boehm-gc/mallocx.c

   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) 1996 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  * These are extra allocation routines which are likely to be less
  18  * frequently used than those in malloc.c.  They are separate in the
  19  * hope that the .o file will be excluded from statically linked
  20  * executables.  We should probably break this up further.
  21  */
  22
  23 #include <stdio.h>
  24 #include "gc_priv.h"
  25
  26 extern ptr_t GC_clear_stack();  /* in misc.c, behaves like identity */
  27 void GC_extend_size_map();      /* in misc.c. */
  28 GC_bool GC_alloc_reclaim_list();        /* in malloc.c */
  29
  30 /* Some externally visible but unadvertised variables to allow access to */
  31 /* free lists from inlined allocators without including gc_priv.h        */
  32 /* or introducing dependencies on internal data structure layouts.       */
  33 ptr_t * CONST GC_objfreelist_ptr = GC_objfreelist;
  34 ptr_t * CONST GC_aobjfreelist_ptr = GC_aobjfreelist;
  35 ptr_t * CONST GC_uobjfreelist_ptr = GC_uobjfreelist;
  36 # ifdef ATOMIC_UNCOLLECTABLE
  37     ptr_t * CONST GC_auobjfreelist_ptr = GC_auobjfreelist;
  38 # endif
  39
  40 /* Allocate a composite object of size n bytes.  The caller guarantees  */
  41 /* that pointers past the first page are not relevant.  Caller holds    */
  42 /* allocation lock.                                                     */
  43 ptr_t GC_generic_malloc_inner_ignore_off_page(lb, k)
  44 register size_t lb;
  45 register int k;
  46 {
  47     register struct hblk * h;
  48     register word n_blocks;
  49     register word lw;
  50     register ptr_t op;
  51
  52     if (lb <= HBLKSIZE)
  53         return(GC_generic_malloc_inner((word)lb, k));
  54     n_blocks = divHBLKSZ(ADD_SLOP(lb) + HDR_BYTES + HBLKSIZE-1);
  55     if (!GC_is_initialized) GC_init_inner();
  56     /* Do our share of marking work */
  57     if(GC_incremental && !GC_dont_gc)
  58         GC_collect_a_little_inner((int)n_blocks);
  59     lw = ROUNDED_UP_WORDS(lb);
  60     h = GC_allochblk(lw, k, IGNORE_OFF_PAGE);
  61 #   ifdef USE_MUNMAP
  62       if (0 == h) {
  63         GC_merge_unmapped();
  64         h = GC_allochblk(lw, k, IGNORE_OFF_PAGE);
  65       }
  66 #   endif
  67     while (0 == h && GC_collect_or_expand(n_blocks, TRUE)) {
  68       h = GC_allochblk(lw, k, IGNORE_OFF_PAGE);
  69     }
  70     if (h == 0) {
  71         op = 0;
  72     } else {
  73         op = (ptr_t) (h -> hb_body);
  74         GC_words_wasted += BYTES_TO_WORDS(n_blocks * HBLKSIZE) - lw;
  75     }
  76     GC_words_allocd += lw;
  77     return((ptr_t)op);
  78 }
  79
  80 ptr_t GC_generic_malloc_ignore_off_page(lb, k)
  81 register size_t lb;
  82 register int k;
  83 {
  84     register ptr_t result;
  85     DCL_LOCK_STATE;
  86
  87     GC_INVOKE_FINALIZERS();
  88     DISABLE_SIGNALS();
  89     LOCK();
  90     result = GC_generic_malloc_inner_ignore_off_page(lb,k);
  91     UNLOCK();
  92     ENABLE_SIGNALS();
  93     if (0 == result) {
  94         return((*GC_oom_fn)(lb));
  95     } else {
  96         return(result);
  97     }
  98 }
  99
 100 # if defined(__STDC__) || defined(__cplusplus)
 101   void * GC_malloc_ignore_off_page(size_t lb)
 102 # else
 103   char * GC_malloc_ignore_off_page(lb)
 104   register size_t lb;
 105 # endif
 106 {
 107     return((GC_PTR)GC_generic_malloc_ignore_off_page(lb, NORMAL));
 108 }
 109
 110 # if defined(__STDC__) || defined(__cplusplus)
 111   void * GC_malloc_atomic_ignore_off_page(size_t lb)
 112 # else
 113   char * GC_malloc_atomic_ignore_off_page(lb)
 114   register size_t lb;
 115 # endif
 116 {
 117     return((GC_PTR)GC_generic_malloc_ignore_off_page(lb, PTRFREE));
 118 }
 119
 120 /* Increment GC_words_allocd from code that doesn't have direct access  */
 121 /* to GC_arrays.                                                        */
 122 # ifdef __STDC__
 123 void GC_incr_words_allocd(size_t n)
 124 {
 125     GC_words_allocd += n;
 126 }
 127
 128 /* The same for GC_mem_freed.                           */
 129 void GC_incr_mem_freed(size_t n)
 130 {
 131     GC_mem_freed += n;
 132 }
 133 # endif /* __STDC__ */
 134
