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/*
* 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.
*/
#include "private/gc_priv.h"
#include <stdio.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;
# if !defined(MSWIN32) && !defined(MSWINCE) && !defined(CYGWIN32)
struct roots * r_next;
# endif
GC_bool r_tmp;
-- Delete before registering new dynamic libraries
};
struct roots GC_static_roots[MAX_ROOT_SETS];
*/
int GC_no_dls = 0; /* Register dynamic library data segments. */
static int n_root_sets = 0;
/* GC_static_roots[0..n_root_sets) contains the valid root sets. */
#if !defined(NO_DEBUGGING) || defined(GC_ASSERTIONS)
/* Should return the same value as GC_root_size. */
GC_INNER word GC_compute_root_size(void)
{
int i;
word size = 0;
for (i = 0; i < n_root_sets; i++) {
size += GC_static_roots[i].r_end - GC_static_roots[i].r_start;
}
return size;
}
#endif /* !NO_DEBUGGING || GC_ASSERTIONS */
#if !defined(NO_DEBUGGING)
/* For debugging: */
void GC_print_static_roots(void)
{
int i;
word size;
for (i = 0; i < n_root_sets; i++) {
GC_printf("From %p to %p%s\n",
GC_static_roots[i].r_start, GC_static_roots[i].r_end,
GC_static_roots[i].r_tmp ? " (temporary)" : "");
}
GC_printf("GC_root_size: %lu\n", (unsigned long)GC_root_size);
if ((size = GC_compute_root_size()) != GC_root_size)
GC_err_printf("GC_root_size incorrect!! Should be: %lu\n",
(unsigned long)size);
}
#endif /* !NO_DEBUGGING */
#ifndef THREADS
/* Primarily for debugging support: */
/* Is the address p in one of the registered static root sections? */
GC_INNER GC_bool GC_is_static_root(ptr_t p)
{
static int last_root_set = MAX_ROOT_SETS;
int i;
if (last_root_set < n_root_sets
&& (word)p >= (word)GC_static_roots[last_root_set].r_start
&& (word)p < (word)GC_static_roots[last_root_set].r_end)
return(TRUE);
for (i = 0; i < n_root_sets; i++) {
if ((word)p >= (word)GC_static_roots[i].r_start
&& (word)p < (word)GC_static_roots[i].r_end) {
last_root_set = i;
return(TRUE);
}
}
return(FALSE);
}
#endif /* !THREADS */
#if !defined(MSWIN32) && !defined(MSWINCE) && !defined(CYGWIN32)
/*
# 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
*/
GC_INLINE int rt_hash(ptr_t 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 NULL. */
GC_INNER void * GC_roots_present(ptr_t b)
{
int h = rt_hash(b);
struct roots *p = GC_root_index[h];
while (p != 0) {
if (p -> r_start == (ptr_t)b) return(p);
p = p -> r_next;
}
return NULL;
}
/* Add the given root structure to the index. */
GC_INLINE void add_roots_to_index(struct roots *p)
{
int h = rt_hash(p -> r_start);
p -> r_next = GC_root_index[h];
GC_root_index[h] = p;
}
#endif /* !MSWIN32 && !MSWINCE && !CYGWIN32 */
GC_INNER word GC_root_size = 0;
GC_API void GC_CALL GC_add_roots(void *b, void *e)
{
DCL_LOCK_STATE;
if (!EXPECT(GC_is_initialized, TRUE)) GC_init();
LOCK();
GC_add_roots_inner((ptr_t)b, (ptr_t)e, FALSE);
UNLOCK();
}
/* Add [b,e) to the root set. Adding the same interval a second time */
/* is a moderately fast no-op, 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 */
