/* +----------------------------------------------------------------------+ | Zend Engine | +----------------------------------------------------------------------+ | Copyright (c) 1998-2013 Zend Technologies Ltd. (http://www.zend.com) | +----------------------------------------------------------------------+ | This source file is subject to version 2.00 of the Zend license, | | that is bundled with this package in the file LICENSE, and is | | available through the world-wide-web at the following url: | | http://www.zend.com/license/2_00.txt. | | If you did not receive a copy of the Zend license and are unable to | | obtain it through the world-wide-web, please send a note to | | license@zend.com so we can mail you a copy immediately. | +----------------------------------------------------------------------+ | Authors: David Wang | | Dmitry Stogov | +----------------------------------------------------------------------+ */ /* $Id$ */ #include "zend.h" #include "zend_API.h" #define GC_ROOT_BUFFER_MAX_ENTRIES 10000 #ifdef ZTS ZEND_API int gc_globals_id; #else ZEND_API zend_gc_globals gc_globals; #endif static void root_buffer_dtor(zend_gc_globals *gc_globals TSRMLS_DC) { if (gc_globals->buf) { free(gc_globals->buf); gc_globals->buf = NULL; } } static void gc_globals_ctor_ex(zend_gc_globals *gc_globals TSRMLS_DC) { gc_globals->gc_enabled = 0; gc_globals->gc_active = 0; gc_globals->buf = NULL; gc_globals->roots.next = &gc_globals->roots; gc_globals->roots.prev = &gc_globals->roots; gc_globals->unused = NULL; gc_globals->zval_to_free = NULL; gc_globals->free_list = NULL; gc_globals->next_to_free = NULL; gc_globals->gc_runs = 0; gc_globals->collected = 0; #if GC_BENCH gc_globals->root_buf_length = 0; gc_globals->root_buf_peak = 0; gc_globals->zval_possible_root = 0; gc_globals->zobj_possible_root = 0; gc_globals->zval_buffered = 0; gc_globals->zobj_buffered = 0; gc_globals->zval_remove_from_buffer = 0; gc_globals->zobj_remove_from_buffer = 0; gc_globals->zval_marked_grey = 0; gc_globals->zobj_marked_grey = 0; #endif } ZEND_API void gc_globals_ctor(TSRMLS_D) { #ifdef ZTS ts_allocate_id(&gc_globals_id, sizeof(zend_gc_globals), (ts_allocate_ctor) gc_globals_ctor_ex, (ts_allocate_dtor) root_buffer_dtor); #else gc_globals_ctor_ex(&gc_globals); #endif } ZEND_API void gc_globals_dtor(TSRMLS_D) { #ifndef ZTS root_buffer_dtor(&gc_globals TSRMLS_DC); #endif } ZEND_API void gc_reset(TSRMLS_D) { GC_G(gc_runs) = 0; GC_G(collected) = 0; #if GC_BENCH GC_G(root_buf_length) = 0; GC_G(root_buf_peak) = 0; GC_G(zval_possible_root) = 0; GC_G(zobj_possible_root) = 0; GC_G(zval_buffered) = 0; GC_G(zobj_buffered) = 0; GC_G(zval_remove_from_buffer) = 0; GC_G(zobj_remove_from_buffer) = 0; GC_G(zval_marked_grey) = 0; GC_G(zobj_marked_grey) = 0; #endif GC_G(roots).next = &GC_G(roots); GC_G(roots).prev = &GC_G(roots); if (GC_G(buf)) { GC_G(unused) = NULL; GC_G(first_unused) = GC_G(buf); GC_G(zval_to_free) = NULL; } else { GC_G(unused) = NULL; GC_G(first_unused) = NULL; GC_G(last_unused) = NULL; } } ZEND_API void gc_init(TSRMLS_D) { if (GC_G(buf) == NULL && GC_G(gc_enabled)) { GC_G(buf) = (gc_root_buffer*) malloc(sizeof(gc_root_buffer) * GC_ROOT_BUFFER_MAX_ENTRIES); GC_G(last_unused) = &GC_G(buf)[GC_ROOT_BUFFER_MAX_ENTRIES]; gc_reset(TSRMLS_C); } } ZEND_API void gc_zval_possible_root(zval *zv TSRMLS_DC) { if (UNEXPECTED(GC_G(free_list) != NULL && GC_ZVAL_ADDRESS(zv) != NULL && GC_ZVAL_GET_COLOR(zv) == GC_BLACK) && (GC_ZVAL_ADDRESS(zv) < GC_G(buf) || GC_ZVAL_ADDRESS(zv) >= GC_G(last_unused))) { /* The given zval is a garbage that is going to be deleted by * currently running GC */ return; } if (zv->type == IS_OBJECT) { GC_ZOBJ_CHECK_POSSIBLE_ROOT(zv); return; } GC_BENCH_INC(zval_possible_root); if (GC_ZVAL_GET_COLOR(zv) != GC_PURPLE) { GC_ZVAL_SET_PURPLE(zv); if (!GC_ZVAL_ADDRESS(zv)) { gc_root_buffer *newRoot = GC_G(unused); if (newRoot) { GC_G(unused) = newRoot->prev; } else if (GC_G(first_unused) != GC_G(last_unused)) { newRoot = GC_G(first_unused); GC_G(first_unused)++; } else { if (!GC_G(gc_enabled)) { GC_ZVAL_SET_BLACK(zv); return; } zv->refcount__gc++; gc_collect_cycles(TSRMLS_C); zv->refcount__gc--; newRoot = GC_G(unused); if (!newRoot) { return; } GC_ZVAL_SET_PURPLE(zv); GC_G(unused) = newRoot->prev; } newRoot->next = GC_G(roots).next; newRoot->prev = &GC_G(roots); GC_G(roots).next->prev = newRoot; GC_G(roots).next = newRoot; GC_ZVAL_SET_ADDRESS(zv, newRoot); newRoot->handle = 0; newRoot->u.pz = zv; GC_BENCH_INC(zval_buffered); GC_BENCH_INC(root_buf_length); GC_BENCH_PEAK(root_buf_peak, root_buf_length); } } } ZEND_API void gc_zobj_possible_root(zval *zv TSRMLS_DC) { struct _store_object *obj; if (UNEXPECTED(Z_OBJ_HT_P(zv)->get_properties == NULL || EG(objects_store).object_buckets == NULL)) { return; } GC_BENCH_INC(zobj_possible_root); obj = &EG(objects_store).object_buckets[Z_OBJ_HANDLE_P(zv)].bucket.obj; if (GC_GET_COLOR(obj->buffered) != GC_PURPLE) { GC_SET_PURPLE(obj->buffered); if (!GC_ADDRESS(obj->buffered)) { gc_root_buffer *newRoot = GC_G(unused); if (newRoot) { GC_G(unused) = newRoot->prev; } else if (GC_G(first_unused) != GC_G(last_unused)) { newRoot = GC_G(first_unused); GC_G(first_unused)++; } else { if (!GC_G(gc_enabled)) { GC_ZVAL_SET_BLACK(zv); return; } zv->refcount__gc++; gc_collect_cycles(TSRMLS_C); zv->refcount__gc--; newRoot = GC_G(unused); if (!newRoot) { return; } obj = &EG(objects_store).object_buckets[Z_OBJ_HANDLE_P(zv)].bucket.obj; GC_SET_PURPLE(obj->buffered); GC_G(unused) = newRoot->prev; } newRoot->next = GC_G(roots).next; newRoot->prev = &GC_G(roots); GC_G(roots).next->prev = newRoot; GC_G(roots).next = newRoot; GC_SET_ADDRESS(obj->buffered, newRoot); newRoot->handle = Z_OBJ_HANDLE_P(zv); newRoot->u.handlers = Z_OBJ_HT_P(zv); GC_BENCH_INC(zobj_buffered); GC_BENCH_INC(root_buf_length); GC_BENCH_PEAK(root_buf_peak, root_buf_length); } } } ZEND_API