-/* Copyright (C) 1995,1996,1997,1998,1999,2000,2001 Free Software Foundation, Inc.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2, or (at your option)
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this software; see the file COPYING. If not, write to
- * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
- * Boston, MA 02111-1307 USA
- *
- * As a special exception, the Free Software Foundation gives permission
- * for additional uses of the text contained in its release of GUILE.
- *
- * The exception is that, if you link the GUILE library with other files
- * to produce an executable, this does not by itself cause the
- * resulting executable to be covered by the GNU General Public License.
- * Your use of that executable is in no way restricted on account of
- * linking the GUILE library code into it.
- *
- * This exception does not however invalidate any other reasons why
- * the executable file might be covered by the GNU General Public License.
- *
- * This exception applies only to the code released by the
- * Free Software Foundation under the name GUILE. If you copy
- * code from other Free Software Foundation releases into a copy of
- * GUILE, as the General Public License permits, the exception does
- * not apply to the code that you add in this way. To avoid misleading
- * anyone as to the status of such modified files, you must delete
- * this exception notice from them.
- *
- * If you write modifications of your own for GUILE, it is your choice
- * whether to permit this exception to apply to your modifications.
- * If you do not wish that, delete this exception notice. */
-
-/* Software engineering face-lift by Greg J. Badros, 11-Dec-1999,
- gjb@cs.washington.edu, http://www.cs.washington.edu/homes/gjb */
-
-/* #define DEBUGINFO */
-
-/* SECTION: This code is compiled once.
- */
-
-#ifndef MARK_DEPENDENCIES
-
-\f
-#include <stdio.h>
-#include <errno.h>
-#include <string.h>
-
-#include "libguile/_scm.h"
-#include "libguile/eval.h"
-#include "libguile/stime.h"
-#include "libguile/stackchk.h"
-#include "libguile/struct.h"
-#include "libguile/smob.h"
-#include "libguile/unif.h"
-#include "libguile/async.h"
-#include "libguile/ports.h"
-#include "libguile/root.h"
-#include "libguile/strings.h"
-#include "libguile/vectors.h"
-#include "libguile/weaks.h"
-#include "libguile/hashtab.h"
-#include "libguile/tags.h"
-
-#include "libguile/validate.h"
-#include "libguile/deprecation.h"
-#include "libguile/gc.h"
-
-#ifdef GUILE_DEBUG_MALLOC
-#include "libguile/debug-malloc.h"
-#endif
-
-#ifdef HAVE_MALLOC_H
-#include <malloc.h>
-#endif
-
-#ifdef HAVE_UNISTD_H
-#include <unistd.h>
-#endif
-
-#ifdef __STDC__
-#include <stdarg.h>
-#define var_start(x, y) va_start(x, y)
-#else
-#include <varargs.h>
-#define var_start(x, y) va_start(x)
-#endif
-
-\f
-
-unsigned int scm_gc_running_p = 0;
-
-\f
-
-#if (SCM_DEBUG_CELL_ACCESSES == 1)
-
-scm_bits_t scm_tc16_allocated;
-
-/* Set this to != 0 if every cell that is accessed shall be checked:
- */
-unsigned int scm_debug_cell_accesses_p = 1;
-
-
-/* Assert that the given object is a valid reference to a valid cell. This
- * test involves to determine whether the object is a cell pointer, whether
- * this pointer actually points into a heap segment and whether the cell
- * pointed to is not a free cell.
- */
-void
-scm_assert_cell_valid (SCM cell)
-{
- static unsigned int already_running = 0;
-
- if (scm_debug_cell_accesses_p && !already_running)
- {
- already_running = 1; /* set to avoid recursion */
-
- if (!scm_cellp (cell))
- {
- fprintf (stderr, "scm_assert_cell_valid: Not a cell object: %lux\n",
- (unsigned long) SCM_UNPACK (cell));
- abort ();
- }
- else if (!scm_gc_running_p)
- {
- /* Dirk::FIXME:: During garbage collection there occur references to
- free cells. This is allright during conservative marking, but
- should not happen otherwise (I think). The case of free cells
- accessed during conservative marking is handled in function
- scm_mark_locations. However, there still occur accesses to free
- cells during gc. I don't understand why this happens. If it is
- a bug and gets fixed, the following test should also work while
- gc is running.
- */
- if (SCM_FREE_CELL_P (cell))
- {
- fprintf (stderr, "scm_assert_cell_valid: Accessing free cell: %lux\n",
- (unsigned long) SCM_UNPACK (cell));
- abort ();
- }
- }
- already_running = 0; /* re-enable */
- }
-}
-
-
-SCM_DEFINE (scm_set_debug_cell_accesses_x, "set-debug-cell-accesses!", 1, 0, 0,
- (SCM flag),
- "If @var{flag} is @code{#f}, cell access checking is disabled.\n"
- "If @var{flag} is @code{#t}, cell access checking is enabled.\n"
- "This procedure only exists when the compile-time flag\n"
- "@code{SCM_DEBUG_CELL_ACCESSES} was set to 1.")
-#define FUNC_NAME s_scm_set_debug_cell_accesses_x
-{
- if (SCM_FALSEP (flag)) {
- scm_debug_cell_accesses_p = 0;
- } else if (SCM_EQ_P (flag, SCM_BOOL_T)) {
- scm_debug_cell_accesses_p = 1;
- } else {
- SCM_WRONG_TYPE_ARG (1, flag);
- }
- return SCM_UNSPECIFIED;
-}
-#undef FUNC_NAME
-
-#endif /* SCM_DEBUG_CELL_ACCESSES == 1 */
-
-\f
-
-/* {heap tuning parameters}
- *
- * These are parameters for controlling memory allocation. The heap
- * is the area out of which scm_cons, and object headers are allocated.
- *
- * Each heap cell is 8 bytes on a 32 bit machine and 16 bytes on a
- * 64 bit machine. The units of the _SIZE parameters are bytes.
- * Cons pairs and object headers occupy one heap cell.
- *
- * SCM_INIT_HEAP_SIZE is the initial size of heap. If this much heap is
- * allocated initially the heap will grow by half its current size
- * each subsequent time more heap is needed.
- *
- * If SCM_INIT_HEAP_SIZE heap cannot be allocated initially, SCM_HEAP_SEG_SIZE
- * will be used, and the heap will grow by SCM_HEAP_SEG_SIZE when more
- * heap is needed. SCM_HEAP_SEG_SIZE must fit into type size_t. This code
- * is in scm_init_storage() and alloc_some_heap() in sys.c
- *
- * If SCM_INIT_HEAP_SIZE can be allocated initially, the heap will grow by
- * SCM_EXPHEAP(scm_heap_size) when more heap is needed.
- *
- * SCM_MIN_HEAP_SEG_SIZE is minimum size of heap to accept when more heap
- * is needed.
- *
- * INIT_MALLOC_LIMIT is the initial amount of malloc usage which will
- * trigger a GC.
- *
- * SCM_MTRIGGER_HYSTERESIS is the amount of malloc storage that must be
- * reclaimed by a GC triggered by must_malloc. If less than this is
- * reclaimed, the trigger threshold is raised. [I don't know what a
- * good value is. I arbitrarily chose 1/10 of the INIT_MALLOC_LIMIT to
- * work around a oscillation that caused almost constant GC.]
- */
-
-/*
- * Heap size 45000 and 40% min yield gives quick startup and no extra
- * heap allocation. Having higher values on min yield may lead to
- * large heaps, especially if code behaviour is varying its
- * maximum consumption between different freelists.
- */
-
-#define SCM_DATA_CELLS2CARDS(n) (((n) + SCM_GC_CARD_N_DATA_CELLS - 1) / SCM_GC_CARD_N_DATA_CELLS)
-#define SCM_CARDS_PER_CLUSTER SCM_DATA_CELLS2CARDS (2000L)
-#define SCM_CLUSTER_SIZE_1 (SCM_CARDS_PER_CLUSTER * SCM_GC_CARD_N_DATA_CELLS)
-size_t scm_default_init_heap_size_1 = (((SCM_DATA_CELLS2CARDS (45000L) + SCM_CARDS_PER_CLUSTER - 1)
- / SCM_CARDS_PER_CLUSTER) * SCM_GC_CARD_SIZE);
-int scm_default_min_yield_1 = 40;
-
-#define SCM_CLUSTER_SIZE_2 (SCM_CARDS_PER_CLUSTER * (SCM_GC_CARD_N_DATA_CELLS / 2))
-size_t scm_default_init_heap_size_2 = (((SCM_DATA_CELLS2CARDS (2500L * 2) + SCM_CARDS_PER_CLUSTER - 1)
- / SCM_CARDS_PER_CLUSTER) * SCM_GC_CARD_SIZE);
-/* The following value may seem large, but note that if we get to GC at
- * all, this means that we have a numerically intensive application
- */
-int scm_default_min_yield_2 = 40;
-
-size_t scm_default_max_segment_size = 2097000L;/* a little less (adm) than 2 Mb */
-
-#define SCM_MIN_HEAP_SEG_SIZE (8 * SCM_GC_CARD_SIZE)
-#ifdef _QC
-# define SCM_HEAP_SEG_SIZE 32768L
-#else
-# ifdef sequent
-# define SCM_HEAP_SEG_SIZE (7000L * sizeof (scm_cell))
-# else
-# define SCM_HEAP_SEG_SIZE (16384L * sizeof (scm_cell))
-# endif
-#endif
-/* Make heap grow with factor 1.5 */
-#define SCM_EXPHEAP(scm_heap_size) (scm_heap_size / 2)
-#define SCM_INIT_MALLOC_LIMIT 100000
-#define SCM_MTRIGGER_HYSTERESIS (SCM_INIT_MALLOC_LIMIT/10)
-
-/* CELL_UP and CELL_DN are used by scm_init_heap_seg to find (scm_cell * span)
- aligned inner bounds for allocated storage */
-
-#ifdef PROT386
-/*in 386 protected mode we must only adjust the offset */
-# define CELL_UP(p, span) MK_FP(FP_SEG(p), ~(8*(span)-1)&(FP_OFF(p)+8*(span)-1))
-# define CELL_DN(p, span) MK_FP(FP_SEG(p), ~(8*(span)-1)&FP_OFF(p))
-#else
-# ifdef _UNICOS
-# define CELL_UP(p, span) (SCM_CELLPTR)(~(span) & ((long)(p)+(span)))
-# define CELL_DN(p, span) (SCM_CELLPTR)(~(span) & (long)(p))
-# else
-# define CELL_UP(p, span) (SCM_CELLPTR)(~(sizeof(scm_cell)*(span)-1L) & ((long)(p)+sizeof(scm_cell)*(span)-1L))
-# define CELL_DN(p, span) (SCM_CELLPTR)(~(sizeof(scm_cell)*(span)-1L) & (long)(p))
-# endif /* UNICOS */
-#endif /* PROT386 */
-
-#define DOUBLECELL_ALIGNED_P(x) (((2 * sizeof (scm_cell) - 1) & SCM_UNPACK (x)) == 0)
-
-#define ALIGNMENT_SLACK(freelist) (SCM_GC_CARD_SIZE - 1)
-#define CLUSTER_SIZE_IN_BYTES(freelist) \
- (((freelist)->cluster_size / (SCM_GC_CARD_N_DATA_CELLS / (freelist)->span)) * SCM_GC_CARD_SIZE)
-
-\f
-/* scm_freelists
- */
-
-typedef struct scm_freelist_t {
- /* collected cells */
- SCM cells;
- /* number of cells left to collect before cluster is full */
- unsigned int left_to_collect;
- /* number of clusters which have been allocated */
- unsigned int clusters_allocated;
- /* a list of freelists, each of size cluster_size,
- * except the last one which may be shorter
- */
- SCM clusters;
- SCM *clustertail;
- /* this is the number of objects in each cluster, including the spine cell */
- unsigned int cluster_size;
- /* indicates that we should grow heap instead of GC:ing
- */
- int grow_heap_p;
- /* minimum yield on this list in order not to grow the heap
- */
- long min_yield;
- /* defines min_yield as percent of total heap size
- */
- int min_yield_fraction;
- /* number of cells per object on this list */
- int span;
- /* number of collected cells during last GC */
- unsigned long collected;
- /* number of collected cells during penultimate GC */
- unsigned long collected_1;
- /* total number of cells in heap segments
- * belonging to this list.
- */
- unsigned long heap_size;
-} scm_freelist_t;
-
-SCM scm_freelist = SCM_EOL;
-scm_freelist_t scm_master_freelist = {
- SCM_EOL, 0, 0, SCM_EOL, 0, SCM_CLUSTER_SIZE_1, 0, 0, 0, 1, 0, 0
-};
-SCM scm_freelist2 = SCM_EOL;
-scm_freelist_t scm_master_freelist2 = {
- SCM_EOL, 0, 0, SCM_EOL, 0, SCM_CLUSTER_SIZE_2, 0, 0, 0, 2, 0, 0
-};
-
-/* scm_mtrigger
- * is the number of bytes of must_malloc allocation needed to trigger gc.
- */
-unsigned long scm_mtrigger;
-
-/* scm_gc_heap_lock
- * If set, don't expand the heap. Set only during gc, during which no allocation
- * is supposed to take place anyway.
- */
-int scm_gc_heap_lock = 0;
-
-/* GC Blocking
- * Don't pause for collection if this is set -- just
- * expand the heap.
- */
-int scm_block_gc = 1;
-
-/* During collection, this accumulates objects holding
- * weak references.
- */
-SCM scm_weak_vectors;
-
-/* During collection, this accumulates structures which are to be freed.
- */
-SCM scm_structs_to_free;
-
-/* GC Statistics Keeping
- */
-unsigned long scm_cells_allocated = 0;
-unsigned long scm_mallocated = 0;
-unsigned long scm_gc_cells_collected;
-unsigned long scm_gc_yield;
-static unsigned long scm_gc_yield_1 = 0; /* previous GC yield */
-unsigned long scm_gc_malloc_collected;
-unsigned long scm_gc_ports_collected;
-unsigned long scm_gc_time_taken = 0;
-static unsigned long t_before_gc;
-static unsigned long t_before_sweep;
-unsigned long scm_gc_mark_time_taken = 0;
-unsigned long scm_gc_sweep_time_taken = 0;
-unsigned long scm_gc_times = 0;
-unsigned long scm_gc_cells_swept = 0;
-double scm_gc_cells_marked_acc = 0.;
-double scm_gc_cells_swept_acc = 0.;
-
-SCM_SYMBOL (sym_cells_allocated, "cells-allocated");
-SCM_SYMBOL (sym_heap_size, "cell-heap-size");
-SCM_SYMBOL (sym_mallocated, "bytes-malloced");
-SCM_SYMBOL (sym_mtrigger, "gc-malloc-threshold");
-SCM_SYMBOL (sym_heap_segments, "cell-heap-segments");
-SCM_SYMBOL (sym_gc_time_taken, "gc-time-taken");
-SCM_SYMBOL (sym_gc_mark_time_taken, "gc-mark-time-taken");
-SCM_SYMBOL (sym_gc_sweep_time_taken, "gc-sweep-time-taken");
-SCM_SYMBOL (sym_times, "gc-times");
-SCM_SYMBOL (sym_cells_marked, "cells-marked");
-SCM_SYMBOL (sym_cells_swept, "cells-swept");
-
-typedef struct scm_heap_seg_data_t
-{
- /* lower and upper bounds of the segment */
- SCM_CELLPTR bounds[2];
-
- /* address of the head-of-freelist pointer for this segment's cells.
