text: /*
   * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
   * Copyright (c) 1991-1994 by Xerox Corporation.  All rights reserved.
   * Copyright (c) 1996 by Silicon Graphics.  All rights reserved.
   * Copyright (c) 2000 by Hewlett-Packard Company.  All rights reserved.
   *
   * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
   * OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.
   *
   * Permission is hereby granted to use or copy this program
   * for any purpose,  provided the above notices are retained on all copies.
   * Permission to modify the code and to distribute modified code is granted,
   * provided the above notices are retained, and a notice that the code was
   * modified is included with the above copyright notice.
   */
  
  /*
   * These are extra allocation routines which are likely to be less
   * frequently used than those in malloc.c.  They are separate in the
   * hope that the .o file will be excluded from statically linked
   * executables.  We should probably break this up further.
   */
  
  #include <stdio.h>
  #include "private/gc_priv.h"
  
  extern ptr_t GC_clear_stack();  /* in misc.c, behaves like identity */
  void GC_extend_size_map();      /* in misc.c. */
  GC_bool GC_alloc_reclaim_list();	/* in malloc.c */
  
  /* Some externally visible but unadvertised variables to allow access to */
  /* free lists from inlined allocators without including gc_priv.h	 */
  /* or introducing dependencies on internal data structure layouts.	 */
  ptr_t * GC_CONST GC_objfreelist_ptr = GC_objfreelist;
  ptr_t * GC_CONST GC_aobjfreelist_ptr = GC_aobjfreelist;
  ptr_t * GC_CONST GC_uobjfreelist_ptr = GC_uobjfreelist;
  # ifdef ATOMIC_UNCOLLECTABLE
      ptr_t * GC_CONST GC_auobjfreelist_ptr = GC_auobjfreelist;
  # endif
  
  
  GC_PTR GC_generic_or_special_malloc(lb,knd)
  word lb;
  int knd;
  {
      switch(knd) {
  #     ifdef STUBBORN_ALLOC
  	case STUBBORN:
  	    return(GC_malloc_stubborn((size_t)lb));
  #     endif
  	case PTRFREE:
  	    return(GC_malloc_atomic((size_t)lb));
  	case NORMAL:
  	    return(GC_malloc((size_t)lb));
  	case UNCOLLECTABLE:
  	    return(GC_malloc_uncollectable((size_t)lb));
  #       ifdef ATOMIC_UNCOLLECTABLE
  	  case AUNCOLLECTABLE:
  	    return(GC_malloc_atomic_uncollectable((size_t)lb));
  #	endif /* ATOMIC_UNCOLLECTABLE */
  	default:
  	    return(GC_generic_malloc(lb,knd));
      }
  }
  
  
  /* Change the size of the block pointed to by p to contain at least   */
  /* lb bytes.  The object may be (and quite likely will be) moved.     */
  /* The kind (e.g. atomic) is the same as that of the old.	      */
  /* Shrinking of large blocks is not implemented well.                 */
  # ifdef __STDC__
      GC_PTR GC_realloc(GC_PTR p, size_t lb)
  # else
      GC_PTR GC_realloc(p,lb)
      GC_PTR p;
      size_t lb;
  # endif
  {
  register struct hblk * h;
  register hdr * hhdr;
  register word sz;	 /* Current size in bytes	*/
  register word orig_sz;	 /* Original sz in bytes	*/
  int obj_kind;
  
      if (p == 0) return(GC_malloc(lb));	/* Required by ANSI */
      h = HBLKPTR(p);
      hhdr = HDR(h);
      sz = hhdr -> hb_sz;
      obj_kind = hhdr -> hb_obj_kind;
      sz = WORDS_TO_BYTES(sz);
      orig_sz = sz;
  
      if (sz > MAXOBJBYTES) {
  	/* Round it up to the next whole heap block */
  	  register word descr;
  	  