/* re-registering dynamic libraries. */
void GC_add_roots_inner(ptr_t b, ptr_t e, GC_bool tmp)
{
struct roots * old;
GC_ASSERT((word)b <= (word)e);
b = (ptr_t)(((word)b + (sizeof(word) - 1)) & ~(sizeof(word) - 1));
/* round b up to word boundary */
e = (ptr_t)((word)e & ~(sizeof(word) - 1));
/* round e down to word boundary */
if ((word)b >= (word)e) return; /* nothing to do */
# if defined(MSWIN32) || defined(MSWINCE) || defined(CYGWIN32)
/* 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;
old = 0; /* initialized to prevent warning. */
for (i = 0; i < n_root_sets; i++) {
old = GC_static_roots + i;
if ((word)b <= (word)old->r_end
&& (word)e >= (word)old->r_start) {
if ((word)b < (word)old->r_start) {
GC_root_size += old->r_start - b;
old -> r_start = b;
}
if ((word)e > (word)old->r_end) {
GC_root_size += e - old->r_end;
old -> r_end = e;
}
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 = other -> r_start;
e = other -> r_end;
if ((word)b <= (word)old->r_end
&& (word)e >= (word)old->r_start) {
if ((word)b < (word)old->r_start) {
GC_root_size += old->r_start - b;
old -> r_start = b;
}
if ((word)e > (word)old->r_end) {
GC_root_size += e - old->r_end;
old -> r_end = e;
}
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 = (struct roots *)GC_roots_present(b);
if (old != 0) {
if ((word)e <= (word)old->r_end) /* already there */ return;
/* else extend */
GC_root_size += e - old -> r_end;
old -> r_end = e;
return;
}
# endif
if (n_root_sets == MAX_ROOT_SETS) {
ABORT("Too many root sets");
}
# ifdef DEBUG_ADD_DEL_ROOTS
GC_log_printf("Adding data root section %d: %p .. %p\n",
n_root_sets, b, e);
# endif
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;
# if !defined(MSWIN32) && !defined(MSWINCE) && !defined(CYGWIN32)
GC_static_roots[n_root_sets].r_next = 0;
add_roots_to_index(GC_static_roots + n_root_sets);
# endif
GC_root_size += e - b;
n_root_sets++;
}
static GC_bool roots_were_cleared = FALSE;
GC_API void GC_CALL GC_clear_roots(void)
{
DCL_LOCK_STATE;
if (!EXPECT(GC_is_initialized, TRUE)) GC_init();
LOCK();
roots_were_cleared = TRUE;
n_root_sets = 0;
GC_root_size = 0;
# if !defined(MSWIN32) && !defined(MSWINCE) && !defined(CYGWIN32)
BZERO(GC_root_index, RT_SIZE * sizeof(void *));
# endif
# ifdef DEBUG_ADD_DEL_ROOTS
GC_log_printf("Clear all data root sections\n");
# endif
UNLOCK();
}
/* Internal use only; lock held. */
STATIC void GC_remove_root_at_pos(int i)
{
# ifdef DEBUG_ADD_DEL_ROOTS
GC_log_printf("Remove data root section %d: %p .. %p\n",
i, GC_static_roots[i].r_start, GC_static_roots[i].r_end);
# endif
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--;
}
#if !defined(MSWIN32) && !defined(MSWINCE) && !defined(CYGWIN32)
STATIC void GC_rebuild_root_index(void)
{
int i;
BZERO(GC_root_index, RT_SIZE * sizeof(void *));
for (i = 0; i < n_root_sets; i++)
add_roots_to_index(GC_static_roots + i);
}
#endif
#if defined(DYNAMIC_LOADING) || defined(MSWIN32) || defined(MSWINCE) \
|| defined(PCR) || defined(CYGWIN32)
