mirror of
https://github.com/mozilla/gecko-dev.git
synced 2024-12-05 03:54:35 +00:00
522 lines
14 KiB
C
522 lines
14 KiB
C
/*
|
|
* Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
|
|
* Copyright (c) 1991-1994 by Xerox Corporation. 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.
|
|
*/
|
|
/* Boehm, October 9, 1995 1:06 pm PDT */
|
|
# include <stdio.h>
|
|
# include "gc_priv.h"
|
|
|
|
/* Data structure for list of root sets. */
|
|
/* We keep a hash table, so that we can filter out duplicate additions. */
|
|
/* Under Win32, we need to do a better job of filtering overlaps, so */
|
|
/* we resort to sequential search, and pay the price. */
|
|
/* This is really declared in gc_priv.h:
|
|
struct roots {
|
|
ptr_t r_start;
|
|
ptr_t r_end;
|
|
# ifndef MSWIN32
|
|
struct roots * r_next;
|
|
# endif
|
|
GC_bool r_tmp;
|
|
-- Delete before registering new dynamic libraries
|
|
};
|
|
|
|
struct roots GC_static_roots[MAX_ROOT_SETS];
|
|
*/
|
|
|
|
static int n_root_sets = 0;
|
|
|
|
/* GC_static_roots[0..n_root_sets) contains the valid root sets. */
|
|
|
|
# if !defined(NO_DEBUGGING)
|
|
/* For debugging: */
|
|
void GC_print_static_roots()
|
|
{
|
|
register int i;
|
|
size_t total = 0;
|
|
|
|
for (i = 0; i < n_root_sets; i++) {
|
|
GC_printf2("From 0x%lx to 0x%lx ",
|
|
(unsigned long) GC_static_roots[i].r_start,
|
|
(unsigned long) GC_static_roots[i].r_end);
|
|
if (GC_static_roots[i].r_tmp) {
|
|
GC_printf0(" (temporary)\n");
|
|
} else {
|
|
GC_printf0("\n");
|
|
}
|
|
total += GC_static_roots[i].r_end - GC_static_roots[i].r_start;
|
|
}
|
|
GC_printf1("Total size: %ld\n", (unsigned long) total);
|
|
if (GC_root_size != total) {
|
|
GC_printf1("GC_root_size incorrect: %ld!!\n",
|
|
(unsigned long) GC_root_size);
|
|
}
|
|
}
|
|
# endif /* NO_DEBUGGING */
|
|
|
|
/* Primarily for debugging support: */
|
|
/* Is the address p in one of the registered static */
|
|
/* root sections? */
|
|
GC_bool GC_is_static_root(p)
|
|
ptr_t p;
|
|
{
|
|
static int last_root_set = 0;
|
|
register int i;
|
|
|
|
|
|
if (p >= GC_static_roots[last_root_set].r_start
|
|
&& p < GC_static_roots[last_root_set].r_end) return(TRUE);
|
|
for (i = 0; i < n_root_sets; i++) {
|
|
if (p >= GC_static_roots[i].r_start
|
|
&& p < GC_static_roots[i].r_end) {
|
|
last_root_set = i;
|
|
return(TRUE);
|
|
}
|
|
}
|
|
return(FALSE);
|
|
}
|
|
|
|
#ifndef MSWIN32
|
|
/*
|
|
# define LOG_RT_SIZE 6
|
|
# define RT_SIZE (1 << LOG_RT_SIZE) -- Power of 2, may be != MAX_ROOT_SETS
|
|
|
|
struct roots * GC_root_index[RT_SIZE];
|
|
-- Hash table header. Used only to check whether a range is
|
|
-- already present.