void gc_remove_zval_from_buffer(zval *zv TSRMLS_DC) { gc_root_buffer* root_buffer = GC_ADDRESS(((zval_gc_info*)zv)->u.buffered); if (UNEXPECTED(GC_G(free_list) != NULL && GC_ZVAL_GET_COLOR(zv) == GC_BLACK) && (GC_ZVAL_ADDRESS(zv) < GC_G(buf) || GC_ZVAL_ADDRESS(zv) >= GC_G(last_unused))) { /* The given zval is a garbage that is going to be deleted by * currently running GC */ if (GC_G(next_to_free) == (zval_gc_info*)zv) { GC_G(next_to_free) = ((zval_gc_info*)zv)->u.next; } return; } GC_BENCH_INC(zval_remove_from_buffer); GC_REMOVE_FROM_BUFFER(root_buffer); ((zval_gc_info*)zv)->u.buffered = NULL; } static void zval_scan_black(zval *pz TSRMLS_DC) { Bucket *p; tail_call: p = NULL; GC_ZVAL_SET_BLACK(pz); if (Z_TYPE_P(pz) == IS_OBJECT && EG(objects_store).object_buckets) { struct _store_object *obj = &EG(objects_store).object_buckets[Z_OBJ_HANDLE_P(pz)].bucket.obj; obj->refcount++; if (GC_GET_COLOR(obj->buffered) != GC_BLACK) { GC_SET_BLACK(obj->buffered); if (EXPECTED(EG(objects_store).object_buckets[Z_OBJ_HANDLE_P(pz)].valid && Z_OBJ_HANDLER_P(pz, get_properties) != NULL)) { HashTable *props = Z_OBJPROP_P(pz); if(!props) { return; } p = props->pListHead; } } } else if (Z_TYPE_P(pz) == IS_ARRAY) { if (Z_ARRVAL_P(pz) != &EG(symbol_table)) { p = Z_ARRVAL_P(pz)->pListHead; } } while (p != NULL) { pz = *(zval**)p->pData; if (Z_TYPE_P(pz) != IS_ARRAY || Z_ARRVAL_P(pz) != &EG(symbol_table)) { pz->refcount__gc++; } if (GC_ZVAL_GET_COLOR(pz) != GC_BLACK) { if (p->pListNext == NULL) { goto tail_call; } else { zval_scan_black(pz TSRMLS_CC); } } p = p->pListNext; } } static void zobj_scan_black(struct _store_object *obj, zval *pz TSRMLS_DC) { Bucket *p; GC_SET_BLACK(obj->buffered); if (EXPECTED(EG(objects_store).object_buckets[Z_OBJ_HANDLE_P(pz)].valid && Z_OBJ_HANDLER_P(pz, get_properties) != NULL)) { HashTable *props = Z_OBJPROP_P(pz); if(!props) { return; } p = props->pListHead; while (p != NULL) { pz = *(zval**)p->pData; if (Z_TYPE_P(pz) != IS_ARRAY || Z_ARRVAL_P(pz) != &EG(symbol_table)) { pz->refcount__gc++; } if (GC_ZVAL_GET_COLOR(pz) != GC_BLACK) { zval_scan_black(pz TSRMLS_CC); } p = p->pListNext; } } } static void zval_mark_grey(zval *pz TSRMLS_DC) { Bucket *p; tail_call: if (GC_ZVAL_GET_COLOR(pz) != GC_GREY) { p = NULL; GC_BENCH_INC(zval_marked_grey); GC_ZVAL_SET_COLOR(pz, GC_GREY); if (Z_TYPE_P(pz) == IS_OBJECT && EG(objects_store).object_buckets) { struct _store_object *obj = &EG(objects_store).object_buckets[Z_OBJ_HANDLE_P(pz)].bucket.obj; obj->refcount--; if (GC_GET_COLOR(obj->buffered) != GC_GREY) { GC_BENCH_INC(zobj_marked_grey); GC_SET_COLOR(obj->buffered, GC_GREY); if (EXPECTED(EG(objects_store).object_buckets[Z_OBJ_HANDLE_P(pz)].valid && Z_OBJ_HANDLER_P(pz, get_properties) != NULL)) { HashTable *props = Z_OBJPROP_P(pz); if(!props) { return; } p = props->pListHead; } } } else if (Z_TYPE_P(pz) == IS_ARRAY) { if (Z_ARRVAL_P(pz) == &EG(symbol_table)) { GC_ZVAL_SET_BLACK(pz); } else { p = Z_ARRVAL_P(pz)->pListHead; } } while (p != NULL) { pz = *(zval**)p->pData; if (Z_TYPE_P(pz) != IS_ARRAY || Z_ARRVAL_P(pz) != &EG(symbol_table)) { pz->refcount__gc--; } if (p->pListNext == NULL) { goto tail_call; } else { zval_mark_grey(pz TSRMLS_CC); } p = p->pListNext; } } } static void zobj_mark_grey(struct _store_object *obj, zval *pz TSRMLS_DC) { Bucket *p; if (GC_GET_COLOR(obj->buffered) != GC_GREY) { GC_BENCH_INC(zobj_marked_grey); GC_SET_COLOR(obj->buffered, GC_GREY); if (EXPECTED(EG(objects_store).object_buckets[Z_OBJ_HANDLE_P(pz)].valid && Z_OBJ_HANDLER_P(pz, get_properties) != NULL)) { HashTable *props = Z_OBJPROP_P(pz); if(!props) { return; } p = props->pListHead; while (p != NULL) { pz = *(zval**)p->pData; if (Z_TYPE_P(pz) != IS_ARRAY || Z_ARRVAL_P(pz) != &EG(symbol_table)) { pz->refcount__gc--; } zval_mark_grey(pz TSRMLS_CC); p = p->pListNext; } } } } static void gc_mark_roots(TSRMLS_D) { gc_root_buffer *current = GC_G(roots).next; while (current != &GC_G(roots)) { if (current->handle) { if (EG(objects_store).object_buckets) { struct _store_object *obj = &EG(objects_store).object_buckets[current->handle].bucket.obj; if (GC_GET_COLOR(obj->buffered) == GC_PURPLE) { zval z; INIT_PZVAL(&z); Z_OBJ_HANDLE(z) = current->handle; Z_OBJ_HT(z) = current->u.handlers; zobj_mark_grey(obj, &z TSRMLS_CC); } else { GC_SET_ADDRESS(obj->buffered, NULL); GC_REMOVE_FROM_BUFFER(current); } } } else { if (GC_ZVAL_GET_COLOR(current->u.pz) == GC_PURPLE) { zval_mark_grey(current->u.pz TSRMLS_CC); } else { GC_ZVAL_SET_ADDRESS(current->u.pz, NULL); GC_REMOVE_FROM_BUFFER(current); } } current = current->next; } } static int zval_scan(zval *pz TSRMLS_DC) { Bucket *p; tail_call: if (GC_ZVAL_GET_COLOR(pz) == GC_GREY) { p = NULL; if (pz->refcount__gc > 0) { zval_scan_black(pz TSRMLS_CC); } else { GC_ZVAL_SET_COLOR(pz, GC_WHITE); if (Z_TYPE_P(pz) == IS_OBJECT && EG(objects_store).object_buckets) { struct _store_object *obj = &EG(objects_store).object_buckets[Z_OBJ_HANDLE_P(pz)].bucket.obj; if (GC_GET_COLOR(obj->buffered) == GC_GREY) { if (obj->refcount > 0) { zobj_scan_black(obj, pz TSRMLS_CC); } else { GC_SET_COLOR(obj->buffered, GC_WHITE); if (EXPECTED(EG(objects_store).object_buckets[Z_OBJ_HANDLE_P(pz)].valid && Z_OBJ_HANDLER_P(pz, get_properties) != NULL)) { HashTable *props = Z_OBJPROP_P(pz); if(!props) { return 0; } p = props->pListHead; } } } } else if (Z_TYPE_P(pz) == IS_ARRAY) { if (Z_ARRVAL_P(pz) == &EG(symbol_table)) { GC_ZVAL_SET_BLACK(pz); } else { p = Z_ARRVAL_P(pz)->pListHead; } } } while (p != NULL) { if (p->pListNext == NULL) { pz = *(zval**)p->pData; goto tail_call; } else { zval_scan(*(zval**)p->pData TSRMLS_CC); } p = p->pListNext; } } return 0; } static void zobj_scan(zval *pz TSRMLS_DC) { Bucket *p; if (EG(objects_store).object_buckets) { struct _store_object *obj = &EG(objects_store).object_buckets[Z_OBJ_HANDLE_P(pz)].bucket.obj; if (GC_GET_COLOR(obj->buffered) == GC_GREY) { if (obj->refcount > 0) { zobj_scan_black(obj, pz TSRMLS_CC); } else { GC_SET_COLOR(obj->buffered, GC_WHITE); if (EXPECTED(EG(objects_store).object_buckets[Z_OBJ_HANDLE_P(pz)].valid && Z_OBJ_HANDLER_P(pz, get_properties) != NULL)) { HashTable *props = Z_OBJPROP_P(pz); if(!props) { return; } p = props->pListHead; while (p != NULL) { zval_scan(*(zval**)p->pData TSRMLS_CC); p = p->pListNext; } } } } } } static void gc_scan_roots(TSRMLS_D) { gc_root_buffer *current = GC_G(roots).next; while (current != &GC_G(roots)) { if (current->handle) { zval z; INIT_PZVAL(&z); Z_OBJ_HANDLE(z) = current->handle; Z_OBJ_HT(z) = current->u.handlers; zobj_scan(&z TSRMLS_CC); } else { zval_scan(current->u.pz TSRMLS_CC); } current = current->next; } } static void zval_collect_white(zval *pz TSRMLS_DC) { Bucket *p; tail_call: if (((zval_gc_info*)(pz))->u.buffered == (gc_root_buffer*)GC_WHITE) { p = NULL; GC_ZVAL_SET_BLACK(pz); if (Z_TYPE_P(pz) == IS_OBJECT && EG(objects_store).object_buckets) { struct _store_object *obj = &EG(objects_store).object_buckets[Z_OBJ_HANDLE_P(pz)].bucket.obj; if (obj->buffered == (gc_root_buffer*)GC_WHITE) { /* PURPLE instead of BLACK to prevent buffering in nested gc calls */ GC_SET_PURPLE(obj->buffered); if (EXPECTED(EG(objects_store).object_buckets[Z_OBJ_HANDLE_P(pz)].valid && Z_OBJ_HANDLER_P(pz, get_properties) != NULL)) { HashTable *props = Z_OBJPROP_P(pz); if(!props) { return; } p = props->pListHead; } } } else { if (Z_TYPE_P(pz) == IS_ARRAY) { p = Z_ARRVAL_P(pz)->pListHead; } } /* restore refcount and put into list to free */ pz->refcount__gc++; ((zval_gc_info*)pz)->u.next = GC_G(zval_to_free); GC_G(zval_to_free) = (zval_gc_info*)pz; while (p != NULL) { pz = *(zval**)p->pData; if (Z_TYPE_P(pz) != IS_ARRAY || Z_ARRVAL_P(pz) != &EG(symbol_table)) { pz->refcount__gc++; } if (p->pListNext == NULL) { goto tail_call; } else { zval_collect_white(pz TSRMLS_CC); } p = p->pListNext; } } } static void zobj_collect_white(zval *pz TSRMLS_DC) { Bucket *p; if (EG(objects_store).object_buckets) { struct _store_object *obj = &EG(objects_store).object_buckets[Z_OBJ_HANDLE_P(pz)].bucket.obj; if (obj->buffered == (gc_root_buffer*)GC_WHITE) { /* PURPLE instead of BLACK to prevent buffering in nested gc calls */ GC_SET_PURPLE(obj->buffered); if (EXPECTED(EG(objects_store).object_buckets[Z_OBJ_HANDLE_P(pz)].valid && Z_OBJ_HANDLER_P(pz, get_properties) != NULL)) { HashTable *props = Z_OBJPROP_P(pz); if(!props) { return; } p = props->pListHead; while (p != NULL) { pz = *(zval**)p->pData; if (Z_TYPE_P(pz) != IS_ARRAY || Z_ARRVAL_P(pz) != &EG(symbol_table)) { pz->refcount__gc++; } zval_collect_white(pz TSRMLS_CC); p = p->pListNext; } } } } } static void gc_collect_roots(TSRMLS_D) { gc_root_buffer *current = GC_G(roots).next; while (current != &GC_G(roots)) { if (current->handle) { if (EG(objects_store).object_buckets) { struct _store_object *obj = &EG(objects_store).object_buckets[current->handle].bucket.obj; zval z; GC_SET_ADDRESS(obj->buffered, NULL); INIT_PZVAL(&z); Z_OBJ_HANDLE(z) = current->handle; Z_OBJ_HT(z) = current->u.handlers; zobj_collect_white(&z TSRMLS_CC); } } else { GC_ZVAL_SET_ADDRESS(current->u.pz, NULL); zval_collect_white(current->u.pz TSRMLS_CC); } GC_REMOVE_FROM_BUFFER(current); current = current->next; } } #define FREE_LIST_END ((zval_gc_info*)(~(zend_uintptr_t)GC_COLOR)) ZEND_API int gc_collect_cycles(TSRMLS_D) { int count = 0; if (GC_G(roots).next != &GC_G(roots)) { zval_gc_info *p, *q, *orig_free_list, *orig_next_to_free; if (GC_G(gc_active)) { return 0; } GC_G(gc_runs)++; GC_G(zval_to_free) = FREE_LIST_END; GC_G(gc_active) = 1; gc_mark_roots(TSRMLS_C); gc_scan_roots(TSRMLS_C); gc_collect_roots(TSRMLS_C); orig_free_list = GC_G(free_list); orig_next_to_free = GC_G(next_to_free); p = GC_G(free_list) = GC_G(zval_to_free); GC_G(zval_to_free) = NULL; GC_G(gc_active) = 0; /* First call destructors */ while (p != FREE_LIST_END) { if (Z_TYPE(p->z) == IS_OBJECT) { if (EG(objects_store).object_buckets && EG(objects_store).object_buckets[Z_OBJ_HANDLE(p->z)].valid && EG(objects_store).object_buckets[Z_OBJ_HANDLE(p->z)].bucket.obj.refcount <= 0 && EG(objects_store).object_buckets[Z_OBJ_HANDLE(p->z)].bucket.obj.dtor && !EG(objects_store).object_buckets[Z_OBJ_HANDLE(p->z)].destructor_called) { EG(objects_store).object_buckets[Z_OBJ_HANDLE(p->z)].destructor_called = 1; EG(objects_store).object_buckets[Z_OBJ_HANDLE(p->z)].bucket.obj.refcount++; EG(objects_store).object_buckets[Z_OBJ_HANDLE(p->z)].bucket.obj.dtor(EG(objects_store).object_buckets[Z_OBJ_HANDLE(p->z)].bucket.obj.object, Z_OBJ_HANDLE(p->z) TSRMLS_CC); EG(objects_store).object_buckets[Z_OBJ_HANDLE(p->z)].bucket.obj.refcount--; } } count++; p = p->u.next; } /* Destroy zvals */ p = GC_G(free_list); while (p != FREE_LIST_END) { GC_G(next_to_free) = p->u.next; if (Z_TYPE(p->z) == IS_OBJECT) { if (EG(objects_store).object_buckets && EG(objects_store).object_buckets[Z_OBJ_HANDLE(p->z)].valid && EG(objects_store).object_buckets[Z_OBJ_HANDLE(p->z)].bucket.obj.refcount <= 0) { EG(objects_store).object_buckets[Z_OBJ_HANDLE(p->z)].bucket.obj.refcount = 1; Z_TYPE(p->z) = IS_NULL; zend_objects_store_del_ref_by_handle_ex(Z_OBJ_HANDLE(p->z), Z_OBJ_HT(p->z) TSRMLS_CC); } } else if (Z_TYPE(p->z) == IS_ARRAY) { Z_TYPE(p->z) = IS_NULL; zend_hash_destroy(Z_ARRVAL(p->z)); FREE_HASHTABLE(Z_ARRVAL(p->z)); } else { zval_dtor(&p->z); Z_TYPE(p->z) = IS_NULL; } p = GC_G(next_to_free); } /* Free zvals */ p = GC_G(free_list); while (p != FREE_LIST_END) { q = p->u.next; FREE_ZVAL_EX(&p->z); p = q; } GC_G(collected) += count; GC_G(free_list) = orig_free_list; GC_G(next_to_free) = orig_next_to_free; } return count; } /* * Local variables: * tab-width: 4 * c-basic-offset: 4 * indent-tabs-mode: t * End: */