-/* Copyright (C) 1998, 1999 Free Software Foundation, Inc.
+/* Copyright (C) 1998, 1999, 2000 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
* 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 */
+
\f
/* This is an implementation of guardians as described in
* Programming Language Design and Implementation, June 1993
* ftp://ftp.cs.indiana.edu/pub/scheme-repository/doc/pubs/guardians.ps.gz
*
- * Author: Michael N. Livshin
- * Modified by: Mikael Djurfeldt
+ * By this point, the semantics are actually quite different from
+ * those described in the abovementioned paper. The semantic changes
+ * are there to improve safety and intuitiveness. The interface is
+ * still (mostly) the one described by the paper, however.
+ *
+ * Original design: Mikael Djurfeldt
+ * Original implementation: Michael Livshin
+ * Hacked on since by: everybody
*/
-#include <stdio.h>
-#include <assert.h>
-#include "_scm.h"
-#include "print.h"
-#include "smob.h"
-#include "genio.h"
+#include "libguile/_scm.h"
+#include "libguile/ports.h"
+#include "libguile/print.h"
+#include "libguile/smob.h"
+#include "libguile/validate.h"
+#include "libguile/root.h"
+#include "libguile/hashtab.h"
+#include "libguile/weaks.h"
-#include "guardians.h"
+#include "libguile/guardians.h"
-static long scm_tc16_guardian;
/* The live and zombies FIFOs are implemented as tconcs as described
in Dybvig's paper. This decouples addition and removal of elements
so that no synchronization between these needs to take place.
*/
+
+typedef struct tconc_t
+{
+ SCM head;
+ SCM tail;
+} tconc_t;
+
+#define TCONC_EMPTYP(tc) (SCM_EQ_P ((tc).head, (tc).tail))
+
#define TCONC_IN(tc, obj, pair) \
-{ \
+do { \
SCM_SETCAR ((tc).tail, obj); \
SCM_SETCAR (pair, SCM_BOOL_F); \
- SCM_SETCDR (pair, SCM_BOOL_F); \
+ SCM_SETCDR (pair, SCM_EOL); \
SCM_SETCDR ((tc).tail, pair); \
(tc).tail = pair; \
-} \
+} while (0)
#define TCONC_OUT(tc, res) \
-{ \
+do { \
(res) = SCM_CAR ((tc).head); \
(tc).head = SCM_CDR ((tc).head); \
-} \
+} while (0)
-#define TCONC_EMPTYP(tc) ((tc).head == (tc).tail)
-typedef struct tconc_t
-{
- SCM head;
- SCM tail;
-} tconc_t;
+static scm_bits_t tc16_guardian;
typedef struct guardian_t
{
tconc_t live;
tconc_t zombies;
struct guardian_t *next;
+ unsigned long flags;
} guardian_t;
-#define GUARDIAN(x) ((guardian_t *) SCM_CDR (x))
-#define GUARDIAN_LIVE(x) (GUARDIAN (x)->live)
-#define GUARDIAN_ZOMBIES(x) (GUARDIAN (x)->zombies)
-#define GUARDIAN_NEXT(x) (GUARDIAN (x)->next)
+#define GUARDIAN_P(x) SCM_SMOB_PREDICATE(tc16_guardian, x)
+#define GUARDIAN(x) ((guardian_t *) SCM_CELL_WORD_1 (x))
+
+#define F_GREEDY 1L
+#define F_LISTED (1L << 1)
+#define F_DESTROYED (1L << 2)
+
+#define GREEDY_P(x) (((x)->flags & F_GREEDY) != 0)
+#define SET_GREEDY(x) ((x)->flags |= F_GREEDY)
+
+#define LISTED_P(x) (((x)->flags & F_LISTED) != 0)
+#define SET_LISTED(x) ((x)->flags |= F_LISTED)
+#define CLR_LISTED(x) ((x)->flags &= ~F_LISTED)
-static guardian_t *first_live_guardian = NULL;
-static guardian_t **current_link_field = NULL;