  	  sz = (sz+HBLKSIZE-1) & (~HBLKMASK);
  	  hhdr -> hb_sz = BYTES_TO_WORDS(sz);
  	  descr = GC_obj_kinds[obj_kind].ok_descriptor;
            if (GC_obj_kinds[obj_kind].ok_relocate_descr) descr += sz;
            hhdr -> hb_descr = descr;
  	  if (IS_UNCOLLECTABLE(obj_kind)) GC_non_gc_bytes += (sz - orig_sz);
  	  /* Extra area is already cleared by GC_alloc_large_and_clear. */
      }
      if (ADD_SLOP(lb) <= sz) {
  	if (lb >= (sz >> 1)) {
  #	    ifdef STUBBORN_ALLOC
  	        if (obj_kind == STUBBORN) GC_change_stubborn(p);
  #	    endif
  	    if (orig_sz > lb) {
  	      /* Clear unneeded part of object to avoid bogus pointer */
  	      /* tracing.					      */
  	      /* Safe for stubborn objects.			      */
  	        BZERO(((ptr_t)p) + lb, orig_sz - lb);
  	    }
  	    return(p);
  	} else {
  	    /* shrink */
  	      GC_PTR result =
  	      		GC_generic_or_special_malloc((word)lb, obj_kind);
  
  	      if (result == 0) return(0);
  	          /* Could also return original object.  But this 	*/
  	          /* gives the client warning of imminent disaster.	*/
  	      BCOPY(p, result, lb);
  #	      ifndef IGNORE_FREE
  	        GC_free(p);
  #	      endif
  	      return(result);
  	}
      } else {
  	/* grow */
  	  GC_PTR result =
  	  	GC_generic_or_special_malloc((word)lb, obj_kind);
  
  	  if (result == 0) return(0);
  	  BCOPY(p, result, sz);
  #	  ifndef IGNORE_FREE
  	    GC_free(p);
  #	  endif
  	  return(result);
      }
  }
  
  # if defined(REDIRECT_MALLOC) || defined(REDIRECT_REALLOC)
  # ifdef __STDC__
      GC_PTR realloc(GC_PTR p, size_t lb)
  # else
      GC_PTR realloc(p,lb)
      GC_PTR p;
      size_t lb;
  # endif
    {
  #   ifdef REDIRECT_REALLOC
        return(REDIRECT_REALLOC(p, lb));
  #   else
        return(GC_realloc(p, lb));
  #   endif
    }
  # endif /* REDIRECT_MALLOC */
  
  
  /* The same thing, except caller does not hold allocation lock.	*/
  /* We avoid holding allocation lock while we clear memory.	*/
  ptr_t GC_generic_malloc_ignore_off_page(lb, k)
  register size_t lb;
  register int k;
  {
      register ptr_t result;
      word lw;
      word n_blocks;
      GC_bool init;
      DCL_LOCK_STATE;
      
      if (SMALL_OBJ(lb))
          return(GC_generic_malloc((word)lb, k));
      lw = ROUNDED_UP_WORDS(lb);
      n_blocks = OBJ_SZ_TO_BLOCKS(lw);
      init = GC_obj_kinds[k].ok_init;
      GC_INVOKE_FINALIZERS();
      DISABLE_SIGNALS();
      LOCK();
      result = (ptr_t)GC_alloc_large(lw, k, IGNORE_OFF_PAGE);
      if (0 != result) {
          if (GC_debugging_started) {
  	    BZERO(result, n_blocks * HBLKSIZE);
          } else {
  #           ifdef THREADS
  	      /* Clear any memory that might be used for GC descriptors */
  	      /* before we release the lock.			      */
  	        ((word *)result)[0] = 0;
  	        ((word *)result)[1] = 0;
  	        ((word *)result)[lw-1] = 0;
  	        ((word *)result)[lw-2] = 0;
  #	    endif
          }
      }
      GC_words_allocd += lw;
      UNLOCK();
      ENABLE_SIGNALS();
      if (0 == result) {
          return((*GC_oom_fn)(lb));
      } else {
      	if (init & !GC_debugging_started) {
  	    BZERO(result, n_blocks * HBLKSIZE);
          }
          return(result);
      }
  }
  