- All segments usually point to the same one, scm_freelist. */
- scm_freelist_t *freelist;
-
- /* number of cells per object in this segment */
- int span;
-} scm_heap_seg_data_t;
-
-
-
-static size_t init_heap_seg (SCM_CELLPTR, size_t, scm_freelist_t *);
-
-typedef enum { return_on_error, abort_on_error } policy_on_error;
-static void alloc_some_heap (scm_freelist_t *, policy_on_error);
-
-
-#define SCM_HEAP_SIZE \
- (scm_master_freelist.heap_size + scm_master_freelist2.heap_size)
-#define SCM_MAX(A, B) ((A) > (B) ? (A) : (B))
-
-#define BVEC_GROW_SIZE 256
-#define BVEC_GROW_SIZE_IN_LIMBS (SCM_GC_CARD_BVEC_SIZE_IN_LIMBS * BVEC_GROW_SIZE)
-#define BVEC_GROW_SIZE_IN_BYTES (BVEC_GROW_SIZE_IN_LIMBS * sizeof (scm_c_bvec_limb_t))
-
-/* mark space allocation */
-
-typedef struct scm_mark_space_t
-{
- scm_c_bvec_limb_t *bvec_space;
- struct scm_mark_space_t *next;
-} scm_mark_space_t;
-
-static scm_mark_space_t *current_mark_space;
-static scm_mark_space_t **mark_space_ptr;
-static ptrdiff_t current_mark_space_offset;
-static scm_mark_space_t *mark_space_head;
-
-static scm_c_bvec_limb_t *
-get_bvec ()
-#define FUNC_NAME "get_bvec"
-{
- scm_c_bvec_limb_t *res;
-
- if (!current_mark_space)
- {
- SCM_SYSCALL (current_mark_space = (scm_mark_space_t *) malloc (sizeof (scm_mark_space_t)));
- if (!current_mark_space)
- SCM_MISC_ERROR ("could not grow heap", SCM_EOL);
-
- current_mark_space->bvec_space = NULL;
- current_mark_space->next = NULL;
-
- *mark_space_ptr = current_mark_space;
- mark_space_ptr = &(current_mark_space->next);
-
- return get_bvec ();
- }
-
- if (!(current_mark_space->bvec_space))
- {
- SCM_SYSCALL (current_mark_space->bvec_space =
- (scm_c_bvec_limb_t *) calloc (BVEC_GROW_SIZE_IN_BYTES, 1));
- if (!(current_mark_space->bvec_space))
- SCM_MISC_ERROR ("could not grow heap", SCM_EOL);
-
- current_mark_space_offset = 0;
-
- return get_bvec ();
- }
-
- if (current_mark_space_offset == BVEC_GROW_SIZE_IN_LIMBS)
- {
- current_mark_space = NULL;
-
- return get_bvec ();
- }
-
- res = current_mark_space->bvec_space + current_mark_space_offset;
- current_mark_space_offset += SCM_GC_CARD_BVEC_SIZE_IN_LIMBS;
-
- return res;
-}
-#undef FUNC_NAME
-
-
-static void
-clear_mark_space ()
-{
- scm_mark_space_t *ms;
-
- for (ms = mark_space_head; ms; ms = ms->next)
- memset (ms->bvec_space, 0, BVEC_GROW_SIZE_IN_BYTES);
-}
-
-
-\f
-/* Debugging functions. */
-
-#if defined (GUILE_DEBUG) || defined (GUILE_DEBUG_FREELIST)
-
-/* Return the number of the heap segment containing CELL. */
-static long
-which_seg (SCM cell)
-{
- long i;
-
- for (i = 0; i < scm_n_heap_segs; i++)
- if (SCM_PTR_LE (scm_heap_table[i].bounds[0], SCM2PTR (cell))
- && SCM_PTR_GT (scm_heap_table[i].bounds[1], SCM2PTR (cell)))
- return i;
- fprintf (stderr, "which_seg: can't find segment containing cell %lux\n",
- (unsigned long) SCM_UNPACK (cell));
- abort ();
-}
-
-
-static void
-map_free_list (scm_freelist_t *master, SCM freelist)
-{
- long last_seg = -1, count = 0;
- SCM f;
-
- for (f = freelist; !SCM_NULLP (f); f = SCM_FREE_CELL_CDR (f))
- {
- long this_seg = which_seg (f);
-
- if (this_seg != last_seg)
- {
- if (last_seg != -1)
- fprintf (stderr, " %5ld %d-cells in segment %ld\n",
- (long) count, master->span, (long) last_seg);
- last_seg = this_seg;
- count = 0;
- }
- count++;
- }
- if (last_seg != -1)
- fprintf (stderr, " %5ld %d-cells in segment %ld\n",
- (long) count, master->span, (long) last_seg);
-}
-
-SCM_DEFINE (scm_map_free_list, "map-free-list", 0, 0, 0,
- (),
- "Print debugging information about the free-list.\n"
- "@code{map-free-list} is only included in\n"
- "@code{--enable-guile-debug} builds of Guile.")
-#define FUNC_NAME s_scm_map_free_list
-{
- long i;
- fprintf (stderr, "%ld segments total (%d:%ld",
- (long) scm_n_heap_segs,
- scm_heap_table[0].span,
- (long) (scm_heap_table[0].bounds[1] - scm_heap_table[0].bounds[0]));
- for (i = 1; i < scm_n_heap_segs; i++)
- fprintf (stderr, ", %d:%ld",
- scm_heap_table[i].span,
- (long) (scm_heap_table[i].bounds[1] - scm_heap_table[i].bounds[0]));
- fprintf (stderr, ")\n");
- map_free_list (&scm_master_freelist, scm_freelist);
- map_free_list (&scm_master_freelist2, scm_freelist2);
- fflush (stderr);
-
- return SCM_UNSPECIFIED;
-}
-#undef FUNC_NAME
-
-static long last_cluster;
-static long last_size;
-
-static long
-free_list_length (char *title, long i, SCM freelist)
-{
- SCM ls;
- long n = 0;
- for (ls = freelist; !SCM_NULLP (ls); ls = SCM_FREE_CELL_CDR (ls))
- if (SCM_FREE_CELL_P (ls))
- ++n;
- else
- {
- fprintf (stderr, "bad cell in %s at position %ld\n", title, (long) n);
- abort ();
- }
- if (n != last_size)
- {
- if (i > 0)
- {
- if (last_cluster == i - 1)
- fprintf (stderr, "\t%ld\n", (long) last_size);
- else
- fprintf (stderr, "-%ld\t%ld\n", (long) (i - 1), (long) last_size);
- }
- if (i >= 0)
- fprintf (stderr, "%s %ld", title, (long) i);
- else
- fprintf (stderr, "%s\t%ld\n", title, (long) n);
- last_cluster = i;
- last_size = n;
- }
- return n;
-}
-
-static void
-free_list_lengths (char *title, scm_freelist_t *master, SCM freelist)
-{
- SCM clusters;
- long i = 0, len, n = 0;
- fprintf (stderr, "%s\n\n", title);
- n += free_list_length ("free list", -1, freelist);
- for (clusters = master->clusters;
- SCM_NNULLP (clusters);
- clusters = SCM_CDR (clusters))
- {
- len = free_list_length ("cluster", i++, SCM_CAR (clusters));
- n += len;
- }
- if (last_cluster == i - 1)
- fprintf (stderr, "\t%ld\n", (long) last_size);
- else
- fprintf (stderr, "-%ld\t%ld\n", (long) (i - 1), (long) last_size);
- fprintf (stderr, "\ntotal %ld objects\n\n", (long) n);
-}
-
-SCM_DEFINE (scm_free_list_length, "free-list-length", 0, 0, 0,
- (),
- "Print debugging information about the free-list.\n"
- "@code{free-list-length} is only included in\n"
- "@code{--enable-guile-debug} builds of Guile.")
-#define FUNC_NAME s_scm_free_list_length
-{
- free_list_lengths ("1-cells", &scm_master_freelist, scm_freelist);
- free_list_lengths ("2-cells", &scm_master_freelist2, scm_freelist2);
- return SCM_UNSPECIFIED;
-}
-#undef FUNC_NAME
-
-#endif
-
-#ifdef GUILE_DEBUG_FREELIST
-
-/* Non-zero if freelist debugging is in effect. Set this via
- `gc-set-debug-check-freelist!'. */
-static int scm_debug_check_freelist = 0;
-
-/* Number of calls to SCM_NEWCELL since startup. */
-static unsigned long scm_newcell_count;
-static unsigned long scm_newcell2_count;
-
-/* Search freelist for anything that isn't marked as a free cell.
- Abort if we find something. */
-static void
-scm_check_freelist (SCM freelist)
-{
- SCM f;
- long i = 0;
-
- for (f = freelist; !SCM_NULLP (f); f = SCM_FREE_CELL_CDR (f), i++)
- if (!SCM_FREE_CELL_P (f))
- {
- fprintf (stderr, "Bad cell in freelist on newcell %lu: %lu'th elt\n",
- (long) scm_newcell_count, (long) i);
- abort ();
- }
-}
-
-SCM_DEFINE (scm_gc_set_debug_check_freelist_x, "gc-set-debug-check-freelist!", 1, 0, 0,
- (SCM flag),
- "If @var{flag} is @code{#t}, check the freelist for consistency\n"
- "on each cell allocation. This procedure only exists when the\n"
- "@code{GUILE_DEBUG_FREELIST} compile-time flag was selected.")
-#define FUNC_NAME s_scm_gc_set_debug_check_freelist_x
-{
- /* [cmm] I did a double-take when I read this code the first time.
- well, FWIW. */
- SCM_VALIDATE_BOOL_COPY (1, flag, scm_debug_check_freelist);
- return SCM_UNSPECIFIED;
-}
-#undef FUNC_NAME
-
-
-SCM
-scm_debug_newcell (void)
-{
- SCM new;
-
- scm_newcell_count++;
- if (scm_debug_check_freelist)
- {
- scm_check_freelist (scm_freelist);
- scm_gc();
- }
-
- /* The rest of this is supposed to be identical to the SCM_NEWCELL
- macro. */
- if (SCM_NULLP (scm_freelist))
- {
- new = scm_gc_for_newcell (&scm_master_freelist, &scm_freelist);
- SCM_GC_SET_ALLOCATED (new);
- }
- else
- {
- new = scm_freelist;
- scm_freelist = SCM_FREE_CELL_CDR (scm_freelist);
- SCM_GC_SET_ALLOCATED (new);
- }
-
- return new;
-}
-
-SCM
-scm_debug_newcell2 (void)
-{
- SCM new;
-
- scm_newcell2_count++;
- if (scm_debug_check_freelist)
- {
- scm_check_freelist (scm_freelist2);
- scm_gc ();
- }
-
- /* The rest of this is supposed to be identical to the SCM_NEWCELL
- macro. */
- if (SCM_NULLP (scm_freelist2))
- {
- new = scm_gc_for_newcell (&scm_master_freelist2, &scm_freelist2);
- SCM_GC_SET_ALLOCATED (new);
- }
- else
- {
- new = scm_freelist2;
- scm_freelist2 = SCM_FREE_CELL_CDR (scm_freelist2);
- SCM_GC_SET_ALLOCATED (new);
- }
-
- return new;
-}
-
-#endif /* GUILE_DEBUG_FREELIST */
-
-\f
-
-static unsigned long
-master_cells_allocated (scm_freelist_t *master)
-{
- /* the '- 1' below is to ignore the cluster spine cells. */
- long objects = master->clusters_allocated * (master->cluster_size - 1);
- if (SCM_NULLP (master->clusters))
- objects -= master->left_to_collect;
- return master->span * objects;
-}
-
-static unsigned long
-freelist_length (SCM freelist)
-{
- long n;
- for (n = 0; !SCM_NULLP (freelist); freelist = SCM_FREE_CELL_CDR (freelist))
- ++n;
- return n;
-}
-
-static unsigned long
-compute_cells_allocated ()
-{
- return (scm_cells_allocated
- + master_cells_allocated (&scm_master_freelist)
- + master_cells_allocated (&scm_master_freelist2)
- - scm_master_freelist.span * freelist_length (scm_freelist)
- - scm_master_freelist2.span * freelist_length (scm_freelist2));
-}
-
-/* {Scheme Interface to GC}
- */
-
-SCM_DEFINE (scm_gc_stats, "gc-stats", 0, 0, 0,
- (),
- "Return an association list of statistics about Guile's current\n"
- "use of storage.")
-#define FUNC_NAME s_scm_gc_stats
-{
- long i;
- long n;
- SCM heap_segs;
- unsigned long int local_scm_mtrigger;
- unsigned long int local_scm_mallocated;
- unsigned long int local_scm_heap_size;
- unsigned long int local_scm_cells_allocated;
- unsigned long int local_scm_gc_time_taken;
- unsigned long int local_scm_gc_times;
- unsigned long int local_scm_gc_mark_time_taken;
- unsigned long int local_scm_gc_sweep_time_taken;
- double local_scm_gc_cells_swept;
- double local_scm_gc_cells_marked;
- SCM answer;
-
- SCM_DEFER_INTS;
-
- ++scm_block_gc;
-
- retry:
- heap_segs = SCM_EOL;
- n = scm_n_heap_segs;
- for (i = scm_n_heap_segs; i--; )
- heap_segs = scm_cons (scm_cons (scm_ulong2num ((unsigned long)scm_heap_table[i].bounds[1]),
- scm_ulong2num ((unsigned long)scm_heap_table[i].bounds[0])),
- heap_segs);
- if (scm_n_heap_segs != n)
- goto retry;
-
- --scm_block_gc;
-
- /* Below, we cons to produce the resulting list. We want a snapshot of
- * the heap situation before consing.
- */
- local_scm_mtrigger = scm_mtrigger;
- local_scm_mallocated = scm_mallocated;
- local_scm_heap_size = SCM_HEAP_SIZE;
- local_scm_cells_allocated = compute_cells_allocated ();
- local_scm_gc_time_taken = scm_gc_time_taken;
- local_scm_gc_mark_time_taken = scm_gc_mark_time_taken;
- local_scm_gc_sweep_time_taken = scm_gc_sweep_time_taken;
- local_scm_gc_times = scm_gc_times;
- local_scm_gc_cells_swept = scm_gc_cells_swept_acc;
- local_scm_gc_cells_marked = scm_gc_cells_marked_acc;
-
- answer = scm_listify (scm_cons (sym_gc_time_taken, scm_ulong2num (local_scm_gc_time_taken)),
- scm_cons (sym_cells_allocated, scm_ulong2num (local_scm_cells_allocated)),
- scm_cons (sym_heap_size, scm_ulong2num (local_scm_heap_size)),
- scm_cons (sym_mallocated, scm_ulong2num (local_scm_mallocated)),
- scm_cons (sym_mtrigger, scm_ulong2num (local_scm_mtrigger)),
- scm_cons (sym_times, scm_ulong2num (local_scm_gc_times)),
- scm_cons (sym_gc_mark_time_taken, scm_ulong2num (local_scm_gc_mark_time_taken)),
- scm_cons (sym_gc_sweep_time_taken, scm_ulong2num (local_scm_gc_sweep_time_taken)),
- scm_cons (sym_cells_marked, scm_i_dbl2big (local_scm_gc_cells_marked)),
- scm_cons (sym_cells_swept, scm_i_dbl2big (local_scm_gc_cells_swept)),
- scm_cons (sym_heap_segments, heap_segs),
- SCM_UNDEFINED);
- SCM_ALLOW_INTS;
- return answer;
-}
-#undef FUNC_NAME
-
-
-static void
-gc_start_stats (const char *what)
-{
- t_before_gc = scm_c_get_internal_run_time ();
- scm_gc_cells_swept = 0;
- scm_gc_cells_collected = 0;
- scm_gc_yield_1 = scm_gc_yield;
- scm_gc_yield = (scm_cells_allocated
- + master_cells_allocated (&scm_master_freelist)
- + master_cells_allocated (&scm_master_freelist2));
- scm_gc_malloc_collected = 0;
- scm_gc_ports_collected = 0;
-}
-
-
-static void
-gc_end_stats ()
-{
- unsigned long t = scm_c_get_internal_run_time ();
- scm_gc_time_taken += (t - t_before_gc);
- scm_gc_sweep_time_taken += (t - t_before_sweep);
- ++scm_gc_times;
-
- scm_gc_cells_marked_acc += scm_gc_cells_swept - scm_gc_cells_collected;
- scm_gc_cells_swept_acc += scm_gc_cells_swept;
-}
-
-
-SCM_DEFINE (scm_object_address, "object-address", 1, 0, 0,
- (SCM obj),
- "Return an integer that for the lifetime of @var{obj} is uniquely\n"
- "returned by this function for @var{obj}")
-#define FUNC_NAME s_scm_object_address
-{
- return scm_ulong2num ((unsigned long) SCM_UNPACK (obj));
-}
-#undef FUNC_NAME
-
-
-SCM_DEFINE (scm_gc, "gc", 0, 0, 0,
- (),
- "Scans all of SCM objects and reclaims for further use those that are\n"
- "no longer accessible.")
-#define FUNC_NAME s_scm_gc
-{
- SCM_DEFER_INTS;
- scm_igc ("call");
- SCM_ALLOW_INTS;
- return SCM_UNSPECIFIED;
-}
-#undef FUNC_NAME
-
-
-\f
-/* {C Interface For When GC is Triggered}
- */
-
-static void
-adjust_min_yield (scm_freelist_t *freelist)
-{
- /* min yield is adjusted upwards so that next predicted total yield
- * (allocated cells actually freed by GC) becomes
- * `min_yield_fraction' of total heap size. Note, however, that
- * the absolute value of min_yield will correspond to `collected'
- * on one master (the one which currently is triggering GC).
- *
- * The reason why we look at total yield instead of cells collected
- * on one list is that we want to take other freelists into account.
- * On this freelist, we know that (local) yield = collected cells,
- * but that's probably not the case on the other lists.
- *
- * (We might consider computing a better prediction, for example
- * by computing an average over multiple GC:s.)
- */
- if (freelist->min_yield_fraction)
- {
- /* Pick largest of last two yields. */
- long delta = ((SCM_HEAP_SIZE * freelist->min_yield_fraction / 100)
- - (long) SCM_MAX (scm_gc_yield_1, scm_gc_yield));
-#ifdef DEBUGINFO
- fprintf (stderr, " after GC = %lu, delta = %ld\n",
- (long) scm_cells_allocated,
- (long) delta);
-#endif
- if (delta > 0)
- freelist->min_yield += delta;
- }
-}
-
-
-/* When we get POSIX threads support, the master will be global and
- * common while the freelist will be individual for each thread.