+#define DESTROYED_P(x) (((x)->flags & F_DESTROYED) != 0)
+#define SET_DESTROYED(x) ((x)->flags |= F_DESTROYED)
+/* during the gc mark phase, live guardians are linked into the lists
+ here. */
+static guardian_t *greedy_guardians = NULL;
+static guardian_t *sharing_guardians = NULL;
+
+static SCM greedily_guarded_whash = SCM_EOL;
+
+/* this is the list of guarded objects that are parts of cycles. we
+ don't know in which order to return them from guardians, so we just
+ unguard them and whine about it in after-gc-hook */
+static SCM self_centered_zombies = SCM_EOL;
+
+
+static void
+add_to_live_list (guardian_t *g)
+{
+ if (LISTED_P (g))
+ return;
+
+ if (GREEDY_P (g))
+ {
+ g->next = greedy_guardians;
+ greedy_guardians = g;
+ }
+ else
+ {
+ g->next = sharing_guardians;
+ sharing_guardians = g;
+ }
+
+ SET_LISTED (g);
+}
+
+/* mark a guardian by adding it to the live guardian list. */
static SCM
-g_mark (SCM ptr)
+guardian_mark (SCM ptr)
{
- *current_link_field = GUARDIAN (ptr);
- current_link_field = &GUARDIAN_NEXT (ptr);
- GUARDIAN_NEXT (ptr) = NULL;
+ add_to_live_list (GUARDIAN (ptr));
- /* Can't mark zombies here since they can refer to objects which are
- living dead, thereby preventing them to join the zombies. */
+ /* the objects protected by the guardian are not marked here: that
+ would prevent them from ever getting collected. instead marking
+ is done at the end of the mark phase by guardian_zombify. */
return SCM_BOOL_F;
}
+
+static scm_sizet
+guardian_free (SCM ptr)
+{
+ scm_must_free (GUARDIAN (ptr));
+ return sizeof (guardian_t);
+}
+
+
static int
-g_print (SCM exp, SCM port, scm_print_state *pstate)
+guardian_print (SCM guardian, SCM port, scm_print_state *pstate)
{
- char buf[256];
- sprintf (buf, "#<guardian live objs: %lu zombies: %lu>",
- scm_ilength (SCM_CDR (GUARDIAN_LIVE (exp).head)),
- scm_ilength (SCM_CDR (GUARDIAN_ZOMBIES (exp).head)));
- scm_puts (buf, port);
+ guardian_t *g = GUARDIAN (guardian);
+
+ scm_puts ("#<", port);
+
+ if (DESTROYED_P (g))
+ scm_puts ("destroyed ", port);
+
+ if (GREEDY_P (g))
+ scm_puts ("greedy", port);
+ else
+ scm_puts ("sharing", port);
+
+ scm_puts (" guardian 0x", port);
+ scm_intprint ((long) g, 16, port);
+
+ if (! DESTROYED_P (g))
+ {
+ scm_puts (" (reachable: ", port);
+ scm_display (scm_length (SCM_CDR (g->live.head)), port);
+ scm_puts (" unreachable: ", port);
+ scm_display (scm_length (SCM_CDR (g->zombies.head)), port);
+ scm_puts (")", port);
+ }
+
+ scm_puts (">", port);
return 1;
}
-#define CCLO_G(cclo) (SCM_VELTS (cclo)[1])
+/* This is the Scheme entry point for each guardian: If OBJ is an
+ * object, it's added to the guardian's live list. If OBJ is unbound,
+ * the next available unreachable object (or #f if none) is returned.
+ *
+ * If the second optional argument THROW_P is true (the default), then
+ * an error is raised if GUARDIAN is greedy and OBJ is already greedily
+ * guarded. If THROW_P is false, #f is returned instead of raising the
+ * error, and #t is returned if everything is fine.