  # if defined(__STDC__) || defined(__cplusplus)
    void * GC_malloc_ignore_off_page(size_t lb)
  # else
    char * GC_malloc_ignore_off_page(lb)
    register size_t lb;
  # endif
  {
      return((GC_PTR)GC_generic_malloc_ignore_off_page(lb, NORMAL));
  }
  
  # if defined(__STDC__) || defined(__cplusplus)
    void * GC_malloc_atomic_ignore_off_page(size_t lb)
  # else
    char * GC_malloc_atomic_ignore_off_page(lb)
    register size_t lb;
  # endif
  {
      return((GC_PTR)GC_generic_malloc_ignore_off_page(lb, PTRFREE));
  }
  
  /* Increment GC_words_allocd from code that doesn't have direct access 	*/
  /* to GC_arrays.							*/
  # ifdef __STDC__
  void GC_incr_words_allocd(size_t n)
  {
      GC_words_allocd += n;
  }
  
  /* The same for GC_mem_freed.				*/
  void GC_incr_mem_freed(size_t n)
  {
      GC_mem_freed += n;
  }
  # endif /* __STDC__ */
  
  /* Analogous to the above, but assumes a small object size, and 	*/
  /* bypasses MERGE_SIZES mechanism.  Used by gc_inline.h.		*/
  ptr_t GC_generic_malloc_words_small_inner(lw, k)
  register word lw;
  register int k;
  {
  register ptr_t op;
  register ptr_t *opp;
  register struct obj_kind * kind = GC_obj_kinds + k;
  
      opp = &(kind -> ok_freelist[lw]);
      if( (op = *opp) == 0 ) {
          if (!GC_is_initialized) {
              GC_init_inner();
          }
  	if (kind -> ok_reclaim_list != 0 || GC_alloc_reclaim_list(kind)) {
  	    op = GC_clear_stack(GC_allocobj((word)lw, k));
  	}
  	if (op == 0) {
  	    UNLOCK();
  	    ENABLE_SIGNALS();
  	    return ((*GC_oom_fn)(WORDS_TO_BYTES(lw)));
  	}
      }
      *opp = obj_link(op);
      obj_link(op) = 0;
      GC_words_allocd += lw;
      return((ptr_t)op);
  }
  
  /* Analogous to the above, but assumes a small object size, and 	*/
  /* bypasses MERGE_SIZES mechanism.  Used by gc_inline.h.		*/
  #ifdef __STDC__
       ptr_t GC_generic_malloc_words_small(size_t lw, int k)
  #else 
       ptr_t GC_generic_malloc_words_small(lw, k)
       register word lw;
       register int k;
  #endif
  {
  register ptr_t op;
  DCL_LOCK_STATE;
  
      GC_INVOKE_FINALIZERS();
      DISABLE_SIGNALS();
      LOCK();
      op = GC_generic_malloc_words_small_inner(lw, k);
      UNLOCK();
      ENABLE_SIGNALS();
      return((ptr_t)op);
  }
  
  #if defined(THREADS) && !defined(SRC_M3)
  
  extern signed_word GC_mem_found;   /* Protected by GC lock.  */
  
  #ifdef PARALLEL_MARK
  volatile signed_word GC_words_allocd_tmp = 0;
                          /* Number of words of memory allocated since    */
                          /* we released the GC lock.  Instead of         */
                          /* reacquiring the GC lock just to add this in, */
                          /* we add it in the next time we reacquire      */
                          /* the lock.  (Atomically adding it doesn't     */
                          /* work, since we would have to atomically      */
                          /* update it in GC_malloc, which is too         */
                          /* expensive.                                   */
  #endif /* PARALLEL_MARK */
  
  /* See reclaim.c: */
  extern ptr_t GC_reclaim_generic();
  
