--- /dev/null
+/*
+ * Copyright (c) 2018 Petter A. Urkedal
+ *
+ * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
+ * OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
+ *
+ * Permission is hereby granted to use or copy this program
+ * for any purpose, provided the above notices are retained on all copies.
+ * Permission to modify the code and to distribute modified code is granted,
+ * provided the above notices are retained, and a notice that the code was
+ * modified is included with the above copyright notice.
+ */
+
+/* This tests a case where disclaim notifiers sometimes return non-zero */
+/* in order to protect objects from collection. */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#ifdef HAVE_CONFIG_H
+ /* For GC_[P]THREADS */
+# include "config.h"
+#endif
+
+#include "gc_disclaim.h" /* includes gc.h */
+#include "gc_mark.h"
+
+#ifdef GC_PTHREADS
+# ifndef NTHREADS
+# define NTHREADS 8
+# endif
+# include <errno.h>
+# include <pthread.h>
+# include "private/gc_atomic_ops.h" /* for AO_t and AO_fetch_and_add1 */
+#else
+# undef NTHREADS
+# define NTHREADS 1
+#endif
+
+#ifdef LINT2
+ /* Avoid include gc_priv.h. */
+# ifndef GC_API_PRIV
+# define GC_API_PRIV GC_API
+# endif
+# ifdef __cplusplus
+ extern "C" {
+# endif
+ GC_API_PRIV long GC_random(void);
+# ifdef __cplusplus
+ } /* extern "C" */
+# endif
+# undef rand
+# define rand() (int)GC_random()
+#endif /* LINT2 */
+
+#define POP_SIZE 200
+#define MUTATE_CNT (5000000 / NTHREADS)
+#define GROW_LIMIT (MUTATE_CNT / 10)
+
+#define WEAKMAP_CAPACITY 256
+#define WEAKMAP_MUTEX_COUNT 32
+
+/* FINALIZER_CLOSURE_FLAG definition matches the one in fnlz_mlc.c. */
+#if defined(KEEP_BACK_PTRS) || defined(MAKE_BACK_GRAPH)
+# define FINALIZER_CLOSURE_FLAG 0x2
+# define INVALIDATE_FLAG 0x1
+#else
+# define FINALIZER_CLOSURE_FLAG 0x1
+# define INVALIDATE_FLAG 0x2
+#endif
+
+#define my_assert(e) \
+ if (!(e)) { \
+ fflush(stdout); \
+ fprintf(stderr, "Assertion failure, line %d: %s\n", __LINE__, #e); \
+ exit(70); \
+ }
+
+#define CHECK_OOM(p) \
+ do { \
+ if (NULL == (p)) { \
+ fprintf(stderr, "Out of memory\n"); \
+ exit(69); \
+ } \
+ } while (0)
+
+/* Define AO primitives in case of no threads support. */
+#ifndef AO_CLEAR
+ /* AO_t not defined. */
+# define AO_t GC_word
+#endif
+#ifndef AO_HAVE_fetch_and_add1
+# define AO_fetch_and_add1(p) ((*(p))++)
+ /* This is used only to update counters. */
+#endif
+
+unsigned memhash(void *src, size_t len)
+{
+ unsigned acc = 0;
+ size_t i;
+
+ my_assert(len % sizeof(GC_word) == 0);
+ for (i = 0; i < len / sizeof(GC_word); ++i) {
+ acc = (2003 * acc + ((GC_word *)src)[i]) / 3;
+ }
+ return acc;
+}
+
+static volatile AO_t stat_added;
+static volatile AO_t stat_found;
+static volatile AO_t stat_removed;
+static volatile AO_t stat_skip_locked;
+static volatile AO_t stat_skip_marked;
+
+struct weakmap_link {
+ GC_hidden_pointer obj;
+ struct weakmap_link *next;
+};
+
+struct weakmap {
+# ifdef GC_PTHREADS
+ pthread_mutex_t mutex[WEAKMAP_MUTEX_COUNT];
+# endif
+ size_t key_size;
+ size_t obj_size;