+ */
static SCM
-guard (SCM cclo, SCM arg)
+guardian_apply (SCM guardian, SCM obj, SCM throw_p)
+{
+ if (DESTROYED_P (GUARDIAN (guardian)))
+ scm_misc_error ("guard", "attempted use of destroyed guardian: ~A",
+ SCM_LIST1 (guardian));
+
+ if (!SCM_UNBNDP (obj))
+ return scm_guard (guardian, obj,
+ (SCM_UNBNDP (throw_p)
+ ? 1
+ : SCM_NFALSEP (throw_p)));
+ else
+ return scm_get_one_zombie (guardian);
+}
+
+
+SCM
+scm_guard (SCM guardian, SCM obj, int throw_p)
{
- if (!SCM_UNBNDP (arg))
+ guardian_t *g = GUARDIAN (guardian);
+
+ if (!SCM_IMP (obj))
{
- scm_guard (cclo, arg);
- return SCM_UNSPECIFIED;
+ SCM z;
+
+ SCM_NEWCELL (z);
+
+ /* This critical section barrier will be replaced by a mutex. */
+ SCM_DEFER_INTS;
+
+ if (GREEDY_P (g))
+ {
+ if (SCM_NFALSEP (scm_hashq_get_handle
+ (greedily_guarded_whash, obj)))
+ {
+ SCM_ALLOW_INTS;
+
+ if (throw_p)
+ scm_misc_error ("guard",
+ "object is already greedily guarded: ~A",
+ SCM_LIST1 (obj));
+ else
+ return SCM_BOOL_F;
+ }
+ else
+ scm_hashq_create_handle_x (greedily_guarded_whash,
+ obj, guardian);
+ }
+
+ TCONC_IN (g->live, obj, z);
+
+ SCM_ALLOW_INTS;
}
- else
- return scm_get_one_zombie (cclo);
+
+ return throw_p ? SCM_UNSPECIFIED : SCM_BOOL_T;
+
}
-static SCM guard1;
-SCM_PROC (s_make_guardian, "make-guardian", 0, 0, 0, scm_make_guardian);
SCM
-scm_make_guardian ()
+scm_get_one_zombie (SCM guardian)
{
- SCM cclo = scm_makcclo (guard1, 2L);
- guardian_t *g = (guardian_t *) scm_must_malloc (sizeof (guardian_t),
- s_make_guardian);
- SCM z1 = scm_cons (SCM_BOOL_F, SCM_BOOL_F);
- SCM z2 = scm_cons (SCM_BOOL_F, SCM_BOOL_F);
+ guardian_t *g = GUARDIAN (guardian);
+ SCM res = SCM_BOOL_F;
+
+ /* This critical section barrier will be replaced by a mutex. */
+ SCM_DEFER_INTS;
+
+ if (!TCONC_EMPTYP (g->zombies))
+ TCONC_OUT (g->zombies, res);
+
+ if (SCM_NFALSEP (res)
+ && GREEDY_P (g))
+ scm_hashq_remove_x (greedily_guarded_whash, res);
+
+ SCM_ALLOW_INTS;
+
+ return res;
+}
+
+
+SCM_DEFINE (scm_make_guardian, "make-guardian", 0, 1, 0,
+ (SCM greedy_p),
+ "Create a new guardian.\n"
+ "A guardian protects a set of objects from garbage collection,\n"
+ "allowing a program to apply cleanup or other actions.\n\n"
+
+ "make-guardian returns a procedure representing the guardian.\n"
+ "Calling the guardian procedure with an argument adds the\n"
+ "argument to the guardian's set of protected objects.\n"
+ "Calling the guardian procedure without an argument returns\n"
+ "one of the protected objects which are ready for garbage\n"
+ "collection or @code{#f} if no such object is available.\n"
+ "Objects which are returned in this way are removed from\n"
+ "the guardian.\n\n"
+
+ "make-guardian takes one optional argument that says whether the\n"
+ "new guardian should be greedy or sharing. if there is any chance\n"
+ "that any object protected by the guardian may be resurrected,\n"
+ "then you should make the guardian greedy (this is the default).\n\n"
+
+ "See R. Kent Dybvig, Carl Bruggeman, and David Eby (1993)\n"
+ "\"Guardians in a Generation-Based Garbage Collector\".\n"
+ "ACM SIGPLAN Conference on Programming Language Design\n"
+ "and Implementation, June 1993.\n\n"
+
+ "(the semantics are slightly different at this point, but the\n"
+ "paper still (mostly) accurately describes the interface).")
+#define FUNC_NAME s_scm_make_guardian
+{
+ guardian_t *g = SCM_MUST_MALLOC_TYPE (guardian_t);
+ SCM z1 = scm_cons (SCM_BOOL_F, SCM_EOL);
+ SCM z2 = scm_cons (SCM_BOOL_F, SCM_EOL);
SCM z;
+
/* A tconc starts out with one tail pair. */
g->live.head = g->live.tail = z1;
g->zombies.head = g->zombies.tail = z2;
- SCM_NEWSMOB (z, scm_tc16_guardian, g);
+ g->next = NULL;
+ g->flags = 0L;
- CCLO_G (cclo) = z;
+ /* [cmm] the UNBNDP check below is redundant but I like it. */
+ if (SCM_UNBNDP (greedy_p) || SCM_NFALSEP (greedy_p))
+ SET_GREEDY (g);
+
+ SCM_NEWSMOB (z, tc16_guardian, g);
- return cclo;
+ return z;
}
+#undef FUNC_NAME
-void
-scm_guardian_gc_init()
+
+SCM_DEFINE (scm_guardian_destroyed_p, "guardian-destroyed?", 1, 0, 0,
+ (SCM guardian),
+ "Is @var{guardian} destroyed?")