  /* Return a list of 1 or more objects of the indicated size, linked	*/
  /* through the first word in the object.  This has the advantage that	*/
  /* it acquires the allocation lock only once, and may greatly reduce	*/
  /* time wasted contending for the allocation lock.  Typical usage would */
  /* be in a thread that requires many items of the same size.  It would	*/
  /* keep its own free list in thread-local storage, and call		*/
  /* GC_malloc_many or friends to replenish it.  (We do not round up	*/
  /* object sizes, since a call indicates the intention to consume many	*/
  /* objects of exactly this size.)					*/
  /* We return the free-list by assigning it to *result, since it is	*/
  /* not safe to return, e.g. a linked list of pointer-free objects,	*/
  /* since the collector would not retain the entire list if it were 	*/
  /* invoked just as we were returning.					*/
  /* Note that the client should usually clear the link field.		*/
  void GC_generic_malloc_many(lb, k, result)
  register word lb;
  register int k;
  ptr_t *result;
  {
  ptr_t op;
  ptr_t p;
  ptr_t *opp;
  word lw;
  word my_words_allocd = 0;
  struct obj_kind * ok = &(GC_obj_kinds[k]);
  DCL_LOCK_STATE;
  
  #   if defined(GATHERSTATS) || defined(PARALLEL_MARK)
  #     define COUNT_ARG , &my_words_allocd
  #   else
  #     define COUNT_ARG
  #     define NEED_TO_COUNT
  #   endif
      if (!SMALL_OBJ(lb)) {
          op = GC_generic_malloc(lb, k);
          if(0 != op) obj_link(op) = 0;
  	*result = op;
          return;
      }
      lw = ALIGNED_WORDS(lb);
      GC_INVOKE_FINALIZERS();
      DISABLE_SIGNALS();
      LOCK();
      if (!GC_is_initialized) GC_init_inner();
      /* Do our share of marking work */
        if (GC_incremental && !GC_dont_gc) {
          ENTER_GC();
  	GC_collect_a_little_inner(1);
          EXIT_GC();
        }
      /* First see if we can reclaim a page of objects waiting to be */
      /* reclaimed.						   */
      {
  	struct hblk ** rlh = ok -> ok_reclaim_list;
  	struct hblk * hbp;
  	hdr * hhdr;
  
  	rlh += lw;
      	while ((hbp = *rlh) != 0) {
              hhdr = HDR(hbp);
              *rlh = hhdr -> hb_next;
  #	    ifdef PARALLEL_MARK
  		{
  		  signed_word my_words_allocd_tmp = GC_words_allocd_tmp;
  
