alloc.c

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		        (unsigned long)GC_atomic_in_use);
	}
        if (GC_is_full_gc)  {
	    GC_used_heap_size_after_full = USED_HEAP_SIZE;
	    GC_need_full_gc = FALSE;
	} else {
	    GC_need_full_gc =
		 USED_HEAP_SIZE - GC_used_heap_size_after_full
		 > min_bytes_allocd();
	}

    if (GC_print_stats == VERBOSE) {
	GC_log_printf(
		  "Immediately reclaimed %ld bytes in heap of size %lu bytes",
	          (long)GC_bytes_found,
	          (unsigned long)GC_heapsize);
#	ifdef USE_MUNMAP
	  GC_log_printf("(%lu unmapped)", (unsigned long)GC_unmapped_bytes);
#	endif
	GC_log_printf("\n");
    }

    /* Reset or increment counters for next cycle */
      GC_n_attempts = 0;
      GC_is_full_gc = FALSE;
      GC_bytes_allocd_before_gc += GC_bytes_allocd;
      GC_non_gc_bytes_at_gc = GC_non_gc_bytes;
      GC_bytes_allocd = 0;
      GC_bytes_freed = 0;
      GC_finalizer_bytes_freed = 0;
      
#   ifdef USE_MUNMAP
      GC_unmap_old();
#   endif
    if (GC_print_stats) {
	GET_TIME(done_time);
	GC_log_printf("Finalize + initiate sweep took %lu + %lu msecs\n",
	              MS_TIME_DIFF(finalize_time,start_time),
	              MS_TIME_DIFF(done_time,finalize_time));
    }
}

/* Externally callable routine to invoke full, stop-world collection */
int GC_try_to_collect(GC_stop_func stop_func)
{
    int result;
    DCL_LOCK_STATE;
    
    if (!GC_is_initialized) GC_init();
    if (GC_debugging_started) GC_print_all_smashed();
    GC_INVOKE_FINALIZERS();
    LOCK();
    ENTER_GC();
    if (!GC_is_initialized) GC_init_inner();
    /* Minimize junk left in my registers */
      GC_noop(0,0,0,0,0,0);
    result = (int)GC_try_to_collect_inner(stop_func);
    EXIT_GC();
    UNLOCK();
    if(result) {
        if (GC_debugging_started) GC_print_all_smashed();
        GC_INVOKE_FINALIZERS();
    }
    return(result);
}

void GC_gcollect(void)
{
    (void)GC_try_to_collect(GC_never_stop_func);
    if (GC_have_errors) GC_print_all_errors();
}

word GC_n_heap_sects = 0;	/* Number of sections currently in heap. */

/*
 * Use the chunk of memory starting at p of size bytes as part of the heap.
 * Assumes p is HBLKSIZE aligned, and bytes is a multiple of HBLKSIZE.
 */
void GC_add_to_heap(struct hblk *p, size_t bytes)
{
    hdr * phdr;
    
    if (GC_n_heap_sects >= MAX_HEAP_SECTS) {
    	ABORT("Too many heap sections: Increase MAXHINCR or MAX_HEAP_SECTS");
    }
    phdr = GC_install_header(p);
    if (0 == phdr) {
    	/* This is extremely unlikely. Can't add it.  This will		*/
    	/* almost certainly result in a	0 return from the allocator,	*/
    	/* which is entirely appropriate.				*/
    	return;
    }
    GC_heap_sects[GC_n_heap_sects].hs_start = (ptr_t)p;
    GC_heap_sects[GC_n_heap_sects].hs_bytes = bytes;
    GC_n_heap_sects++;
    phdr -> hb_sz = bytes;
    phdr -> hb_flags = 0;
    GC_freehblk(p);
    GC_heapsize += bytes;
    if ((ptr_t)p <= (ptr_t)GC_least_plausible_heap_addr
        || GC_least_plausible_heap_addr == 0) {
        GC_least_plausible_heap_addr = (void *)((ptr_t)p - sizeof(word));
        	/* Making it a little smaller than necessary prevents	*/
        	/* us from getting a false hit from the variable	*/
        	/* itself.  There's some unintentional reflection	*/
        	/* here.						*/
    }
    if ((ptr_t)p + bytes >= (ptr_t)GC_greatest_plausible_heap_addr) {
        GC_greatest_plausible_heap_addr = (void *)((ptr_t)p + bytes);
    }
}