+#define FUNC_NAME s_scm_guardian_destroyed_p
{
- current_link_field = &first_live_guardian;
- first_live_guardian = NULL;
+ SCM res = SCM_BOOL_F;
+
+ /* This critical section barrier will be replaced by a mutex. */
+ SCM_DEFER_INTS;
+
+ res = SCM_BOOL (DESTROYED_P (GUARDIAN (guardian)));
+
+ SCM_ALLOW_INTS;
+
+ return res;
}
+#undef FUNC_NAME
-void
-scm_guardian_zombify ()
+SCM_DEFINE (scm_guardian_greedy_p, "guardian_greedy?", 1, 0, 0,
+ (SCM guardian),
+ "Is @var{guardian} greedy?")
+#define FUNC_NAME s_scm_guardian_greedy_p
{
- guardian_t *g;
+ return SCM_BOOL (GREEDY_P (GUARDIAN (guardian)));
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_destroy_guardian_x, "destroy-guardian!", 1, 0, 0,
+ (SCM guardian),
+ "Destroys @var{guardian}, by making it impossible to put any more\n"
+ "objects in it or get any objects from it. It also unguards any\n"
+ "objects guarded by @var{guardian}.")
+#define FUNC_NAME s_scm_destroy_guardian_x
+{
+ guardian_t *g = GUARDIAN (guardian);
- /* Note that new guardians may be stuck on the end of the live
- guardian list as we run this loop. As we move unmarked objects
- to the zombie list and mark them, we may find some guarded
- guardians. The guardian mark function will stick them on the end
- of this list, so they'll be processed properly. */
- for (g = first_live_guardian; g; g = g->next)
+ /* This critical section barrier will be replaced by a mutex. */
+ SCM_DEFER_INTS;
+
+ if (DESTROYED_P (g))
{
- /* Scan the live list for unmarked objects, and move them to the
- zombies tconc. */
- SCM tconc_tail = g->live.tail;
- SCM *prev_ptr = &g->live.head;
- SCM pair = g->live.head;
-
- while (pair != tconc_tail)
- {
- SCM next_pair = SCM_CDR (pair);
-
- if (SCM_NMARKEDP (SCM_CAR (pair)))
- {
- /* got you, zombie! */
-
- /* out of the live list! */
- *prev_ptr = next_pair;
-
- /* to the zombie list! */
- TCONC_IN (g->zombies, SCM_CAR (pair), pair);
- }
- else
- prev_ptr = SCM_CDRLOC (pair);
-
- pair = next_pair;
- }
-
- /* Mark the cells of the live list. */
- for (pair = g->live.head; SCM_NIMP (pair); pair = SCM_GCCDR (pair))
- SCM_SETGCMARK (pair);
-
- /* Bring the zombies back from the dead. */
- scm_gc_mark (g->zombies.head);
+ SCM_ALLOW_INTS;
+ SCM_MISC_ERROR ("guardian is already destroyed: ~A", SCM_LIST1 (guardian));
}
+
+ if (GREEDY_P (g))
+ {
+ /* clear the "greedily guarded" property of the objects */
+ SCM pair;
+ for (pair = g->live.head; pair != g->live.tail; pair = SCM_CDR (pair))
+ scm_hashq_remove_x (greedily_guarded_whash, SCM_CAR (pair));
+ for (pair = g->zombies.head; pair != g->zombies.tail; pair = SCM_CDR (pair))
+ scm_hashq_remove_x (greedily_guarded_whash, SCM_CAR (pair));
+ }
+
+ /* empty the lists */
+ g->live.head = g->live.tail;
+ g->zombies.head = g->zombies.tail;
+
+ SET_DESTROYED (g);
+
+ SCM_ALLOW_INTS;
+
+ return SCM_UNSPECIFIED;
}
+#undef FUNC_NAME
+
+/* called before gc mark phase begins to initialise the live guardian list. */
+static void *
+guardian_gc_init (void *dummy1, void *dummy2, void *dummy3)
+{
+ greedy_guardians = sharing_guardians = NULL;
-void
-scm_guard (SCM guardian, SCM obj)