- */
-
-SCM
-scm_gc_for_newcell (scm_freelist_t *master, SCM *freelist)
-{
- SCM cell;
- ++scm_ints_disabled;
- do
- {
- if (SCM_NULLP (master->clusters))
- {
- if (master->grow_heap_p || scm_block_gc)
- {
- /* In order to reduce gc frequency, try to allocate a new heap
- * segment first, even if gc might find some free cells. If we
- * can't obtain a new heap segment, we will try gc later.
- */
- master->grow_heap_p = 0;
- alloc_some_heap (master, return_on_error);
- }
- if (SCM_NULLP (master->clusters))
- {
- /* The heap was not grown, either because it wasn't scheduled to
- * grow, or because there was not enough memory available. In
- * both cases we have to try gc to get some free cells.
- */
-#ifdef DEBUGINFO
- fprintf (stderr, "allocated = %lu, ",
- (long) (scm_cells_allocated
- + master_cells_allocated (&scm_master_freelist)
- + master_cells_allocated (&scm_master_freelist2)));
-#endif
- scm_igc ("cells");
- adjust_min_yield (master);
- if (SCM_NULLP (master->clusters))
- {
- /* gc could not free any cells. Now, we _must_ allocate a
- * new heap segment, because there is no other possibility
- * to provide a new cell for the caller.
- */
- alloc_some_heap (master, abort_on_error);
- }
- }
- }
- cell = SCM_CAR (master->clusters);
- master->clusters = SCM_CDR (master->clusters);
- ++master->clusters_allocated;
- }
- while (SCM_NULLP (cell));
-
-#ifdef GUILE_DEBUG_FREELIST
- scm_check_freelist (cell);
-#endif
-
- --scm_ints_disabled;
- *freelist = SCM_FREE_CELL_CDR (cell);
- return cell;
-}
-
-
-#if 0
-/* This is a support routine which can be used to reserve a cluster
- * for some special use, such as debugging. It won't be useful until
- * free cells are preserved between garbage collections.
- */
-
-void
-scm_alloc_cluster (scm_freelist_t *master)
-{
- SCM freelist, cell;
- cell = scm_gc_for_newcell (master, &freelist);
- SCM_SETCDR (cell, freelist);
- return cell;
-}
-#endif
-
-
-scm_c_hook_t scm_before_gc_c_hook;
-scm_c_hook_t scm_before_mark_c_hook;
-scm_c_hook_t scm_before_sweep_c_hook;
-scm_c_hook_t scm_after_sweep_c_hook;
-scm_c_hook_t scm_after_gc_c_hook;
-
-
-void
-scm_igc (const char *what)
-{
- long j;
-
- ++scm_gc_running_p;
- scm_c_hook_run (&scm_before_gc_c_hook, 0);
-#ifdef DEBUGINFO
- fprintf (stderr,
- SCM_NULLP (scm_freelist)
- ? "*"
- : (SCM_NULLP (scm_freelist2) ? "o" : "m"));
-#endif
- /* During the critical section, only the current thread may run. */
- SCM_CRITICAL_SECTION_START;
-
- /* fprintf (stderr, "gc: %s\n", what); */
-
- if (!scm_stack_base || scm_block_gc)
- {
- --scm_gc_running_p;
- return;
- }
-
- gc_start_stats (what);
-
- if (scm_gc_heap_lock)
- /* We've invoked the collector while a GC is already in progress.
- That should never happen. */
- abort ();
-
- ++scm_gc_heap_lock;
-
- /* flush dead entries from the continuation stack */
- {
- long x;
- long bound;
- SCM * elts;
- elts = SCM_VELTS (scm_continuation_stack);
- bound = SCM_VECTOR_LENGTH (scm_continuation_stack);
- x = SCM_INUM (scm_continuation_stack_ptr);
- while (x < bound)
- {
- elts[x] = SCM_BOOL_F;
- ++x;
- }
- }
-
- scm_c_hook_run (&scm_before_mark_c_hook, 0);
-
- clear_mark_space ();
-
-#ifndef USE_THREADS
-
- /* Mark objects on the C stack. */
- SCM_FLUSH_REGISTER_WINDOWS;
- /* This assumes that all registers are saved into the jmp_buf */
- setjmp (scm_save_regs_gc_mark);
- scm_mark_locations ((SCM_STACKITEM *) scm_save_regs_gc_mark,
- ( (size_t) (sizeof (SCM_STACKITEM) - 1 +
- sizeof scm_save_regs_gc_mark)
- / sizeof (SCM_STACKITEM)));
-
- {
- unsigned long stack_len = scm_stack_size (scm_stack_base);
-#ifdef SCM_STACK_GROWS_UP
- scm_mark_locations (scm_stack_base, stack_len);
-#else
- scm_mark_locations (scm_stack_base - stack_len, stack_len);
-#endif
- }
-
-#else /* USE_THREADS */
-
- /* Mark every thread's stack and registers */
- scm_threads_mark_stacks ();
-
-#endif /* USE_THREADS */
-
- j = SCM_NUM_PROTECTS;
- while (j--)
- scm_gc_mark (scm_sys_protects[j]);
-
- /* mark the registered roots */
- {
- long i;
- for (i = 0; i < SCM_VECTOR_LENGTH (scm_gc_registered_roots); ++i) {
- SCM l = SCM_VELTS (scm_gc_registered_roots)[i];
- for (; ! SCM_NULLP (l); l = SCM_CDR (l)) {
- SCM *p = (SCM *) (scm_num2long (SCM_CAAR (l), 0, NULL));
- scm_gc_mark (*p);
- }
- }
- }
-
- /* FIXME: we should have a means to register C functions to be run
- * in different phases of GC
- */
- scm_mark_subr_table ();
-
-#ifndef USE_THREADS
- scm_gc_mark (scm_root->handle);
-#endif
-
- t_before_sweep = scm_c_get_internal_run_time ();
- scm_gc_mark_time_taken += (t_before_sweep - t_before_gc);
-
- scm_c_hook_run (&scm_before_sweep_c_hook, 0);
-
- scm_gc_sweep ();
-
- scm_c_hook_run (&scm_after_sweep_c_hook, 0);
-
- --scm_gc_heap_lock;
- gc_end_stats ();
-
- SCM_CRITICAL_SECTION_END;
- scm_c_hook_run (&scm_after_gc_c_hook, 0);
- --scm_gc_running_p;
-}
-
-\f
-
-/* {Mark/Sweep}
- */
-
-#define MARK scm_gc_mark
-#define FNAME "scm_gc_mark"
-
-#endif /*!MARK_DEPENDENCIES*/
-
-/* Mark an object precisely.
- */
-void
-MARK (SCM p)
-#define FUNC_NAME FNAME
-{
- register long i;
- register SCM ptr;
- scm_bits_t cell_type;
-
-#ifndef MARK_DEPENDENCIES
-# define RECURSE scm_gc_mark
-#else
- /* go through the usual marking, but not for self-cycles. */
-# define RECURSE(x) do { if ((x) != p) scm_gc_mark (x); } while (0)
-#endif
- ptr = p;
-
-#ifdef MARK_DEPENDENCIES
- goto gc_mark_loop_first_time;
-#endif
-
-/* A simple hack for debugging. Chose the second branch to get a
- meaningful backtrace for crashes inside the GC.
-*/
-#if 1
-#define goto_gc_mark_loop goto gc_mark_loop
-#define goto_gc_mark_nimp goto gc_mark_nimp
-#else
-#define goto_gc_mark_loop RECURSE(ptr); return
-#define goto_gc_mark_nimp RECURSE(ptr); return
-#endif
-
-gc_mark_loop:
- if (SCM_IMP (ptr))
- return;
-
-gc_mark_nimp:
-
-#ifdef MARK_DEPENDENCIES
- if (SCM_EQ_P (ptr, p))
- return;
-
- scm_gc_mark (ptr);
- return;
-
-gc_mark_loop_first_time:
-#endif
-
-#if (SCM_DEBUG_CELL_ACCESSES == 1) || (defined (GUILE_DEBUG_FREELIST))
- /* We are in debug mode. Check the ptr exhaustively. */
- if (!scm_cellp (ptr))
- SCM_MISC_ERROR ("rogue pointer in heap", SCM_EOL);
-#else
- /* In non-debug mode, do at least some cheap testing. */
- if (!SCM_CELLP (ptr))
- SCM_MISC_ERROR ("rogue pointer in heap", SCM_EOL);
-#endif
-
-#ifndef MARK_DEPENDENCIES
-
- if (SCM_GCMARKP (ptr))
- return;
-
- SCM_SETGCMARK (ptr);
-
-#endif
-
- cell_type = SCM_GC_CELL_TYPE (ptr);
- switch (SCM_ITAG7 (cell_type))
- {
- case scm_tcs_cons_nimcar:
- if (SCM_IMP (SCM_CDR (ptr)))
- {
- ptr = SCM_CAR (ptr);
- goto_gc_mark_nimp;
- }
- RECURSE (SCM_CAR (ptr));
- ptr = SCM_CDR (ptr);
- goto_gc_mark_nimp;
- case scm_tcs_cons_imcar:
- ptr = SCM_CDR (ptr);
- goto_gc_mark_loop;
- case scm_tc7_pws:
- RECURSE (SCM_SETTER (ptr));
- ptr = SCM_PROCEDURE (ptr);
- goto_gc_mark_loop;
- case scm_tcs_cons_gloc:
- {
- /* Dirk:FIXME:: The following code is super ugly: ptr may be a
- * struct or a gloc. If it is a gloc, the cell word #0 of ptr
- * is the address of a scm_tc16_variable smob. If it is a
- * struct, the cell word #0 of ptr is a pointer to a struct
- * vtable data region. (The fact that these are accessed in
- * the same way restricts the possibilites to change the data
- * layout of structs or heap cells.) To discriminate between
- * the two, it is guaranteed that the scm_vtable_index_vcell
- * element of the prospective vtable is always zero. For a
- * gloc, this location has the CDR of the variable smob, which
- * is guaranteed to be non-zero.
- */
- scm_bits_t word0 = SCM_CELL_WORD_0 (ptr) - scm_tc3_cons_gloc;
- scm_bits_t * vtable_data = (scm_bits_t *) word0; /* access as struct */
- if (vtable_data [scm_vtable_index_vcell] != 0)
- {
- /* ptr is a gloc */
- SCM gloc_car = SCM_PACK (word0);
- RECURSE (gloc_car);
- ptr = SCM_CDR (ptr);
- goto gc_mark_loop;
- }
- else
- {
- /* ptr is a struct */
- SCM layout = SCM_PACK (vtable_data [scm_vtable_index_layout]);
- long len = SCM_SYMBOL_LENGTH (layout);
- char * fields_desc = SCM_SYMBOL_CHARS (layout);
- scm_bits_t * struct_data = (scm_bits_t *) SCM_STRUCT_DATA (ptr);
-
- if (vtable_data[scm_struct_i_flags] & SCM_STRUCTF_ENTITY)
- {
- RECURSE (SCM_PACK (struct_data[scm_struct_i_procedure]));
- RECURSE (SCM_PACK (struct_data[scm_struct_i_setter]));
- }
- if (len)
- {
- long x;
-
- for (x = 0; x < len - 2; x += 2, ++struct_data)
- if (fields_desc[x] == 'p')
- RECURSE (SCM_PACK (*struct_data));
- if (fields_desc[x] == 'p')
- {
- if (SCM_LAYOUT_TAILP (fields_desc[x + 1]))
- for (x = *struct_data++; x; --x, ++struct_data)
- RECURSE (SCM_PACK (*struct_data));
- else
- RECURSE (SCM_PACK (*struct_data));
- }
- }
- /* mark vtable */
- ptr = SCM_PACK (vtable_data [scm_vtable_index_vtable]);
- goto_gc_mark_loop;
- }
- }
- break;
- case scm_tcs_closures:
- if (SCM_IMP (SCM_ENV (ptr)))
- {
- ptr = SCM_CLOSCAR (ptr);
- goto_gc_mark_nimp;
- }
- RECURSE (SCM_CLOSCAR (ptr));
- ptr = SCM_ENV (ptr);
- goto_gc_mark_nimp;
- case scm_tc7_vector:
- i = SCM_VECTOR_LENGTH (ptr);
- if (i == 0)
- break;
- while (--i > 0)
- if (SCM_NIMP (SCM_VELTS (ptr)[i]))
- RECURSE (SCM_VELTS (ptr)[i]);
- ptr = SCM_VELTS (ptr)[0];
- goto_gc_mark_loop;
-#ifdef CCLO
- case scm_tc7_cclo:
- {
- size_t i = SCM_CCLO_LENGTH (ptr);
- size_t j;
- for (j = 1; j != i; ++j)
- {
- SCM obj = SCM_CCLO_REF (ptr, j);
- if (!SCM_IMP (obj))
- RECURSE (obj);
- }
- ptr = SCM_CCLO_REF (ptr, 0);
- goto_gc_mark_loop;
- }
-#endif
-#ifdef HAVE_ARRAYS
- case scm_tc7_bvect:
- case scm_tc7_byvect:
- case scm_tc7_ivect:
- case scm_tc7_uvect:
- case scm_tc7_fvect:
- case scm_tc7_dvect:
- case scm_tc7_cvect:
- case scm_tc7_svect:
-#ifdef HAVE_LONG_LONGS
- case scm_tc7_llvect:
-#endif
-#endif
- case scm_tc7_string:
- break;
-
- case scm_tc7_substring:
- ptr = SCM_CDR (ptr);
- goto_gc_mark_loop;
-
- case scm_tc7_wvect:
- SCM_WVECT_GC_CHAIN (ptr) = scm_weak_vectors;
- scm_weak_vectors = ptr;
- if (SCM_IS_WHVEC_ANY (ptr))
- {
- long x;
- long len;
- int weak_keys;
- int weak_values;
-
- len = SCM_VECTOR_LENGTH (ptr);
- weak_keys = SCM_IS_WHVEC (ptr) || SCM_IS_WHVEC_B (ptr);
- weak_values = SCM_IS_WHVEC_V (ptr) || SCM_IS_WHVEC_B (ptr);
-
- for (x = 0; x < len; ++x)
- {
- SCM alist;
- alist = SCM_VELTS (ptr)[x];
-
- /* mark everything on the alist except the keys or
- * values, according to weak_values and weak_keys. */
- while ( SCM_CONSP (alist)
- && !SCM_GCMARKP (alist)
- && SCM_CONSP (SCM_CAR (alist)))
- {
- SCM kvpair;
- SCM next_alist;
-
- kvpair = SCM_CAR (alist);
- next_alist = SCM_CDR (alist);
- /*
- * Do not do this:
- * SCM_SETGCMARK (alist);
- * SCM_SETGCMARK (kvpair);
- *
- * It may be that either the key or value is protected by
- * an escaped reference to part of the spine of this alist.
- * If we mark the spine here, and only mark one or neither of the
- * key and value, they may never be properly marked.
- * This leads to a horrible situation in which an alist containing
- * freelist cells is exported.
- *
- * So only mark the spines of these arrays last of all marking.
- * If somebody confuses us by constructing a weak vector
- * with a circular alist then we are hosed, but at least we
- * won't prematurely drop table entries.
- */
- if (!weak_keys)
- RECURSE (SCM_CAR (kvpair));
- if (!weak_values)
- RECURSE (SCM_CDR (kvpair));
- alist = next_alist;
- }
- if (SCM_NIMP (alist))
- RECURSE (alist);
- }
- }
- break;
-
- case scm_tc7_symbol:
- ptr = SCM_PROP_SLOTS (ptr);
- goto_gc_mark_loop;
- case scm_tcs_subrs:
- break;
- case scm_tc7_port:
- i = SCM_PTOBNUM (ptr);
-#if (SCM_DEBUG_CELL_ACCESSES == 1) || (defined (GUILE_DEBUG_FREELIST))
- if (!(i < scm_numptob))
- SCM_MISC_ERROR ("undefined port type", SCM_EOL);
-#endif
- if (SCM_PTAB_ENTRY(ptr))
- RECURSE (SCM_FILENAME (ptr));
- if (scm_ptobs[i].mark)
- {
- ptr = (scm_ptobs[i].mark) (ptr);
- goto_gc_mark_loop;
- }
- else
- return;
- break;
- case scm_tc7_smob:
- switch (SCM_TYP16 (ptr))
- { /* should be faster than going through scm_smobs */
- case scm_tc_free_cell:
- /* printf("found free_cell %X ", ptr); fflush(stdout); */
- case scm_tc16_big:
- case scm_tc16_real:
- case scm_tc16_complex:
- break;
- default:
- i = SCM_SMOBNUM (ptr);
-#if (SCM_DEBUG_CELL_ACCESSES == 1) || (defined (GUILE_DEBUG_FREELIST))
- if (!(i < scm_numsmob))
- SCM_MISC_ERROR ("undefined smob type", SCM_EOL);
-#endif
- if (scm_smobs[i].mark)
- {
- ptr = (scm_smobs[i].mark) (ptr);
- goto_gc_mark_loop;
- }
- else
- return;
- }
- break;
- default:
- SCM_MISC_ERROR ("unknown type", SCM_EOL);
- }
-#undef RECURSE
-}
-#undef FUNC_NAME
-
-#ifndef MARK_DEPENDENCIES
-
-#undef MARK
-#undef FNAME
-
-/* And here we define `scm_gc_mark_dependencies', by including this
- * same file in itself.