# if !defined(NO_DEBUGGING)
void GC_print_heap_sects(void)
{
    unsigned i;
    
    GC_printf("Total heap size: %lu\n", (unsigned long) GC_heapsize);
    for (i = 0; i < GC_n_heap_sects; i++) {
        ptr_t start = GC_heap_sects[i].hs_start;
        size_t len = GC_heap_sects[i].hs_bytes;
        struct hblk *h;
        unsigned nbl = 0;
        
    	GC_printf("Section %d from %p to %p ", i,
    		   start, start + len);
    	for (h = (struct hblk *)start; h < (struct hblk *)(start + len); h++) {
    	    if (GC_is_black_listed(h, HBLKSIZE)) nbl++;
    	}
    	GC_printf("%lu/%lu blacklisted\n", (unsigned long)nbl,
    		   (unsigned long)(len/HBLKSIZE));
    }
}
# endif

void * GC_least_plausible_heap_addr = (void *)ONES;
void * GC_greatest_plausible_heap_addr = 0;

static INLINE ptr_t GC_max(ptr_t x, ptr_t y)
{
    return(x > y? x : y);
}

static INLINE ptr_t GC_min(ptr_t x, ptr_t y)
{
    return(x < y? x : y);
}

void GC_set_max_heap_size(GC_word n)
{
    GC_max_heapsize = n;
}

GC_word GC_max_retries = 0;

/*
 * this explicitly increases the size of the heap.  It is used
 * internally, but may also be invoked from GC_expand_hp by the user.
 * The argument is in units of HBLKSIZE.
 * Tiny values of n are rounded up.
 * Returns FALSE on failure.
 */
GC_bool GC_expand_hp_inner(word n)
{
    word bytes;
    struct hblk * space;
    word expansion_slop;	/* Number of bytes by which we expect the */
    				/* heap to expand soon.			  */

    if (n < MINHINCR) n = MINHINCR;
    bytes = n * HBLKSIZE;
    /* Make sure bytes is a multiple of GC_page_size */
      {
	word mask = GC_page_size - 1;
	bytes += mask;
	bytes &= ~mask;
      }
    
    if (GC_max_heapsize != 0 && GC_heapsize + bytes > GC_max_heapsize) {
        /* Exceeded self-imposed limit */
        return(FALSE);
    }
    space = GET_MEM(bytes);
    if( space == 0 ) {
	if (GC_print_stats) {
	    GC_log_printf("Failed to expand heap by %ld bytes\n",
		          (unsigned long)bytes);
	}
	return(FALSE);
    }
    if (GC_print_stats) {
	GC_log_printf("Increasing heap size by %lu after %lu allocated bytes\n",
	              (unsigned long)bytes,
	              (unsigned long)GC_bytes_allocd);
    }
    expansion_slop = min_bytes_allocd() + 4*MAXHINCR*HBLKSIZE;
    if ((GC_last_heap_addr == 0 && !((word)space & SIGNB))
        || (GC_last_heap_addr != 0 && GC_last_heap_addr < (ptr_t)space)) {
        /* Assume the heap is growing up */
        GC_greatest_plausible_heap_addr =
            (void *)GC_max((ptr_t)GC_greatest_plausible_heap_addr,
                           (ptr_t)space + bytes + expansion_slop);
    } else {
        /* Heap is growing down */
        GC_least_plausible_heap_addr =
            (void *)GC_min((ptr_t)GC_least_plausible_heap_addr,
                           (ptr_t)space - expansion_slop);
    }
#   if defined(LARGE_CONFIG)
      if (((ptr_t)GC_greatest_plausible_heap_addr <= (ptr_t)space + bytes
           || (ptr_t)GC_least_plausible_heap_addr >= (ptr_t)space)
	  && GC_heapsize > 0) {
	/* GC_add_to_heap will fix this, but ... */
	WARN("Too close to address space limit: blacklisting ineffective\n", 0);
      }
#   endif
    GC_prev_heap_addr = GC_last_heap_addr;
    GC_last_heap_addr = (ptr_t)space;
    GC_add_to_heap(space, bytes);
    /* Force GC before we are likely to allocate past expansion_slop */
      GC_collect_at_heapsize =
         GC_heapsize + expansion_slop - 2*MAXHINCR*HBLKSIZE;
#     if defined(LARGE_CONFIG)
        if (GC_collect_at_heapsize < GC_heapsize /* wrapped */)
         GC_collect_at_heapsize = (word)(-1);
#     endif
    return(TRUE);
}