/* Internal use only; lock held. */
STATIC void GC_remove_tmp_roots(void)
{
int i;
for (i = 0; i < n_root_sets; ) {
if (GC_static_roots[i].r_tmp) {
GC_remove_root_at_pos(i);
} else {
i++;
}
}
# if !defined(MSWIN32) && !defined(MSWINCE) && !defined(CYGWIN32)
GC_rebuild_root_index();
# endif
}
#endif
#if !defined(MSWIN32) && !defined(MSWINCE) && !defined(CYGWIN32)
STATIC void GC_remove_roots_inner(ptr_t b, ptr_t e);
GC_API void GC_CALL GC_remove_roots(void *b, void *e)
{
DCL_LOCK_STATE;
/* Quick check whether has nothing to do */
if ((((word)b + (sizeof(word) - 1)) & ~(sizeof(word) - 1)) >=
((word)e & ~(sizeof(word) - 1)))
return;
LOCK();
GC_remove_roots_inner((ptr_t)b, (ptr_t)e);
UNLOCK();
}
/* Should only be called when the lock is held */
STATIC void GC_remove_roots_inner(ptr_t b, ptr_t e)
{
int i;
for (i = 0; i < n_root_sets; ) {
if ((word)GC_static_roots[i].r_start >= (word)b
&& (word)GC_static_roots[i].r_end <= (word)e) {
GC_remove_root_at_pos(i);
} else {
i++;
}
}
GC_rebuild_root_index();
}
#endif /* !defined(MSWIN32) && !defined(MSWINCE) && !defined(CYGWIN32) */
#if (defined(MSWIN32) || defined(MSWINCE) || defined(CYGWIN32)) \
&& !defined(NO_DEBUGGING)
/* Not used at present (except for, may be, debugging purpose). */
/* Workaround for the OS mapping and unmapping behind our back: */
/* Is the address p in one of the temporary static root sections? */
GC_bool GC_is_tmp_root(ptr_t p)
{
static int last_root_set = MAX_ROOT_SETS;
register int i;
if (last_root_set < n_root_sets
&& (word)p >= (word)GC_static_roots[last_root_set].r_start
&& (word)p < (word)GC_static_roots[last_root_set].r_end)
return GC_static_roots[last_root_set].r_tmp;
for (i = 0; i < n_root_sets; i++) {
if ((word)p >= (word)GC_static_roots[i].r_start
&& (word)p < (word)GC_static_roots[i].r_end) {
last_root_set = i;
return GC_static_roots[i].r_tmp;
}
}
return(FALSE);
}
#endif /* MSWIN32 || MSWINCE || CYGWIN32 */
GC_INNER ptr_t GC_approx_sp(void)
{
volatile word sp;
sp = (word)&sp;
/* Also force stack to grow if necessary. Otherwise the */
/* later accesses might cause the kernel to think we're */
/* doing something wrong. */
return((ptr_t)sp);
/* GNU C: alternatively, we may return the value of */
/*__builtin_frame_address(0). */
}
/*
* 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.
*/
STATIC 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). */
STATIC struct exclusion * GC_next_exclusion(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;
}
/* Should only be called when the lock is held. The range boundaries */
/* should be properly aligned and valid. */
GC_INNER void GC_exclude_static_roots_inner(void *start, void *finish)
{
struct exclusion * next;
size_t next_index, i;
GC_ASSERT((word)start % sizeof(word) == 0);
GC_ASSERT((word)start < (word)finish);
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;
}
GC_API void GC_CALL GC_exclude_static_roots(void *b, void *e)
{
DCL_LOCK_STATE;
if (b == e) return; /* nothing to exclude? */
/* Round boundaries (in direction reverse to that of GC_add_roots). */