+ size_t capacity;
+ unsigned weakobj_kind;
+ struct weakmap_link **links; /* NULL means weakmap is destroyed */
+};
+
+void weakmap_lock(struct weakmap *wm, unsigned h)
+{
+# ifdef GC_PTHREADS
+ int err = pthread_mutex_lock(&wm->mutex[h % WEAKMAP_MUTEX_COUNT]);
+ my_assert(0 == err);
+# else
+ (void)wm; (void)h;
+# endif
+}
+
+int weakmap_trylock(struct weakmap *wm, unsigned h)
+{
+# ifdef GC_PTHREADS
+ int err = pthread_mutex_trylock(&wm->mutex[h % WEAKMAP_MUTEX_COUNT]);
+ if (err != 0 && err != EBUSY) {
+ fprintf(stderr, "pthread_mutex_trylock: %s\n", strerror(err));
+ exit(69);
+ }
+ return err;
+# else
+ (void)wm; (void)h;
+ return 0;
+# endif
+}
+
+void weakmap_unlock(struct weakmap *wm, unsigned h)
+{
+# ifdef GC_PTHREADS
+ int err = pthread_mutex_unlock(&wm->mutex[h % WEAKMAP_MUTEX_COUNT]);
+ my_assert(0 == err);
+# else
+ (void)wm; (void)h;
+# endif
+}
+
+void *GC_CALLBACK set_mark_bit(void *obj)
+{
+ GC_set_mark_bit(obj);
+ return NULL;
+}
+
+void *weakmap_add(struct weakmap *wm, void *obj)
+{
+ struct weakmap_link *link, *new_link, **first;
+ GC_word *new_base;
+ void *new_obj;
+ unsigned h;
+ size_t key_size = wm->key_size;
+
+ /* Lock and look for an existing entry. */
+ h = memhash(obj, key_size);
+ first = &wm->links[h % wm->capacity];
+ weakmap_lock(wm, h);
+
+ for (link = *first; link != NULL; link = link->next) {
+ void *old_obj = GC_get_find_leak() ? (void *)link->obj
+ : GC_REVEAL_POINTER(link->obj);
+
+ if (memcmp(old_obj, obj, key_size) == 0) {
+ GC_call_with_alloc_lock(set_mark_bit, (GC_word *)old_obj - 1);
+ /* Pointers in the key part may have been freed and reused, */
+ /* changing the keys without memcmp noticing. This is okay */
+ /* as long as we update the mapped value. */
+ if (memcmp((char *)old_obj + key_size, (char *)obj + key_size,
+ wm->obj_size - key_size) != 0) {
+ memcpy((char *)old_obj + key_size, (char *)obj + key_size,
+ wm->obj_size - key_size);
+ GC_end_stubborn_change((char *)old_obj + key_size);
+ }
+ weakmap_unlock(wm, h);
+ AO_fetch_and_add1(&stat_found);
+# ifdef DEBUG_DISCLAIM_WEAKMAP
+ printf("Found %p, hash=%p\n", old_obj, (void *)(GC_word)h);
+# endif
+ return old_obj;
+ }
+ }
+
+ /* Create new object. */
+ new_base = (GC_word *)GC_generic_malloc(sizeof(GC_word) + wm->obj_size,
+ wm->weakobj_kind);
+ CHECK_OOM(new_base);
+ *new_base = (GC_word)wm | FINALIZER_CLOSURE_FLAG;
+ new_obj = (void *)(new_base + 1);
+ memcpy(new_obj, obj, wm->obj_size);
+ GC_end_stubborn_change(new_base);
+
+ /* Add the object to the map. */
+ new_link = GC_NEW(struct weakmap_link);
+ CHECK_OOM(new_link);
+ new_link->obj = GC_get_find_leak() ? (GC_word)new_obj
+ : GC_HIDE_POINTER(new_obj);
+ new_link->next = *first;
+ GC_END_STUBBORN_CHANGE(new_link);
+ GC_PTR_STORE_AND_DIRTY(first, new_link);
+ weakmap_unlock(wm, h);
+ AO_fetch_and_add1(&stat_added);
+# ifdef DEBUG_DISCLAIM_WEAKMAP
+ printf("Added %p, hash=%p\n", new_obj, (void *)(GC_word)h);
+# endif
+ return new_obj;
+}
+
+int GC_CALLBACK weakmap_disclaim(void *obj_base)
+{
+ struct weakmap *wm;
+ struct weakmap_link **link;