- */
-#define MARK scm_gc_mark_dependencies
-#define FNAME "scm_gc_mark_dependencies"
-#define MARK_DEPENDENCIES
-#include "gc.c"
-#undef MARK_DEPENDENCIES
-#undef MARK
-#undef FNAME
-
-
-/* Mark a Region Conservatively
- */
-
-void
-scm_mark_locations (SCM_STACKITEM x[], unsigned long n)
-{
- unsigned long m;
-
- for (m = 0; m < n; ++m)
- {
- SCM obj = * (SCM *) &x[m];
- if (SCM_CELLP (obj))
- {
- SCM_CELLPTR ptr = SCM2PTR (obj);
- long i = 0;
- long j = scm_n_heap_segs - 1;
- if (SCM_PTR_LE (scm_heap_table[i].bounds[0], ptr)
- && SCM_PTR_GT (scm_heap_table[j].bounds[1], ptr))
- {
- while (i <= j)
- {
- long seg_id;
- seg_id = -1;
- if ((i == j)
- || SCM_PTR_GT (scm_heap_table[i].bounds[1], ptr))
- seg_id = i;
- else if (SCM_PTR_LE (scm_heap_table[j].bounds[0], ptr))
- seg_id = j;
- else
- {
- long k;
- k = (i + j) / 2;
- if (k == i)
- break;
- if (SCM_PTR_GT (scm_heap_table[k].bounds[1], ptr))
- {
- j = k;
- ++i;
- if (SCM_PTR_LE (scm_heap_table[i].bounds[0], ptr))
- continue;
- else
- break;
- }
- else if (SCM_PTR_LE (scm_heap_table[k].bounds[0], ptr))
- {
- i = k;
- --j;
- if (SCM_PTR_GT (scm_heap_table[j].bounds[1], ptr))
- continue;
- else
- break;
- }
- }
-
- if (SCM_GC_IN_CARD_HEADERP (ptr))
- break;
-
- if (scm_heap_table[seg_id].span == 1
- || DOUBLECELL_ALIGNED_P (obj))
- scm_gc_mark (obj);
-
- break;
- }
- }
- }
- }
-}
-
-
-/* The function scm_cellp determines whether an SCM value can be regarded as a
- * pointer to a cell on the heap. Binary search is used in order to determine
- * the heap segment that contains the cell.
- */
-int
-scm_cellp (SCM value)
-{
- if (SCM_CELLP (value)) {
- scm_cell * ptr = SCM2PTR (value);
- unsigned long i = 0;
- unsigned long j = scm_n_heap_segs - 1;
-
- if (SCM_GC_IN_CARD_HEADERP (ptr))
- return 0;
-
- while (i < j) {
- long k = (i + j) / 2;
- if (SCM_PTR_GT (scm_heap_table[k].bounds[1], ptr)) {
- j = k;
- } else if (SCM_PTR_LE (scm_heap_table[k].bounds[0], ptr)) {
- i = k + 1;
- }
- }
-
- if (SCM_PTR_LE (scm_heap_table[i].bounds[0], ptr)
- && SCM_PTR_GT (scm_heap_table[i].bounds[1], ptr)
- && (scm_heap_table[i].span == 1 || DOUBLECELL_ALIGNED_P (value))
- && !SCM_GC_IN_CARD_HEADERP (ptr)
- )
- return 1;
- else
- return 0;
- } else
- return 0;
-}
-
-
-static void
-gc_sweep_freelist_start (scm_freelist_t *freelist)
-{
- freelist->cells = SCM_EOL;
- freelist->left_to_collect = freelist->cluster_size;
- freelist->clusters_allocated = 0;
- freelist->clusters = SCM_EOL;
- freelist->clustertail = &freelist->clusters;
- freelist->collected_1 = freelist->collected;
- freelist->collected = 0;
-}
-
-static void
-gc_sweep_freelist_finish (scm_freelist_t *freelist)
-{
- long collected;
- *freelist->clustertail = freelist->cells;
- if (!SCM_NULLP (freelist->cells))
- {
- SCM c = freelist->cells;
- SCM_SET_CELL_WORD_0 (c, SCM_FREE_CELL_CDR (c));
- SCM_SET_CELL_WORD_1 (c, SCM_EOL);
- freelist->collected +=
- freelist->span * (freelist->cluster_size - freelist->left_to_collect);
- }
- scm_gc_cells_collected += freelist->collected;
-
- /* Although freelist->min_yield is used to test freelist->collected
- * (which is the local GC yield for freelist), it is adjusted so
- * that *total* yield is freelist->min_yield_fraction of total heap
- * size. This means that a too low yield is compensated by more
- * heap on the list which is currently doing most work, which is
- * just what we want.
- */
- collected = SCM_MAX (freelist->collected_1, freelist->collected);
- freelist->grow_heap_p = (collected < freelist->min_yield);
-}
-
-#define NEXT_DATA_CELL(ptr, span) \
- do { \
- scm_cell *nxt__ = CELL_UP ((char *) (ptr) + 1, (span)); \
- (ptr) = (SCM_GC_IN_CARD_HEADERP (nxt__) ? \
- CELL_UP (SCM_GC_CELL_CARD (nxt__) + SCM_GC_CARD_N_HEADER_CELLS, span) \
- : nxt__); \
- } while (0)
-
-void
-scm_gc_sweep ()
-#define FUNC_NAME "scm_gc_sweep"
-{
- register SCM_CELLPTR ptr;
- register SCM nfreelist;
- register scm_freelist_t *freelist;
- register unsigned long m;
- register int span;
- long i;
- size_t seg_size;
-
- m = 0;
-
- gc_sweep_freelist_start (&scm_master_freelist);
- gc_sweep_freelist_start (&scm_master_freelist2);
-
- for (i = 0; i < scm_n_heap_segs; i++)
- {
- register long left_to_collect;
- register size_t j;
-
- /* Unmarked cells go onto the front of the freelist this heap
- segment points to. Rather than updating the real freelist
- pointer as we go along, we accumulate the new head in
- nfreelist. Then, if it turns out that the entire segment is
- free, we free (i.e., malloc's free) the whole segment, and
- simply don't assign nfreelist back into the real freelist. */
- freelist = scm_heap_table[i].freelist;
- nfreelist = freelist->cells;
- left_to_collect = freelist->left_to_collect;
- span = scm_heap_table[i].span;
-
- ptr = CELL_UP (scm_heap_table[i].bounds[0], span);
- seg_size = CELL_DN (scm_heap_table[i].bounds[1], span) - ptr;
-
- /* use only data cells in seg_size */
- seg_size = (seg_size / SCM_GC_CARD_N_CELLS) * (SCM_GC_CARD_N_DATA_CELLS / span) * span;
-
- scm_gc_cells_swept += seg_size;
-
- for (j = seg_size + span; j -= span; ptr += span)
- {
- SCM scmptr;
-
- if (SCM_GC_IN_CARD_HEADERP (ptr))
- {
- SCM_CELLPTR nxt;
-
- /* cheat here */
- nxt = ptr;
- NEXT_DATA_CELL (nxt, span);
- j += span;
-
- ptr = nxt - span;
- continue;
- }
-
- scmptr = PTR2SCM (ptr);
-
- if (SCM_GCMARKP (scmptr))
- continue;
-
- switch SCM_TYP7 (scmptr)
- {
- case scm_tcs_cons_gloc:
- {
- /* Dirk:FIXME:: Again, super ugly code: scmptr may be a
- * struct or a gloc. See the corresponding comment in
- * scm_gc_mark.
- */
- scm_bits_t word0 = (SCM_CELL_WORD_0 (scmptr)
- - scm_tc3_cons_gloc);
- /* access as struct */
- scm_bits_t * vtable_data = (scm_bits_t *) word0;
- if (vtable_data[scm_vtable_index_vcell] == 0)
- {
- /* Structs need to be freed in a special order.
- * This is handled by GC C hooks in struct.c.
- */
- SCM_SET_STRUCT_GC_CHAIN (scmptr, scm_structs_to_free);
- scm_structs_to_free = scmptr;
- continue;
- }
- /* fall through so that scmptr gets collected */
- }
- break;
- case scm_tcs_cons_imcar:
- case scm_tcs_cons_nimcar:
- case scm_tcs_closures:
- case scm_tc7_pws:
- break;
- case scm_tc7_wvect:
- m += (2 + SCM_VECTOR_LENGTH (scmptr)) * sizeof (SCM);
- scm_must_free (SCM_VECTOR_BASE (scmptr) - 2);
- break;
- case scm_tc7_vector:
- {
- unsigned long int length = SCM_VECTOR_LENGTH (scmptr);
- if (length > 0)
- {
- m += length * sizeof (scm_bits_t);
- scm_must_free (SCM_VECTOR_BASE (scmptr));
- }
- break;
- }
-#ifdef CCLO
- case scm_tc7_cclo:
- m += (SCM_CCLO_LENGTH (scmptr) * sizeof (SCM));
- scm_must_free (SCM_CCLO_BASE (scmptr));
- break;
-#endif
-#ifdef HAVE_ARRAYS
- case scm_tc7_bvect:
- {
- unsigned long int length = SCM_BITVECTOR_LENGTH (scmptr);
- if (length > 0)
- {
- m += sizeof (long) * ((length + SCM_LONG_BIT - 1) / SCM_LONG_BIT);
- scm_must_free (SCM_BITVECTOR_BASE (scmptr));
- }
- }
- break;
- case scm_tc7_byvect:
- case scm_tc7_ivect:
- case scm_tc7_uvect:
- case scm_tc7_svect:
-#ifdef HAVE_LONG_LONGS
- case scm_tc7_llvect:
-#endif
- case scm_tc7_fvect:
- case scm_tc7_dvect:
- case scm_tc7_cvect:
- m += SCM_UVECTOR_LENGTH (scmptr) * scm_uniform_element_size (scmptr);
- scm_must_free (SCM_UVECTOR_BASE (scmptr));
- break;
-#endif
- case scm_tc7_substring:
- break;
- case scm_tc7_string:
- m += SCM_STRING_LENGTH (scmptr) + 1;
- scm_must_free (SCM_STRING_CHARS (scmptr));
- break;
- case scm_tc7_symbol:
- m += SCM_SYMBOL_LENGTH (scmptr) + 1;
- scm_must_free (SCM_SYMBOL_CHARS (scmptr));
- break;
- case scm_tcs_subrs:
- /* the various "subrs" (primitives) are never freed */
- continue;
- case scm_tc7_port:
- if SCM_OPENP (scmptr)
- {
- int k = SCM_PTOBNUM (scmptr);
-#if (SCM_DEBUG_CELL_ACCESSES == 1) || (defined (GUILE_DEBUG_FREELIST))
- if (!(k < scm_numptob))
- SCM_MISC_ERROR ("undefined port type", SCM_EOL);
-#endif
- /* Keep "revealed" ports alive. */
- if (scm_revealed_count (scmptr) > 0)
- continue;
- /* Yes, I really do mean scm_ptobs[k].free */
- /* rather than ftobs[k].close. .close */
- /* is for explicit CLOSE-PORT by user */
- m += (scm_ptobs[k].free) (scmptr);
- SCM_SETSTREAM (scmptr, 0);
- scm_remove_from_port_table (scmptr);
- scm_gc_ports_collected++;
- SCM_CLR_PORT_OPEN_FLAG (scmptr);
- }
- break;
- case scm_tc7_smob:
- switch SCM_TYP16 (scmptr)
- {
- case scm_tc_free_cell:
- case scm_tc16_real:
- break;
-#ifdef SCM_BIGDIG
- case scm_tc16_big:
- m += (SCM_NUMDIGS (scmptr) * SCM_BITSPERDIG / SCM_CHAR_BIT);
- scm_must_free (SCM_BDIGITS (scmptr));
- break;
-#endif /* def SCM_BIGDIG */
- case scm_tc16_complex:
- m += sizeof (scm_complex_t);
- scm_must_free (SCM_COMPLEX_MEM (scmptr));
- break;
- default:
- {
- int k;
- k = SCM_SMOBNUM (scmptr);
-#if (SCM_DEBUG_CELL_ACCESSES == 1) || (defined (GUILE_DEBUG_FREELIST))
- if (!(k < scm_numsmob))
- SCM_MISC_ERROR ("undefined smob type", SCM_EOL);
-#endif
- if (scm_smobs[k].free)
- m += (scm_smobs[k].free) (scmptr);
- break;
- }
- }
- break;
- default:
- SCM_MISC_ERROR ("unknown type", SCM_EOL);
- }
-
- if (!--left_to_collect)
- {
- SCM_SET_CELL_WORD_0 (scmptr, nfreelist);
- *freelist->clustertail = scmptr;
- freelist->clustertail = SCM_CDRLOC (scmptr);
-
- nfreelist = SCM_EOL;
- freelist->collected += span * freelist->cluster_size;
- left_to_collect = freelist->cluster_size;
- }
- else
- {
- /* Stick the new cell on the front of nfreelist. It's
- critical that we mark this cell as freed; otherwise, the
- conservative collector might trace it as some other type
- of object. */
- SCM_SET_CELL_TYPE (scmptr, scm_tc_free_cell);
- SCM_SET_FREE_CELL_CDR (scmptr, nfreelist);
- nfreelist = scmptr;
- }
- }
-
-#ifdef GC_FREE_SEGMENTS
- if (n == seg_size)
- {
- register long j;
-
- freelist->heap_size -= seg_size;
- free ((char *) scm_heap_table[i].bounds[0]);
- scm_heap_table[i].bounds[0] = 0;
- for (j = i + 1; j < scm_n_heap_segs; j++)
- scm_heap_table[j - 1] = scm_heap_table[j];
- scm_n_heap_segs -= 1;
- i--; /* We need to scan the segment just moved. */
- }
- else
-#endif /* ifdef GC_FREE_SEGMENTS */
- {
- /* Update the real freelist pointer to point to the head of
- the list of free cells we've built for this segment. */
- freelist->cells = nfreelist;
- freelist->left_to_collect = left_to_collect;
- }
-
-#ifdef GUILE_DEBUG_FREELIST
- scm_map_free_list ();
-#endif
- }
-
- gc_sweep_freelist_finish (&scm_master_freelist);
- gc_sweep_freelist_finish (&scm_master_freelist2);
-
- /* When we move to POSIX threads private freelists should probably
- be GC-protected instead. */
- scm_freelist = SCM_EOL;
- scm_freelist2 = SCM_EOL;
-
- scm_cells_allocated = (SCM_HEAP_SIZE - scm_gc_cells_collected);
- scm_gc_yield -= scm_cells_allocated;
-
- if (scm_mallocated < m)
- /* The byte count of allocated objects has underflowed. This is
- probably because you forgot to report the sizes of objects you
- have allocated, by calling scm_done_malloc or some such. When
- the GC freed them, it subtracted their size from
- scm_mallocated, which underflowed. */
- abort ();
-
- scm_mallocated -= m;
- scm_gc_malloc_collected = m;
-}
-#undef FUNC_NAME
-
-
-\f
-/* {Front end to malloc}
- *
- * scm_must_malloc, scm_must_realloc, scm_must_free, scm_done_malloc,
- * scm_done_free
- *
- * These functions provide services comparable to malloc, realloc, and
- * free. They should be used when allocating memory that will be under
- * control of the garbage collector, i.e., if the memory may be freed
- * during garbage collection.
- */
-
-/* scm_must_malloc
- * Return newly malloced storage or throw an error.
- *
- * The parameter WHAT is a string for error reporting.
- * If the threshold scm_mtrigger will be passed by this
- * allocation, or if the first call to malloc fails,
- * garbage collect -- on the presumption that some objects
- * using malloced storage may be collected.
- *
- * The limit scm_mtrigger may be raised by this allocation.
