/* tagtest.c: TAGGED POINTER TEST
*
* $Id: //info.ravenbrook.com/project/mps/master/code/tagtest.c#8 $
* Copyright (c) 2015-2020 Ravenbrook Limited. See end of file for license.
*
* .overview: This test case checks that the MPS correctly handles
* tagged pointers via the object format and tagged area scanning.
*/
#include <stdio.h> /* printf */
#include "mpm.h"
#include "mps.h"
#include "mpsavm.h"
#include "mpscamc.h"
#include "testlib.h"
#define OBJCOUNT 1000 /* Number of conses to allocate */
typedef struct cons_s {
mps_word_t car, cdr;
} cons_s, *cons_t;
typedef mps_word_t imm_t; /* Immediate value. */
typedef mps_word_t fwd_t; /* Fowarding pointer. */
static mps_word_t tag_bits; /* Number of tag bits */
static mps_word_t tag_cons; /* Tag bits indicating pointer to cons */
static mps_word_t tag_fwd; /* Tag bits indicating forwarding pointer */
static mps_word_t tag_imm; /* Tag bits indicating immediate value */
static mps_word_t tag_invalid; /* Invalid tag bits */
static mps_addr_t refs[OBJCOUNT]; /* Tagged references to objects */
#define TAG_COUNT ((mps_word_t)1 << tag_bits) /* Number of distinct tags */
#define TAG_MASK (TAG_COUNT - 1) /* Tag mask */
#define TAG(word) ((mps_word_t)(word) & TAG_MASK)
#define TAGGED(value, type) (((mps_word_t)(value) & ~TAG_MASK) + tag_ ## type)
#define UNTAGGED(word, type) ((type ## _t)((mps_word_t)(word) & ~TAG_MASK))
static mps_word_t make_cons(mps_ap_t ap, mps_word_t car, mps_word_t cdr)
{
cons_t obj;
mps_addr_t addr;
size_t size = sizeof(cons_s);
do {
mps_res_t res = mps_reserve(&addr, ap, size);
if (res != MPS_RES_OK) error("out of memory in cons");
obj = addr;
obj->car = car;
obj->cdr = cdr;
} while (!mps_commit(ap, addr, size));
return TAGGED(obj, cons);
}
static void fwd(mps_addr_t old, mps_addr_t new)
{
cons_t cons = old;
cons->car = TAGGED(0, fwd);
cons->cdr = (mps_word_t)new;
}
static mps_addr_t isfwd(mps_addr_t addr)
{
cons_t cons = addr;
if (TAG(cons->car) != tag_fwd)
return NULL;
return (mps_addr_t)cons->cdr;
}
static void pad(mps_addr_t addr, size_t size)
{
mps_word_t *word = addr;
mps_word_t *limit = (mps_word_t *)((char *)addr + size);
while (word < limit) {
*word = TAGGED(0, imm);
++ word;
}
}
static mps_arena_t arena;
static mps_res_t scan(mps_ss_t ss, mps_addr_t base,
mps_addr_t limit)
{
Insist(mps_arena_busy(arena));
MPS_SCAN_BEGIN(ss) {
mps_word_t *p = base;
while (p < (mps_word_t *)limit) {
mps_word_t word = *p;
mps_word_t tag = TAG(word);
if (tag == tag_cons) {
mps_addr_t ref = UNTAGGED(word, cons);
if (MPS_FIX1(ss, ref)) {
mps_res_t res = MPS_FIX2(ss, &ref);
if (res != MPS_RES_OK)
return res;
*p = TAGGED(ref, cons);
}
}
++p;
}
} MPS_SCAN_END(ss);
return MPS_RES_OK;
}
static mps_addr_t skip(mps_addr_t addr)
{
return (mps_addr_t)((char *)addr + sizeof(cons_s));
}
static void collect(size_t expected)
{
size_t finalized = 0;
mps_arena_collect(arena);
while (mps_message_poll(arena)) {
mps_message_t message;
mps_addr_t objaddr;
cdie(mps_message_get(&message, arena, mps_message_type_finalization()),
"message_get");
mps_message_finalization_ref(&objaddr, arena, message);
Insist(TAG(objaddr) == 0);
mps_message_discard(arena, message);
++ finalized;
}
printf("finalized=%lu expected=%lu\n",
(unsigned long)finalized, (unsigned long)expected);
Insist(finalized == expected);
}
/* test -- Run the test case in the specified mode. */
#define MODES(R, X) \
R(X, CONS, "Scan words tagged \"cons\".") \
R(X, INVALID, "Scan words tagged \"invalid\".")
