mirror of
https://github.com/mozilla/gecko-dev.git
synced 2024-11-01 06:35:42 +00:00
296 lines
8.0 KiB
C
296 lines
8.0 KiB
C
/*
|
|
* 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.
|
|
*
|
|
* 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.
|
|
*/
|
|
|
|
/*
|
|
* This implements:
|
|
* 1. allocation of heap block headers
|
|
* 2. A map from addresses to heap block addresses to heap block headers
|
|
*
|
|
* Access speed is crucial. We implement an index structure based on a 2
|
|
* level tree.
|
|
*/
|
|
|
|
# include "gc_priv.h"
|
|
|
|
bottom_index * GC_all_bottom_indices = 0;
|
|
|
|
/* Non-macro version of header location routine */
|
|
hdr * GC_find_header(h)
|
|
ptr_t h;
|
|
{
|
|
# ifdef HASH_TL
|
|
register hdr * result;
|
|
GET_HDR(h, result);
|
|
return(result);
|
|
# else
|
|
return(HDR_INNER(h));
|
|
# endif
|
|
}
|
|
|
|
/* Routines to dynamically allocate collector data structures that will */
|
|
/* never be freed. */
|
|
|
|
static ptr_t scratch_free_ptr = 0;
|
|
|
|
ptr_t GC_scratch_end_ptr = 0;
|
|
|
|
ptr_t GC_scratch_last_end_ptr = 0;
|
|
/* End point of last obtained scratch area */
|
|
|
|
ptr_t GC_scratch_alloc(bytes)
|
|
register word bytes;
|
|
{
|
|
register ptr_t result = scratch_free_ptr;
|
|
|
|
# ifdef ALIGN_DOUBLE
|
|
# define GRANULARITY (2 * sizeof(word))
|
|
# else
|
|
# define GRANULARITY sizeof(word)
|
|
# endif
|
|
bytes += GRANULARITY-1;
|
|
bytes &= ~(GRANULARITY-1);
|
|
scratch_free_ptr += bytes;
|
|
if (scratch_free_ptr <= GC_scratch_end_ptr) {
|
|
return(result);
|
|
}
|
|
{
|
|
word bytes_to_get = MINHINCR * HBLKSIZE;
|
|
|
|
if (bytes_to_get <= bytes) {
|
|
/* Undo the damage, and get memory directly */
|
|
bytes_to_get = bytes;
|
|
# ifdef USE_MMAP
|
|
bytes_to_get += GC_page_size - 1;
|
|
bytes_to_get &= ~(GC_page_size - 1);
|
|
# endif
|
|
result = (ptr_t)GET_MEM(bytes_to_get);
|
|
scratch_free_ptr -= bytes;
|
|
GC_scratch_last_end_ptr = result + bytes;
|
|
return(result);
|
|
}
|
|
result = (ptr_t)GET_MEM(bytes_to_get);
|
|
if (result == 0) {
|
|
# ifdef PRINTSTATS
|
|
GC_printf0("Out of memory - trying to allocate less\n");
|
|
# endif
|
|
scratch_free_ptr -= bytes;
|
|
bytes_to_get = bytes;
|
|
# ifdef USE_MMAP
|
|
bytes_to_get += GC_page_size - 1;
|
|
bytes_to_get &= ~(GC_page_size - 1);
|
|
# endif
|
|
return((ptr_t)GET_MEM(bytes_to_get));
|
|
}
|
|
scratch_free_ptr = result;
|
|
GC_scratch_end_ptr = scratch_free_ptr + bytes_to_get;
|
|
GC_scratch_last_end_ptr = GC_scratch_end_ptr;
|
|
return(GC_scratch_alloc(bytes));
|
|
}
|
|
}
|
|
|
|
static hdr * hdr_free_list = 0;
|
|
|
|
/* Return an uninitialized header */
|
|
static hdr * alloc_hdr()
|
|
{
|
|
register hdr * result;
|
|
|
|
if (hdr_free_list == 0) {
|
|
result = (hdr *) GC_scratch_alloc((word)(sizeof(hdr)));
|
|
} else {
|
|
result = hdr_free_list;
|
|
hdr_free_list = (hdr *) (result -> hb_next);
|
|
}
|
|
return(result);
|
|
}
|
|
|
|
static void free_hdr(hhdr)
|
|
hdr * hhdr;
|
|
{
|
|
hhdr -> hb_next = (struct hblk *) hdr_free_list;
|
|
hdr_free_list = hhdr;
|
|
}
|
|
|
|
void GC_init_headers()
|
|
{
|
|
register unsigned i;
|
|
|
|
GC_all_nils = (bottom_index *)GC_scratch_alloc((word)sizeof(bottom_index));
|
|
BZERO(GC_all_nils, sizeof(bottom_index));
|
|
for (i = 0; i < TOP_SZ; i++) {
|
|
GC_top_index[i] = GC_all_nils;
|
|
}
|
|
}
|
|
|
|
/* Make sure that there is a bottom level index block for address addr */
|
|
/* Return FALSE on failure. */
|
|
static GC_bool get_index(addr)
|
|
register word addr;
|
|
{
|
|
register word hi =
|
|
(word)(addr) >> (LOG_BOTTOM_SZ + LOG_HBLKSIZE);
|
|
register bottom_index * r;
|
|
register bottom_index * p;
|
|
register bottom_index ** prev;
|
|
# ifdef HASH_TL
|
|
register unsigned i = TL_HASH(hi);
|
|
register bottom_index * old;
|
|
|
|
old = p = GC_top_index[i];
|
|