- */
-void *
-scm_must_malloc (size_t size, const char *what)
-{
- void *ptr;
- unsigned long nm = scm_mallocated + size;
-
- if (nm < size)
- /* The byte count of allocated objects has overflowed. This is
- probably because you forgot to report the correct size of freed
- memory in some of your smob free methods. */
- abort ();
-
- if (nm <= scm_mtrigger)
- {
- SCM_SYSCALL (ptr = malloc (size));
- if (NULL != ptr)
- {
- scm_mallocated = nm;
-#ifdef GUILE_DEBUG_MALLOC
- scm_malloc_register (ptr, what);
-#endif
- return ptr;
- }
- }
-
- scm_igc (what);
-
- nm = scm_mallocated + size;
-
- if (nm < size)
- /* The byte count of allocated objects has overflowed. This is
- probably because you forgot to report the correct size of freed
- memory in some of your smob free methods. */
- abort ();
-
- SCM_SYSCALL (ptr = malloc (size));
- if (NULL != ptr)
- {
- scm_mallocated = nm;
- if (nm > scm_mtrigger - SCM_MTRIGGER_HYSTERESIS) {
- if (nm > scm_mtrigger)
- scm_mtrigger = nm + nm / 2;
- else
- scm_mtrigger += scm_mtrigger / 2;
- }
-#ifdef GUILE_DEBUG_MALLOC
- scm_malloc_register (ptr, what);
-#endif
-
- return ptr;
- }
-
- scm_memory_error (what);
-}
-
-
-/* scm_must_realloc
- * is similar to scm_must_malloc.
- */
-void *
-scm_must_realloc (void *where,
- size_t old_size,
- size_t size,
- const char *what)
-{
- void *ptr;
- unsigned long nm;
-
- if (size <= old_size)
- return where;
-
- nm = scm_mallocated + size - old_size;
-
- if (nm < (size - old_size))
- /* The byte count of allocated objects has overflowed. This is
- probably because you forgot to report the correct size of freed
- memory in some of your smob free methods. */
- abort ();
-
- if (nm <= scm_mtrigger)
- {
- SCM_SYSCALL (ptr = realloc (where, size));
- if (NULL != ptr)
- {
- scm_mallocated = nm;
-#ifdef GUILE_DEBUG_MALLOC
- scm_malloc_reregister (where, ptr, what);
-#endif
- return ptr;
- }
- }
-
- scm_igc (what);
-
- nm = scm_mallocated + size - old_size;
-
- if (nm < (size - old_size))
- /* The byte count of allocated objects has overflowed. This is
- probably because you forgot to report the correct size of freed
- memory in some of your smob free methods. */
- abort ();
-
- SCM_SYSCALL (ptr = realloc (where, size));
- if (NULL != ptr)
- {
- scm_mallocated = nm;
- if (nm > scm_mtrigger - SCM_MTRIGGER_HYSTERESIS) {
- if (nm > scm_mtrigger)
- scm_mtrigger = nm + nm / 2;
- else
- scm_mtrigger += scm_mtrigger / 2;
- }
-#ifdef GUILE_DEBUG_MALLOC
- scm_malloc_reregister (where, ptr, what);
-#endif
- return ptr;
- }
-
- scm_memory_error (what);
-}
-
-char *
-scm_must_strndup (const char *str, size_t length)
-{
- char * dst = scm_must_malloc (length + 1, "scm_must_strndup");
- memcpy (dst, str, length);
- dst[length] = 0;
- return dst;
-}
-
-char *
-scm_must_strdup (const char *str)
-{
- return scm_must_strndup (str, strlen (str));
-}
-
-void
-scm_must_free (void *obj)
-#define FUNC_NAME "scm_must_free"
-{
-#ifdef GUILE_DEBUG_MALLOC
- scm_malloc_unregister (obj);
-#endif
- if (obj)
- free (obj);
- else
- SCM_MISC_ERROR ("freeing NULL pointer", SCM_EOL);
-}
-#undef FUNC_NAME
-
-
-/* Announce that there has been some malloc done that will be freed
- * during gc. A typical use is for a smob that uses some malloced
- * memory but can not get it from scm_must_malloc (for whatever
- * reason). When a new object of this smob is created you call
- * scm_done_malloc with the size of the object. When your smob free
- * function is called, be sure to include this size in the return
- * value.
- *
- * If you can't actually free the memory in the smob free function,
- * for whatever reason (like reference counting), you still can (and
- * should) report the amount of memory freed when you actually free it.
- * Do it by calling scm_done_malloc with the _negated_ size. Clever,
- * eh? Or even better, call scm_done_free. */
-
-void
-scm_done_malloc (long size)
-{
- if (size < 0) {
- if (scm_mallocated < size)
- /* The byte count of allocated objects has underflowed. This is
- probably because you forgot to report the sizes of objects you
- have allocated, by calling scm_done_malloc or some such. When
- the GC freed them, it subtracted their size from
- scm_mallocated, which underflowed. */
- abort ();
- } else {
- unsigned long nm = scm_mallocated + size;
- if (nm < size)
- /* The byte count of allocated objects has overflowed. This is
- probably because you forgot to report the correct size of freed
- memory in some of your smob free methods. */
- abort ();
- }
-
- scm_mallocated += size;
-
- if (scm_mallocated > scm_mtrigger)
- {
- scm_igc ("foreign mallocs");
- if (scm_mallocated > scm_mtrigger - SCM_MTRIGGER_HYSTERESIS)
- {
- if (scm_mallocated > scm_mtrigger)
- scm_mtrigger = scm_mallocated + scm_mallocated / 2;
- else
- scm_mtrigger += scm_mtrigger / 2;
- }
- }
-}
-
-void
-scm_done_free (long size)
-{
- if (size >= 0) {
- if (scm_mallocated < size)
- /* The byte count of allocated objects has underflowed. This is
- probably because you forgot to report the sizes of objects you
- have allocated, by calling scm_done_malloc or some such. When
- the GC freed them, it subtracted their size from
- scm_mallocated, which underflowed. */
- abort ();
- } else {
- unsigned long nm = scm_mallocated + size;
- if (nm < size)
- /* The byte count of allocated objects has overflowed. This is
- probably because you forgot to report the correct size of freed
- memory in some of your smob free methods. */
- abort ();
- }
-
- scm_mallocated -= size;
-}
-
-
-\f
-/* {Heap Segments}
- *
- * Each heap segment is an array of objects of a particular size.
- * Every segment has an associated (possibly shared) freelist.
- * A table of segment records is kept that records the upper and
- * lower extents of the segment; this is used during the conservative
- * phase of gc to identify probably gc roots (because they point
- * into valid segments at reasonable offsets). */
-
-/* scm_expmem
- * is true if the first segment was smaller than INIT_HEAP_SEG.
- * If scm_expmem is set to one, subsequent segment allocations will
- * allocate segments of size SCM_EXPHEAP(scm_heap_size).
- */
-int scm_expmem = 0;
-
-size_t scm_max_segment_size;
-
-/* scm_heap_org
- * is the lowest base address of any heap segment.
- */
-SCM_CELLPTR scm_heap_org;
-
-scm_heap_seg_data_t * scm_heap_table = 0;
-static size_t heap_segment_table_size = 0;
-size_t scm_n_heap_segs = 0;
-
-/* init_heap_seg
- * initializes a new heap segment and returns the number of objects it contains.
- *
- * The segment origin and segment size in bytes are input parameters.
- * The freelist is both input and output.
- *
- * This function presumes that the scm_heap_table has already been expanded
- * to accomodate a new segment record and that the markbit space was reserved
- * for all the cards in this segment.
- */
-
-#define INIT_CARD(card, span) \
- do { \
- SCM_GC_SET_CARD_BVEC (card, get_bvec ()); \
- if ((span) == 2) \
- SCM_GC_SET_CARD_DOUBLECELL (card); \
- } while (0)
-
-static size_t
-init_heap_seg (SCM_CELLPTR seg_org, size_t size, scm_freelist_t *freelist)
-{
- register SCM_CELLPTR ptr;
- SCM_CELLPTR seg_end;
- long new_seg_index;
- ptrdiff_t n_new_cells;
- int span = freelist->span;
-
- if (seg_org == NULL)
- return 0;
-
- /* Align the begin ptr up.
- */
- ptr = SCM_GC_CARD_UP (seg_org);
-
- /* Compute the ceiling on valid object pointers w/in this segment.
- */
- seg_end = SCM_GC_CARD_DOWN ((char *)seg_org + size);
-
- /* Find the right place and insert the segment record.
- *
- */
- for (new_seg_index = 0;
- ( (new_seg_index < scm_n_heap_segs)
- && SCM_PTR_LE (scm_heap_table[new_seg_index].bounds[0], seg_org));
- new_seg_index++)
- ;
-
- {
- int i;
- for (i = scm_n_heap_segs; i > new_seg_index; --i)
- scm_heap_table[i] = scm_heap_table[i - 1];
- }
-
- ++scm_n_heap_segs;
-
- scm_heap_table[new_seg_index].span = span;
- scm_heap_table[new_seg_index].freelist = freelist;
- scm_heap_table[new_seg_index].bounds[0] = ptr;
- scm_heap_table[new_seg_index].bounds[1] = seg_end;
-
- /*n_new_cells*/
- n_new_cells = seg_end - ptr;
-
- freelist->heap_size += n_new_cells;
-
- /* Partition objects in this segment into clusters */
- {
- SCM clusters;
- SCM *clusterp = &clusters;
-
- NEXT_DATA_CELL (ptr, span);
- while (ptr < seg_end)
- {
- scm_cell *nxt = ptr;
- scm_cell *prv = NULL;
- scm_cell *last_card = NULL;
- int n_data_cells = (SCM_GC_CARD_N_DATA_CELLS / span) * SCM_CARDS_PER_CLUSTER - 1;
- NEXT_DATA_CELL(nxt, span);
-
- /* Allocate cluster spine
- */
- *clusterp = PTR2SCM (ptr);
- SCM_SETCAR (*clusterp, PTR2SCM (nxt));
- clusterp = SCM_CDRLOC (*clusterp);
- ptr = nxt;
-
- while (n_data_cells--)
- {
- scm_cell *card = SCM_GC_CELL_CARD (ptr);
- SCM scmptr = PTR2SCM (ptr);
- nxt = ptr;
- NEXT_DATA_CELL (nxt, span);
- prv = ptr;
-
- if (card != last_card)
- {
- INIT_CARD (card, span);
- last_card = card;
- }
-
- SCM_SET_CELL_TYPE (scmptr, scm_tc_free_cell);
- SCM_SET_FREE_CELL_CDR (scmptr, PTR2SCM (nxt));
-
- ptr = nxt;
- }
-
- SCM_SET_FREE_CELL_CDR (PTR2SCM (prv), SCM_EOL);
- }
-
- /* sanity check */
- {
- scm_cell *ref = seg_end;
- NEXT_DATA_CELL (ref, span);
- if (ref != ptr)
- /* [cmm] looks like the segment size doesn't divide cleanly by
- cluster size. bad cmm! */
- abort();
- }
-
- /* Patch up the last cluster pointer in the segment
- * to join it to the input freelist.
- */
- *clusterp = freelist->clusters;
- freelist->clusters = clusters;
- }
-
-#ifdef DEBUGINFO
- fprintf (stderr, "H");
-#endif
- return size;
-}
-
-static size_t
-round_to_cluster_size (scm_freelist_t *freelist, size_t len)
-{
- size_t cluster_size_in_bytes = CLUSTER_SIZE_IN_BYTES (freelist);
-
- return
- (len + cluster_size_in_bytes - 1) / cluster_size_in_bytes * cluster_size_in_bytes
- + ALIGNMENT_SLACK (freelist);
-}
-
-static void
-alloc_some_heap (scm_freelist_t *freelist, policy_on_error error_policy)
-#define FUNC_NAME "alloc_some_heap"
-{
- SCM_CELLPTR ptr;
- size_t len;
-
- if (scm_gc_heap_lock)
- {
- /* Critical code sections (such as the garbage collector) aren't
- * supposed to add heap segments.
- */
- fprintf (stderr, "alloc_some_heap: Can not extend locked heap.\n");
- abort ();
- }
-
- if (scm_n_heap_segs == heap_segment_table_size)
- {
- /* We have to expand the heap segment table to have room for the new
- * segment. Do not yet increment scm_n_heap_segs -- that is done by
- * init_heap_seg only if the allocation of the segment itself succeeds.
- */
- size_t new_table_size = scm_n_heap_segs + 1;
- size_t size = new_table_size * sizeof (scm_heap_seg_data_t);
- scm_heap_seg_data_t *new_heap_table;
-
- SCM_SYSCALL (new_heap_table = ((scm_heap_seg_data_t *)
- realloc ((char *)scm_heap_table, size)));
- if (!new_heap_table)
- {
- if (error_policy == abort_on_error)
- {
- fprintf (stderr, "alloc_some_heap: Could not grow heap segment table.\n");
- abort ();
- }
- else
- {
- return;
- }
- }
- else
- {
- scm_heap_table = new_heap_table;
- heap_segment_table_size = new_table_size;
- }
- }
-
- /* Pick a size for the new heap segment.
- * The rule for picking the size of a segment is explained in
- * gc.h
- */
- {
- /* Assure that the new segment is predicted to be large enough.
- *
- * New yield should at least equal GC fraction of new heap size, i.e.
- *
- * y + dh > f * (h + dh)
- *
- * y : yield
- * f : min yield fraction
- * h : heap size
- * dh : size of new heap segment
- *
- * This gives dh > (f * h - y) / (1 - f)
- */
- int f = freelist->min_yield_fraction;
- unsigned long h = SCM_HEAP_SIZE;
- size_t min_cells = (f * h - 100 * (long) scm_gc_yield) / (99 - f);
- len = SCM_EXPHEAP (freelist->heap_size);
-#ifdef DEBUGINFO
- fprintf (stderr, "(%ld < %ld)", (long) len, (long) min_cells);
-#endif
- if (len < min_cells)
- len = min_cells + freelist->cluster_size;
- len *= sizeof (scm_cell);
- /* force new sampling */
- freelist->collected = LONG_MAX;
- }
-
- if (len > scm_max_segment_size)
- len = scm_max_segment_size;
-
- {
- size_t smallest;
-
- smallest = CLUSTER_SIZE_IN_BYTES (freelist);
-
- if (len < smallest)
- len = smallest;
-
- /* Allocate with decaying ambition. */
- while ((len >= SCM_MIN_HEAP_SEG_SIZE)
- && (len >= smallest))
- {
- size_t rounded_len = round_to_cluster_size (freelist, len);
- SCM_SYSCALL (ptr = (SCM_CELLPTR) malloc (rounded_len));
- if (ptr)
- {
- init_heap_seg (ptr, rounded_len, freelist);
- return;
- }
- len /= 2;
- }
- }
-
- if (error_policy == abort_on_error)
- {
- fprintf (stderr, "alloc_some_heap: Could not grow heap.\n");
- abort ();
- }
-}
-#undef FUNC_NAME
-
-\f
-/* {GC Protection Helper Functions}
- */
-
-
-/*
- * If within a function you need to protect one or more scheme objects from
- * garbage collection, pass them as parameters to one of the
- * scm_remember_upto_here* functions below. These functions don't do
- * anything, but since the compiler does not know that they are actually
- * no-ops, it will generate code that calls these functions with the given
- * parameters. Therefore, you can be sure that the compiler will keep those
- * scheme values alive (on the stack or in a register) up to the point where
- * scm_remember_upto_here* is called. In other words, place the call to
- * scm_remember_upt_here* _behind_ the last code in your function, that
- * depends on the scheme object to exist.
- *
- * Example: We want to make sure, that the string object str does not get
- * garbage collected during the execution of 'some_function', because
- * otherwise the characters belonging to str would be freed and
- * 'some_function' might access freed memory. To make sure that the compiler
- * keeps str alive on the stack or in a register such that it is visible to
- * the conservative gc we add the call to scm_remember_upto_here_1 _after_ the
- * call to 'some_function'. Note that this would not be necessary if str was
- * used anyway after the call to 'some_function'.
- * char *chars = SCM_STRING_CHARS (str);
- * some_function (chars);
- * scm_remember_upto_here_1 (str); // str will be alive up to this point.
- */
-
-void
-scm_remember_upto_here_1 (SCM obj)
-{
- /* Empty. Protects a single object from garbage collection. */
-}
-
-void
-scm_remember_upto_here_2 (SCM obj1, SCM obj2)
-{
- /* Empty. Protects two objects from garbage collection. */
-}
-
-void
-scm_remember_upto_here (SCM obj, ...)
-{
- /* Empty. Protects any number of objects from garbage collection. */
-}
-
-
-#if (SCM_DEBUG_DEPRECATED == 0)
-
-void
-scm_remember (SCM *ptr)
-{
- scm_c_issue_deprecation_warning ("`scm_remember' is deprecated. "
- "Use the `scm_remember_upto_here*' family of functions instead.");
-}
-
-SCM
-scm_protect_object (SCM obj)
-{
- scm_c_issue_deprecation_warning ("`scm_protect_object' is deprecated. "
- "Use `scm_gc_protect_object' instead.");
- return scm_gc_protect_object (obj);
-}
-
-SCM
-scm_unprotect_object (SCM obj)
-{
- scm_c_issue_deprecation_warning ("`scm_unprotect_object' is deprecated. "
- "Use `scm_gc_unprotect_object' instead.");
- return scm_gc_unprotect_object (obj);
-}
-
-#endif /* SCM_DEBUG_DEPRECATED == 0 */
-
-/*
- These crazy functions prevent garbage collection
- of arguments after the first argument by
- ensuring they remain live throughout the
- function because they are used in the last
- line of the code block.