/* Really returns a bool, but it's externally visible, so that's clumsy. */
/* Arguments is in bytes.						*/
int GC_expand_hp(size_t bytes)
{
    int result;
    DCL_LOCK_STATE;
    
    LOCK();
    if (!GC_is_initialized) GC_init_inner();
    result = (int)GC_expand_hp_inner(divHBLKSZ((word)bytes));
    if (result) GC_requested_heapsize += bytes;
    UNLOCK();
    return(result);
}

unsigned GC_fail_count = 0;  
			/* How many consecutive GC/expansion failures?	*/
			/* Reset by GC_allochblk.			*/

GC_bool GC_collect_or_expand(word needed_blocks, GC_bool ignore_off_page)
{
    if (!GC_incremental && !GC_dont_gc &&
	((GC_dont_expand && GC_bytes_allocd > 0) || GC_should_collect())) {
      GC_gcollect_inner();
    } else {
      word blocks_to_get = GC_heapsize/(HBLKSIZE*GC_free_space_divisor)
      			   + needed_blocks;
      
      if (blocks_to_get > MAXHINCR) {
          word slop;
          
	  /* Get the minimum required to make it likely that we		*/
	  /* can satisfy the current request in the presence of black-	*/
	  /* listing.  This will probably be more than MAXHINCR.	*/
          if (ignore_off_page) {
              slop = 4;
          } else {
	      slop = 2*divHBLKSZ(BL_LIMIT);
	      if (slop > needed_blocks) slop = needed_blocks;
	  }
          if (needed_blocks + slop > MAXHINCR) {
              blocks_to_get = needed_blocks + slop;
          } else {
              blocks_to_get = MAXHINCR;
          }
      }
      if (!GC_expand_hp_inner(blocks_to_get)
        && !GC_expand_hp_inner(needed_blocks)) {
      	if (GC_fail_count++ < GC_max_retries) {
      	    WARN("Out of Memory!  Trying to continue ...\n", 0);
	    GC_gcollect_inner();
	} else {
#	    if !defined(AMIGA) || !defined(GC_AMIGA_FASTALLOC)
	      WARN("Out of Memory!  Returning NIL!\n", 0);
#	    endif
	    return(FALSE);
	}
      } else {
          if (GC_fail_count && GC_print_stats) {
	      GC_printf("Memory available again ...\n");
	  }
      }
    }
    return(TRUE);
}

/*
 * Make sure the object free list for size gran (in granules) is not empty.
 * Return a pointer to the first object on the free list.
 * The object MUST BE REMOVED FROM THE FREE LIST BY THE CALLER.
 * Assumes we hold the allocator lock and signals are disabled.
 *
 */
ptr_t GC_allocobj(size_t gran, int kind)
{
    void ** flh = &(GC_obj_kinds[kind].ok_freelist[gran]);
    GC_bool tried_minor = FALSE;
    
    if (gran == 0) return(0);

    while (*flh == 0) {
      ENTER_GC();
      /* Do our share of marking work */
        if(TRUE_INCREMENTAL) GC_collect_a_little_inner(1);
      /* Sweep blocks for objects of this size */
        GC_continue_reclaim(gran, kind);
      EXIT_GC();
      if (*flh == 0) {
        GC_new_hblk(gran, kind);
      }
      if (*flh == 0) {
        ENTER_GC();
	if (GC_incremental && GC_time_limit == GC_TIME_UNLIMITED
	    && ! tried_minor ) {
	    GC_collect_a_little_inner(1);
	    tried_minor = TRUE;
	} else {
          if (!GC_collect_or_expand((word)1,FALSE)) {
	    EXIT_GC();
	    return(0);
	  }
	}
	EXIT_GC();
      }
    }
    /* Successful allocation; reset failure count.	*/
    GC_fail_count = 0;
    
    return(*flh);
}