picrin/extlib/benz/gc.c

877 lines
17 KiB
C

/**
* See Copyright Notice in picrin.h
*/
#include "picrin.h"
union header {
struct {
union header *ptr;
size_t size;
char mark;
} s;
long alignment[2];
};
struct heap_page {
union header *basep, *endp;
struct heap_page *next;
};
struct pic_heap {
union header base, *freep;
struct heap_page *pages;
};
static void
heap_init(struct pic_heap *heap)
{
heap->base.s.ptr = &heap->base;
heap->base.s.size = 0; /* not 1, since it must never be used for allocation */
heap->base.s.mark = PIC_GC_UNMARK;
heap->freep = &heap->base;
heap->pages = NULL;
#if GC_DEBUG
printf("freep = %p\n", (void *)heap->freep);
#endif
}
struct pic_heap *
pic_heap_open(pic_state *pic)
{
struct pic_heap *heap;
heap = pic_calloc(pic, 1, sizeof(struct pic_heap));
heap_init(heap);
return heap;
}
void
pic_heap_close(pic_state *pic, struct pic_heap *heap)
{
struct heap_page *page;
while (heap->pages) {
page = heap->pages;
heap->pages = heap->pages->next;
pic_free(pic, page);
}
}
static void gc_free(pic_state *, union header *);
static void
add_heap_page(pic_state *pic)
{
union header *up, *np;
struct heap_page *page;
size_t nu;
#if GC_DEBUG
puts("adding heap page!");
#endif
nu = (PIC_HEAP_PAGE_SIZE + sizeof(union header) - 1) / sizeof(union header) + 1;
up = pic_calloc(pic, 1 + nu + 1, sizeof(union header));
up->s.size = nu + 1;
up->s.mark = PIC_GC_UNMARK;
gc_free(pic, up);
np = up + 1;
np->s.size = nu;
np->s.ptr = up->s.ptr;
up->s.size = 1;
up->s.ptr = np;
page = pic_malloc(pic, sizeof(struct heap_page));
page->basep = up;
page->endp = up + nu + 1;
page->next = pic->heap->pages;
pic->heap->pages = page;
}
#if PIC_ENABLE_LIBC
void *
pic_default_allocf(void *ptr, size_t size)
{
if (size == 0) {
if (ptr) {
free(ptr);
}
return NULL;
}
if (ptr) {
return realloc(ptr, size);
} else {
return malloc(size);
}
}
#endif
void *
pic_malloc(pic_state *pic, size_t size)
{
void *ptr;
ptr = pic->allocf(NULL, size);
if (ptr == NULL && size > 0) {
pic_panic(pic, "memory exhausted");
}
return ptr;
}
void *
pic_realloc(pic_state *pic, void *ptr, size_t size)
{
ptr = pic->allocf(ptr, size);
if (ptr == NULL && size > 0) {
pic_panic(pic, "memory exhausted");
}
return ptr;
}
void *
pic_calloc(pic_state *pic, size_t count, size_t size)
{
void *ptr;
size *= count;
ptr = pic->allocf(NULL, size);
if (ptr == NULL && size > 0) {
pic_panic(pic, "memory exhausted");
}
memset(ptr, 0, size);
return ptr;
}
void
pic_free(pic_state *pic, void *ptr)
{
pic->allocf(ptr, 0);
}
static void
gc_protect(pic_state *pic, struct pic_object *obj)
{
if (pic->arena_idx >= pic->arena_size) {
pic->arena_size = pic->arena_size * 2 + 1;
pic->arena = pic_realloc(pic, pic->arena, sizeof(struct pic_object *) * pic->arena_size);
}
pic->arena[pic->arena_idx++] = obj;
}
pic_value
pic_gc_protect(pic_state *pic, pic_value v)
{
struct pic_object *obj;
if (pic_vtype(v) != PIC_VTYPE_HEAP) {
return v;
}
obj = pic_obj_ptr(v);
gc_protect(pic, obj);
return v;
}
size_t
pic_gc_arena_preserve(pic_state *pic)
{
return pic->arena_idx;
}
void
pic_gc_arena_restore(pic_state *pic, size_t state)
{
pic->arena_idx = state;
}
static void *
gc_alloc(pic_state *pic, size_t size)
{
union header *freep, *p, *prevp;
