 731: # if defined(__STDC__) || defined(__cplusplus)
! 732: void GC_set_max_heap_size(GC_word n)
! 733: # else
! 734: void GC_set_max_heap_size(n)
! 735: GC_word n;
! 736: # endif
! 737: {
! 738: GC_max_heapsize = n;
! 739: }
! 740:
! 741: GC_word GC_max_retries = 0;
! 742:
! 743: /*
! 744: * this explicitly increases the size of the heap. It is used
! 745: * internally, but may also be invoked from GC_expand_hp by the user.
! 746: * The argument is in units of HBLKSIZE.
! 747: * Tiny values of n are rounded up.
! 748: * Returns FALSE on failure.
! 749: */
! 750: GC_bool GC_expand_hp_inner(n)
! 751: word n;
! 752: {
! 753: word bytes;
! 754: struct hblk * space;
! 755: word expansion_slop; /* Number of bytes by which we expect the */
! 756: /* heap to expand soon. */
! 757:
! 758: if (n < MINHINCR) n = MINHINCR;
! 759: bytes = n * HBLKSIZE;
! 760: /* Make sure bytes is a multiple of GC_page_size */
! 761: {
! 762: word mask = GC_page_size - 1;
! 763: bytes += mask;
! 764: bytes &= ~mask;
! 765: }
! 766:
! 767: if (GC_max_heapsize != 0 && GC_heapsize + bytes > GC_max_heapsize) {
! 768: /* Exceeded self-imposed limit */
! 769: return(FALSE);
! 770: }
! 771: space = GET_MEM(bytes);
! 772: if( space == 0 ) {
! 773: return(FALSE);
! 774: }
! 775: # ifdef PRINTSTATS
! 776: GC_printf2("Increasing heap size by %lu after %lu allocated bytes\n",
! 777: (unsigned long)bytes,
! 778: (unsigned long)WORDS_TO_BYTES(GC_words_allocd));
! 779: # ifdef UNDEFINED
! 780: GC_printf1("Root size = %lu\n", GC_root_size);
! 781: GC_print_block_list(); GC_print_hblkfreelist();
! 782: GC_printf0("\n");
! 783: # endif
! 784: # endif
! 785: expansion_slop = 8 * WORDS_TO_BYTES(min_words_allocd());
! 786: if (5 * HBLKSIZE * MAXHINCR > expansion_slop) {
! 787: expansion_slop = 5 * HBLKSIZE * MAXHINCR;
! 788: }
! 789: if (GC_last_heap_addr == 0 && !((word)space & SIGNB)
! 790: || GC_last_heap_addr != 0 && GC_last_heap_addr < (ptr_t)space) {
! 791: /* Assume the heap is growing up */
! 792: GC_greatest_plausible_heap_addr =
! 793: GC_max(GC_greatest_plausible_heap_addr,
! 794: (ptr_t)space + bytes + expansion_slop);
! 795: } else {
! 796: /* Heap is growing down */
! 797: GC_least_plausible_heap_addr =
! 798: GC_min(GC_least_plausible_heap_addr,
! 799: (ptr_t)space - expansion_slop);
! 800: }
! 801: GC_prev_heap_addr = GC_last_heap_addr;
! 802: GC_last_heap_addr = (ptr_t)space;
! 803: GC_add_to_heap(space, bytes);
! 804: #if defined(VISUAL_LIB)
! 805: SendHeapSize();
! 806: #endif
! 807: return(TRUE);
! 808: }
! 809:
! 810: /* Really returns a bool, but it's externally visible, so that's clumsy. */
! 811: /* Arguments is in bytes. */
! 812: # if defined(__STDC__) || defined(__cplusplus)
! 813: int GC_expand_hp(size_t bytes)
! 814: # else
! 815: int GC_expand_hp(bytes)
! 816: size_t bytes;
! 817: # endif
! 818: {
! 819: int result;
! 820: DCL_LOCK_STATE;
! 821:
! 822: DISABLE_SIGNALS();
! 823: LOCK();
! 824: if (!GC_is_initialized) GC_init_inner();
! 825: result = (int)GC_expand_hp_inner(divHBLKSZ((word)bytes));
! 826: # ifdef PRESERVE_LAST
! 827: if (result) GC_protect_last_block = FALSE;
! 828: # endif
! 829: UNLOCK();
! 830: ENABLE_SIGNALS();