|
|
-- really defined in gc_priv.h
|
|
*/
|
|
|
|
static int rt_hash(addr)
|
|
char * addr;
|
|
{
|
|
word result = (word) addr;
|
|
# if CPP_WORDSZ > 8*LOG_RT_SIZE
|
|
result ^= result >> 8*LOG_RT_SIZE;
|
|
# endif
|
|
# if CPP_WORDSZ > 4*LOG_RT_SIZE
|
|
result ^= result >> 4*LOG_RT_SIZE;
|
|
# endif
|
|
result ^= result >> 2*LOG_RT_SIZE;
|
|
result ^= result >> LOG_RT_SIZE;
|
|
result &= (RT_SIZE-1);
|
|
return(result);
|
|
}
|
|
|
|
/* Is a range starting at b already in the table? If so return a */
|
|
/* pointer to it, else NIL. */
|
|
struct roots * GC_roots_present(b)
|
|
char *b;
|
|
{
|
|
register int h = rt_hash(b);
|
|
register struct roots *p = GC_root_index[h];
|
|
|
|
while (p != 0) {
|
|
if (p -> r_start == (ptr_t)b) return(p);
|
|
p = p -> r_next;
|
|
}
|
|
return(FALSE);
|
|
}
|
|
|
|
/* Add the given root structure to the index. */
|
|
static void add_roots_to_index(p)
|
|
struct roots *p;
|
|
{
|
|
register int h = rt_hash(p -> r_start);
|
|
|
|
p -> r_next = GC_root_index[h];
|
|
GC_root_index[h] = p;
|
|
}
|
|
|
|
# else /* MSWIN32 */
|
|
|
|
# define add_roots_to_index(p)
|
|
|
|
# endif
|
|
|
|
|
|
|
|
|
|
word GC_root_size = 0;
|
|
|
|
void GC_add_roots(b, e)
|
|
char * b; char * e;
|
|
{
|
|
DCL_LOCK_STATE;
|
|
|
|
DISABLE_SIGNALS();
|
|
LOCK();
|
|
GC_add_roots_inner(b, e, FALSE);
|
|
UNLOCK();
|
|
ENABLE_SIGNALS();
|
|
}
|
|
|
|
/* Add [b,e) to the root set. Adding the same interval a second time */
|
|
/* is a moderately fast noop, and hence benign. We do not handle */
|
|
/* different but overlapping intervals efficiently. (We do handle */
|
|
/* them correctly.) */
|
|
/* Tmp specifies that the interval may be deleted before */
|
|
/* reregistering dynamic libraries. */
|
|
void GC_add_roots_inner(b, e, tmp)
|
|
char * b; char * e;
|
|
GC_bool tmp;
|
|
{
|
|
struct roots * old;
|
|
|
|
# ifdef MSWIN32
|
|
/* Spend the time to ensure that there are no overlapping */
|
|
/* or adjacent intervals. */
|
|
/* This could be done faster with e.g. a */
|
|
/* balanced tree. But the execution time here is */
|
|
/* virtually guaranteed to be dominated by the time it */
|
|
/* takes to scan the roots. */
|
|
{
|
|
register int i;
|
|
|
|
for (i = 0; i < n_root_sets; i++) {
|
|
old = GC_static_roots + i;
|
|
if ((ptr_t)b <= old -> r_end && (ptr_t)e >= old -> r_start) {
|
|
if ((ptr_t)b < old -> r_start) {
|
|
old -> r_start = (ptr_t)b;
|
|
GC_root_size += (old -> r_start - (ptr_t)b);
|
|
}
|
|
if ((ptr_t)e > old -> r_end) {
|
|
old -> r_end = (ptr_t)e;
|
|
GC_root_size += ((ptr_t)e - old -> r_end);
|
|
}
|
|
old -> r_tmp &= tmp;
|
|
break;
|
|
}
|
|
}
|
|
if (i < n_root_sets) {
|
|
/* merge other overlapping intervals */
|
|
struct roots *other;
|
|
|
|
for (i++; i < n_root_sets; i++) {
|
|
other = GC_static_roots + i;
|
|
b = (char *)(other -> r_start);
|
|
e = (char *)(other -> r_end);
|
|
if ((ptr_t)b <= old -> r_end && (ptr_t)e >= old -> r_start) {
|
|
if ((ptr_t)b < old -> r_start) {
|
|
old -> r_start = (ptr_t)b;
|
|
GC_root_size += (old -> r_start - (ptr_t)b);
|
|
}
|
|
if ((ptr_t)e > old -> r_end) {
|
|
old -> r_end = (ptr_t)e;
|
|
GC_root_size += ((ptr_t)e - old -> r_end);
|
|
}