+ GC_word hdr;
+ void *obj;
+ unsigned h;
+
+ /* Decode header word. */
+ hdr = *(GC_word *)obj_base;
+ if ((hdr & FINALIZER_CLOSURE_FLAG) == 0)
+ return 0; /* on GC free list, ignore it. */
+
+ my_assert((hdr & INVALIDATE_FLAG) == 0);
+ wm = (struct weakmap *)(hdr & ~(GC_word)FINALIZER_CLOSURE_FLAG);
+ if (NULL == wm->links)
+ return 0; /* weakmap has been already destroyed */
+ obj = (GC_word *)obj_base + 1;
+
+ /* Lock and check for mark. */
+ h = memhash(obj, wm->key_size);
+ if (weakmap_trylock(wm, h) != 0) {
+ AO_fetch_and_add1(&stat_skip_locked);
+# ifdef DEBUG_DISCLAIM_WEAKMAP
+ printf("Skipping locked %p, hash=%p\n", obj, (void *)(GC_word)h);
+# endif
+ return 1;
+ }
+ if (GC_is_marked(obj_base)) {
+ weakmap_unlock(wm, h);
+ AO_fetch_and_add1(&stat_skip_marked);
+# ifdef DEBUG_DISCLAIM_WEAKMAP
+ printf("Skipping marked %p, hash=%p\n", obj, (void *)(GC_word)h);
+# endif
+ return 1;
+ }
+
+ /* Remove obj from wm. */
+ AO_fetch_and_add1(&stat_removed);
+# ifdef DEBUG_DISCLAIM_WEAKMAP
+ printf("Removing %p, hash=%p\n", obj, (void *)(GC_word)h);
+# endif
+ *(GC_word *)obj_base |= INVALIDATE_FLAG;
+ for (link = &wm->links[h % wm->capacity];; link = &(*link)->next) {
+ void *old_obj;
+
+ if (NULL == *link) {
+ fprintf(stderr, "Did not find %p\n", obj);
+ exit(70);
+ }
+ old_obj = GC_get_find_leak() ? (void *)(*link)->obj
+ : GC_REVEAL_POINTER((*link)->obj);
+ if (old_obj == obj)
+ break;
+ my_assert(memcmp(old_obj, obj, wm->key_size) != 0);
+ }
+ GC_PTR_STORE_AND_DIRTY(link, (*link)->next);
+ weakmap_unlock(wm, h);
+ return 0;
+}
+
+struct weakmap *weakmap_new(size_t capacity, size_t key_size, size_t obj_size,
+ unsigned weakobj_kind)
+{
+ struct weakmap *wm = GC_NEW(struct weakmap);
+
+ CHECK_OOM(wm);
+# ifdef GC_PTHREADS
+ {
+ int i;
+ for (i = 0; i < WEAKMAP_MUTEX_COUNT; ++i) {
+ int err = pthread_mutex_init(&wm->mutex[i], NULL);
+ my_assert(err == 0);
+ }
+ }
+# endif
+ wm->key_size = key_size;
+ wm->obj_size = obj_size;
+ wm->capacity = capacity;
+ wm->weakobj_kind = weakobj_kind;
+ GC_PTR_STORE_AND_DIRTY(&wm->links,
+ GC_MALLOC(sizeof(struct weakmap_link *) * capacity));
+ CHECK_OOM(wm->links);
+ return wm;
+}
+
+void weakmap_destroy(struct weakmap *wm)
+{
+# ifdef GC_PTHREADS
+ int i;
+
+ for (i = 0; i < WEAKMAP_MUTEX_COUNT; ++i) {
+ (void)pthread_mutex_destroy(&wm->mutex[i]);
+ }
+# endif
+ wm->links = NULL; /* weakmap is destroyed */
+}
+
+struct weakmap *pair_hcset;
+
+#define PAIR_MAGIC_SIZE 16 /* should not exceed sizeof(pair_magic) */
+
+struct pair_key {
+ struct pair *car, *cdr;
+};
+
+struct pair {
+ struct pair *car;
+ struct pair *cdr;
+ char magic[PAIR_MAGIC_SIZE];
+ int checksum;
+};
+
+static const char * const pair_magic = "PAIR_MAGIC_BYTES";
+
+struct pair *pair_new(struct pair *car, struct pair *cdr)
+{
+ struct pair tmpl;
+
+ memset(&tmpl, 0, sizeof(tmpl)); /* To clear the paddings (to avoid */
+ /* a compiler warning). */
+ tmpl.car = car;
+ tmpl.cdr = cdr;
+ memcpy(tmpl.magic, pair_magic, PAIR_MAGIC_SIZE);
+ tmpl.checksum = 782 + (car? car->checksum : 0) + (cdr? cdr->checksum : 0);
