don't sweep the free-list elements!

implementing heap expansion w/ realloc.
realloc is always giving back the same pointer right now,
so pointer adjusting not tested yet.
This commit is contained in:
Alex Shinn 2009-06-10 00:38:15 +09:00
parent d65e7255f8
commit 54baeaca36

230
gc.c
View file

@ -1,10 +1,11 @@
/* gc.c -- simple garbage collector */
/* gc.c -- simple mark&sweep garbage collector */
/* Copyright (c) 2009 Alex Shinn. All rights reserved. */
/* BSD-style license: http://synthcode.com/license.txt */
#include "sexp.h"
#define SEXP_INITIAL_HEAP_SIZE 50000
#define SEXP_INITIAL_HEAP_SIZE 40000
#define SEXP_MAXIMUM_HEAP_SIZE 0
#define SEXP_MINIMUM_OBJECT_SIZE (sexp_sizeof(flonum))
static char* sexp_heap;
@ -49,15 +50,16 @@ void sexp_mark (sexp x) {
struct sexp_gc_var_t *saves;
loop:
if (((char*)x < sexp_heap) || ((char*)x >= sexp_heap_end)) {
if (x && sexp_pointerp(x) && (sexp_pointer_tag(x) != SEXP_OPCODE))
if (x && sexp_pointerp(x) && (sexp_pointer_tag(x) != SEXP_OPCODE)
&& (sexp_pointer_tag(x) != SEXP_CORE))
fprintf(stderr, "--------------- outside heap: %p (%x) ------------------\n", x, sexp_pointer_tag(x));
return;
}
if ((! x) || (! sexp_pointerp(x)) || sexp_gc_mark(x))
return;
sexp_gc_mark(x) = 1;
fprintf(stderr, "----------------- marking %p (%x) --------------------\n",
x, sexp_pointer_tag(x));
/* fprintf(stderr, "----------------- marking %p (%x) --------------------\n", */
/* x, sexp_pointer_tag(x)); */
switch (sexp_pointer_tag(x)) {
case SEXP_PAIR:
sexp_mark(sexp_car(x));
@ -153,6 +155,88 @@ void sexp_mark (sexp x) {
}
}
#define _adjust(x) if (x && (sexp_pointerp(x)) && (start <= (char*)x) && (((char*)x) <= end)) x = (sexp) (((char*)x)+offset)
void sexp_adjust_pointers (sexp x, char* start, char* end, size_t offset) {
sexp *data;
sexp_uint_t i;
struct sexp_gc_var_t *saves;
switch (sexp_pointer_tag(x)) {
case SEXP_PAIR:
_adjust(sexp_car(x)); _adjust(sexp_cdr(x)); break;
case SEXP_STACK:
data = sexp_stack_data(x);
for (i=sexp_stack_top(x)-1; i>=0; i--)
_adjust(data[i]);
break;
case SEXP_VECTOR:
data = sexp_vector_data(x);
for (i=sexp_vector_length(x)-1; i>=0; i--)
_adjust(data[i]);
break;
case SEXP_SYMBOL:
_adjust(sexp_symbol_string(x)); break;
case SEXP_BYTECODE:
_adjust(sexp_bytecode_literals(x)); break;
case SEXP_ENV:
_adjust(sexp_env_lambda(x));
_adjust(sexp_env_bindings(x));
_adjust(sexp_env_parent(x));
break;
case SEXP_PROCEDURE:
_adjust(sexp_procedure_code(x)); _adjust(sexp_procedure_vars(x)); break;
case SEXP_MACRO:
_adjust(sexp_macro_proc(x)); _adjust(sexp_macro_env(x)); break;
case SEXP_SYNCLO:
_adjust(sexp_synclo_free_vars(x));
_adjust(sexp_synclo_expr(x));
_adjust(sexp_synclo_env(x));
break;
case SEXP_OPCODE:
_adjust(sexp_opcode_proc(x));
_adjust(sexp_opcode_default(x));
_adjust(sexp_opcode_data(x));
break;
case SEXP_IPORT:
case SEXP_OPORT:
_adjust(sexp_port_cookie(x));
case SEXP_LAMBDA:
_adjust(sexp_lambda_name(x));
_adjust(sexp_lambda_params(x));
_adjust(sexp_lambda_locals(x));
_adjust(sexp_lambda_defs(x));
_adjust(sexp_lambda_flags(x));
_adjust(sexp_lambda_body(x));
_adjust(sexp_lambda_fv(x));
_adjust(sexp_lambda_sv(x));
_adjust(sexp_lambda_body(x));
break;
case SEXP_CND:
_adjust(sexp_cnd_test(x));
_adjust(sexp_cnd_fail(x));
_adjust(sexp_cnd_pass(x));
break;
case SEXP_SET:
_adjust(sexp_set_var(x)); _adjust(sexp_set_value(x)); break;
case SEXP_REF:
_adjust(sexp_ref_name(x)); _adjust(sexp_ref_cell(x)); break;
case SEXP_SEQ:
_adjust(sexp_seq_ls(x)); break;
