zend_gc.h

Go to the documentation of this file.

/*
   +----------------------------------------------------------------------+
   | Zend Engine                                                          |
   +----------------------------------------------------------------------+
   | Copyright (c) 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 <planetbeing@gmail.com>                          |
   |          Dmitry Stogov <dmitry@php.net>                              |
   +----------------------------------------------------------------------+
*/
 
#ifndef ZEND_GC_H
#define ZEND_GC_H
 
#include "zend_hrtime.h"
 
#ifndef GC_BENCH
# define GC_BENCH 0
#endif
 
BEGIN_EXTERN_C()
 
typedef struct _zend_gc_status {
    bool active;
    bool gc_protected;
    bool full;
    uint32_t runs;
    uint32_t collected;
    uint32_t threshold;
    uint32_t buf_size;
    uint32_t num_roots;
    zend_hrtime_t application_time;
    zend_hrtime_t collector_time;
    zend_hrtime_t dtor_time;
    zend_hrtime_t free_time;
} zend_gc_status;
 
ZEND_API extern int (*gc_collect_cycles)(void);
 
ZEND_API void ZEND_FASTCALL gc_possible_root(zend_refcounted *ref);
ZEND_API void ZEND_FASTCALL gc_remove_from_buffer(zend_refcounted *ref);
 
/* enable/disable automatic start of GC collection */
ZEND_API bool gc_enable(bool enable);
ZEND_API bool gc_enabled(void);
 
/* enable/disable possible root additions */
ZEND_API bool gc_protect(bool protect);
ZEND_API bool gc_protected(void);
 
#if GC_BENCH
void gc_bench_print(void);
#endif
 
/* The default implementation of the gc_collect_cycles callback. */
ZEND_API int  zend_gc_collect_cycles(void);
 
ZEND_API void zend_gc_get_status(zend_gc_status *status);
 
void gc_init(void);
void gc_globals_ctor(void);
void gc_globals_dtor(void);
void gc_reset(void);
 
#ifdef ZTS
size_t zend_gc_globals_size(void);
#endif
 
#define GC_REMOVE_FROM_BUFFER(p) do { \
        zend_refcounted *_p = (zend_refcounted*)(p); \
        if (GC_TYPE_INFO(_p) & GC_INFO_MASK) { \
            gc_remove_from_buffer(_p); \
        } \
    } while (0)
 
#define GC_MAY_LEAK(ref) \
    ((GC_TYPE_INFO(ref) & \
        (GC_INFO_MASK | (GC_NOT_COLLECTABLE << GC_FLAGS_SHIFT))) == 0)
 
static zend_always_inline void gc_check_possible_root(zend_refcounted *ref)
{
    if (EXPECTED(GC_TYPE_INFO(ref) == GC_REFERENCE)) {
        zval *zv = &((zend_reference*)ref)->val;
 
        if (!Z_COLLECTABLE_P(zv)) {
            return;
        }
        ref = Z_COUNTED_P(zv);
    }
    if (UNEXPECTED(GC_MAY_LEAK(ref))) {
        gc_possible_root(ref);
    }
}
 
static zend_always_inline void gc_check_possible_root_no_ref(zend_refcounted *ref)
{
    ZEND_ASSERT(GC_TYPE_INFO(ref) != GC_REFERENCE);
    if (UNEXPECTED(GC_MAY_LEAK(ref))) {
        gc_possible_root(ref);
    }
}
 
/* These APIs can be used to simplify object get_gc implementations
 * over heterogeneous structures. See zend_generator_get_gc() for
 * a usage example. */
 
typedef struct {
    zval *cur;
    zval *end;
    zval *start;
} zend_get_gc_buffer;
 
ZEND_API zend_get_gc_buffer *zend_get_gc_buffer_create(void);
ZEND_API void zend_get_gc_buffer_grow(zend_get_gc_buffer *gc_buffer);
 
static zend_always_inline void zend_get_gc_buffer_add_zval(
        zend_get_gc_buffer *gc_buffer, zval *zv) {
    if (Z_REFCOUNTED_P(zv)) {
        if (UNEXPECTED(gc_buffer->cur == gc_buffer->end)) {
            zend_get_gc_buffer_grow(gc_buffer);
        }
        ZVAL_COPY_VALUE(gc_buffer->cur, zv);
        gc_buffer->cur++;
    }
}
 
static zend_always_inline void zend_get_gc_buffer_add_obj(
        zend_get_gc_buffer *gc_buffer, zend_object *obj) {
    if (UNEXPECTED(gc_buffer->cur == gc_buffer->end)) {
        zend_get_gc_buffer_grow(gc_buffer);
    }
    ZVAL_OBJ(gc_buffer->cur, obj);
    gc_buffer->cur++;
}
 
static zend_always_inline void zend_get_gc_buffer_add_ptr(
        zend_get_gc_buffer *gc_buffer, void *ptr) {
    if (UNEXPECTED(gc_buffer->cur == gc_buffer->end)) {
        zend_get_gc_buffer_grow(gc_buffer);
    }
    ZVAL_PTR(gc_buffer->cur, ptr);
    gc_buffer->cur++;
}
 
static zend_always_inline void zend_get_gc_buffer_use(
        zend_get_gc_buffer *gc_buffer, zval **table, int *n) {
    *table = gc_buffer->start;
    *n = gc_buffer->cur - gc_buffer->start;
}
 
END_EXTERN_C()
 
#endif /* ZEND_GC_H */