+ return (struct pair *)weakmap_add(pair_hcset, &tmpl);
+}
+
+void pair_check_rec(struct pair *p, int line)
+{
+ while (p != NULL) {
+ int checksum = 782;
+
+ if (memcmp(p->magic, pair_magic, PAIR_MAGIC_SIZE) != 0) {
+ fprintf(stderr, "Magic bytes wrong for %p at %d\n", (void *)p, line);
+ exit(70);
+ }
+ if (p->car != NULL)
+ checksum += p->car->checksum;
+ if (p->cdr != NULL)
+ checksum += p->cdr->checksum;
+ if (p->checksum != checksum) {
+ fprintf(stderr, "Checksum failure for %p = (%p, %p) at %d\n",
+ (void *)p, (void *)p->car, (void *)p->cdr, line);
+ exit(70);
+ }
+ p = (rand() & 1) != 0 ? p->cdr : p->car;
+ }
+}
+
+void *test(void *data)
+{
+ int i;
+ struct pair *p0, *p1;
+ struct pair *pop[POP_SIZE];
+
+ memset(pop, 0, sizeof(pop));
+ for (i = 0; i < MUTATE_CNT; ++i) {
+ int bits = rand();
+ int t = (bits >> 3) % POP_SIZE;
+
+ switch (bits % (i > GROW_LIMIT ? 5 : 3)) {
+ case 0:
+ case 3:
+ if (pop[t] != NULL)
+ pop[t] = pop[t]->car;
+ break;
+ case 1:
+ case 4:
+ if (pop[t] != NULL)
+ pop[t] = pop[t]->cdr;
+ break;
+ case 2:
+ p0 = pop[rand() % POP_SIZE];
+ p1 = pop[rand() % POP_SIZE];
+ pop[t] = pair_new(p0, p1);
+ my_assert(pair_new(p0, p1) == pop[t]);
+ my_assert(pop[t]->car == p0);
+ my_assert(pop[t]->cdr == p1);
+ break;
+ }
+ pair_check_rec(pop[rand() % POP_SIZE], __LINE__);
+ }
+ return data;
+}
+
+int main(void)
+{
+ unsigned weakobj_kind;
+ void **weakobj_free_list;
+# ifdef GC_PTHREADS
+ int i;
+ pthread_t th[NTHREADS];
+# endif
+
+ GC_set_all_interior_pointers(0); /* for a stricter test */
+# ifdef TEST_MANUAL_VDB
+ GC_set_manual_vdb_allowed(1);
+# endif
+ GC_INIT();
+ GC_init_finalized_malloc(); /* to register the displacements */
+# ifndef NO_INCREMENTAL
+ GC_enable_incremental();
+# endif
+ if (GC_get_find_leak())
+ printf("This test program is not designed for leak detection mode\n");
+
+ weakobj_free_list = GC_new_free_list();
+ CHECK_OOM(weakobj_free_list);
+ weakobj_kind = GC_new_kind(weakobj_free_list, /* 0 | */ GC_DS_LENGTH,
+ 1 /* adjust */, 1 /* clear */);
+ GC_register_disclaim_proc(weakobj_kind, weakmap_disclaim,
+ 1 /* mark_unconditionally */);
+ pair_hcset = weakmap_new(WEAKMAP_CAPACITY, sizeof(struct pair_key),
+ sizeof(struct pair), weakobj_kind);
+
+# ifdef GC_PTHREADS
+ for (i = 0; i < NTHREADS; ++i) {
+ int err = pthread_create(&th[i], NULL, test, NULL);
+ if (err != 0) {
+ fprintf(stderr, "Failed to create thread #%d: %s\n",
+ i, strerror(err));
+ exit(1);
+ }
+ }
+ for (i = 0; i < NTHREADS; ++i) {
+ int err = pthread_join(th[i], NULL);
+ if (err != 0) {
+ fprintf(stderr, "Failed to join thread #%d: %s\n", i, strerror(err));
+ exit(69);
+ }
+ }
+# else
+ (void)test(NULL);
+# endif
+ weakmap_destroy(pair_hcset);
+ printf("%u added, %u found; %u removed, %u locked, %u marked; %u remains\n",
+ (unsigned)stat_added, (unsigned)stat_found, (unsigned)stat_removed,
+ (unsigned)stat_skip_locked, (unsigned)stat_skip_marked,
+ (unsigned)stat_added - (unsigned)stat_removed);
+ return 0;
+}
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