case SEXP_LIT:
_adjust(sexp_lit_value(x)); break;
case SEXP_CONTEXT:
_adjust(sexp_context_env(x));
_adjust(sexp_context_bc(x));
_adjust(sexp_context_fv(x));
_adjust(sexp_context_lambda(x));
_adjust(sexp_context_parent(x));
for (saves=sexp_context_saves(x); saves; saves=saves->next)
if (saves->var) _adjust(*(saves->var));
_adjust(sexp_context_stack(x));
break;
}
}
void simple_write (sexp obj, int depth, FILE *out) {
unsigned long len, c, res;
long i=0;
@ -161,7 +245,7 @@ void simple_write (sexp obj, int depth, FILE *out) {
if (! obj) {
fputs("#<null>", out);
} if (! sexp_pointerp(obj)) {
} else if (! sexp_pointerp(obj)) {
if (sexp_integerp(obj)) {
fprintf(out, "%ld", sexp_unbox_integer(obj));
} else if (sexp_charp(obj)) {
@ -334,10 +418,15 @@ void simple_write (sexp obj, int depth, FILE *out) {
}
void sexp_show_free_list (sexp ctx) {
sexp p=sexp_free_list;
sexp p=sexp_free_list, prev=NULL;
fputs("free-list:", stderr);
while (p && sexp_pairp(p) && ((char*) p < sexp_heap_end)) {
fprintf(stderr, " %p-%p", p, p+(sexp_uint_t)sexp_car(p));
if (p < prev) {
fprintf(stderr, " \x1B[31m%p-%p\x1B[0m", p, ((char*)p)+(sexp_uint_t)sexp_car(p));
} else {
fprintf(stderr, " %p-%p", p, ((char*)p)+(sexp_uint_t)sexp_car(p));
}
prev = (sexp) (((char*)p)+(sexp_uint_t)sexp_car(p));
p = sexp_cdr(p);
}
putc('\n', stderr);
@ -346,33 +435,36 @@ void sexp_show_free_list (sexp ctx) {
sexp sexp_sweep (sexp ctx) {
sexp_uint_t freed=0, size;
sexp p=(sexp)(sexp_heap+sexp_align(SEXP_MINIMUM_OBJECT_SIZE, 4));
sexp f1=sexp_free_list, f2;
sexp q=sexp_free_list, r;
/* scan over the whole heap */
while ((char*)p<sexp_heap_end) {
while (((char*)p) < sexp_heap_end) {
/* find the preceding and succeeding free list pointers */
for (f2=sexp_cdr(f1); f2 && sexp_pairp(f2) && (f2 < p); f1=f2, f2=sexp_cdr(f2))
for (r=sexp_cdr(q); r && sexp_pairp(r) && (r<p); q=r, r=sexp_cdr(r))
;
fprintf(stderr, "p: %p f1: %p f2: %p\n", p, f1, f2);
/* fprintf(stderr, "p: %p q: %p r: %p\n", p, q, r); */
if (r == p) {
p = (sexp) (((char*)p) + (sexp_uint_t)sexp_car(p));
continue;
}
size = sexp_align(sexp_allocated_bytes(p), 4);
if (! sexp_gc_mark(p)) {
fprintf(stderr, "freeing %lu bytes @ %p (%x) ", size, p, sexp_pointer_tag(p));
simple_write(p, 1, stderr);
fprintf(stderr, " -\n");
/* fprintf(stderr, "\x1B[31mfreeing %lu bytes @ %p (%x) ", size, p, sexp_pointer_tag(p)); */
/* simple_write(p, 1, stderr); */
/* fprintf(stderr, "\x1B[0m\n"); */
freed += size;
sexp_pointer_tag(p) = SEXP_PAIR;
sexp_car(p) = (sexp)size;
sexp_cdr(p) = f2;
sexp_cdr(f1) = p;
/* f1 = f2; */
sexp_cdr(p) = r;
sexp_cdr(q) = p;
} else {
fprintf(stderr, "saving %lu bytes @ %p (%x) ", size, p, sexp_pointer_tag(p));
simple_write(p, 1, stderr);
fprintf(stderr, " +\n");
/* fprintf(stderr, "\x1B[32msaving %lu bytes @ %p (%x) ", size, p, sexp_pointer_tag(p)); */
/* simple_write(p, 1, stderr); */
/* fprintf(stderr, "\x1B[0m\n"); */
sexp_gc_mark(p) = 0;
}
p = (sexp) (((char*)p)+size);
}
fprintf(stderr, "**************** freed %ld bytes ****************\n", freed);
/* fprintf(stderr, "**************** freed %ld bytes ****************\n", freed); */
return sexp_make_integer(freed);
}
@ -380,8 +472,8 @@ extern sexp continuation_resumer, final_resumer;
sexp sexp_gc (sexp ctx) {
int i;
fprintf(stderr, "************* garbage collecting *************\n");
sexp_show_free_list(ctx);
/* fprintf(stderr, "************* garbage collecting *************\n"); */
/* sexp_show_free_list(ctx); */