  		  GC_ASSERT(my_words_allocd_tmp >= 0);
  		  /* We only decrement it while holding the GC lock.	*/
  		  /* Thus we can't accidentally adjust it down in more	*/
  		  /* than one thread simultaneously.			*/
  		  if (my_words_allocd_tmp != 0) {
  		    (void)GC_atomic_add(
  				(volatile GC_word *)(&GC_words_allocd_tmp),
  				(GC_word)(-my_words_allocd_tmp));
  		    GC_words_allocd += my_words_allocd_tmp;
  		  }
  		}
  		GC_acquire_mark_lock();
  		++ GC_fl_builder_count;
  		UNLOCK();
  		ENABLE_SIGNALS();
  		GC_release_mark_lock();
  #	    endif
  	    op = GC_reclaim_generic(hbp, hhdr, lw,
  				    ok -> ok_init, 0 COUNT_ARG);
              if (op != 0) {
  #	      ifdef NEED_TO_COUNT
  		/* We are neither gathering statistics, nor marking in	*/
  		/* parallel.  Thus GC_reclaim_generic doesn't count	*/
  		/* for us.						*/
      		for (p = op; p != 0; p = obj_link(p)) {
          	  my_words_allocd += lw;
  		}
  #	      endif
  #	      if defined(GATHERSTATS)
  	        /* We also reclaimed memory, so we need to adjust 	*/
  	        /* that count.						*/
  		/* This should be atomic, so the results may be		*/
  		/* inaccurate.						*/
  		GC_mem_found += my_words_allocd;
  #	      endif
  #	      ifdef PARALLEL_MARK
  		*result = op;
  		(void)GC_atomic_add(
  				(volatile GC_word *)(&GC_words_allocd_tmp),
  				(GC_word)(my_words_allocd));
  		GC_acquire_mark_lock();
  		-- GC_fl_builder_count;
  		if (GC_fl_builder_count == 0) GC_notify_all_builder();
  		GC_release_mark_lock();
  		(void) GC_clear_stack(0);
  		return;
  #	      else
  	        GC_words_allocd += my_words_allocd;
  	        goto out;
  #	      endif
  	    }
  #	    ifdef PARALLEL_MARK
  	      GC_acquire_mark_lock();
  	      -- GC_fl_builder_count;
  	      if (GC_fl_builder_count == 0) GC_notify_all_builder();
  	      GC_release_mark_lock();
  	      DISABLE_SIGNALS();
  	      LOCK();
  	      /* GC lock is needed for reclaim list access.	We	*/
  	      /* must decrement fl_builder_count before reaquiring GC	*/
  	      /* lock.  Hopefully this path is rare.			*/
  #	    endif
      	}
      }
      /* Next try to use prefix of global free list if there is one.	*/
      /* We don't refill it, but we need to use it up before allocating	*/
      /* a new block ourselves.						*/
        opp = &(GC_obj_kinds[k].ok_freelist[lw]);
        if ( (op = *opp) != 0 ) {
  	*opp = 0;
          my_words_allocd = 0;
          for (p = op; p != 0; p = obj_link(p)) {
            my_words_allocd += lw;
            if (my_words_allocd >= BODY_SZ) {
              *opp = obj_link(p);
              obj_link(p) = 0;
              break;
  	  }
          }
  	GC_words_allocd += my_words_allocd;
  	goto out;
        }
      /* Next try to allocate a new block worth of objects of this size.	*/
      {
  	struct hblk *h = GC_allochblk(lw, k, 0);
  	if (h != 0) {
  	  if (IS_UNCOLLECTABLE(k)) GC_set_hdr_marks(HDR(h));
  	  GC_words_allocd += BYTES_TO_WORDS(HBLKSIZE)
  			       - BYTES_TO_WORDS(HBLKSIZE) % lw;
  #	  ifdef PARALLEL_MARK
  	    GC_acquire_mark_lock();
  	    ++ GC_fl_builder_count;
  	    UNLOCK();
  	    ENABLE_SIGNALS();
  	    GC_release_mark_lock();
  #	  endif
  
  	  op = GC_build_fl(h, lw, ok -> ok_init, 0);
  #	  ifdef PARALLEL_MARK
  	    *result = op;
  	    GC_acquire_mark_lock();
  	    -- GC_fl_builder_count;
  	    if (GC_fl_builder_count == 0) GC_notify_all_builder();
  	    GC_release_mark_lock();
  	    (void) GC_clear_stack(0);
  	    return;
  #	  else
  	    goto out;
  #	  endif
  	}
      }
      
      /* As a last attempt, try allocating a single object.  Note that	*/
      /* this may trigger a collection or expand the heap.		*/
        op = GC_generic_malloc_inner(lb, k);
        if (0 != op) obj_link(op) = 0;
      
    out:
      *result = op;
      UNLOCK();
      ENABLE_SIGNALS();
      (void) GC_clear_stack(0);
  }
  
  GC_PTR GC_malloc_many(size_t lb)
  {
      ptr_t result;
      GC_generic_malloc_many(lb, NORMAL, &result);
      return result;
  }
  
  /* Note that the "atomic" version of this would be unsafe, since the	*/
  /* links would not be seen by the collector.				*/
  # endif
  
  /* Allocate lb bytes of pointerful, traced, but not collectable data */
  # ifdef __STDC__
      GC_PTR GC_malloc_uncollectable(size_t lb)
  # else
      GC_PTR GC_malloc_uncollectable(lb)
      size_t lb;
  # endif
  {
  register ptr_t op;
  register ptr_t *opp;
  register word lw;
  DCL_LOCK_STATE;
  