- It'd be better to have a nice compiler hint to
- aid the conservative stack-scanning GC. --03/09/00 gjb */
-SCM
-scm_return_first (SCM elt, ...)
-{
- return elt;
-}
-
-int
-scm_return_first_int (int i, ...)
-{
- return i;
-}
-
-
-SCM
-scm_permanent_object (SCM obj)
-{
- SCM_REDEFER_INTS;
- scm_permobjs = scm_cons (obj, scm_permobjs);
- SCM_REALLOW_INTS;
- return obj;
-}
-
-
-/* Protect OBJ from the garbage collector. OBJ will not be freed, even if all
- other references are dropped, until the object is unprotected by calling
- scm_gc_unprotect_object (OBJ). Calls to scm_gc_protect/unprotect_object nest,
- i. e. it is possible to protect the same object several times, but it is
- necessary to unprotect the object the same number of times to actually get
- the object unprotected. It is an error to unprotect an object more often
- than it has been protected before. The function scm_protect_object returns
- OBJ.
-*/
-
-/* Implementation note: For every object X, there is a counter which
- scm_gc_protect_object(X) increments and scm_gc_unprotect_object(X) decrements.
-*/
-
-SCM
-scm_gc_protect_object (SCM obj)
-{
- SCM handle;
-
- /* This critical section barrier will be replaced by a mutex. */
- SCM_REDEFER_INTS;
-
- handle = scm_hashq_create_handle_x (scm_protects, obj, SCM_MAKINUM (0));
- SCM_SETCDR (handle, scm_sum (SCM_CDR (handle), SCM_MAKINUM (1)));
-
- SCM_REALLOW_INTS;
-
- return obj;
-}
-
-
-/* Remove any protection for OBJ established by a prior call to
- scm_protect_object. This function returns OBJ.
-
- See scm_protect_object for more information. */
-SCM
-scm_gc_unprotect_object (SCM obj)
-{
- SCM handle;
-
- /* This critical section barrier will be replaced by a mutex. */
- SCM_REDEFER_INTS;
-
- handle = scm_hashq_get_handle (scm_protects, obj);
-
- if (SCM_FALSEP (handle))
- {
- fprintf (stderr, "scm_unprotect_object called on unprotected object\n");
- abort ();
- }
- else
- {
- SCM count = scm_difference (SCM_CDR (handle), SCM_MAKINUM (1));
- if (SCM_EQ_P (count, SCM_MAKINUM (0)))
- scm_hashq_remove_x (scm_protects, obj);
- else
- SCM_SETCDR (handle, count);
- }
-
- SCM_REALLOW_INTS;
-
- return obj;
-}
-
-void
-scm_gc_register_root (SCM *p)
-{
- SCM handle;
- SCM key = scm_long2num ((long) p);
-
- /* This critical section barrier will be replaced by a mutex. */
- SCM_REDEFER_INTS;
-
- handle = scm_hashv_create_handle_x (scm_gc_registered_roots, key, SCM_MAKINUM (0));
- SCM_SETCDR (handle, scm_sum (SCM_CDR (handle), SCM_MAKINUM (1)));
-
- SCM_REALLOW_INTS;
-}
-
-void
-scm_gc_unregister_root (SCM *p)
-{
- SCM handle;
- SCM key = scm_long2num ((long) p);
-
- /* This critical section barrier will be replaced by a mutex. */
- SCM_REDEFER_INTS;
-
- handle = scm_hashv_get_handle (scm_gc_registered_roots, key);
-
- if (SCM_FALSEP (handle))
- {
- fprintf (stderr, "scm_gc_unregister_root called on unregistered root\n");
- abort ();
- }
- else
- {
- SCM count = scm_difference (SCM_CDR (handle), SCM_MAKINUM (1));
- if (SCM_EQ_P (count, SCM_MAKINUM (0)))
- scm_hashv_remove_x (scm_gc_registered_roots, key);
- else
- SCM_SETCDR (handle, count);
- }
-
- SCM_REALLOW_INTS;
-}
-
-void
-scm_gc_register_roots (SCM *b, unsigned long n)
-{
- SCM *p = b;
- for (; p < b + n; ++p)
- scm_gc_register_root (p);
-}
-
-void
-scm_gc_unregister_roots (SCM *b, unsigned long n)
-{
- SCM *p = b;
- for (; p < b + n; ++p)
- scm_gc_unregister_root (p);
-}
-
-int terminating;
-
-/* called on process termination. */
-#ifdef HAVE_ATEXIT
-static void
-cleanup (void)
-#else
-#ifdef HAVE_ON_EXIT
-extern int on_exit (void (*procp) (), int arg);
-
-static void
-cleanup (int status, void *arg)
-#else
-#error Dont know how to setup a cleanup handler on your system.
-#endif
-#endif
-{
- terminating = 1;
- scm_flush_all_ports ();
-}
-
-\f
-static int
-make_initial_segment (size_t init_heap_size, scm_freelist_t *freelist)
-{
- size_t rounded_size = round_to_cluster_size (freelist, init_heap_size);
-
- if (!init_heap_seg ((SCM_CELLPTR) malloc (rounded_size),
- rounded_size,
- freelist))
- {
- rounded_size = round_to_cluster_size (freelist, SCM_HEAP_SEG_SIZE);
- if (!init_heap_seg ((SCM_CELLPTR) malloc (rounded_size),
- rounded_size,
- freelist))
- return 1;
- }
- else
- scm_expmem = 1;
-
- if (freelist->min_yield_fraction)
- freelist->min_yield = (freelist->heap_size * freelist->min_yield_fraction
- / 100);
- freelist->grow_heap_p = (freelist->heap_size < freelist->min_yield);
-
- return 0;
-}
-
-\f
-static void
-init_freelist (scm_freelist_t *freelist,
- int span,
- long cluster_size,
- int min_yield)
-{
- freelist->clusters = SCM_EOL;
- freelist->cluster_size = cluster_size + 1;
- freelist->left_to_collect = 0;
- freelist->clusters_allocated = 0;
- freelist->min_yield = 0;
- freelist->min_yield_fraction = min_yield;
- freelist->span = span;
- freelist->collected = 0;
- freelist->collected_1 = 0;
- freelist->heap_size = 0;
-}
-
-
-/* Get an integer from an environment variable. */
-static int
-scm_i_getenv_int (const char *var, int def)
-{
- char *end, *val = getenv (var);
- long res;
- if (!val)
- return def;
- res = strtol (val, &end, 10);
- if (end == val)
- return def;
- return res;
-}
-
-
-int
-scm_init_storage ()
-{
- unsigned long gc_trigger_1;
- unsigned long gc_trigger_2;
- size_t init_heap_size_1;
- size_t init_heap_size_2;
- size_t j;
-
-#if (SCM_DEBUG_CELL_ACCESSES == 1)
- scm_tc16_allocated = scm_make_smob_type ("allocated cell", 0);
-#endif /* SCM_DEBUG_CELL_ACCESSES == 1 */
-
- j = SCM_NUM_PROTECTS;
- while (j)
- scm_sys_protects[--j] = SCM_BOOL_F;
- scm_block_gc = 1;
-
- scm_freelist = SCM_EOL;
- scm_freelist2 = SCM_EOL;
- gc_trigger_1 = scm_i_getenv_int ("GUILE_MIN_YIELD_1", scm_default_min_yield_1);
- init_freelist (&scm_master_freelist, 1, SCM_CLUSTER_SIZE_1, gc_trigger_1);
- gc_trigger_2 = scm_i_getenv_int ("GUILE_MIN_YIELD_2", scm_default_min_yield_2);
- init_freelist (&scm_master_freelist2, 2, SCM_CLUSTER_SIZE_2, gc_trigger_2);
- scm_max_segment_size = scm_i_getenv_int ("GUILE_MAX_SEGMENT_SIZE", scm_default_max_segment_size);
-
- scm_expmem = 0;
-
- j = SCM_HEAP_SEG_SIZE;
- scm_mtrigger = SCM_INIT_MALLOC_LIMIT;
- scm_heap_table = ((scm_heap_seg_data_t *)
- scm_must_malloc (sizeof (scm_heap_seg_data_t) * 2, "hplims"));
- heap_segment_table_size = 2;
-
- mark_space_ptr = &mark_space_head;
-
- init_heap_size_1 = scm_i_getenv_int ("GUILE_INIT_SEGMENT_SIZE_1", scm_default_init_heap_size_1);
- init_heap_size_2 = scm_i_getenv_int ("GUILE_INIT_SEGMENT_SIZE_2", scm_default_init_heap_size_2);
- if (make_initial_segment (init_heap_size_1, &scm_master_freelist) ||
- make_initial_segment (init_heap_size_2, &scm_master_freelist2))
- return 1;
-
- /* scm_hplims[0] can change. do not remove scm_heap_org */
- scm_heap_org = CELL_UP (scm_heap_table[0].bounds[0], 1);
-
- scm_c_hook_init (&scm_before_gc_c_hook, 0, SCM_C_HOOK_NORMAL);
- scm_c_hook_init (&scm_before_mark_c_hook, 0, SCM_C_HOOK_NORMAL);
- scm_c_hook_init (&scm_before_sweep_c_hook, 0, SCM_C_HOOK_NORMAL);
- scm_c_hook_init (&scm_after_sweep_c_hook, 0, SCM_C_HOOK_NORMAL);
- scm_c_hook_init (&scm_after_gc_c_hook, 0, SCM_C_HOOK_NORMAL);
-
- /* Initialise the list of ports. */
- scm_port_table = (scm_port_t **)
- malloc (sizeof (scm_port_t *) * scm_port_table_room);
- if (!scm_port_table)
- return 1;
-
-#ifdef HAVE_ATEXIT
- atexit (cleanup);
-#else
-#ifdef HAVE_ON_EXIT
- on_exit (cleanup, 0);
-#endif
-#endif
-
- scm_stand_in_procs = SCM_EOL;
- scm_permobjs = SCM_EOL;
- scm_protects = scm_c_make_hash_table (31);
- scm_gc_registered_roots = scm_c_make_hash_table (31);
-
- return 0;
-}
-
-\f
-
-SCM scm_after_gc_hook;
-
-static SCM gc_async;
-
-/* The function gc_async_thunk causes the execution of the after-gc-hook. It
- * is run after the gc, as soon as the asynchronous events are handled by the
- * evaluator.
- */
-static SCM
-gc_async_thunk (void)
-{
- scm_c_run_hook (scm_after_gc_hook, SCM_EOL);
- return SCM_UNSPECIFIED;
-}
-
-
-/* The function mark_gc_async is run by the scm_after_gc_c_hook at the end of
- * the garbage collection. The only purpose of this function is to mark the
- * gc_async (which will eventually lead to the execution of the
- * gc_async_thunk).
- */
-static void *
-mark_gc_async (void * hook_data, void *func_data, void *data)
-{
- scm_system_async_mark (gc_async);
- return NULL;
-}
-
-
-void
-scm_init_gc ()
-{
- SCM after_gc_thunk;
-
- /* Dirk:FIXME:: scm_create_hook is strange. */
- scm_after_gc_hook = scm_create_hook ("after-gc-hook", 0);
-
- after_gc_thunk = scm_c_make_subr ("%gc-thunk", scm_tc7_subr_0,
- gc_async_thunk);
- gc_async = scm_system_async (after_gc_thunk); /* protected via scm_asyncs */
-
- scm_c_hook_add (&scm_after_gc_c_hook, mark_gc_async, NULL, 0);
-
-#ifndef SCM_MAGIC_SNARFER
-#include "libguile/gc.x"
-#endif
-}
-
-#endif /*MARK_DEPENDENCIES*/
-
-/*
- Local Variables:
- c-file-style: "gnu"
- End:
-*/
+/* Copyright (C) 1995,1996,1997,1998,1999,2000,2001, 2002, 2003, 2006 Free Software Foundation, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#define _GNU_SOURCE
+
+/* #define DEBUGINFO */
+
+#if HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+#include <assert.h>
+
+#include "libguile/_scm.h"
+#include "libguile/eval.h"
+#include "libguile/stime.h"
+#include "libguile/stackchk.h"
+#include "libguile/struct.h"
+#include "libguile/smob.h"
+#include "libguile/unif.h"
+#include "libguile/async.h"
+#include "libguile/ports.h"
+#include "libguile/root.h"
+#include "libguile/strings.h"
+#include "libguile/vectors.h"
+#include "libguile/weaks.h"
+#include "libguile/hashtab.h"
+#include "libguile/tags.h"
+
+#include "libguile/private-gc.h"
+#include "libguile/validate.h"
+#include "libguile/deprecation.h"
+#include "libguile/gc.h"
+#include "libguile/dynwind.h"
+
+#ifdef GUILE_DEBUG_MALLOC
+#include "libguile/debug-malloc.h"
+#endif
+
+#ifdef HAVE_MALLOC_H
+#include <malloc.h>
+#endif
+
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+
+/* Lock this mutex before doing lazy sweeping.
+ */
+scm_i_pthread_mutex_t scm_i_sweep_mutex = SCM_I_PTHREAD_MUTEX_INITIALIZER;
+
+/* Set this to != 0 if every cell that is accessed shall be checked:
+ */
+int scm_debug_cell_accesses_p = 0;
+int scm_expensive_debug_cell_accesses_p = 0;
+
+/* Set this to 0 if no additional gc's shall be performed, otherwise set it to
+ * the number of cell accesses after which a gc shall be called.
+ */
+int scm_debug_cells_gc_interval = 0;
+
+/*
+ Global variable, so you can switch it off at runtime by setting
+ scm_i_cell_validation_already_running.
+ */
+int scm_i_cell_validation_already_running ;
+
+#if (SCM_DEBUG_CELL_ACCESSES == 1)
+
+
+/*
+
+ Assert that the given object is a valid reference to a valid cell. This
+ test involves to determine whether the object is a cell pointer, whether
+ this pointer actually points into a heap segment and whether the cell
+ pointed to is not a free cell. Further, additional garbage collections may
+ get executed after a user defined number of cell accesses. This helps to
+ find places in the C code where references are dropped for extremely short
+ periods.
+
+*/
+void
+scm_i_expensive_validation_check (SCM cell)
+{
+ if (!scm_in_heap_p (cell))
+ {
+ fprintf (stderr, "scm_assert_cell_valid: this object does not live in the heap: %lux\n",
+ (unsigned long) SCM_UNPACK (cell));
+ abort ();
+ }
+
+ /* If desired, perform additional garbage collections after a user
+ * defined number of cell accesses.
+ */
+ if (scm_debug_cells_gc_interval)
+ {
+ static unsigned int counter = 0;
+
+ if (counter != 0)
+ {
+ --counter;
+ }
+ else
+ {
+ counter = scm_debug_cells_gc_interval;
+ scm_gc ();
+ }
+ }
+}
+
+void
+scm_assert_cell_valid (SCM cell)
+{
+ if (!scm_i_cell_validation_already_running && scm_debug_cell_accesses_p)
+ {
+ scm_i_cell_validation_already_running = 1; /* set to avoid recursion */
+
+ /*
+ During GC, no user-code should be run, and the guile core
+ should use non-protected accessors.
+ */
+ if (scm_gc_running_p)
+ return;
+
+ /*
+ Only scm_in_heap_p and rescanning the heap is wildly
+ expensive.
+ */
+ if (scm_expensive_debug_cell_accesses_p)
+ scm_i_expensive_validation_check (cell);
+
+ if (!SCM_GC_MARK_P (cell))
+ {
+ fprintf (stderr,
+ "scm_assert_cell_valid: this object is unmarked. \n"
+ "It has been garbage-collected in the last GC run: "
+ "%lux\n",
+ (unsigned long) SCM_UNPACK (cell));
+ abort ();
+ }
+
+ scm_i_cell_validation_already_running = 0; /* re-enable */
+ }
+}
+
+
+
+SCM_DEFINE (scm_set_debug_cell_accesses_x, "set-debug-cell-accesses!", 1, 0, 0,
+ (SCM flag),
+ "If @var{flag} is @code{#f}, cell access checking is disabled.\n"
+ "If @var{flag} is @code{#t}, cheap cell access checking is enabled,\n"
+ "but no additional calls to garbage collection are issued.\n"
+ "If @var{flag} is a number, strict cell access checking is enabled,\n"
+ "with an additional garbage collection after the given\n"
+ "number of cell accesses.\n"
+ "This procedure only exists when the compile-time flag\n"
+ "@code{SCM_DEBUG_CELL_ACCESSES} was set to 1.")
