root/Zend/zend_gc.h

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INCLUDED FROM


DEFINITIONS

This source file includes following definitions.
  1. BEGIN_EXTERN_C
  2. gc_zval_check_possible_root
  3. gc_remove_from_buffer

/*
   +----------------------------------------------------------------------+
   | 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 <planetbeing@gmail.com>                          |
   |          Dmitry Stogov <dmitry@zend.com>                             |
   +----------------------------------------------------------------------+
*/

/* $Id$ */

#ifndef ZEND_GC_H
#define ZEND_GC_H

#ifndef GC_BENCH
# define GC_BENCH 0
#endif

#if GC_BENCH
# define GC_BENCH_INC(counter) GC_G(counter)++
# define GC_BENCH_DEC(counter) GC_G(counter)--
# define GC_BENCH_PEAK(peak, counter) do {              \
                if (GC_G(counter) > GC_G(peak)) {               \
                        GC_G(peak) = GC_G(counter);                     \
                }                                                                               \
        } while (0)
#else
# define GC_BENCH_INC(counter)
# define GC_BENCH_DEC(counter)
# define GC_BENCH_PEAK(peak, counter)
#endif

#define GC_COLOR  0x03

#define GC_BLACK  0x00
#define GC_WHITE  0x01
#define GC_GREY   0x02
#define GC_PURPLE 0x03

#define GC_ADDRESS(v) \
        ((gc_root_buffer*)(((zend_uintptr_t)(v)) & ~GC_COLOR))
#define GC_SET_ADDRESS(v, a) \
        (v) = ((gc_root_buffer*)((((zend_uintptr_t)(v)) & GC_COLOR) | ((zend_uintptr_t)(a))))
#define GC_GET_COLOR(v) \
        (((zend_uintptr_t)(v)) & GC_COLOR)
#define GC_SET_COLOR(v, c) \
        (v) = ((gc_root_buffer*)((((zend_uintptr_t)(v)) & ~GC_COLOR) | (c)))
#define GC_SET_BLACK(v) \
        (v) = ((gc_root_buffer*)(((zend_uintptr_t)(v)) & ~GC_COLOR))
#define GC_SET_PURPLE(v) \
        (v) = ((gc_root_buffer*)(((zend_uintptr_t)(v)) | GC_PURPLE))

#define GC_ZVAL_INIT(z) \
        ((zval_gc_info*)(z))->u.buffered = NULL
#define GC_ZVAL_ADDRESS(v) \
        GC_ADDRESS(((zval_gc_info*)(v))->u.buffered)
#define GC_ZVAL_SET_ADDRESS(v, a) \
        GC_SET_ADDRESS(((zval_gc_info*)(v))->u.buffered, (a))
#define GC_ZVAL_GET_COLOR(v) \
        GC_GET_COLOR(((zval_gc_info*)(v))->u.buffered)
#define GC_ZVAL_SET_COLOR(v, c) \
        GC_SET_COLOR(((zval_gc_info*)(v))->u.buffered, (c))
#define GC_ZVAL_SET_BLACK(v) \
        GC_SET_BLACK(((zval_gc_info*)(v))->u.buffered)
#define GC_ZVAL_SET_PURPLE(v) \
        GC_SET_PURPLE(((zval_gc_info*)(v))->u.buffered)

#define GC_OBJ_INIT(z) \
        (z)->buffered = NULL

typedef struct _gc_root_buffer {
        struct _gc_root_buffer   *prev;         /* double-linked list               */
        struct _gc_root_buffer   *next;
        zend_object_handle        handle;       /* must be 0 for zval               */
        union {
                zval                 *pz;
                const zend_object_handlers *handlers;
        } u;
} gc_root_buffer;

typedef struct _zval_gc_info {
        zval z;
        union {
                gc_root_buffer       *buffered;
                struct _zval_gc_info *next;
        } u;
} zval_gc_info;

typedef struct _zend_gc_globals {
        zend_bool         gc_enabled;
        zend_bool         gc_active;

        gc_root_buffer   *buf;                          /* preallocated arrays of buffers   */
        gc_root_buffer    roots;                        /* list of possible roots of cycles */
        gc_root_buffer   *unused;                       /* list of unused buffers           */
        gc_root_buffer   *first_unused;         /* pointer to first unused buffer   */
        gc_root_buffer   *last_unused;          /* pointer to last unused buffer    */

        zval_gc_info     *zval_to_free;         /* temporary list of zvals to free */
        zval_gc_info     *free_list;
        zval_gc_info     *next_to_free;

        zend_uint gc_runs;
        zend_uint collected;

#if GC_BENCH
        zend_uint root_buf_length;
        zend_uint root_buf_peak;
        zend_uint zval_possible_root;
        zend_uint zobj_possible_root;
        zend_uint zval_buffered;
        zend_uint zobj_buffered;
        zend_uint zval_remove_from_buffer;
        zend_uint zobj_remove_from_buffer;
        zend_uint zval_marked_grey;
        zend_uint zobj_marked_grey;
#endif