size_t nunits;
#if GC_DEBUG
assert(size > 0);
#endif
nunits = (size + sizeof(union header) - 1) / sizeof(union header) + 1;
prevp = freep = pic->heap->freep;
for (p = prevp->s.ptr; ; prevp = p, p = p->s.ptr) {
if (p->s.size >= nunits)
break;
if (p == freep) {
return NULL;
}
}
#if GC_DEBUG
{
unsigned char *c;
size_t s, i, j;
if (p->s.size == nunits) {
c = (unsigned char *)(p + p->s.size - nunits + 1);
s = nunits - 1;
} else {
c = (unsigned char *)(p + p->s.size - nunits);
s = nunits;
}
for (i = 0; i < s; ++i) {
for (j = 0; j < sizeof(union header); ++j) {
assert(c[i * sizeof(union header) + j] == 0xAA);
}
}
}
#endif
if (p->s.size == nunits) {
prevp->s.ptr = p->s.ptr;
}
else {
p->s.size -= nunits;
p += p->s.size;
p->s.size = nunits;
}
pic->heap->freep = prevp;
p->s.mark = PIC_GC_UNMARK;
#if GC_DEBUG
memset(p+1, 0, sizeof(union header) * (nunits - 1));
p->s.ptr = (union header *)0xcafebabe;
#endif
return (void *)(p + 1);
}
static void
gc_free(pic_state *pic, union header *bp)
{
union header *freep, *p;
#if GC_DEBUG
assert(bp != NULL);
assert(bp->s.size > 1);
#endif
#if GC_DEBUG
memset(bp + 1, 0xAA, (bp->s.size - 1) * sizeof(union header));
#endif
freep = pic->heap->freep;
for (p = freep; ! (bp > p && bp < p->s.ptr); p = p->s.ptr) {
if (p >= p->s.ptr && (bp > p || bp < p->s.ptr)) {
break;
}
}
if (bp + bp->s.size == p->s.ptr) {
bp->s.size += p->s.ptr->s.size;
bp->s.ptr = p->s.ptr->s.ptr;
#if GC_DEBUG
memset(p->s.ptr, 0xAA, sizeof(union header));
#endif
}
else {
bp->s.ptr = p->s.ptr;
}
if (p + p->s.size == bp && p->s.size > 1) {
p->s.size += bp->s.size;
p->s.ptr = bp->s.ptr;
#if GC_DEBUG
memset(bp, 0xAA, sizeof(union header));
#endif
}
else {
p->s.ptr = bp;
}
pic->heap->freep = p;
}
static void gc_mark(pic_state *, pic_value);
static void gc_mark_object(pic_state *pic, struct pic_object *obj);
static bool
gc_is_marked(union header *p)
{
return p->s.mark == PIC_GC_MARK;
}
static bool
gc_obj_is_marked(struct pic_object *obj)
{
union header *p;
p = ((union header *)obj) - 1;
return gc_is_marked(p);
}
static void
gc_unmark(union header *p)
{
p->s.mark = PIC_GC_UNMARK;
}
static void
gc_mark_winder(pic_state *pic, struct pic_winder *wind)
{
if (wind->prev) {
gc_mark_object(pic, (struct pic_object *)wind->prev);
}
if (wind->in) {
gc_mark_object(pic, (struct pic_object *)wind->in);
}
if (wind->out) {
gc_mark_object(pic, (struct pic_object *)wind->out);
}
}
static void
gc_mark_object(pic_state *pic, struct pic_object *obj)
{
union header *p;
p = ((union header *)obj) - 1;
if (gc_is_marked(p))
return;
p->s.mark = PIC_GC_MARK;
switch (obj->tt) {
case PIC_TT_PAIR: {
gc_mark(pic, ((struct pic_pair *)obj)->car);
gc_mark(pic, ((struct pic_pair *)obj)->cdr);
break;
}
case PIC_TT_CXT: {
struct pic_context *cxt = (struct pic_context *)obj;
int i;
for (i = 0; i < cxt->regc; ++i) {
gc_mark(pic, cxt->regs[i]);
}
if (cxt->up) {
gc_mark_object(pic, (struct pic_object *)cxt->up);
}
break;
}
case PIC_TT_PROC: {
struct pic_proc *proc = (struct pic_proc *)obj;
if (pic_proc_irep_p(proc)) {
gc_mark_object(pic, (struct pic_object *)proc->u.i.irep);
if (proc->u.i.cxt) {
gc_mark_object(pic, (struct pic_object *)proc->u.i.cxt);
}
} else {