+#define FUNC_NAME s_scm_set_debug_cell_accesses_x
+{
+ if (scm_is_false (flag))
+ {
+ scm_debug_cell_accesses_p = 0;
+ }
+ else if (scm_is_eq (flag, SCM_BOOL_T))
+ {
+ scm_debug_cells_gc_interval = 0;
+ scm_debug_cell_accesses_p = 1;
+ scm_expensive_debug_cell_accesses_p = 0;
+ }
+ else
+ {
+ scm_debug_cells_gc_interval = scm_to_signed_integer (flag, 0, INT_MAX);
+ scm_debug_cell_accesses_p = 1;
+ scm_expensive_debug_cell_accesses_p = 1;
+ }
+ return SCM_UNSPECIFIED;
+}
+#undef FUNC_NAME
+
+
+#endif /* SCM_DEBUG_CELL_ACCESSES == 1 */
+
+\f
+
+
+/* scm_mtrigger
+ * is the number of bytes of malloc allocation needed to trigger gc.
+ */
+unsigned long scm_mtrigger;
+
+/* GC Statistics Keeping
+ */
+unsigned long scm_cells_allocated = 0;
+unsigned long scm_mallocated = 0;
+
+/* Global GC sweep statistics since the last full GC. */
+static scm_t_sweep_statistics scm_i_gc_sweep_stats = { 0, 0 };
+static scm_t_sweep_statistics scm_i_gc_sweep_stats_1 = { 0, 0 };
+
+/* Total count of cells marked/swept. */
+static double scm_gc_cells_marked_acc = 0.;
+static double scm_gc_cells_swept_acc = 0.;
+
+static unsigned long scm_gc_time_taken = 0;
+static unsigned long t_before_gc;
+static unsigned long scm_gc_mark_time_taken = 0;
+
+static unsigned long scm_gc_times = 0;
+
+static int scm_gc_cell_yield_percentage = 0;
+static unsigned long protected_obj_count = 0;
+
+/* The following are accessed from `gc-malloc.c' and `gc-card.c'. */
+int scm_gc_malloc_yield_percentage = 0;
+unsigned long scm_gc_malloc_collected = 0;
+unsigned long scm_gc_ports_collected = 0;
+
+
+SCM_SYMBOL (sym_cells_allocated, "cells-allocated");
+SCM_SYMBOL (sym_heap_size, "cell-heap-size");
+SCM_SYMBOL (sym_mallocated, "bytes-malloced");
+SCM_SYMBOL (sym_mtrigger, "gc-malloc-threshold");
+SCM_SYMBOL (sym_heap_segments, "cell-heap-segments");
+SCM_SYMBOL (sym_gc_time_taken, "gc-time-taken");
+SCM_SYMBOL (sym_gc_mark_time_taken, "gc-mark-time-taken");
+SCM_SYMBOL (sym_times, "gc-times");
+SCM_SYMBOL (sym_cells_marked, "cells-marked");
+SCM_SYMBOL (sym_cells_swept, "cells-swept");
+SCM_SYMBOL (sym_malloc_yield, "malloc-yield");
+SCM_SYMBOL (sym_cell_yield, "cell-yield");
+SCM_SYMBOL (sym_protected_objects, "protected-objects");
+
+
+
+
+/* Number of calls to SCM_NEWCELL since startup. */
+unsigned scm_newcell_count;
+unsigned scm_newcell2_count;
+
+
+/* {Scheme Interface to GC}
+ */
+static SCM
+tag_table_to_type_alist (void *closure, SCM key, SCM val, SCM acc)
+{
+ if (scm_is_integer (key))
+ {
+ int c_tag = scm_to_int (key);
+
+ char const * name = scm_i_tag_name (c_tag);
+ if (name != NULL)
+ {
+ key = scm_from_locale_string (name);
+ }
+ else
+ {
+ char s[100];
+ sprintf (s, "tag %d", c_tag);
+ key = scm_from_locale_string (s);
+ }
+ }
+
+ return scm_cons (scm_cons (key, val), acc);
+}
+
+SCM_DEFINE (scm_gc_live_object_stats, "gc-live-object-stats", 0, 0, 0,
+ (),
+ "Return an alist of statistics of the current live objects. ")
+#define FUNC_NAME s_scm_gc_live_object_stats
+{
+ SCM tab = scm_make_hash_table (scm_from_int (57));
+ SCM alist;
+
+ scm_i_all_segments_statistics (tab);
+
+ alist
+ = scm_internal_hash_fold (&tag_table_to_type_alist, NULL, SCM_EOL, tab);
+
+ return alist;
+}
+#undef FUNC_NAME
+
+extern int scm_gc_malloc_yield_percentage;
+SCM_DEFINE (scm_gc_stats, "gc-stats", 0, 0, 0,
+ (),
+ "Return an association list of statistics about Guile's current\n"
+ "use of storage.\n")
+#define FUNC_NAME s_scm_gc_stats
+{
+ long i = 0;
+ SCM heap_segs = SCM_EOL ;
+ unsigned long int local_scm_mtrigger;
+ unsigned long int local_scm_mallocated;
+ unsigned long int local_scm_heap_size;
+ int local_scm_gc_cell_yield_percentage;
+ int local_scm_gc_malloc_yield_percentage;
+ unsigned long int local_scm_cells_allocated;
+ unsigned long int local_scm_gc_time_taken;
+ unsigned long int local_scm_gc_times;
+ unsigned long int local_scm_gc_mark_time_taken;
+ unsigned long int local_protected_obj_count;
+ double local_scm_gc_cells_swept;
+ double local_scm_gc_cells_marked;
+ SCM answer;
+ unsigned long *bounds = 0;
+ int table_size = scm_i_heap_segment_table_size;
+ SCM_CRITICAL_SECTION_START;
+
+ /*
+ temporarily store the numbers, so as not to cause GC.
+ */
+
+ bounds = malloc (sizeof (unsigned long) * table_size * 2);
+ if (!bounds)
+ abort();
+ for (i = table_size; i--; )
+ {
+ bounds[2*i] = (unsigned long)scm_i_heap_segment_table[i]->bounds[0];
+ bounds[2*i+1] = (unsigned long)scm_i_heap_segment_table[i]->bounds[1];
+ }
+
+
+ /* Below, we cons to produce the resulting list. We want a snapshot of
+ * the heap situation before consing.
+ */
+ local_scm_mtrigger = scm_mtrigger;
+ local_scm_mallocated = scm_mallocated;
+ local_scm_heap_size = SCM_HEAP_SIZE;
+
+ local_scm_cells_allocated = scm_cells_allocated;
+
+ local_scm_gc_time_taken = scm_gc_time_taken;
+ local_scm_gc_mark_time_taken = scm_gc_mark_time_taken;
+ local_scm_gc_times = scm_gc_times;
+ local_scm_gc_malloc_yield_percentage = scm_gc_malloc_yield_percentage;
+ local_scm_gc_cell_yield_percentage= scm_gc_cell_yield_percentage;
+ local_protected_obj_count = protected_obj_count;
+ local_scm_gc_cells_swept =
+ (double) scm_gc_cells_swept_acc
+ + (double) scm_i_gc_sweep_stats.swept;
+ local_scm_gc_cells_marked = scm_gc_cells_marked_acc
+ +(double) scm_i_gc_sweep_stats.swept
+ -(double) scm_i_gc_sweep_stats.collected;
+
+ for (i = table_size; i--;)
+ {
+ heap_segs = scm_cons (scm_cons (scm_from_ulong (bounds[2*i]),
+ scm_from_ulong (bounds[2*i+1])),
+ heap_segs);
+ }
+ /* njrev: can any of these scm_cons's or scm_list_n signal a memory
+ error? If so we need a frame here. */
+ answer =
+ scm_list_n (scm_cons (sym_gc_time_taken,
+ scm_from_ulong (local_scm_gc_time_taken)),
+ scm_cons (sym_cells_allocated,
+ scm_from_ulong (local_scm_cells_allocated)),
+ scm_cons (sym_heap_size,
+ scm_from_ulong (local_scm_heap_size)),
+ scm_cons (sym_mallocated,
+ scm_from_ulong (local_scm_mallocated)),
+ scm_cons (sym_mtrigger,
+ scm_from_ulong (local_scm_mtrigger)),
+ scm_cons (sym_times,
+ scm_from_ulong (local_scm_gc_times)),
+ scm_cons (sym_gc_mark_time_taken,
+ scm_from_ulong (local_scm_gc_mark_time_taken)),
+ scm_cons (sym_cells_marked,
+ scm_from_double (local_scm_gc_cells_marked)),
+ scm_cons (sym_cells_swept,
+ scm_from_double (local_scm_gc_cells_swept)),
+ scm_cons (sym_malloc_yield,
+ scm_from_long(local_scm_gc_malloc_yield_percentage)),
+ scm_cons (sym_cell_yield,
+ scm_from_long (local_scm_gc_cell_yield_percentage)),
+ scm_cons (sym_protected_objects,
+ scm_from_ulong (local_protected_obj_count)),
+ scm_cons (sym_heap_segments, heap_segs),
+ SCM_UNDEFINED);
+ SCM_CRITICAL_SECTION_END;
+
+ free (bounds);
+ return answer;
+}
+#undef FUNC_NAME
+
+/* Update the global sweeping/collection statistics by adding SWEEP_STATS to
+ SCM_I_GC_SWEEP_STATS and updating related variables. */
+static inline void
+gc_update_stats (scm_t_sweep_statistics sweep_stats)
+{
+ /* CELLS SWEPT is another word for the number of cells that were examined
+ during GC. YIELD is the number that we cleaned out. MARKED is the number
+ that weren't cleaned. */
+
+ scm_gc_cell_yield_percentage = (sweep_stats.collected * 100) / SCM_HEAP_SIZE;
+
+ scm_i_sweep_statistics_sum (&scm_i_gc_sweep_stats, sweep_stats);
+
+ if ((scm_i_gc_sweep_stats.collected > scm_i_gc_sweep_stats.swept)
+ || (scm_cells_allocated < sweep_stats.collected))
+ {
+ printf ("internal GC error, please report to `"
+ PACKAGE_BUGREPORT "'\n");
+ abort ();
+ }
+
+ scm_cells_allocated -= sweep_stats.collected;
+}
+
+static void
+gc_start_stats (const char *what SCM_UNUSED)
+{
+ t_before_gc = scm_c_get_internal_run_time ();
+
+ scm_gc_malloc_collected = 0;
+ scm_gc_ports_collected = 0;
+}
+
+static void
+gc_end_stats (scm_t_sweep_statistics sweep_stats)
+{
+ unsigned long t = scm_c_get_internal_run_time ();
+
+ scm_gc_time_taken += (t - t_before_gc);
+
+ /* Reset the number of cells swept/collected since the last full GC. */
+ scm_i_gc_sweep_stats_1 = scm_i_gc_sweep_stats;
+ scm_i_gc_sweep_stats.collected = scm_i_gc_sweep_stats.swept = 0;
+
+ gc_update_stats (sweep_stats);
+
+ scm_gc_cells_marked_acc += (double) scm_i_gc_sweep_stats.swept
+ - (double) scm_i_gc_sweep_stats.collected;
+ scm_gc_cells_swept_acc += (double) scm_i_gc_sweep_stats.swept;
+
+ ++scm_gc_times;
+}
+
+
+SCM_DEFINE (scm_object_address, "object-address", 1, 0, 0,
+ (SCM obj),
+ "Return an integer that for the lifetime of @var{obj} is uniquely\n"
+ "returned by this function for @var{obj}")
+#define FUNC_NAME s_scm_object_address
+{
+ return scm_from_ulong (SCM_UNPACK (obj));
+}
+#undef FUNC_NAME
+
+
+SCM_DEFINE (scm_gc, "gc", 0, 0, 0,
+ (),
+ "Scans all of SCM objects and reclaims for further use those that are\n"
+ "no longer accessible.")
+#define FUNC_NAME s_scm_gc
+{
+ scm_i_scm_pthread_mutex_lock (&scm_i_sweep_mutex);
+ scm_gc_running_p = 1;
+ scm_i_gc ("call");
+ /* njrev: It looks as though other places, e.g. scm_realloc,
+ can call scm_i_gc without acquiring the sweep mutex. Does this
+ matter? Also scm_i_gc (or its descendants) touch the
+ scm_sys_protects, which are protected in some cases
+ (e.g. scm_permobjs above in scm_gc_stats) by a critical section,
+ not by the sweep mutex. Shouldn't all the GC-relevant objects be
+ protected in the same way? */
+ scm_gc_running_p = 0;
+ scm_i_pthread_mutex_unlock (&scm_i_sweep_mutex);
+ scm_c_hook_run (&scm_after_gc_c_hook, 0);
+ return SCM_UNSPECIFIED;
+}
+#undef FUNC_NAME
+
+
+\f
+
+/* The master is global and common while the freelist will be
+ * individual for each thread.
+ */
+
+SCM
+scm_gc_for_newcell (scm_t_cell_type_statistics *freelist, SCM *free_cells)
+{
+ SCM cell;
+ int did_gc = 0;
+ scm_t_sweep_statistics sweep_stats;
+
+ scm_i_scm_pthread_mutex_lock (&scm_i_sweep_mutex);
+ scm_gc_running_p = 1;
+
+ *free_cells = scm_i_sweep_some_segments (freelist, &sweep_stats);
+ gc_update_stats (sweep_stats);
+
+ if (*free_cells == SCM_EOL && scm_i_gc_grow_heap_p (freelist))
+ {
+ freelist->heap_segment_idx =
+ scm_i_get_new_heap_segment (freelist,
+ scm_i_gc_sweep_stats,
+ abort_on_error);
+
+ *free_cells = scm_i_sweep_some_segments (freelist, &sweep_stats);
+ gc_update_stats (sweep_stats);
+ }
+
+ if (*free_cells == SCM_EOL)
+ {
+ /*
+ with the advent of lazy sweep, GC yield is only known just
+ before doing the GC.
+ */
+ scm_i_adjust_min_yield (freelist,
+ scm_i_gc_sweep_stats,
+ scm_i_gc_sweep_stats_1);
+
+ /*
+ out of fresh cells. Try to get some new ones.
+ */
+
+ did_gc = 1;
+ scm_i_gc ("cells");
+
+ *free_cells = scm_i_sweep_some_segments (freelist, &sweep_stats);
+ gc_update_stats (sweep_stats);
+ }
+
+ if (*free_cells == SCM_EOL)
+ {
+ /*
+ failed getting new cells. Get new juice or die.
+ */
+ freelist->heap_segment_idx =
+ scm_i_get_new_heap_segment (freelist,
+ scm_i_gc_sweep_stats,
+ abort_on_error);
+
+ *free_cells = scm_i_sweep_some_segments (freelist, &sweep_stats);
+ gc_update_stats (sweep_stats);
+ }
+
+ if (*free_cells == SCM_EOL)
+ abort ();
+
+ cell = *free_cells;
+
+ *free_cells = SCM_FREE_CELL_CDR (cell);
+
+ scm_gc_running_p = 0;
+ scm_i_pthread_mutex_unlock (&scm_i_sweep_mutex);
+
+ if (did_gc)
+ scm_c_hook_run (&scm_after_gc_c_hook, 0);
+
+ return cell;
+}
+
+
+scm_t_c_hook scm_before_gc_c_hook;
+scm_t_c_hook scm_before_mark_c_hook;
+scm_t_c_hook scm_before_sweep_c_hook;
+scm_t_c_hook scm_after_sweep_c_hook;
+scm_t_c_hook scm_after_gc_c_hook;
+
+/* Must be called while holding scm_i_sweep_mutex.
+ */
+
+void
+scm_i_gc (const char *what)
+{
+ scm_t_sweep_statistics sweep_stats;
+
+ scm_i_thread_put_to_sleep ();
+
+ scm_c_hook_run (&scm_before_gc_c_hook, 0);
+
+#ifdef DEBUGINFO
+ fprintf (stderr,"gc reason %s\n", what);
+
+ fprintf (stderr,
+ scm_is_null (*SCM_FREELIST_LOC (scm_i_freelist))
+ ? "*"
+ : (scm_is_null (*SCM_FREELIST_LOC (scm_i_freelist2)) ? "o" : "m"));
+#endif
+
+ gc_start_stats (what);
+
+ /*
+ Set freelists to NULL so scm_cons() always triggers gc, causing
+ the assertion above to fail.
+ */
+ *SCM_FREELIST_LOC (scm_i_freelist) = SCM_EOL;
+ *SCM_FREELIST_LOC (scm_i_freelist2) = SCM_EOL;
+
+ /*
+ Let's finish the sweep. The conservative GC might point into the
+ garbage, and marking that would create a mess.