 135 /* Analogous to the above, but assumes a small object size, and         */
 136 /* bypasses MERGE_SIZES mechanism.  Used by gc_inline.h.                */
 137 #ifdef __STDC__
 138      ptr_t GC_generic_malloc_words_small(size_t lw, int k)
 139 #else
 140      ptr_t GC_generic_malloc_words_small(lw, k)
 141      register word lw;
 142      register int k;
 143 #endif
 144 {
 145 register ptr_t op;
 146 register ptr_t *opp;
 147 register struct obj_kind * kind = GC_obj_kinds + k;
 148 DCL_LOCK_STATE;
 149
 150     GC_INVOKE_FINALIZERS();
 151     DISABLE_SIGNALS();
 152     LOCK();
 153     opp = &(kind -> ok_freelist[lw]);
 154     if( (op = *opp) == 0 ) {
 155         if (!GC_is_initialized) {
 156             GC_init_inner();
 157         }
 158         if (kind -> ok_reclaim_list != 0 || GC_alloc_reclaim_list(kind)) {
 159             op = GC_clear_stack(GC_allocobj((word)lw, k));
 160         }
 161         if (op == 0) {
 162             UNLOCK();
 163             ENABLE_SIGNALS();
 164             return ((*GC_oom_fn)(WORDS_TO_BYTES(lw)));
 165         }
 166     }
 167     *opp = obj_link(op);
 168     obj_link(op) = 0;
 169     GC_words_allocd += lw;
 170     UNLOCK();
 171     ENABLE_SIGNALS();
 172     return((ptr_t)op);
 173 }
 174
 175 #if defined(THREADS) && !defined(SRC_M3)
 176 /* Return a list of 1 or more objects of the indicated size, linked     */
 177 /* through the first word in the object.  This has the advantage that   */
 178 /* it acquires the allocation lock only once, and may greatly reduce    */
 179 /* time wasted contending for the allocation lock.  Typical usage would */
 180 /* be in a thread that requires many items of the same size.  It would  */
 181 /* keep its own free list in thread-local storage, and call             */
 182 /* GC_malloc_many or friends to replenish it.  (We do not round up      */
 183 /* object sizes, since a call indicates the intention to consume many   */
 184 /* objects of exactly this size.)                                       */
 185 /* Note that the client should usually clear the link field.            */
 186 ptr_t GC_generic_malloc_many(lb, k)
 187 register word lb;
 188 register int k;
 189 {
 190 ptr_t op;
 191 register ptr_t p;
 192 ptr_t *opp;
 193 word lw;
 194 register word my_words_allocd;
 195 DCL_LOCK_STATE;
 196
 197     if (!SMALL_OBJ(lb)) {
 198         op = GC_generic_malloc(lb, k);
 199         if(0 != op) obj_link(op) = 0;
 200         return(op);
 201     }
 202     lw = ALIGNED_WORDS(lb);
 203     GC_INVOKE_FINALIZERS();
 204     DISABLE_SIGNALS();
 205     LOCK();
 206     opp = &(GC_obj_kinds[k].ok_freelist[lw]);
 207     if( (op = *opp) == 0 ) {
 208         if (!GC_is_initialized) {
 209             GC_init_inner();
 210         }
 211         op = GC_clear_stack(GC_allocobj(lw, k));
 212         if (op == 0) {
 213             UNLOCK();
 214             ENABLE_SIGNALS();
 215             op = (*GC_oom_fn)(lb);
 216             if(0 != op) obj_link(op) = 0;
 217             return(op);
 218         }
 219     }
 220     *opp = 0;
 221     my_words_allocd = 0;
 222     for (p = op; p != 0; p = obj_link(p)) {
 223         my_words_allocd += lw;
 224         if (my_words_allocd >= BODY_SZ) {
 225             *opp = obj_link(p);
 226             obj_link(p) = 0;
 227             break;
 228         }
 229     }
 230     GC_words_allocd += my_words_allocd;
 231
 232 out:
 233     UNLOCK();
 234     ENABLE_SIGNALS();
 235     return(op);
 236
 237 }
 238
 239 void * GC_malloc_many(size_t lb)
 240 {
 241     return(GC_generic_malloc_many(lb, NORMAL));
 242 }
 243
 244 /* Note that the "atomic" version of this would be unsafe, since the    */
 245 /* links would not be seen by the collector.                            */
 246 # endif
 247
 248 /* Allocate lb bytes of pointerful, traced, but not collectable data */
 249 # ifdef __STDC__
 250     GC_PTR GC_malloc_uncollectable(size_t lb)
 251 # else
 252     GC_PTR GC_malloc_uncollectable(lb)
 253     size_t lb;
 254 # endif
 255 {
 256 register ptr_t op;
 257 register ptr_t *opp;
 258 register word lw;
 259 DCL_LOCK_STATE;
 260
 261     if( SMALL_OBJ(lb) ) {
 262 #       ifdef MERGE_SIZES
 263 #         ifdef ADD_BYTE_AT_END
