xref: /PHP-5.6/Zend/zend_gc.h (revision 3537e95d)
1 /*
2    +----------------------------------------------------------------------+
3    | Zend Engine                                                          |
4    +----------------------------------------------------------------------+
5    | Copyright (c) 1998-2016 Zend Technologies Ltd. (http://www.zend.com) |
6    +----------------------------------------------------------------------+
7    | This source file is subject to version 2.00 of the Zend license,     |
8    | that is bundled with this package in the file LICENSE, and is        |
9    | available through the world-wide-web at the following url:           |
10    | http://www.zend.com/license/2_00.txt.                                |
11    | If you did not receive a copy of the Zend license and are unable to  |
12    | obtain it through the world-wide-web, please send a note to          |
13    | license@zend.com so we can mail you a copy immediately.              |
14    +----------------------------------------------------------------------+
15    | Authors: David Wang <planetbeing@gmail.com>                          |
16    |          Dmitry Stogov <dmitry@zend.com>                             |
17    +----------------------------------------------------------------------+
18 */
19 
20 /* $Id$ */
21 
22 #ifndef ZEND_GC_H
23 #define ZEND_GC_H
24 
25 #ifndef GC_BENCH
26 # define GC_BENCH 0
27 #endif
28 
29 #if GC_BENCH
30 # define GC_BENCH_INC(counter) GC_G(counter)++
31 # define GC_BENCH_DEC(counter) GC_G(counter)--
32 # define GC_BENCH_PEAK(peak, counter) do {		\
33 		if (GC_G(counter) > GC_G(peak)) {		\
34 			GC_G(peak) = GC_G(counter);			\
35 		}										\
36 	} while (0)
37 #else
38 # define GC_BENCH_INC(counter)
39 # define GC_BENCH_DEC(counter)
40 # define GC_BENCH_PEAK(peak, counter)
41 #endif
42 
43 #define GC_COLOR  0x03
44 
45 #define GC_BLACK  0x00
46 #define GC_WHITE  0x01
47 #define GC_GREY   0x02
48 #define GC_PURPLE 0x03
49 
50 #define GC_ADDRESS(v) \
51 	((gc_root_buffer*)(((zend_uintptr_t)(v)) & ~GC_COLOR))
52 #define GC_SET_ADDRESS(v, a) \
53 	(v) = ((gc_root_buffer*)((((zend_uintptr_t)(v)) & GC_COLOR) | ((zend_uintptr_t)(a))))
54 #define GC_GET_COLOR(v) \
55 	(((zend_uintptr_t)(v)) & GC_COLOR)
56 #define GC_SET_COLOR(v, c) \
57 	(v) = ((gc_root_buffer*)((((zend_uintptr_t)(v)) & ~GC_COLOR) | (c)))
58 #define GC_SET_BLACK(v) \
59 	(v) = ((gc_root_buffer*)(((zend_uintptr_t)(v)) & ~GC_COLOR))
60 #define GC_SET_PURPLE(v) \
61 	(v) = ((gc_root_buffer*)(((zend_uintptr_t)(v)) | GC_PURPLE))
62 
63 #define GC_ZVAL_INIT(z) \
64 	((zval_gc_info*)(z))->u.buffered = NULL
65 #define GC_ZVAL_ADDRESS(v) \
66 	GC_ADDRESS(((zval_gc_info*)(v))->u.buffered)
67 #define GC_ZVAL_SET_ADDRESS(v, a) \
68 	GC_SET_ADDRESS(((zval_gc_info*)(v))->u.buffered, (a))
69 #define GC_ZVAL_GET_COLOR(v) \
70 	GC_GET_COLOR(((zval_gc_info*)(v))->u.buffered)
71 #define GC_ZVAL_SET_COLOR(v, c) \
72 	GC_SET_COLOR(((zval_gc_info*)(v))->u.buffered, (c))
73 #define GC_ZVAL_SET_BLACK(v) \
74 	GC_SET_BLACK(((zval_gc_info*)(v))->u.buffered)
75 #define GC_ZVAL_SET_PURPLE(v) \
76 	GC_SET_PURPLE(((zval_gc_info*)(v))->u.buffered)
77 
78 #define GC_OBJ_INIT(z) \
79 	(z)->buffered = NULL
80 
81 typedef struct _gc_root_buffer {
82 	struct _gc_root_buffer   *prev;		/* double-linked list               */
83 	struct _gc_root_buffer   *next;
84 	zend_object_handle        handle;	/* must be 0 for zval               */
85 	union {
86 		zval                 *pz;
87 		const zend_object_handlers *handlers;
88 	} u;
89 } gc_root_buffer;
90 
91 typedef struct _zval_gc_info {
92 	zval z;
93 	union {
94 		gc_root_buffer       *buffered;
95 		struct _zval_gc_info *next;
96 	} u;
97 } zval_gc_info;
98 
99 typedef struct _zend_gc_globals {
100 	zend_bool         gc_enabled;
101 	zend_bool         gc_active;
102 
103 	gc_root_buffer   *buf;				/* preallocated arrays of buffers   */
104 	gc_root_buffer    roots;			/* list of possible roots of cycles */
105 	gc_root_buffer   *unused;			/* list of unused buffers           */
106 	gc_root_buffer   *first_unused;		/* pointer to first unused buffer   */
107 	gc_root_buffer   *last_unused;		/* pointer to last unused buffer    */