+ return 0;
+}
+
+static void
+mark_dependencies_in_tconc (tconc_t *tc)
+{
+ SCM pair, next_pair;
+ SCM *prev_ptr;
+
+ /* scan the list for unmarked objects, and mark their
+ dependencies */
+ for (pair = tc->head, prev_ptr = &tc->head;
+ ! SCM_EQ_P (pair, tc->tail);
+ pair = next_pair)
+ {
+ SCM obj = SCM_CAR (pair);
+ next_pair = SCM_CDR (pair);
+
+ if (! SCM_MARKEDP (obj))
+ {
+ /* a candidate for finalizing */
+ scm_gc_mark_dependencies (obj);
+
+ if (SCM_MARKEDP (obj))
+ {
+ /* uh oh. a cycle. transfer this object (the
+ spine cell, to be exact) to
+ self_centered_zombies, so we'll be able to
+ complain about it later. */
+ *prev_ptr = next_pair;
+ SCM_SETGCMARK (pair);
+ SCM_SETCDR (pair, SCM_CDR (self_centered_zombies));
+ SCM_SETCDR (self_centered_zombies, pair);
+ }
+ else
+ {
+ /* see if this is a guardian. if yes, list it (but don't
+ mark it yet). */
+ if (GUARDIAN_P (obj))
+ add_to_live_list (GUARDIAN (obj));
+
+ prev_ptr = SCM_CDRLOC (pair);
+ }
+ }
+ }
+}
+
+static void
+mark_dependencies (guardian_t *g)
{
- SCM g = CCLO_G (guardian);
+ mark_dependencies_in_tconc (&g->zombies);
+ mark_dependencies_in_tconc (&g->live);
+}
- if (SCM_NIMP (obj))
+static void
+mark_and_zombify (guardian_t *g)
+{
+ SCM tconc_tail = g->live.tail;
+ SCM *prev_ptr = &g->live.head;
+ SCM pair = g->live.head;
+
+ while (! SCM_EQ_P (pair, tconc_tail))
{
- SCM z;
-
- SCM_NEWCELL (z);
+ SCM next_pair = SCM_CDR (pair);
- /* This critical section barrier will be replaced by a mutex. */
- SCM_DEFER_INTS;
- TCONC_IN (GUARDIAN_LIVE (g), obj, z);
- SCM_ALLOW_INTS;
+ if (SCM_NMARKEDP (SCM_CAR (pair)))
+ {
+ /* got you, zombie! */
+
+ /* out of the live list! */
+ *prev_ptr = next_pair;
+
+ if (GREEDY_P (g))
+ /* if the guardian is greedy, mark this zombie now. this
+ way it won't be zombified again this time around. */
+ SCM_SETGCMARK (SCM_CAR (pair));
+
+ /* into the zombie list! */
+ TCONC_IN (g->zombies, SCM_CAR (pair), pair);
+ }
+ else
+ prev_ptr = SCM_CDRLOC (pair);
+
+ pair = next_pair;
}
+
+ /* Mark the cells of the live list (yes, the cells in the list, we
+ don't care about objects pointed to by the list cars, since we
+ know they are already marked). */
+ for (pair = g->live.head; !SCM_NULLP (pair); pair = SCM_CDR (pair))
+ SCM_SETGCMARK (pair);
}
-SCM
-scm_get_one_zombie (SCM guardian)
+
+/* this is called by the garbage collector between the mark and sweep
+ phases. for each marked guardian, it moves any unmarked object in
+ its live list (tconc) to its zombie list (tconc). */
+static void *
+guardian_zombify (void *dummy1, void *dummy2, void *dummy3)
{
- SCM g = CCLO_G (guardian);
- SCM res = SCM_BOOL_F;
+ guardian_t *last_greedy_guardian = NULL;
+ guardian_t *last_sharing_guardian = NULL;
+ guardian_t *first_greedy_guardian = NULL;
+ guardian_t *first_sharing_guardian = NULL;
+ guardian_t *g;
- /* This critical section barrier will be replaced by a mutex. */
- SCM_DEFER_INTS;
- if (!TCONC_EMPTYP (GUARDIAN_ZOMBIES (g)))
- TCONC_OUT (GUARDIAN_ZOMBIES (g), res);
- SCM_ALLOW_INTS;
+ /* First, find all newly unreachable objects and mark their
+ dependencies.