b = (void *)((word)b & ~(sizeof(word) - 1));
e = (void *)(((word)e + (sizeof(word) - 1)) & ~(sizeof(word) - 1));
if (0 == e) e = (void *)(~(sizeof(word) - 1)); /* handle overflow */
LOCK();
GC_exclude_static_roots_inner(b, e);
UNLOCK();
}
/* Invoke push_conditional on ranges that are not excluded. */
STATIC void GC_push_conditional_with_exclusions(ptr_t bottom, ptr_t top,
GC_bool all GC_ATTR_UNUSED)
{
struct exclusion * next;
ptr_t excl_start;
while ((word)bottom < (word)top) {
next = GC_next_exclusion(bottom);
if (0 == next || (word)(excl_start = next -> e_start) >= (word)top) {
GC_PUSH_CONDITIONAL(bottom, top, all);
return;
}
if ((word)excl_start > (word)bottom)
GC_PUSH_CONDITIONAL(bottom, excl_start, all);
bottom = next -> e_end;
}
}
#ifdef IA64
/* Similar to GC_push_all_stack_sections() but for IA-64 registers store. */
GC_INNER void GC_push_all_register_sections(ptr_t bs_lo, ptr_t bs_hi,
int eager, struct GC_traced_stack_sect_s *traced_stack_sect)
{
while (traced_stack_sect != NULL) {
ptr_t frame_bs_lo = traced_stack_sect -> backing_store_end;
GC_ASSERT((word)frame_bs_lo <= (word)bs_hi);
if (eager) {
GC_push_all_eager(frame_bs_lo, bs_hi);
} else {
GC_push_all_stack(frame_bs_lo, bs_hi);
}
bs_hi = traced_stack_sect -> saved_backing_store_ptr;
traced_stack_sect = traced_stack_sect -> prev;
}
GC_ASSERT((word)bs_lo <= (word)bs_hi);
if (eager) {
GC_push_all_eager(bs_lo, bs_hi);
} else {
GC_push_all_stack(bs_lo, bs_hi);
}
}
#endif /* IA64 */
#ifdef THREADS
GC_INNER void GC_push_all_stack_sections(ptr_t lo, ptr_t hi,
struct GC_traced_stack_sect_s *traced_stack_sect)
{
while (traced_stack_sect != NULL) {
GC_ASSERT((word)lo HOTTER_THAN (word)traced_stack_sect);
# ifdef STACK_GROWS_UP
GC_push_all_stack((ptr_t)traced_stack_sect, lo);
# else /* STACK_GROWS_DOWN */
GC_push_all_stack(lo, (ptr_t)traced_stack_sect);
# endif
lo = traced_stack_sect -> saved_stack_ptr;
GC_ASSERT(lo != NULL);
traced_stack_sect = traced_stack_sect -> prev;
}
GC_ASSERT(!((word)hi HOTTER_THAN (word)lo));
# ifdef STACK_GROWS_UP
/* We got them backwards! */
GC_push_all_stack(hi, lo);
# else /* STACK_GROWS_DOWN */
GC_push_all_stack(lo, hi);
# endif
}
#else /* !THREADS */
# ifdef TRACE_BUF
/* Defined in mark.c. */
void GC_add_trace_entry(char *kind, word arg1, word arg2);
# endif
/* Similar to GC_push_all_eager, but only the */
/* part hotter than cold_gc_frame is scanned */
/* immediately. Needed to ensure that callee- */
/* save registers are not missed. */
/*
* A version of GC_push_all that treats all interior pointers as valid
* and scans part of the area immediately, to make sure that saved
* register values are not lost.
* Cold_gc_frame delimits the stack section that must be scanned
* eagerly. A zero value indicates that no eager scanning is needed.
* We don't need to worry about the MANUAL_VDB case here, since this
* is only called in the single-threaded case. We assume that we
* cannot collect between an assignment and the corresponding
* GC_dirty() call.