 264             if (lb != 0) lb--;
 265                   /* We don't need the extra byte, since this won't be  */
 266                   /* collected anyway.                                  */
 267 #         endif
 268           lw = GC_size_map[lb];
 269 #       else
 270           lw = ALIGNED_WORDS(lb);
 271 #       endif
 272         opp = &(GC_uobjfreelist[lw]);
 273         FASTLOCK();
 274         if( FASTLOCK_SUCCEEDED() && (op = *opp) != 0 ) {
 275             /* See above comment on signals.    */
 276             *opp = obj_link(op);
 277             obj_link(op) = 0;
 278             GC_words_allocd += lw;
 279             /* Mark bit ws already set on free list.  It will be        */
 280             /* cleared only temporarily during a collection, as a       */
 281             /* result of the normal free list mark bit clearing.        */
 282             GC_non_gc_bytes += WORDS_TO_BYTES(lw);
 283             FASTUNLOCK();
 284             return((GC_PTR) op);
 285         }
 286         FASTUNLOCK();
 287         op = (ptr_t)GC_generic_malloc((word)lb, UNCOLLECTABLE);
 288     } else {
 289         op = (ptr_t)GC_generic_malloc((word)lb, UNCOLLECTABLE);
 290     }
 291     if (0 == op) return(0);
 292     /* We don't need the lock here, since we have an undisguised        */
 293     /* pointer.  We do need to hold the lock while we adjust            */
 294     /* mark bits.                                                       */
 295     {
 296         register struct hblk * h;
 297
 298         h = HBLKPTR(op);
 299         lw = HDR(h) -> hb_sz;
 300
 301         DISABLE_SIGNALS();
 302         LOCK();
 303         GC_set_mark_bit(op);
 304         GC_non_gc_bytes += WORDS_TO_BYTES(lw);
 305         UNLOCK();
 306         ENABLE_SIGNALS();
 307         return((GC_PTR) op);
 308     }
 309 }
 310
 311 # ifdef ATOMIC_UNCOLLECTABLE
 312 /* Allocate lb bytes of pointerfree, untraced, uncollectable data       */
 313 /* This is normally roughly equivalent to the system malloc.            */
 314 /* But it may be useful if malloc is redefined.                         */
 315 # ifdef __STDC__
 316     GC_PTR GC_malloc_atomic_uncollectable(size_t lb)
 317 # else
 318     GC_PTR GC_malloc_atomic_uncollectable(lb)
 319     size_t lb;
 320 # endif
 321 {
 322 register ptr_t op;
 323 register ptr_t *opp;
 324 register word lw;
 325 DCL_LOCK_STATE;
 326
 327     if( SMALL_OBJ(lb) ) {
 328 #       ifdef MERGE_SIZES
 329 #         ifdef ADD_BYTE_AT_END
 330             if (lb != 0) lb--;
 331                   /* We don't need the extra byte, since this won't be  */
 332                   /* collected anyway.                                  */
 333 #         endif
 334           lw = GC_size_map[lb];
 335 #       else
 336           lw = ALIGNED_WORDS(lb);
 337 #       endif
 338         opp = &(GC_auobjfreelist[lw]);
 339         FASTLOCK();
 340         if( FASTLOCK_SUCCEEDED() && (op = *opp) != 0 ) {
 341             /* See above comment on signals.    */
 342             *opp = obj_link(op);
 343             obj_link(op) = 0;
 344             GC_words_allocd += lw;
 345             /* Mark bit was already set while object was on free list. */
 346             GC_non_gc_bytes += WORDS_TO_BYTES(lw);
 347             FASTUNLOCK();
 348             return((GC_PTR) op);
 349         }
 350         FASTUNLOCK();
 351         op = (ptr_t)GC_generic_malloc((word)lb, AUNCOLLECTABLE);
 352     } else {
 353         op = (ptr_t)GC_generic_malloc((word)lb, AUNCOLLECTABLE);
 354     }
 355     if (0 == op) return(0);
 356     /* We don't need the lock here, since we have an undisguised        */
 357     /* pointer.  We do need to hold the lock while we adjust            */
 358     /* mark bits.                                                       */
 359     {
 360         register struct hblk * h;
 361
 362         h = HBLKPTR(op);
 363         lw = HDR(h) -> hb_sz;
 364
 365         DISABLE_SIGNALS();
 366         LOCK();
 367         GC_set_mark_bit(op);
 368         GC_non_gc_bytes += WORDS_TO_BYTES(lw);
 369         UNLOCK();
 370         ENABLE_SIGNALS();
 371         return((GC_PTR) op);
 372     }
 373 }
 374
 375 #endif /* ATOMIC_UNCOLLECTABLE */