+
+ Note that new guardians may be stuck on the end of the live
+ guardian lists as we run this loop, since guardians might be
+ guarded too. When we mark a guarded guardian, its mark function
+ sticks in the appropriate live guardian list. The loop
+ terminates when no new guardians are found. */
+
+ do {
+ first_greedy_guardian = greedy_guardians;
+ first_sharing_guardian = sharing_guardians;
+
+ for (g = greedy_guardians; g != last_greedy_guardian;
+ g = g->next)
+ mark_dependencies (g);
+ for (g = sharing_guardians; g != last_sharing_guardian;
+ g = g->next)
+ mark_dependencies (g);
+
+ last_greedy_guardian = first_greedy_guardian;
+ last_sharing_guardian = first_sharing_guardian;
+ } while (first_greedy_guardian != greedy_guardians
+ || first_sharing_guardian != sharing_guardians);
+
+ /* now, scan all the guardians that are currently known to be live
+ and move their unmarked objects to zombie lists. */
+
+ for (g = greedy_guardians; g; g = g->next)
+ {
+ mark_and_zombify (g);
+ CLR_LISTED (g);
+ }
+ for (g = sharing_guardians; g; g = g->next)
+ {
+ mark_and_zombify (g);
+ CLR_LISTED (g);
+ }
+
+ /* Preserve the zombies in their undead state, by marking to prevent
+ collection. */
+ for (g = greedy_guardians; g; g = g->next)
+ scm_gc_mark (g->zombies.head);
+ for (g = sharing_guardians; g; g = g->next)
+ scm_gc_mark (g->zombies.head);
+
+ return 0;
+}
- return res;
+static void *
+whine_about_self_centered_zombies (void *dummy1, void *dummy2, void *dummy3)
+{
+ if (! SCM_NULLP (SCM_CDR (self_centered_zombies)))
+ {
+ SCM pair;
+
+ scm_puts ("** WARNING: the following guarded objects were unguarded due to cycles:",
+ scm_cur_errp);
+ scm_newline (scm_cur_errp);
+ for (pair = SCM_CDR (self_centered_zombies);
+ ! SCM_NULLP (pair); pair = SCM_CDR (pair))
+ {
+ scm_display (SCM_CAR (pair), scm_cur_errp);
+ scm_newline (scm_cur_errp);
+ }
+
+ SCM_SETCDR (self_centered_zombies, SCM_EOL);
+ }
+
+ return 0;
}
void
-scm_init_guardian()
+scm_init_guardians ()
{
- scm_tc16_guardian = scm_make_smob_type_mfpe ("guardian", sizeof (guardian_t),
- g_mark, NULL, g_print, NULL);
- guard1 = scm_make_subr_opt ("guardian", scm_tc7_subr_2o, guard, 0);
-
-#include "guardians.x"
+ tc16_guardian = scm_make_smob_type ("guardian", 0);
+ scm_set_smob_mark (tc16_guardian, guardian_mark);
+ scm_set_smob_free (tc16_guardian, guardian_free);
+ scm_set_smob_print (tc16_guardian, guardian_print);
+ scm_set_smob_apply (tc16_guardian, guardian_apply, 0, 2, 0);
+
+ scm_c_hook_add (&scm_before_mark_c_hook, guardian_gc_init, 0, 0);
+ scm_c_hook_add (&scm_before_sweep_c_hook, guardian_zombify, 0, 0);
+
+ self_centered_zombies =
+ scm_permanent_object (scm_cons (SCM_UNDEFINED, SCM_EOL));
+ scm_c_hook_add (&scm_after_gc_c_hook,
+ whine_about_self_centered_zombies, 0, 0);
+
+ greedily_guarded_whash =
+ scm_permanent_object (scm_make_doubly_weak_hash_table (SCM_MAKINUM (31)));
+
+#ifndef SCM_MAGIC_SNARFER
+#include "libguile/guardians.x"
+#endif
}
+
+/*
+ Local Variables:
+ c-file-style: "gnu"
+ End:
+*/
HCoop / bpt / guile.git / blobdiff