*/
STATIC void GC_push_all_stack_partially_eager(ptr_t bottom, ptr_t top,
ptr_t cold_gc_frame)
{
if (!NEED_FIXUP_POINTER && GC_all_interior_pointers) {
/* Push the hot end of the stack eagerly, so that register values */
/* saved inside GC frames are marked before they disappear. */
/* The rest of the marking can be deferred until later. */
if (0 == cold_gc_frame) {
GC_push_all_stack(bottom, top);
return;
}
GC_ASSERT((word)bottom <= (word)cold_gc_frame
&& (word)cold_gc_frame <= (word)top);
# ifdef STACK_GROWS_DOWN
GC_push_all(cold_gc_frame - sizeof(ptr_t), top);
GC_push_all_eager(bottom, cold_gc_frame);
# else /* STACK_GROWS_UP */
GC_push_all(bottom, cold_gc_frame + sizeof(ptr_t));
GC_push_all_eager(cold_gc_frame, top);
# endif /* STACK_GROWS_UP */
} else {
GC_push_all_eager(bottom, top);
}
# ifdef TRACE_BUF
GC_add_trace_entry("GC_push_all_stack", bottom, top);
# endif
}
/* Similar to GC_push_all_stack_sections() but also uses cold_gc_frame. */
STATIC void GC_push_all_stack_part_eager_sections(ptr_t lo, ptr_t hi,
ptr_t cold_gc_frame, struct GC_traced_stack_sect_s *traced_stack_sect)
{
GC_ASSERT(traced_stack_sect == NULL || cold_gc_frame == NULL ||
(word)cold_gc_frame HOTTER_THAN (word)traced_stack_sect);
while (traced_stack_sect != NULL) {
GC_ASSERT((word)lo HOTTER_THAN (word)traced_stack_sect);
# ifdef STACK_GROWS_UP
GC_push_all_stack_partially_eager((ptr_t)traced_stack_sect, lo,
cold_gc_frame);
# else /* STACK_GROWS_DOWN */
GC_push_all_stack_partially_eager(lo, (ptr_t)traced_stack_sect,
cold_gc_frame);
# endif
lo = traced_stack_sect -> saved_stack_ptr;
GC_ASSERT(lo != NULL);
traced_stack_sect = traced_stack_sect -> prev;
cold_gc_frame = NULL; /* Use at most once. */
}
GC_ASSERT(!((word)hi HOTTER_THAN (word)lo));
# ifdef STACK_GROWS_UP
/* We got them backwards! */
GC_push_all_stack_partially_eager(hi, lo, cold_gc_frame);
# else /* STACK_GROWS_DOWN */
GC_push_all_stack_partially_eager(lo, hi, cold_gc_frame);
# endif
}
#endif /* !THREADS */
/* Push enough of the current stack eagerly to */
/* ensure that callee-save registers saved in */
/* GC frames are scanned. */
/* In the non-threads case, schedule entire */
/* stack for scanning. */
/* The second argument is a pointer to the */
/* (possibly null) thread context, for */
/* (currently hypothetical) more precise */
/* stack scanning. */
/*
* 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.
* FIXME: Merge with per-thread stuff.
*/
STATIC void GC_push_current_stack(ptr_t cold_gc_frame,
void * context GC_ATTR_UNUSED)
{
# if defined(THREADS)
if (0 == cold_gc_frame) return;
# ifdef STACK_GROWS_DOWN
GC_push_all_eager(GC_approx_sp(), cold_gc_frame);
/* For IA64, the register stack backing store is handled */
/* in the thread-specific code. */
# else
GC_push_all_eager(cold_gc_frame, GC_approx_sp());
# endif
# else
GC_push_all_stack_part_eager_sections(GC_approx_sp(), GC_stackbottom,
cold_gc_frame, GC_traced_stack_sect);
# ifdef IA64
/* We also need to push the register stack backing store. */
/* This should really be done in the same way as the */
/* regular stack. For now we fudge it a bit. */
/* Note that the backing store grows up, so we can't use */
/* GC_push_all_stack_partially_eager. */
{
ptr_t bsp = GC_save_regs_ret_val;
ptr_t cold_gc_bs_pointer = bsp - 2048;
if (GC_all_interior_pointers
&& (word)cold_gc_bs_pointer > (word)BACKING_STORE_BASE) {
/* Adjust cold_gc_bs_pointer if below our innermost */
/* "traced stack section" in backing store. */
if (GC_traced_stack_sect != NULL
&& (word)cold_gc_bs_pointer
< (word)GC_traced_stack_sect->backing_store_end)
cold_gc_bs_pointer =
GC_traced_stack_sect->backing_store_end;
GC_push_all_register_sections(BACKING_STORE_BASE,
cold_gc_bs_pointer, FALSE, GC_traced_stack_sect);
GC_push_all_eager(cold_gc_bs_pointer, bsp);
} else {
GC_push_all_register_sections(BACKING_STORE_BASE, bsp,
TRUE /* eager */, GC_traced_stack_sect);
}
/* All values should be sufficiently aligned that we */
/* don't have to worry about the boundary. */
}
# endif
# endif /* !THREADS */
}
GC_INNER void (*GC_push_typed_structures)(void) = 0;
/* Push GC internal roots. These are normally */
/* included in the static data segment, and */
/* Thus implicitly pushed. But we must do this */
/* explicitly if normal root processing is */
/* disabled. */
/*
* Push GC internal roots. Only called if there is some reason to believe
* these would not otherwise get registered.