|
|
old -> r_tmp &= other -> r_tmp;
|
|
/* Delete this entry. */
|
|
GC_root_size -= (other -> r_end - other -> r_start);
|
|
other -> r_start = GC_static_roots[n_root_sets-1].r_start;
|
|
other -> r_end = GC_static_roots[n_root_sets-1].r_end;
|
|
n_root_sets--;
|
|
}
|
|
}
|
|
return;
|
|
}
|
|
}
|
|
# else
|
|
old = GC_roots_present(b);
|
|
if (old != 0) {
|
|
if ((ptr_t)e <= old -> r_end) /* already there */ return;
|
|
/* else extend */
|
|
GC_root_size += (ptr_t)e - old -> r_end;
|
|
old -> r_end = (ptr_t)e;
|
|
return;
|
|
}
|
|
# endif
|
|
if (n_root_sets == MAX_ROOT_SETS) {
|
|
ABORT("Too many root sets\n");
|
|
}
|
|
GC_static_roots[n_root_sets].r_start = (ptr_t)b;
|
|
GC_static_roots[n_root_sets].r_end = (ptr_t)e;
|
|
GC_static_roots[n_root_sets].r_tmp = tmp;
|
|
# ifndef MSWIN32
|
|
GC_static_roots[n_root_sets].r_next = 0;
|
|
# endif
|
|
add_roots_to_index(GC_static_roots + n_root_sets);
|
|
GC_root_size += (ptr_t)e - (ptr_t)b;
|
|
n_root_sets++;
|
|
}
|
|
|
|
void GC_remove_roots(b, e)
|
|
char * b; char * e;
|
|
{
|
|
DCL_LOCK_STATE;
|
|
|
|
DISABLE_SIGNALS();
|
|
LOCK();
|
|
GC_remove_roots_inner(b, e);
|
|
UNLOCK();
|
|
ENABLE_SIGNALS();
|
|
}
|
|
|
|
void GC_remove_roots_inner(b, e)
|
|
char * b; char * e;
|
|
{
|
|
register int i;
|
|
|
|
for (i = 0; i < n_root_sets; ) {
|
|
if (GC_static_roots[i].r_start == (ptr_t)b && GC_static_roots[i].r_end == (ptr_t)e) {
|
|
GC_root_size -=
|
|
(GC_static_roots[i].r_end - GC_static_roots[i].r_start);
|
|
GC_static_roots[i].r_start = GC_static_roots[n_root_sets-1].r_start;
|
|
GC_static_roots[i].r_end = GC_static_roots[n_root_sets-1].r_end;
|
|
GC_static_roots[i].r_tmp = GC_static_roots[n_root_sets-1].r_tmp;
|
|
n_root_sets--;
|
|
} else {
|
|
i++;
|
|
}
|
|
}
|
|
# ifndef MSWIN32
|
|
/* rehash the root table. */
|
|
for (i = 0; i < RT_SIZE; i++) GC_root_index[i] = 0;
|
|
for (i = 0; i < n_root_sets; i++)
|
|
add_roots_to_index(GC_static_roots + i);
|
|
# endif
|
|
}
|
|
|
|
void GC_clear_roots GC_PROTO((void))
|
|
{
|
|
DCL_LOCK_STATE;
|
|
|
|
DISABLE_SIGNALS();
|
|
LOCK();
|
|
n_root_sets = 0;
|
|
GC_root_size = 0;
|
|
# ifndef MSWIN32
|
|
{
|
|
register int i;
|
|
|
|
for (i = 0; i < RT_SIZE; i++) GC_root_index[i] = 0;
|
|
}
|
|
# endif
|
|
UNLOCK();
|
|
ENABLE_SIGNALS();
|
|
}
|
|
|
|
/* Internal use only; lock held. */
|
|
void GC_remove_tmp_roots()
|
|
{
|
|
register int i;
|
|
|
|
for (i = 0; i < n_root_sets; ) {
|
|
if (GC_static_roots[i].r_tmp) {
|
|
GC_root_size -=
|
|
(GC_static_roots[i].r_end - GC_static_roots[i].r_start);
|
|
GC_static_roots[i].r_start = GC_static_roots[n_root_sets-1].r_start;
|
|
GC_static_roots[i].r_end = GC_static_roots[n_root_sets-1].r_end;
|
|
GC_static_roots[i].r_tmp = GC_static_roots[n_root_sets-1].r_tmp;
|
|
n_root_sets--;
|
|
} else {
|
|
i++;
|
|
}
|
|
}
|
|
# ifndef MSWIN32
|
|
{
|
|
register int i;
|
|
|
|
for (i = 0; i < RT_SIZE; i++) GC_root_index[i] = 0;
|
|
for (i = 0; i < n_root_sets; i++)
|
|
add_roots_to_index(GC_static_roots + i);
|
|
}
|
|
# endif
|
|
|
|
}
|
|
|
|
ptr_t GC_approx_sp()
|
|
{
|
|
word dummy;
|
|
|
|
return((ptr_t)(&dummy));
|
|
}
|
|
|
|
/*
|
|
* Data structure for excluded static roots.