gc_mark_object(pic, (struct pic_object *)proc->u.f.name);
if (proc->u.f.env) {
gc_mark_object(pic, (struct pic_object *)proc->u.f.env);
}
}
break;
}
case PIC_TT_PORT: {
break;
}
case PIC_TT_ERROR: {
struct pic_error *err = (struct pic_error *)obj;
gc_mark_object(pic, (struct pic_object *)err->type);
gc_mark_object(pic, (struct pic_object *)err->msg);
gc_mark(pic, err->irrs);
gc_mark_object(pic, (struct pic_object *)err->stack);
break;
}
case PIC_TT_STRING: {
break;
}
case PIC_TT_VECTOR: {
size_t i;
for (i = 0; i < ((struct pic_vector *)obj)->len; ++i) {
gc_mark(pic, ((struct pic_vector *)obj)->data[i]);
}
break;
}
case PIC_TT_BLOB: {
break;
}
case PIC_TT_ENV: {
struct pic_env *env = (struct pic_env *)obj;
if (env->up) {
gc_mark_object(pic, (struct pic_object *)env->up);
}
gc_mark(pic, env->defer);
gc_mark_object(pic, (struct pic_object *)env->map);
break;
}
case PIC_TT_LIB: {
struct pic_lib *lib = (struct pic_lib *)obj;
gc_mark(pic, lib->name);
gc_mark_object(pic, (struct pic_object *)lib->env);
gc_mark_object(pic, (struct pic_object *)lib->exports);
break;
}
case PIC_TT_IREP: {
struct pic_irep *irep = (struct pic_irep *)obj;
size_t i;
gc_mark_object(pic, (struct pic_object *)irep->name);
for (i = 0; i < irep->ilen; ++i) {
gc_mark_object(pic, (struct pic_object *)irep->irep[i]);
}
for (i = 0; i < irep->plen; ++i) {
gc_mark(pic, irep->pool[i]);
}
for (i = 0; i < irep->slen; ++i) {
gc_mark_object(pic, (struct pic_object *)irep->syms[i]);
}
break;
}
case PIC_TT_DATA: {
struct pic_data *data = (struct pic_data *)obj;
xh_entry *it;
for (it = xh_begin(&data->storage); it != NULL; it = xh_next(it)) {
gc_mark(pic, xh_val(it, pic_value));
}
if (data->type->mark) {
data->type->mark(pic, data->data, gc_mark);
}
break;
}
case PIC_TT_DICT: {
struct pic_dict *dict = (struct pic_dict *)obj;
xh_entry *it;
for (it = xh_begin(&dict->hash); it != NULL; it = xh_next(it)) {
gc_mark_object(pic, (struct pic_object *)xh_key(it, pic_sym *));
gc_mark(pic, xh_val(it, pic_value));
}
break;
}
case PIC_TT_RECORD: {
struct pic_record *rec = (struct pic_record *)obj;
gc_mark_object(pic, (struct pic_object *)rec->data);
break;
}
case PIC_TT_SYMBOL: {
struct pic_symbol *sym = (struct pic_symbol *)obj;
gc_mark_object(pic, (struct pic_object *)sym->str);
break;
}
case PIC_TT_NIL:
case PIC_TT_BOOL:
#if PIC_ENABLE_FLOAT
case PIC_TT_FLOAT:
#endif
case PIC_TT_INT:
case PIC_TT_CHAR:
case PIC_TT_EOF:
case PIC_TT_UNDEF:
pic_panic(pic, "logic flaw");
}
}
static void
gc_mark(pic_state *pic, pic_value v)
{
struct pic_object *obj;
if (pic_vtype(v) != PIC_VTYPE_HEAP)
return;
obj = pic_obj_ptr(v);
gc_mark_object(pic, obj);
}
#define M(x) gc_mark_object(pic, (struct pic_object *)pic->x)
static void
gc_mark_global_symbols(pic_state *pic)
{
M(sDEFINE); M(sLAMBDA); M(sIF); M(sBEGIN); M(sQUOTE); M(sSETBANG);
M(sQUASIQUOTE); M(sUNQUOTE); M(sUNQUOTE_SPLICING);
M(sDEFINE_SYNTAX); M(sIMPORT); M(sEXPORT);
M(sDEFINE_LIBRARY); M(sIN_LIBRARY);
M(sCOND_EXPAND); M(sAND); M(sOR); M(sELSE); M(sLIBRARY);
M(sONLY); M(sRENAME); M(sPREFIX); M(sEXCEPT);
M(sCONS); M(sCAR); M(sCDR); M(sNILP);
M(sSYMBOLP); M(sPAIRP);
M(sADD); M(sSUB); M(sMUL); M(sDIV); M(sMINUS);
M(sEQ); M(sLT); M(sLE); M(sGT); M(sGE); M(sNOT);
M(sREAD); M(sFILE);