108 
109 	zval_gc_info     *zval_to_free;		/* temporary list of zvals to free */
110 	zval_gc_info     *free_list;
111 	zval_gc_info     *next_to_free;
112 
113 	zend_uint gc_runs;
114 	zend_uint collected;
115 
116 #if GC_BENCH
117 	zend_uint root_buf_length;
118 	zend_uint root_buf_peak;
119 	zend_uint zval_possible_root;
120 	zend_uint zobj_possible_root;
121 	zend_uint zval_buffered;
122 	zend_uint zobj_buffered;
123 	zend_uint zval_remove_from_buffer;
124 	zend_uint zobj_remove_from_buffer;
125 	zend_uint zval_marked_grey;
126 	zend_uint zobj_marked_grey;
127 #endif
128 
129 } zend_gc_globals;
130 
131 #ifdef ZTS
132 BEGIN_EXTERN_C()
133 ZEND_API extern int gc_globals_id;
134 END_EXTERN_C()
135 #define GC_G(v) TSRMG(gc_globals_id, zend_gc_globals *, v)
136 #else
137 #define GC_G(v) (gc_globals.v)
138 extern ZEND_API zend_gc_globals gc_globals;
139 #endif
140 
141 BEGIN_EXTERN_C()
142 ZEND_API int  gc_collect_cycles(TSRMLS_D);
143 ZEND_API void gc_zval_possible_root(zval *zv TSRMLS_DC);
144 ZEND_API void gc_zobj_possible_root(zval *zv TSRMLS_DC);
145 ZEND_API void gc_remove_zval_from_buffer(zval *zv TSRMLS_DC);
146 ZEND_API void gc_globals_ctor(TSRMLS_D);
147 ZEND_API void gc_globals_dtor(TSRMLS_D);
148 ZEND_API void gc_init(TSRMLS_D);
149 ZEND_API void gc_reset(TSRMLS_D);
END_EXTERN_C()150 END_EXTERN_C()
151 
152 #define GC_ZVAL_CHECK_POSSIBLE_ROOT(z) \
153 	gc_zval_check_possible_root((z) TSRMLS_CC)
154 
155 #define GC_REMOVE_FROM_BUFFER(current) \
156 	gc_remove_from_buffer((current) TSRMLS_CC)
157 
158 #define GC_REMOVE_ZVAL_FROM_BUFFER(z)					\
159 	if (GC_ADDRESS(((zval_gc_info*)z)->u.buffered)) {	\
160 		gc_remove_zval_from_buffer(z TSRMLS_CC);		\
161 	}
162 
163 #define GC_ZOBJ_CHECK_POSSIBLE_ROOT(zobject)									\
164 	do {																		\
165 		if (EXPECTED(EG(objects_store).object_buckets != NULL) &&				\
166 		    EG(objects_store).object_buckets[Z_OBJ_HANDLE_P(zobject)].valid) {	\
167 			gc_zobj_possible_root(zobject TSRMLS_CC);							\
168 		}																		\
169 	} while (0)
170 
171 #define GC_REMOVE_ZOBJ_FROM_BUFFER(obj)									\
172 	do {																\
173 		if (GC_ADDRESS((obj)->buffered) && !GC_G(gc_active)) {			\
174 			GC_BENCH_INC(zobj_remove_from_buffer);						\
175 			GC_REMOVE_FROM_BUFFER(GC_ADDRESS((obj)->buffered));			\
176 			(obj)->buffered = NULL;										\
177 		}																\
178 	} while (0)
179 
180 static zend_always_inline void gc_zval_check_possible_root(zval *z TSRMLS_DC)
181 {
182 	if (z->type == IS_ARRAY || z->type == IS_OBJECT) {
183 		gc_zval_possible_root(z TSRMLS_CC);
184 	}
185 }
186 
gc_remove_from_buffer(gc_root_buffer * root TSRMLS_DC)187 static zend_always_inline void gc_remove_from_buffer(gc_root_buffer *root TSRMLS_DC)
188 {
189 	root->next->prev = root->prev;
190 	root->prev->next = root->next;
191 	root->prev = GC_G(unused);
192 	GC_G(unused) = root;
193 	GC_BENCH_DEC(root_buf_length);
194 }
195 
196 #define ALLOC_PERMANENT_ZVAL(z)							\
197 	do {												\
198 		(z) = (zval*)malloc(sizeof(zval_gc_info));		\
199 		GC_ZVAL_INIT(z);								\
200 	} while (0)
201 
202 /* The following macros override macros from zend_alloc.h */
203 #undef  ALLOC_ZVAL
204 #define ALLOC_ZVAL(z) 									\
205 	do {												\
206 		(z) = (zval*)emalloc(sizeof(zval_gc_info));		\
207 		GC_ZVAL_INIT(z);								\
208 	} while (0)
209 
210 #undef  FREE_ZVAL
211 #define FREE_ZVAL(z) 									\
212 	do {												\
213 	    GC_REMOVE_ZVAL_FROM_BUFFER(z);					\
214 		efree(z);										\
215 	} while (0)
216 
217 #undef  ALLOC_ZVAL_REL
218 #define ALLOC_ZVAL_REL(z)								\
219 	do {												\
220 		(z) = (zval*)emalloc_rel(sizeof(zval_gc_info));	\
221 		GC_ZVAL_INIT(z);								\
222 	} while (0)
223 
224 #undef  FREE_ZVAL_REL
225 #define FREE_ZVAL_REL(z)								\
226 	do {												\
227 	    GC_REMOVE_ZVAL_FROM_BUFFER(z);					\
228 		efree_rel(z);									\
229 	} while (0)
230 
231 #define FREE_ZVAL_EX(z)									\
232 	efree(z)
233 
234 #define FREE_ZVAL_REL_EX(z)								\
235 	efree_rel(z)
236 
237 #endif /* ZEND_GC_H */
238 
239 /*
240  * Local variables:
241  * tab-width: 4
242  * c-basic-offset: 4
243  * indent-tabs-mode: t
244  * End:
245  */
246