#define MODES_ENUM(X, id, comment) MODE_ ## id,
enum {
MODES(MODES_ENUM, X)
MODE_LIMIT
};
#define MODES_NAME(X, id, comment) #id,
static const char *mode_name[] = {
MODES(MODES_NAME, X)
};
static void test(int mode)
{
mps_thr_t thread;
mps_root_t root;
mps_fmt_t fmt;
mps_pool_t pool;
mps_ap_t ap;
size_t expected = 0;
size_t i;
printf("test(%s)\n", mode_name[mode]);
die(mps_arena_create_k(&arena, mps_arena_class_vm(), mps_args_none), "arena");
mps_message_type_enable(arena, mps_message_type_finalization());
die(mps_thread_reg(&thread, arena), "thread");
switch (mode) {
default:
Insist(0);
/* fall through */
case MODE_CONS:
/* Scan words tagged "cons" -- everything will live. */
die(mps_root_create_area_tagged(&root, arena, mps_rank_ambig(), 0,
refs, refs + OBJCOUNT,
mps_scan_area_tagged, TAG_MASK, tag_cons),
"root");
expected = 0;
break;
case MODE_INVALID:
/* Scan words tagged "invalid" -- everything will die. */
die(mps_root_create_area_tagged(&root, arena, mps_rank_ambig(), 0,
refs, refs + OBJCOUNT,
mps_scan_area_tagged, TAG_MASK, tag_invalid),
"root");
expected = OBJCOUNT;
break;
}
MPS_ARGS_BEGIN(args) {
MPS_ARGS_ADD(args, MPS_KEY_FMT_SCAN, scan);
MPS_ARGS_ADD(args, MPS_KEY_FMT_SKIP, skip);
MPS_ARGS_ADD(args, MPS_KEY_FMT_FWD, fwd);
MPS_ARGS_ADD(args, MPS_KEY_FMT_ISFWD, isfwd);
MPS_ARGS_ADD(args, MPS_KEY_FMT_PAD, pad);
die(mps_fmt_create_k(&fmt, arena, args), "fmt");
} MPS_ARGS_END(args);
MPS_ARGS_BEGIN(args) {
MPS_ARGS_ADD(args, MPS_KEY_FORMAT, fmt);
die(mps_pool_create_k(&pool, arena, mps_class_amc(), args), "pool");
} MPS_ARGS_END(args);
die(mps_ap_create_k(&ap, pool, mps_args_none), "ap");
for (i = 0; i < OBJCOUNT; ++i) {
mps_word_t p, r;
mps_word_t q = TAGGED(i << tag_bits, imm);
mps_addr_t addr;
p = make_cons(ap, q, q);
Insist(TAG(p) == tag_cons);
r = TAGGED(p, imm);
UNTAGGED(p, cons)->cdr = r;
refs[i] = (mps_addr_t)p;
addr = (mps_addr_t)UNTAGGED(p, cons);
die(mps_finalize(arena, &addr), "finalize");
}
collect(expected);
mps_arena_park(arena);
mps_ap_destroy(ap);
mps_pool_destroy(pool);
mps_fmt_destroy(fmt);
mps_root_destroy(root);
mps_thread_dereg(thread);
mps_arena_destroy(arena);
}
int main(int argc, char *argv[])
{
mps_word_t tags[sizeof(mps_word_t)];
size_t i;
int mode;
testlib_init(argc, argv);
/* Work out how many tags to use. */
tag_bits = SizeLog2(sizeof(mps_word_t));
Insist(TAG_COUNT <= NELEMS(tags));
/* Shuffle the tags. */
for (i = 0; i < TAG_COUNT; ++i) {
tags[i] = i;
}
for (i = 0; i < TAG_COUNT; ++i) {
size_t j = i + rnd() % (TAG_COUNT - i);
mps_word_t t = tags[i];
tags[i] = tags[j];
tags[j] = t;
}
tag_cons = tags[0];
tag_fwd = tags[1];
tag_imm = tags[2];
tag_invalid = tags[3];
printf("tags: cons = %u, fwd = %u, imm = %u, invalid = %u\n",
(unsigned)tag_cons, (unsigned)tag_fwd,
(unsigned)tag_imm, (unsigned)tag_invalid);
for (mode = 0; mode < MODE_LIMIT; ++mode) {
test(mode);
}
printf("%s: Conclusion: Failed to find any defects.\n", argv[0]);
return 0;
}
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*
* Copyright (C) 2015-2020 Ravenbrook Limited <https://www.ravenbrook.com/>.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the
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*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
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