M(sCALL); M(sTAILCALL); M(sCALL_WITH_VALUES); M(sTAILCALL_WITH_VALUES);
M(sGREF); M(sLREF); M(sCREF); M(sRETURN);
M(rDEFINE); M(rLAMBDA); M(rIF); M(rBEGIN); M(rQUOTE); M(rSETBANG);
M(rDEFINE_SYNTAX); M(rIMPORT); M(rEXPORT);
M(rDEFINE_LIBRARY); M(rIN_LIBRARY);
M(rCOND_EXPAND);
}
static void
gc_mark_phase(pic_state *pic)
{
pic_value *stack;
pic_callinfo *ci;
struct pic_proc **xhandler;
size_t j;
xh_entry *it;
struct pic_object *obj;
/* winder */
if (pic->wind) {
gc_mark_winder(pic, pic->wind);
}
/* stack */
for (stack = pic->stbase; stack != pic->sp; ++stack) {
gc_mark(pic, *stack);
}
/* callinfo */
for (ci = pic->ci; ci != pic->cibase; --ci) {
if (ci->cxt) {
gc_mark_object(pic, (struct pic_object *)ci->cxt);
}
}
/* exception handlers */
for (xhandler = pic->xpbase; xhandler != pic->xp; ++xhandler) {
gc_mark_object(pic, (struct pic_object *)*xhandler);
}
/* arena */
for (j = 0; j < pic->arena_idx; ++j) {
gc_mark_object(pic, pic->arena[j]);
}
/* mark reserved symbols */
gc_mark_global_symbols(pic);
/* global variables */
if (pic->globals) {
gc_mark_object(pic, (struct pic_object *)pic->globals);
}
/* macro objects */
if (pic->macros) {
gc_mark_object(pic, (struct pic_object *)pic->macros);
}
/* error object */
gc_mark(pic, pic->err);
/* features */
gc_mark(pic, pic->features);
/* library table */
gc_mark(pic, pic->libs);
/* standard I/O ports */
if (pic->xSTDIN) {
gc_mark_object(pic, (struct pic_object *)pic->xSTDIN);
}
if (pic->xSTDOUT) {
gc_mark_object(pic, (struct pic_object *)pic->xSTDOUT);
}
if (pic->xSTDERR) {
gc_mark_object(pic, (struct pic_object *)pic->xSTDERR);
}
/* attributes */
do {
j = 0;
for (it = xh_begin(&pic->attrs); it != NULL; it = xh_next(it)) {
if (gc_obj_is_marked(xh_key(it, struct pic_object *))) {
obj = (struct pic_object *)xh_val(it, struct pic_dict *);
if (! gc_obj_is_marked(obj)) {
gc_mark_object(pic, obj);
++j;
}
}
}
} while (j > 0);
}
static void
gc_finalize_object(pic_state *pic, struct pic_object *obj)
{
#if GC_DEBUG
printf("* finalizing object: %s", pic_type_repr(pic_type(pic_obj_value(obj))));
// pic_debug(pic, pic_obj_value(obj));
puts("");
#endif
switch (obj->tt) {
case PIC_TT_PAIR: {
break;
}
case PIC_TT_CXT: {
break;
}
case PIC_TT_PROC: {
break;
}
case PIC_TT_VECTOR: {
pic_free(pic, ((struct pic_vector *)obj)->data);
break;
}
case PIC_TT_BLOB: {
pic_free(pic, ((struct pic_blob *)obj)->data);
break;
}
case PIC_TT_STRING: {
pic_rope_decref(pic, ((struct pic_string *)obj)->rope);
break;
}
case PIC_TT_PORT: {
break;
}
case PIC_TT_ERROR: {
break;
}
case PIC_TT_ENV: {
break;
}
case PIC_TT_LIB: {
break;
}
case PIC_TT_IREP: {
struct pic_irep *irep = (struct pic_irep *)obj;
pic_free(pic, irep->code);
pic_free(pic, irep->irep);
pic_free(pic, irep->pool);
pic_free(pic, irep->syms);
break;
}
case PIC_TT_DATA: {
struct pic_data *data = (struct pic_data *)obj;
data->type->dtor(pic, data->data);
xh_destroy(&data->storage);
break;
}
case PIC_TT_DICT: {
struct pic_dict *dict = (struct pic_dict *)obj;
xh_destroy(&dict->hash);
break;
}
case PIC_TT_RECORD: {
break;
}
case PIC_TT_SYMBOL: {
break;
}
case PIC_TT_NIL:
case PIC_TT_BOOL:
#if PIC_ENABLE_FLOAT
case PIC_TT_FLOAT:
#endif
case PIC_TT_INT:
case PIC_TT_CHAR:
case PIC_TT_EOF:
case PIC_TT_UNDEF:
pic_panic(pic, "logic flaw");
}
}
static void
gc_sweep_symbols(pic_state *pic)
{
xh_entry *it;
xvect_t(xh_entry *) xv;
size_t i;
char *cstr;
xv_init(xv);
for (it = xh_begin(&pic->syms); it != NULL; it = xh_next(it)) {
if (! gc_obj_is_marked((struct pic_object *)xh_val(it, pic_sym *))) {
xv_push(xh_entry *, xv, it);
}
}
for (i = 0; i < xv_size(xv); ++i) {
cstr = xh_key(xv_A(xv, i), char *);
xh_del_str(&pic->syms, cstr);
pic_free(pic, cstr);
}
}
static void
gc_sweep_page(pic_state *pic, struct heap_page *page)
{
#if GC_DEBUG
static union header *NIL = (union header *)0xdeadbeef;
#else
static union header *NIL = NULL;
#endif
union header *bp, *p, *s = NIL, *t = NIL;
#if GC_DEBUG
int c = 0;
#endif
for (bp = page->basep; ; bp = bp->s.ptr) {
for (p = bp + bp->s.size; p != bp->s.ptr; p += p->s.size) {
if (p == page->endp) {
goto escape;
}
if (! gc_is_marked(p)) {
if (s == NIL) {
s = p;
}
else {
t->s.ptr = p;
}
t = p;
t->s.ptr = NIL; /* For dead objects we can safely reuse ptr field */
}
gc_unmark(p);
}
}
escape:
/* free! */
while (s != NIL) {
t = s->s.ptr;
gc_finalize_object(pic, (struct pic_object *)(s + 1));
gc_free(pic, s);
s = t;
#if GC_DEBUG
c++;
#endif
}
#if GC_DEBUG
printf("freed objects count: %d\n", c);
#endif
}
static void
gc_sweep_phase(pic_state *pic)
{
struct heap_page *page = pic->heap->pages;
xh_entry *it, *next;
do {
for (it = xh_begin(&pic->attrs); it != NULL; it = next) {
next = xh_next(it);
if (! gc_obj_is_marked(xh_key(it, struct pic_object *))) {
xh_del_ptr(&pic->attrs, xh_key(it, struct pic_object *));
}
}
} while (it != NULL);
gc_sweep_symbols(pic);
while (page) {
gc_sweep_page(pic, page);
page = page->next;
}
}
void
pic_gc_run(pic_state *pic)
{
#if GC_DEBUG
struct heap_page *page;
#endif
if (! pic->gc_enable) {
return;
}
#if DEBUG
puts("gc run!");
#endif
gc_mark_phase(pic);
gc_sweep_phase(pic);
#if GC_DEBUG
for (page = pic->heap->pages; page; page = page->next) {
union header *bp, *p;
unsigned char *c;
for (bp = page->basep; ; bp = bp->s.ptr) {
for (c = (unsigned char *)(bp+1); c != (unsigned char *)(bp + bp->s.size); ++c) {
assert(*c == 0xAA);
}
for (p = bp + bp->s.size; p != bp->s.ptr; p += p->s.size) {
if (p == page->endp) {
/* if (page->next) */
/* assert(bp->s.ptr == page->next->basep); */
/* else */
/* assert(bp->s.ptr == &pic->heap->base); */
goto escape;
}
assert(! gc_is_marked(p));
}
}
escape:
((void)0);
}
puts("not error on heap found! gc successfully finished");
#endif
}
struct pic_object *
pic_obj_alloc_unsafe(pic_state *pic, size_t size, enum pic_tt tt)
{
struct pic_object *obj;
#if GC_DEBUG
printf("*allocating: %s\n", pic_type_repr(tt));
#endif
#if GC_STRESS
pic_gc_run(pic);
#endif
obj = (struct pic_object *)gc_alloc(pic, size);
if (obj == NULL) {
pic_gc_run(pic);
obj = (struct pic_object *)gc_alloc(pic, size);
if (obj == NULL) {
add_heap_page(pic);
obj = (struct pic_object *)gc_alloc(pic, size);
if (obj == NULL)
pic_panic(pic, "GC memory exhausted");
}
}
obj->tt = tt;
return obj;
}
struct pic_object *
pic_obj_alloc(pic_state *pic, size_t size, enum pic_tt tt)
{
struct pic_object *obj;
obj = pic_obj_alloc_unsafe(pic, size, tt);
gc_protect(pic, obj);
return obj;
}