*/
STATIC void GC_push_gc_structures(void)
{
# ifndef GC_NO_FINALIZATION
GC_push_finalizer_structures();
# endif
# if defined(THREADS)
GC_push_thread_structures();
# endif
if( GC_push_typed_structures )
GC_push_typed_structures();
}
GC_INNER void GC_cond_register_dynamic_libraries(void)
{
# if defined(DYNAMIC_LOADING) || defined(MSWIN32) || defined(MSWINCE) \
|| defined(CYGWIN32) || defined(PCR)
GC_remove_tmp_roots();
if (!GC_no_dls) GC_register_dynamic_libraries();
# else
GC_no_dls = TRUE;
# endif
}
STATIC void GC_push_regs_and_stack(ptr_t cold_gc_frame)
{
GC_with_callee_saves_pushed(GC_push_current_stack, cold_gc_frame);
}
/*
* 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.
*/
GC_INNER void GC_push_roots(GC_bool all, ptr_t cold_gc_frame)
{
int i;
unsigned kind;
/*
* Next push static data. This must happen early on, since it's
* not robust against mark stack overflow.
*/
/* Re-register dynamic libraries, in case one got added. */
/* There is some argument for doing this as late as possible, */
/* especially on win32, where it can change asynchronously. */
/* In those cases, we do it here. But on other platforms, it's */
/* not safe with the world stopped, so we do it earlier. */
# if !defined(REGISTER_LIBRARIES_EARLY)
GC_cond_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);
}
/* Mark all free list header blocks, if those were allocated from */
/* the garbage collected heap. This makes sure they don't */
/* disappear if we are not marking from static data. It also */
/* saves us the trouble of scanning them, and possibly that of */
/* marking the freelists. */
for (kind = 0; kind < GC_n_kinds; kind++) {
void *base = GC_base(GC_obj_kinds[kind].ok_freelist);
if (0 != base) {
GC_set_mark_bit(base);
}
}
/* Mark from GC internal roots if those might otherwise have */
/* been excluded. */
if (GC_no_dls || roots_were_cleared) {
GC_push_gc_structures();
}
/* Mark thread local free lists, even if their mark */
/* descriptor excludes the link field. */
/* If the world is not stopped, this is unsafe. It is */
/* also unnecessary, since we will do this again with the */
/* world stopped. */
# if defined(THREAD_LOCAL_ALLOC)
if (GC_world_stopped) GC_mark_thread_local_free_lists();
# endif
/*
* Now traverse stacks, and mark from register contents.
* These must be done last, since they can legitimately overflow
* the mark stack.
* This is usually done by saving the current context on the
* stack, and then just tracing from the stack.
*/
GC_push_regs_and_stack(cold_gc_frame);
if (GC_push_other_roots != 0) (*GC_push_other_roots)();
/* In the threads case, this also pushes thread stacks. */
/* Note that without interior pointer recognition lots */
/* of stuff may have been pushed already, and this */
/* should be careful about mark stack overflows. */
}
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