+ */
+ scm_i_sweep_all_segments ("GC", &sweep_stats);
+
+ /* Invariant: the number of cells collected (i.e., freed) must always be
+ lower than or equal to the number of cells "swept" (i.e., visited). */
+ assert (sweep_stats.collected <= sweep_stats.swept);
+
+ if (scm_mallocated < scm_i_deprecated_memory_return)
+ {
+ /* The byte count of allocated objects has underflowed. This is
+ probably because you forgot to report the sizes of objects you
+ have allocated, by calling scm_done_malloc or some such. When
+ the GC freed them, it subtracted their size from
+ scm_mallocated, which underflowed. */
+ fprintf (stderr,
+ "scm_gc_sweep: Byte count of allocated objects has underflowed.\n"
+ "This is probably because the GC hasn't been correctly informed\n"
+ "about object sizes\n");
+ abort ();
+ }
+ scm_mallocated -= scm_i_deprecated_memory_return;
+
+
+ /* Mark */
+
+ scm_c_hook_run (&scm_before_mark_c_hook, 0);
+ scm_mark_all ();
+ scm_gc_mark_time_taken += (scm_c_get_internal_run_time () - t_before_gc);
+
+ /* Sweep
+
+ TODO: the after_sweep hook should probably be moved to just before
+ the mark, since that's where the sweep is finished in lazy
+ sweeping.
+
+ MDJ 030219 <djurfeldt@nada.kth.se>: No, probably not. The
+ original meaning implied at least two things: that it would be
+ called when
+
+ 1. the freelist is re-initialized (no evaluation possible, though)
+
+ and
+
+ 2. the heap is "fresh"
+ (it is well-defined what data is used and what is not)
+
+ Neither of these conditions would hold just before the mark phase.
+
+ Of course, the lazy sweeping has muddled the distinction between
+ scm_before_sweep_c_hook and scm_after_sweep_c_hook, but even if
+ there were no difference, it would still be useful to have two
+ distinct classes of hook functions since this can prevent some
+ bad interference when several modules adds gc hooks.
+ */
+
+ scm_c_hook_run (&scm_before_sweep_c_hook, 0);
+ scm_gc_sweep ();
+ scm_c_hook_run (&scm_after_sweep_c_hook, 0);
+
+ gc_end_stats (sweep_stats);
+
+ scm_i_thread_wake_up ();
+
+ /*
+ For debugging purposes, you could do
+ scm_i_sweep_all_segments("debug"), but then the remains of the
+ cell aren't left to analyse.
+ */
+}
+
+
+\f
+/* {GC Protection Helper Functions}
+ */
+
+
+/*
+ * If within a function you need to protect one or more scheme objects from
+ * garbage collection, pass them as parameters to one of the
+ * scm_remember_upto_here* functions below. These functions don't do
+ * anything, but since the compiler does not know that they are actually
+ * no-ops, it will generate code that calls these functions with the given
+ * parameters. Therefore, you can be sure that the compiler will keep those
+ * scheme values alive (on the stack or in a register) up to the point where
+ * scm_remember_upto_here* is called. In other words, place the call to
+ * scm_remember_upto_here* _behind_ the last code in your function, that
+ * depends on the scheme object to exist.
+ *
+ * Example: We want to make sure that the string object str does not get
+ * garbage collected during the execution of 'some_function' in the code
+ * below, because otherwise the characters belonging to str would be freed and
+ * 'some_function' might access freed memory. To make sure that the compiler
+ * keeps str alive on the stack or in a register such that it is visible to
+ * the conservative gc we add the call to scm_remember_upto_here_1 _after_ the
+ * call to 'some_function'. Note that this would not be necessary if str was
+ * used anyway after the call to 'some_function'.
+ * char *chars = scm_i_string_chars (str);
+ * some_function (chars);
+ * scm_remember_upto_here_1 (str); // str will be alive up to this point.
+ */
+
+/* Remove any macro versions of these while defining the functions.
+ Functions are always included in the library, for upward binary
+ compatibility and in case combinations of GCC and non-GCC are used. */
+#undef scm_remember_upto_here_1
+#undef scm_remember_upto_here_2
+
+void
+scm_remember_upto_here_1 (SCM obj SCM_UNUSED)
+{
+ /* Empty. Protects a single object from garbage collection. */
+}
+
+void
+scm_remember_upto_here_2 (SCM obj1 SCM_UNUSED, SCM obj2 SCM_UNUSED)
+{
+ /* Empty. Protects two objects from garbage collection. */
+}
+
+void
+scm_remember_upto_here (SCM obj SCM_UNUSED, ...)
+{
+ /* Empty. Protects any number of objects from garbage collection. */
+}
+
+/*
+ These crazy functions prevent garbage collection
+ of arguments after the first argument by
+ ensuring they remain live throughout the
+ function because they are used in the last
+ line of the code block.
+ It'd be better to have a nice compiler hint to
+ aid the conservative stack-scanning GC. --03/09/00 gjb */
+SCM
+scm_return_first (SCM elt, ...)
+{
+ return elt;
+}
+
+int
+scm_return_first_int (int i, ...)
+{
+ return i;
+}
+
+
+SCM
+scm_permanent_object (SCM obj)
+{
+ SCM cell = scm_cons (obj, SCM_EOL);
+ SCM_CRITICAL_SECTION_START;
+ SCM_SETCDR (cell, scm_permobjs);
+ scm_permobjs = cell;
+ SCM_CRITICAL_SECTION_END;
+ return obj;
+}
+
+
+/* Protect OBJ from the garbage collector. OBJ will not be freed, even if all
+ other references are dropped, until the object is unprotected by calling
+ scm_gc_unprotect_object (OBJ). Calls to scm_gc_protect/unprotect_object nest,
+ i. e. it is possible to protect the same object several times, but it is
+ necessary to unprotect the object the same number of times to actually get
+ the object unprotected. It is an error to unprotect an object more often
+ than it has been protected before. The function scm_protect_object returns
+ OBJ.
+*/
+
+/* Implementation note: For every object X, there is a counter which
+ scm_gc_protect_object(X) increments and scm_gc_unprotect_object(X) decrements.
+*/
+
+
+
+SCM
+scm_gc_protect_object (SCM obj)
+{
+ SCM handle;
+
+ /* This critical section barrier will be replaced by a mutex. */
+ /* njrev: Indeed; if my comment above is correct, there is the same
+ critsec/mutex inconsistency here. */
+ SCM_CRITICAL_SECTION_START;
+
+ handle = scm_hashq_create_handle_x (scm_protects, obj, scm_from_int (0));
+ SCM_SETCDR (handle, scm_sum (SCM_CDR (handle), scm_from_int (1)));
+
+ protected_obj_count ++;
+
+ SCM_CRITICAL_SECTION_END;
+
+ return obj;
+}
+
+
+/* Remove any protection for OBJ established by a prior call to
+ scm_protect_object. This function returns OBJ.
+
+ See scm_protect_object for more information. */
+SCM
+scm_gc_unprotect_object (SCM obj)
+{
+ SCM handle;
+
+ /* This critical section barrier will be replaced by a mutex. */
+ /* njrev: and again. */
+ SCM_CRITICAL_SECTION_START;
+
+ if (scm_gc_running_p)
+ {
+ fprintf (stderr, "scm_unprotect_object called during GC.\n");
+ abort ();
+ }
+
+ handle = scm_hashq_get_handle (scm_protects, obj);
+
+ if (scm_is_false (handle))
+ {
+ fprintf (stderr, "scm_unprotect_object called on unprotected object\n");
+ abort ();
+ }
+ else
+ {
+ SCM count = scm_difference (SCM_CDR (handle), scm_from_int (1));
+ if (scm_is_eq (count, scm_from_int (0)))
+ scm_hashq_remove_x (scm_protects, obj);
+ else
+ SCM_SETCDR (handle, count);
+ }
+ protected_obj_count --;
+
+ SCM_CRITICAL_SECTION_END;
+
+ return obj;
+}
+
+void
+scm_gc_register_root (SCM *p)
+{
+ SCM handle;
+ SCM key = scm_from_ulong ((unsigned long) p);
+
+ /* This critical section barrier will be replaced by a mutex. */
+ /* njrev: and again. */
+ SCM_CRITICAL_SECTION_START;
+
+ handle = scm_hashv_create_handle_x (scm_gc_registered_roots, key,
+ scm_from_int (0));
+ /* njrev: note also that the above can probably signal an error */
+ SCM_SETCDR (handle, scm_sum (SCM_CDR (handle), scm_from_int (1)));
+
+ SCM_CRITICAL_SECTION_END;
+}
+
+void
+scm_gc_unregister_root (SCM *p)
+{
+ SCM handle;
+ SCM key = scm_from_ulong ((unsigned long) p);
+
+ /* This critical section barrier will be replaced by a mutex. */
+ /* njrev: and again. */
+ SCM_CRITICAL_SECTION_START;
+
+ handle = scm_hashv_get_handle (scm_gc_registered_roots, key);
+
+ if (scm_is_false (handle))
+ {
+ fprintf (stderr, "scm_gc_unregister_root called on unregistered root\n");
+ abort ();
+ }
+ else
+ {
+ SCM count = scm_difference (SCM_CDR (handle), scm_from_int (1));
+ if (scm_is_eq (count, scm_from_int (0)))
+ scm_hashv_remove_x (scm_gc_registered_roots, key);
+ else
+ SCM_SETCDR (handle, count);
+ }
+
+ SCM_CRITICAL_SECTION_END;
+}
+
+void
+scm_gc_register_roots (SCM *b, unsigned long n)
+{
+ SCM *p = b;
+ for (; p < b + n; ++p)
+ scm_gc_register_root (p);
+}
+
+void
+scm_gc_unregister_roots (SCM *b, unsigned long n)
+{
+ SCM *p = b;
+ for (; p < b + n; ++p)
+ scm_gc_unregister_root (p);
+}
+
+int scm_i_terminating;
+
+\f
+
+
+/*
+ MOVE THIS FUNCTION. IT DOES NOT HAVE ANYTHING TODO WITH GC.
+ */
+
+/* Get an integer from an environment variable. */
+int
+scm_getenv_int (const char *var, int def)
+{
+ char *end = 0;
+ char *val = getenv (var);
+ long res = def;
+ if (!val)
+ return def;
+ res = strtol (val, &end, 10);
+ if (end == val)
+ return def;
+ return res;
+}
+
+void
+scm_storage_prehistory ()
+{
+ scm_c_hook_init (&scm_before_gc_c_hook, 0, SCM_C_HOOK_NORMAL);
+ scm_c_hook_init (&scm_before_mark_c_hook, 0, SCM_C_HOOK_NORMAL);
+ scm_c_hook_init (&scm_before_sweep_c_hook, 0, SCM_C_HOOK_NORMAL);
+ scm_c_hook_init (&scm_after_sweep_c_hook, 0, SCM_C_HOOK_NORMAL);
+ scm_c_hook_init (&scm_after_gc_c_hook, 0, SCM_C_HOOK_NORMAL);
+}
+
+scm_i_pthread_mutex_t scm_i_gc_admin_mutex = SCM_I_PTHREAD_MUTEX_INITIALIZER;
+
+int
+scm_init_storage ()
+{
+ size_t j;
+
+ j = SCM_NUM_PROTECTS;
+ while (j)
+ scm_sys_protects[--j] = SCM_BOOL_F;
+
+ scm_gc_init_freelist();
+ scm_gc_init_malloc ();
+
+ j = SCM_HEAP_SEG_SIZE;
+
+
+ /* Initialise the list of ports. */
+ scm_i_port_table = (scm_t_port **)
+ malloc (sizeof (scm_t_port *) * scm_i_port_table_room);
+ if (!scm_i_port_table)
+ return 1;
+
+#if 0
+ /* We can't have a cleanup handler since we have no thread to run it
+ in. */
+
+#ifdef HAVE_ATEXIT
+ atexit (cleanup);
+#else
+#ifdef HAVE_ON_EXIT
+ on_exit (cleanup, 0);
+#endif
+#endif
+
+#endif
+
+ scm_stand_in_procs = scm_make_weak_key_hash_table (scm_from_int (257));
+ scm_permobjs = SCM_EOL;
+ scm_protects = scm_c_make_hash_table (31);
+ scm_gc_registered_roots = scm_c_make_hash_table (31);
+
+ return 0;
+}
+
+\f
+
+SCM scm_after_gc_hook;
+
+static SCM gc_async;
+
+/* The function gc_async_thunk causes the execution of the after-gc-hook. It
+ * is run after the gc, as soon as the asynchronous events are handled by the
+ * evaluator.
+ */
+static SCM
+gc_async_thunk (void)
+{
+ scm_c_run_hook (scm_after_gc_hook, SCM_EOL);
+ return SCM_UNSPECIFIED;
+}
+
+
+/* The function mark_gc_async is run by the scm_after_gc_c_hook at the end of
+ * the garbage collection. The only purpose of this function is to mark the
+ * gc_async (which will eventually lead to the execution of the
+ * gc_async_thunk).
+ */
+static void *
+mark_gc_async (void * hook_data SCM_UNUSED,
+ void *func_data SCM_UNUSED,
+ void *data SCM_UNUSED)
+{
+ /* If cell access debugging is enabled, the user may choose to perform
+ * additional garbage collections after an arbitrary number of cell
+ * accesses. We don't want the scheme level after-gc-hook to be performed
+ * for each of these garbage collections for the following reason: The
+ * execution of the after-gc-hook causes cell accesses itself. Thus, if the
+ * after-gc-hook was performed with every gc, and if the gc was performed
+ * after a very small number of cell accesses, then the number of cell
+ * accesses during the execution of the after-gc-hook will suffice to cause
+ * the execution of the next gc. Then, guile would keep executing the
+ * after-gc-hook over and over again, and would never come to do other
+ * things.
+ *
+ * To overcome this problem, if cell access debugging with additional
+ * garbage collections is enabled, the after-gc-hook is never run by the
+ * garbage collecter. When running guile with cell access debugging and the
+ * execution of the after-gc-hook is desired, then it is necessary to run
+ * the hook explicitly from the user code. This has the effect, that from
+ * the scheme level point of view it seems that garbage collection is
+ * performed with a much lower frequency than it actually is. Obviously,
+ * this will not work for code that depends on a fixed one to one
+ * relationship between the execution counts of the C level garbage
+ * collection hooks and the execution count of the scheme level
+ * after-gc-hook.
+ */
+
+#if (SCM_DEBUG_CELL_ACCESSES == 1)
+ if (scm_debug_cells_gc_interval == 0)
+ scm_system_async_mark (gc_async);
+#else
+ scm_system_async_mark (gc_async);
+#endif
+
+ return NULL;
+}
+
+void
+scm_init_gc ()
+{
+ scm_gc_init_mark ();
+
+ scm_after_gc_hook = scm_permanent_object (scm_make_hook (SCM_INUM0));
+ scm_c_define ("after-gc-hook", scm_after_gc_hook);
+
+ gc_async = scm_c_make_subr ("%gc-thunk", scm_tc7_subr_0,
+ gc_async_thunk);
+
+ scm_c_hook_add (&scm_after_gc_c_hook, mark_gc_async, NULL, 0);
+
+#include "libguile/gc.x"
+}
+
+#ifdef __ia64__
+# ifdef __hpux
+# include <sys/param.h>
+# include <sys/pstat.h>
+void *
+scm_ia64_register_backing_store_base (void)
+{
+ struct pst_vm_status vm_status;
+ int i = 0;
+ while (pstat_getprocvm (&vm_status, sizeof (vm_status), 0, i++) == 1)
+ if (vm_status.pst_type == PS_RSESTACK)
+ return (void *) vm_status.pst_vaddr;
+ abort ();
+}
+void *
+scm_ia64_ar_bsp (const void *ctx)
+{
+ uint64_t bsp;
+ __uc_get_ar_bsp(ctx, &bsp);
+ return (void *) bsp;
+}
+# endif /* hpux */
+# ifdef linux
+# include <ucontext.h>
+void *
+scm_ia64_register_backing_store_base (void)
+{
+ extern void *__libc_ia64_register_backing_store_base;
+ return __libc_ia64_register_backing_store_base;
+}
+void *
+scm_ia64_ar_bsp (const void *opaque)
+{
+ ucontext_t *ctx = opaque;
+ return (void *) ctx->uc_mcontext.sc_ar_bsp;
+}
+# endif /* linux */
+#endif /* __ia64__ */
+
+void
+scm_gc_sweep (void)
+#define FUNC_NAME "scm_gc_sweep"
+{
+ scm_i_deprecated_memory_return = 0;
+
+ scm_i_gc_sweep_freelist_reset (&scm_i_master_freelist);
+ scm_i_gc_sweep_freelist_reset (&scm_i_master_freelist2);
+
+ /*
+ NOTHING HERE: LAZY SWEEPING !
+ */
+ scm_i_reset_segments ();
+
+ *SCM_FREELIST_LOC (scm_i_freelist) = SCM_EOL;
+ *SCM_FREELIST_LOC (scm_i_freelist2) = SCM_EOL;
+
+ /* Invalidate the freelists of other threads. */
+ scm_i_thread_invalidate_freelists ();
+}
+
+#undef FUNC_NAME
+
+
+
+/*
+ Local Variables:
+ c-file-style: "gnu"
+ End:
+*/
HCoop / bpt / guile.git / blobdiff