xref: /PHP-7.0/Zend/zend_ptr_stack.h (revision 478f119a)
1 /*
2    +----------------------------------------------------------------------+
3    | Zend Engine                                                          |
4    +----------------------------------------------------------------------+
5    | Copyright (c) 1998-2017 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: Andi Gutmans <andi@zend.com>                                |
16    |          Zeev Suraski <zeev@zend.com>                                |
17    +----------------------------------------------------------------------+
18 */
19 
20 /* $Id$ */
21 
22 #ifndef ZEND_PTR_STACK_H
23 #define ZEND_PTR_STACK_H
24 
25 typedef struct _zend_ptr_stack {
26 	int top, max;
27 	void **elements;
28 	void **top_element;
29 	zend_bool persistent;
30 } zend_ptr_stack;
31 
32 
33 #define PTR_STACK_BLOCK_SIZE 64
34 
35 BEGIN_EXTERN_C()
36 ZEND_API void zend_ptr_stack_init(zend_ptr_stack *stack);
37 ZEND_API void zend_ptr_stack_init_ex(zend_ptr_stack *stack, zend_bool persistent);
38 ZEND_API void zend_ptr_stack_n_push(zend_ptr_stack *stack, int count, ...);
39 ZEND_API void zend_ptr_stack_n_pop(zend_ptr_stack *stack, int count, ...);
40 ZEND_API void zend_ptr_stack_destroy(zend_ptr_stack *stack);
41 ZEND_API void zend_ptr_stack_apply(zend_ptr_stack *stack, void (*func)(void *));
42 ZEND_API void zend_ptr_stack_clean(zend_ptr_stack *stack, void (*func)(void *), zend_bool free_elements);
43 ZEND_API int zend_ptr_stack_num_elements(zend_ptr_stack *stack);
END_EXTERN_C()44 END_EXTERN_C()
45 
46 #define ZEND_PTR_STACK_RESIZE_IF_NEEDED(stack, count)		\
47 	if (stack->top+count > stack->max) {					\
48 		/* we need to allocate more memory */				\
49 		do {												\
50 			stack->max += PTR_STACK_BLOCK_SIZE;				\
51 		} while (stack->top+count > stack->max);			\
52 		stack->elements = (void **) perealloc(stack->elements, (sizeof(void *) * (stack->max)), stack->persistent);	\
53 		stack->top_element = stack->elements+stack->top;	\
54 	}
55 
56 /*	Not doing this with a macro because of the loop unrolling in the element assignment.
57 	Just using a macro for 3 in the body for readability sake. */
58 static zend_always_inline void zend_ptr_stack_3_push(zend_ptr_stack *stack, void *a, void *b, void *c)
59 {
60 #define ZEND_PTR_STACK_NUM_ARGS 3
61 
62 	ZEND_PTR_STACK_RESIZE_IF_NEEDED(stack, ZEND_PTR_STACK_NUM_ARGS)
63 
64 	stack->top += ZEND_PTR_STACK_NUM_ARGS;
65 	*(stack->top_element++) = a;
66 	*(stack->top_element++) = b;
67 	*(stack->top_element++) = c;
68 
69 #undef ZEND_PTR_STACK_NUM_ARGS
70 }
71 
zend_ptr_stack_2_push(zend_ptr_stack * stack,void * a,void * b)72 static zend_always_inline void zend_ptr_stack_2_push(zend_ptr_stack *stack, void *a, void *b)
73 {
74 #define ZEND_PTR_STACK_NUM_ARGS 2
75 
76 	ZEND_PTR_STACK_RESIZE_IF_NEEDED(stack, ZEND_PTR_STACK_NUM_ARGS)
77 
78 	stack->top += ZEND_PTR_STACK_NUM_ARGS;
79 	*(stack->top_element++) = a;
80 	*(stack->top_element++) = b;
81 
82 #undef ZEND_PTR_STACK_NUM_ARGS
83 }
84 
zend_ptr_stack_3_pop(zend_ptr_stack * stack,void ** a,void ** b,void ** c)85 static zend_always_inline void zend_ptr_stack_3_pop(zend_ptr_stack *stack, void **a, void **b, void **c)
86 {
87 	*a = *(--stack->top_element);
88 	*b = *(--stack->top_element);
89 	*c = *(--stack->top_element);
90 	stack->top -= 3;
91 }
92 
zend_ptr_stack_2_pop(zend_ptr_stack * stack,void ** a,void ** b)93 static zend_always_inline void zend_ptr_stack_2_pop(zend_ptr_stack *stack, void **a, void **b)
94 {
95 	*a = *(--stack->top_element);
96 	*b = *(--stack->top_element);
97 	stack->top -= 2;
98 }
99 
zend_ptr_stack_push(zend_ptr_stack * stack,void * ptr)100 static zend_always_inline void zend_ptr_stack_push(zend_ptr_stack *stack, void *ptr)
101 {
102 	ZEND_PTR_STACK_RESIZE_IF_NEEDED(stack, 1)
103 
104 	stack->top++;
105 	*(stack->top_element++) = ptr;
106 }
107 
zend_ptr_stack_pop(zend_ptr_stack * stack)108 static zend_always_inline void *zend_ptr_stack_pop(zend_ptr_stack *stack)
109 {
110 	stack->top--;
111 	return *(--stack->top_element);
112 }
113 
zend_ptr_stack_top(zend_ptr_stack * stack)114 static zend_always_inline void *zend_ptr_stack_top(zend_ptr_stack *stack)
115 {
116     return stack->elements[stack->top - 1];
117 }
118 
119 #endif /* ZEND_PTR_STACK_H */
120 
121 /*
122  * Local variables:
123  * tab-width: 4
124  * c-basic-offset: 4
125  * indent-tabs-mode: t
126  * End:
127  */
128