|
|
* Real declaration is in gc_priv.h.
|
|
|
|
struct exclusion {
|
|
ptr_t e_start;
|
|
ptr_t e_end;
|
|
};
|
|
|
|
struct exclusion GC_excl_table[MAX_EXCLUSIONS];
|
|
-- Array of exclusions, ascending
|
|
-- address order.
|
|
*/
|
|
|
|
size_t GC_excl_table_entries = 0; /* Number of entries in use. */
|
|
|
|
/* Return the first exclusion range that includes an address >= start_addr */
|
|
/* Assumes the exclusion table contains at least one entry (namely the */
|
|
/* GC data structures). */
|
|
struct exclusion * GC_next_exclusion(start_addr)
|
|
ptr_t start_addr;
|
|
{
|
|
size_t low = 0;
|
|
size_t high = GC_excl_table_entries - 1;
|
|
size_t mid;
|
|
|
|
while (high > low) {
|
|
mid = (low + high) >> 1;
|
|
/* low <= mid < high */
|
|
if ((word) GC_excl_table[mid].e_end <= (word) start_addr) {
|
|
low = mid + 1;
|
|
} else {
|
|
high = mid;
|
|
}
|
|
}
|
|
if ((word) GC_excl_table[low].e_end <= (word) start_addr) return 0;
|
|
return GC_excl_table + low;
|
|
}
|
|
|
|
void GC_exclude_static_roots(start, finish)
|
|
GC_PTR start;
|
|
GC_PTR finish;
|
|
{
|
|
struct exclusion * next;
|
|
size_t next_index, i;
|
|
|
|
if (0 == GC_excl_table_entries) {
|
|
next = 0;
|
|
} else {
|
|
next = GC_next_exclusion(start);
|
|
}
|
|
if (0 != next) {
|
|
if ((word)(next -> e_start) < (word) finish) {
|
|
/* incomplete error check. */
|
|
ABORT("exclusion ranges overlap");
|
|
}
|
|
if ((word)(next -> e_start) == (word) finish) {
|
|
/* extend old range backwards */
|
|
next -> e_start = (ptr_t)start;
|
|
return;
|
|
}
|
|
next_index = next - GC_excl_table;
|
|
for (i = GC_excl_table_entries; i > next_index; --i) {
|
|
GC_excl_table[i] = GC_excl_table[i-1];
|
|
}
|
|
} else {
|
|
next_index = GC_excl_table_entries;
|
|
}
|
|
if (GC_excl_table_entries == MAX_EXCLUSIONS) ABORT("Too many exclusions");
|
|
GC_excl_table[next_index].e_start = (ptr_t)start;
|
|
GC_excl_table[next_index].e_end = (ptr_t)finish;
|
|
++GC_excl_table_entries;
|
|
}
|
|
|
|
/* Invoke push_conditional on ranges that are not excluded. */
|
|
void GC_push_conditional_with_exclusions(bottom, top, all)
|
|
ptr_t bottom;
|
|
ptr_t top;
|
|
int all;
|
|
{
|
|
struct exclusion * next;
|
|
ptr_t excl_start;
|
|
|
|
while (bottom < top) {
|
|
next = GC_next_exclusion(bottom);
|
|
if (0 == next || (excl_start = next -> e_start) >= top) {
|
|
GC_push_conditional(bottom, top, all);
|
|
return;
|
|
}
|
|
if (excl_start > bottom) GC_push_conditional(bottom, excl_start, all);
|
|
bottom = next -> e_end;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* In the absence of threads, push the stack contents.