      if( SMALL_OBJ(lb) ) {
  #       ifdef MERGE_SIZES
  	  if (EXTRA_BYTES != 0 && lb != 0) lb--;
  	    	  /* We don't need the extra byte, since this won't be	*/
  	    	  /* collected anyway.					*/
  	  lw = GC_size_map[lb];
  #	else
  	  lw = ALIGNED_WORDS(lb);
  #       endif
  	opp = &(GC_uobjfreelist[lw]);
  	FASTLOCK();
          if( FASTLOCK_SUCCEEDED() && (op = *opp) != 0 ) {
              /* See above comment on signals.	*/
              *opp = obj_link(op);
              obj_link(op) = 0;
              GC_words_allocd += lw;
              /* Mark bit ws already set on free list.  It will be	*/
  	    /* cleared only temporarily during a collection, as a 	*/
  	    /* result of the normal free list mark bit clearing.	*/
              GC_non_gc_bytes += WORDS_TO_BYTES(lw);
              FASTUNLOCK();
              return((GC_PTR) op);
          }
          FASTUNLOCK();
          op = (ptr_t)GC_generic_malloc((word)lb, UNCOLLECTABLE);
      } else {
  	op = (ptr_t)GC_generic_malloc((word)lb, UNCOLLECTABLE);
      }
      if (0 == op) return(0);
      /* We don't need the lock here, since we have an undisguised 	*/
      /* pointer.  We do need to hold the lock while we adjust		*/
      /* mark bits.							*/
      {
  	register struct hblk * h;
  	
  	h = HBLKPTR(op);
  	lw = HDR(h) -> hb_sz;
  	
  	DISABLE_SIGNALS();
  	LOCK();
  	GC_set_mark_bit(op);
  	GC_non_gc_bytes += WORDS_TO_BYTES(lw);
  	UNLOCK();
  	ENABLE_SIGNALS();
  	return((GC_PTR) op);
      }
  }
  
  # ifdef ATOMIC_UNCOLLECTABLE
  /* Allocate lb bytes of pointerfree, untraced, uncollectable data 	*/
  /* This is normally roughly equivalent to the system malloc.		*/
  /* But it may be useful if malloc is redefined.				*/
  # ifdef __STDC__
      GC_PTR GC_malloc_atomic_uncollectable(size_t lb)
  # else
      GC_PTR GC_malloc_atomic_uncollectable(lb)
      size_t lb;
  # endif
  {
  register ptr_t op;
  register ptr_t *opp;
  register word lw;
  DCL_LOCK_STATE;
  
      if( SMALL_OBJ(lb) ) {
  #       ifdef MERGE_SIZES
  	  if (EXTRA_BYTES != 0 && lb != 0) lb--;
  	    	  /* We don't need the extra byte, since this won't be	*/
  	    	  /* collected anyway.					*/
  	  lw = GC_size_map[lb];
  #	else
  	  lw = ALIGNED_WORDS(lb);
  #       endif
  	opp = &(GC_auobjfreelist[lw]);
  	FASTLOCK();
          if( FASTLOCK_SUCCEEDED() && (op = *opp) != 0 ) {
              /* See above comment on signals.	*/
              *opp = obj_link(op);
              obj_link(op) = 0;
              GC_words_allocd += lw;
  	    /* Mark bit was already set while object was on free list. */
              GC_non_gc_bytes += WORDS_TO_BYTES(lw);
              FASTUNLOCK();
              return((GC_PTR) op);
          }
          FASTUNLOCK();
          op = (ptr_t)GC_generic_malloc((word)lb, AUNCOLLECTABLE);
      } else {
  	op = (ptr_t)GC_generic_malloc((word)lb, AUNCOLLECTABLE);
      }
      if (0 == op) return(0);
      /* We don't need the lock here, since we have an undisguised 	*/
      /* pointer.  We do need to hold the lock while we adjust		*/
      /* mark bits.							*/
      {
  	register struct hblk * h;
  	
  	h = HBLKPTR(op);
  	lw = HDR(h) -> hb_sz;
  	
  	DISABLE_SIGNALS();
  	LOCK();
  	GC_set_mark_bit(op);
  	GC_non_gc_bytes += WORDS_TO_BYTES(lw);
  	UNLOCK();
  	ENABLE_SIGNALS();
  	return((GC_PTR) op);
      }
  }
  
  #endif /* ATOMIC_UNCOLLECTABLE */
  