} zend_gc_globals;

#ifdef ZTS
BEGIN_EXTERN_C()
ZEND_API extern int gc_globals_id;
END_EXTERN_C()
#define GC_G(v) TSRMG(gc_globals_id, zend_gc_globals *, v)
#else
#define GC_G(v) (gc_globals.v)
extern ZEND_API zend_gc_globals gc_globals;
#endif

BEGIN_EXTERN_C()
ZEND_API int  gc_collect_cycles(TSRMLS_D);
ZEND_API void gc_zval_possible_root(zval *zv TSRMLS_DC);
ZEND_API void gc_zobj_possible_root(zval *zv TSRMLS_DC);
ZEND_API void gc_remove_zval_from_buffer(zval *zv TSRMLS_DC);
ZEND_API void gc_globals_ctor(TSRMLS_D);
ZEND_API void gc_globals_dtor(TSRMLS_D);
ZEND_API void gc_init(TSRMLS_D);
ZEND_API void gc_reset(TSRMLS_D);
END_EXTERN_C()

#define GC_ZVAL_CHECK_POSSIBLE_ROOT(z) \
        gc_zval_check_possible_root((z) TSRMLS_CC)

#define GC_REMOVE_FROM_BUFFER(current) \
        gc_remove_from_buffer((current) TSRMLS_CC)

#define GC_REMOVE_ZVAL_FROM_BUFFER(z)                                   \
        if (GC_ADDRESS(((zval_gc_info*)z)->u.buffered)) {       \
                gc_remove_zval_from_buffer(z TSRMLS_CC);                \
        }

#define GC_ZOBJ_CHECK_POSSIBLE_ROOT(zobject)                                                                    \
        do {                                                                                                                                            \
                if (EXPECTED(EG(objects_store).object_buckets != NULL) &&                               \
                    EG(objects_store).object_buckets[Z_OBJ_HANDLE_P(zobject)].valid) {  \
                        gc_zobj_possible_root(zobject TSRMLS_CC);                                                       \
                }                                                                                                                                               \
        } while (0)

#define GC_REMOVE_ZOBJ_FROM_BUFFER(obj)                                                                 \
        do {                                                                                                                            \
                if (GC_ADDRESS((obj)->buffered) && !GC_G(gc_active)) {                  \
                        GC_BENCH_INC(zobj_remove_from_buffer);                                          \
                        GC_REMOVE_FROM_BUFFER(GC_ADDRESS((obj)->buffered));                     \
                        (obj)->buffered = NULL;                                                                         \
                }                                                                                                                               \
        } while (0)

static zend_always_inline void gc_zval_check_possible_root(zval *z TSRMLS_DC)
{
        if (z->type == IS_ARRAY || z->type == IS_OBJECT) {
                gc_zval_possible_root(z TSRMLS_CC);
        }
}

static zend_always_inline void gc_remove_from_buffer(gc_root_buffer *root TSRMLS_DC)
{
        root->next->prev = root->prev;
        root->prev->next = root->next;
        root->prev = GC_G(unused);
        GC_G(unused) = root;
        GC_BENCH_DEC(root_buf_length);
}

#define ALLOC_PERMANENT_ZVAL(z)                                                 \
        do {                                                                                            \
                (z) = (zval*)malloc(sizeof(zval_gc_info));              \
                GC_ZVAL_INIT(z);                                                                \
        } while (0)

/* The following macros override macros from zend_alloc.h */
#undef  ALLOC_ZVAL
#define ALLOC_ZVAL(z)                                                                   \
        do {                                                                                            \
                (z) = (zval*)emalloc(sizeof(zval_gc_info));             \
                GC_ZVAL_INIT(z);                                                                \
        } while (0)

#undef  FREE_ZVAL
#define FREE_ZVAL(z)                                                                    \
        do {                                                                                            \
            GC_REMOVE_ZVAL_FROM_BUFFER(z);                                      \
                efree(z);                                                                               \
        } while (0)

#undef  ALLOC_ZVAL_REL
#define ALLOC_ZVAL_REL(z)                                                               \
        do {                                                                                            \
                (z) = (zval*)emalloc_rel(sizeof(zval_gc_info)); \
                GC_ZVAL_INIT(z);                                                                \
        } while (0)

#undef  FREE_ZVAL_REL
#define FREE_ZVAL_REL(z)                                                                \
        do {                                                                                            \
            GC_REMOVE_ZVAL_FROM_BUFFER(z);                                      \
                efree_rel(z);                                                                   \
        } while (0)

#define FREE_ZVAL_EX(z)                                                                 \
        efree(z)

#define FREE_ZVAL_REL_EX(z)                                                             \
        efree_rel(z)

#endif /* ZEND_GC_H */

/*
 * Local variables:
 * tab-width: 4
 * c-basic-offset: 4
 * indent-tabs-mode: t
 * End:
 */

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