! 831: return(result);
! 832: }
! 833:
! 834: unsigned GC_fail_count = 0;
! 835: /* How many consecutive GC/expansion failures? */
! 836: /* Reset by GC_allochblk. */
! 837:
! 838: GC_bool GC_collect_or_expand(needed_blocks, ignore_off_page)
! 839: word needed_blocks;
! 840: GC_bool ignore_off_page;
! 841: {
! 842: if (!GC_incremental && !GC_dont_gc && GC_should_collect()) {
! 843: GC_notify_full_gc();
! 844: GC_gcollect_inner();
! 845: } else {
! 846: word blocks_to_get = (GC_heapsize*GC_free_space_numerator)/(HBLKSIZE*GC_free_space_divisor)
! 847: + needed_blocks;
! 848:
! 849: if (blocks_to_get > MAXHINCR) {
! 850: word slop;
! 851:
! 852: if (ignore_off_page) {
! 853: slop = 4;
! 854: } else {
! 855: slop = 2*divHBLKSZ(BL_LIMIT);
! 856: if (slop > needed_blocks) slop = needed_blocks;
! 857: }
! 858: if (needed_blocks + slop > MAXHINCR) {
! 859: blocks_to_get = needed_blocks + slop;
! 860: } else {
! 861: blocks_to_get = MAXHINCR;
! 862: }
! 863: }
! 864: if (!GC_expand_hp_inner(blocks_to_get)
! 865: && !GC_expand_hp_inner(needed_blocks)) {
! 866: if (GC_fail_count++ < GC_max_retries) {
! 867: WARN("Out of Memory! Trying to continue ...\n", 0);
! 868: GC_notify_full_gc();
! 869: GC_gcollect_inner();
! 870: } else {
! 871: WARN("Out of Memory! Returning NIL!\n", 0);
! 872: return(FALSE);
! 873: }
! 874: } else {
! 875: # ifdef PRINTSTATS
! 876: if (GC_fail_count) {
! 877: GC_printf0("Memory available again ...\n");
! 878: }
! 879: # endif
! 880: # ifdef PRESERVE_LAST
! 881: if (needed_blocks > 1) GC_protect_last_block = TRUE;
! 882: /* We were forced to expand the heap as the result */
! 883: /* of a large block allocation. Avoid breaking up */
! 884: /* new block into small pieces. */
! 885: # endif
! 886: }
! 887: }
! 888: return(TRUE);
! 889: }
! 890:
! 891: /*
! 892: * Make sure the object free list for sz is not empty.
! 893: * Return a pointer to the first object on the free list.
! 894: * The object MUST BE REMOVED FROM THE FREE LIST BY THE CALLER.
! 895: * Assumes we hold the allocator lock and signals are disabled.
! 896: *
! 897: */
! 898: ptr_t GC_allocobj(sz, kind)
! 899: word sz;
! 900: int kind;
! 901: {
! 902: register ptr_t * flh = &(GC_obj_kinds[kind].ok_freelist[sz]);
! 903:
! 904: if (sz == 0) return(0);
! 905:
! 906: #if defined(VISUAL)
! 907: {
! 908: #include <signal.h>
! 909: extern int recv_intr;
! 910: if ( recv_intr ) {
! 911: if ( recv_intr == 1 ) {
! 912: recv_intr = 0;
! 913: int_handler();
! 914: } else {
! 915: recv_intr = 0;
! 916: ox_usr1_handler(0);
! 917: }
! 918: }
! 919: }
! 920: #endif
! 921: while (*flh == 0) {
! 922: ENTER_GC();
! 923: /* Do our share of marking work */
! 924: if(GC_incremental && !GC_dont_gc) GC_collect_a_little_inner(1);
! 925: /* Sweep blocks for objects of this size */
! 926: GC_continue_reclaim(sz, kind);
! 927: EXIT_GC();
! 928: if (*flh == 0) {
! 929: GC_new_hblk(sz, kind);
! 930: }
! 931: if (*flh == 0) {
! 932: ENTER_GC();
! 933: if (!GC_collect_or_expand((word)1,FALSE)) {
! 934: EXIT_GC();
! 935: return(0);
! 936: }
! 937: EXIT_GC();
! 938: }
! 939: }
! 940:
! 941: return(*flh);
! 942: }
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