|
|
* In the presence of threads, push enough of the current stack
|
|
* to ensure that callee-save registers saved in collector frames have been
|
|
* seen.
|
|
*/
|
|
void GC_push_current_stack(cold_gc_frame)
|
|
ptr_t cold_gc_frame;
|
|
{
|
|
# if defined(THREADS)
|
|
if (0 == cold_gc_frame) return;
|
|
# ifdef STACK_GROWS_DOWN
|
|
GC_push_all_eager(GC_approx_sp(), cold_gc_frame);
|
|
# else
|
|
GC_push_all_eager( cold_gc_frame, GC_approx_sp() );
|
|
# endif
|
|
# else
|
|
# ifdef STACK_GROWS_DOWN
|
|
GC_push_all_stack_partially_eager( GC_approx_sp(), GC_stackbottom,
|
|
cold_gc_frame );
|
|
# else
|
|
GC_push_all_stack_partially_eager( GC_stackbottom, GC_approx_sp(),
|
|
cold_gc_frame );
|
|
# endif
|
|
# endif /* !THREADS */
|
|
}
|
|
|
|
/*
|
|
* Call the mark routines (GC_tl_push for a single pointer, GC_push_conditional
|
|
* on groups of pointers) on every top level accessible pointer.
|
|
* If all is FALSE, arrange to push only possibly altered values.
|
|
* Cold_gc_frame is an address inside a GC frame that
|
|
* remains valid until all marking is complete.
|
|
* A zero value indicates that it's OK to miss some
|
|
* register values.
|
|
*/
|
|
void GC_push_roots(all, cold_gc_frame)
|
|
GC_bool all;
|
|
ptr_t cold_gc_frame;
|
|
{
|
|
register int i;
|
|
|
|
/*
|
|
* push registers - i.e., call GC_push_one(r) for each
|
|
* register contents r.
|
|
*/
|
|
# ifdef USE_GENERIC_PUSH_REGS
|
|
GC_generic_push_regs(cold_gc_frame);
|
|
# else
|
|
GC_push_regs(); /* usually defined in machine_dep.c */
|
|
# endif
|
|
|
|
/*
|
|
* Next push static data. This must happen early on, since it's
|
|
* not robust against mark stack overflow.
|
|
*/
|
|
/* Reregister dynamic libraries, in case one got added. */
|
|
# if (defined(DYNAMIC_LOADING) || defined(MSWIN32) || defined(PCR)) \
|
|
&& !defined(SRC_M3)
|
|
GC_remove_tmp_roots();
|
|
if (GC_root_size)
|
|
GC_register_dynamic_libraries();
|
|
# endif
|
|
/* Mark everything in static data areas */
|
|
for (i = 0; i < n_root_sets; i++) {
|
|
GC_push_conditional_with_exclusions(
|
|
GC_static_roots[i].r_start,
|
|
GC_static_roots[i].r_end, all);
|
|
}
|
|
|
|
/*
|
|
* Now traverse stacks.
|
|
*/
|
|
# if !defined(USE_GENERIC_PUSH_REGS)
|
|
GC_push_current_stack(cold_gc_frame);
|
|
/* IN the threads case, this only pushes collector frames. */
|
|
/* In the USE_GENERIC_PUSH_REGS case, this is done inside */
|
|
/* GC_push_regs, so that we catch callee-save registers saved */
|
|
/* inside the GC_push_regs frame. */
|
|
# endif
|
|
if (GC_push_other_roots != 0) (*GC_push_other_roots)();
|
|
/* In the threads case, this also pushes thread stacks. */
|
|
}
|
|
|