sexp_mark(continuation_resumer);
sexp_mark(final_resumer);
for (i=0; i<SEXP_SYMBOL_TABLE_SIZE; i++)
@ -390,11 +482,70 @@ sexp sexp_gc (sexp ctx) {
return sexp_sweep(ctx);
}
void *sexp_alloc (sexp ctx, size_t size) {
int tries = 0;
void sexp_adjust_heap (char *start, char *end, size_t offset, size_t new_size) {
sexp p=(sexp)(start+sexp_align(SEXP_MINIMUM_OBJECT_SIZE, 4));
sexp q=(sexp)(((char*)sexp_free_list)+offset), r;
/* fprintf(stderr, "************* adjusting heap *************\n"); */
while (((char*)p) < end) {
/* find the preceding and succeeding free list pointers */
for (r=sexp_cdr(q); r && sexp_pairp(r) && (r<p); q=r, r=sexp_cdr(r))
;
if (r == p) {
p = (sexp) (((char*)p) + (sexp_uint_t)sexp_car(p));
continue;
}
sexp_adjust_pointers(p, start, end, offset);
p = (sexp) (((char*)p) + sexp_align(sexp_allocated_bytes(p), 4));
}
/* adjust the free list */
sexp_free_list += offset;
q = sexp_free_list;
_adjust(sexp_cdr(q));
for (r=sexp_cdr(q); r && (((char*)r) < end); q=r, r=sexp_cdr(r))
_adjust(sexp_cdr(r));
r = (sexp) end;
sexp_cdr(q) = r;
sexp_pointer_tag(r) = SEXP_PAIR;
sexp_car(r) = (sexp) (new_size - (end-start));
sexp_cdr(r) = NULL;
}
int sexp_grow_heap (sexp ctx, size_t size) {
char *tmp1, *tmp2;
sexp q;
size_t cur_size = sexp_heap_end - sexp_heap, new_size;
new_size = sexp_align(((cur_size > size) ? cur_size : size) * 2, 4);
/* fprintf(stderr, "************* growing heap *************\n"); */
if (SEXP_MAXIMUM_HEAP_SIZE && (new_size > SEXP_MAXIMUM_HEAP_SIZE)) {
fprintf(stderr, "************* heap too large *************\n");
return 0;
}
if (! (tmp1 = realloc(sexp_heap, new_size))) {
fprintf(stderr, "************* couldn't realloc *************\n");
return 0;
}
if (tmp1 != sexp_heap) {
sexp_adjust_heap(tmp1, tmp1+cur_size, tmp1-sexp_heap, new_size);
tmp2 = sexp_heap;
sexp_heap = tmp1;
free(tmp2);
} else {
for (q = sexp_free_list;
sexp_cdr(q) && sexp_pairp(sexp_cdr(q));
q = sexp_cdr(q))
;
sexp_cdr(q) = (sexp) sexp_heap_end;
q = sexp_cdr(q);
sexp_pointer_tag(q) = SEXP_PAIR;
sexp_car(q) = (sexp) (new_size - cur_size);
sexp_cdr(q) = SEXP_NULL;
}
sexp_heap_end = sexp_heap + new_size;
return 1;
}
void* sexp_try_alloc (sexp ctx, size_t size) {
sexp ls1, ls2, ls3;
size = sexp_align(size, 4);
try_alloc:
ls1 = sexp_free_list;
ls2 = sexp_cdr(ls1);
for (ls2=sexp_cdr(ls1); sexp_pairp(ls2); ) {
@ -408,22 +559,33 @@ void *sexp_alloc (sexp ctx, size_t size) {
} else { /* take the whole chunk */
sexp_cdr(ls1) = sexp_cdr(ls2);
}
bzero((void*)ls2, size);
bzero((void*)ls2, size); /* maybe not needed */
return ls2;
}
ls1 = ls2;
ls2 = sexp_cdr(ls2);
}
if ((! tries) && (sexp_unbox_integer(sexp_gc(ctx)) >= size)) {
tries++;
goto try_alloc;
} else {
return NULL;
}
void* sexp_alloc (sexp ctx, size_t size) {
void *res;
size = sexp_align(size, 4);
res = sexp_try_alloc(ctx, size);
if (! res) {
if (sexp_unbox_integer(sexp_gc(ctx)) >= size)
res = sexp_try_alloc(ctx, size);
if ((! res) && sexp_grow_heap(ctx, size))
res = sexp_try_alloc(ctx, size);
if (! res) {
fprintf(stderr,
"chibi: out of memory trying to allocate %ld bytes, aborting\n",
size);
exit(70);
}
}
return res;
}
void sexp_gc_init () {
sexp next;
@ -438,6 +600,6 @@ void sexp_gc_init () {
sexp_car(next) = (sexp) (SEXP_INITIAL_HEAP_SIZE
- sexp_align(sexp_sizeof(pair), 4));
sexp_cdr(next) = SEXP_NULL;
fprintf(stderr, "heap: %p - %p, next: %p\n", sexp_heap, sexp_heap_end, next);
/* fprintf(stderr, "heap: %p - %p, next: %p\n", sexp_heap, sexp_heap_end, next); */
}