while(p != GC_all_nils) {
|
|
if (p -> key == hi) return(TRUE);
|
|
p = p -> hash_link;
|
|
}
|
|
r = (bottom_index*)GC_scratch_alloc((word)(sizeof (bottom_index)));
|
|
if (r == 0) return(FALSE);
|
|
BZERO(r, sizeof (bottom_index));
|
|
r -> hash_link = old;
|
|
GC_top_index[i] = r;
|
|
# else
|
|
if (GC_top_index[hi] != GC_all_nils) return(TRUE);
|
|
r = (bottom_index*)GC_scratch_alloc((word)(sizeof (bottom_index)));
|
|
if (r == 0) return(FALSE);
|
|
GC_top_index[hi] = r;
|
|
BZERO(r, sizeof (bottom_index));
|
|
# endif
|
|
r -> key = hi;
|
|
/* Add it to the list of bottom indices */
|
|
prev = &GC_all_bottom_indices;
|
|
while ((p = *prev) != 0 && p -> key < hi) prev = &(p -> asc_link);
|
|
r -> asc_link = p;
|
|
*prev = r;
|
|
return(TRUE);
|
|
}
|
|
|
|
/* Install a header for block h. */
|
|
/* The header is uninitialized. */
|
|
/* Returns FALSE on failure. */
|
|
GC_bool GC_install_header(h)
|
|
register struct hblk * h;
|
|
{
|
|
hdr * result;
|
|
|
|
if (!get_index((word) h)) return(FALSE);
|
|
result = alloc_hdr();
|
|
SET_HDR(h, result);
|
|
return(result != 0);
|
|
}
|
|
|
|
/* Set up forwarding counts for block h of size sz */
|
|
GC_bool GC_install_counts(h, sz)
|
|
register struct hblk * h;
|
|
register word sz; /* bytes */
|
|
{
|
|
register struct hblk * hbp;
|
|
register int i;
|
|
|
|
for (hbp = h; (char *)hbp < (char *)h + sz; hbp += BOTTOM_SZ) {
|
|
if (!get_index((word) hbp)) return(FALSE);
|
|
}
|
|
if (!get_index((word)h + sz - 1)) return(FALSE);
|
|
for (hbp = h + 1; (char *)hbp < (char *)h + sz; hbp += 1) {
|
|
i = HBLK_PTR_DIFF(hbp, h);
|
|
SET_HDR(hbp, (hdr *)(i > MAX_JUMP? MAX_JUMP : i));
|
|
}
|
|
return(TRUE);
|
|
}
|
|
|
|
/* Remove the header for block h */
|
|
void GC_remove_header(h)
|
|
register struct hblk * h;
|
|
{
|
|
hdr ** ha;
|
|
|
|
GET_HDR_ADDR(h, ha);
|
|
free_hdr(*ha);
|
|
*ha = 0;
|
|
}
|
|
|
|
/* Remove forwarding counts for h */
|
|
void GC_remove_counts(h, sz)
|
|
register struct hblk * h;
|
|
register word sz; /* bytes */
|
|
{
|
|
register struct hblk * hbp;
|
|
|
|
for (hbp = h+1; (char *)hbp < (char *)h + sz; hbp += 1) {
|
|
SET_HDR(hbp, 0);
|
|
}
|
|
}
|
|
|
|
/* Apply fn to all allocated blocks */
|
|
/*VARARGS1*/
|
|
void GC_apply_to_all_blocks(fn, client_data)
|
|
void (*fn)(/* struct hblk *h, word client_data */);
|
|
word client_data;
|
|
{
|
|
register int j;
|
|
register bottom_index * index_p;
|
|
|
|
for (index_p = GC_all_bottom_indices; index_p != 0;
|
|
index_p = index_p -> asc_link) {
|
|
for (j = BOTTOM_SZ-1; j >= 0;) {
|
|
if (!IS_FORWARDING_ADDR_OR_NIL(index_p->index[j])) {
|
|
if (index_p->index[j]->hb_map != GC_invalid_map) {
|
|
(*fn)(((struct hblk *)
|
|
(((index_p->key << LOG_BOTTOM_SZ) + (word)j)
|
|
<< LOG_HBLKSIZE)),
|
|
client_data);
|
|
}
|
|
j--;
|
|
} else if (index_p->index[j] == 0) {
|
|
j--;
|
|
} else {
|
|
j -= (word)(index_p->index[j]);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Get the next valid block whose address is at least h */
|
|
/* Return 0 if there is none. */
|
|
struct hblk * GC_next_block(h)
|
|
struct hblk * h;
|
|
{
|
|
register bottom_index * bi;
|
|
register word j = ((word)h >> LOG_HBLKSIZE) & (BOTTOM_SZ-1);
|
|
|
|
GET_BI(h, bi);
|
|
if (bi == GC_all_nils) {
|
|
register word hi = (word)h >> (LOG_BOTTOM_SZ + LOG_HBLKSIZE);
|
|
bi = GC_all_bottom_indices;
|
|
while (bi != 0 && bi -> key < hi) bi = bi -> asc_link;
|
|
j = 0;
|
|
}
|
|
while(bi != 0) {
|
|
while (j < BOTTOM_SZ) {
|
|
if (IS_FORWARDING_ADDR_OR_NIL(bi -> index[j])) {
|
|
j++;
|
|
} else {
|
|
if (bi->index[j]->hb_map != GC_invalid_map) {
|
|
return((struct hblk *)
|
|
(((bi -> key << LOG_BOTTOM_SZ) + j)
|
|
<< LOG_HBLKSIZE));
|
|
} else {
|
|
j += divHBLKSZ(bi->index[j] -> hb_sz);
|
|
}
|
|
}
|
|
}
|
|
j = 0;
|
|
bi = bi -> asc_link;
|
|
}
|
|
return(0);
|
|
}
|