xref: /freebsd/sys/contrib/ck/include/ck_hp_stack.h (revision f39bffc62c1395bde25d152c7f68fdf7cbaab414)
1 /*
2  * Copyright 2010-2015 Samy Al Bahra.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #ifndef CK_HP_STACK_H
28 #define CK_HP_STACK_H
29 
30 #include <ck_cc.h>
31 #include <ck_hp.h>
32 #include <ck_pr.h>
33 #include <ck_stack.h>
34 #include <ck_stddef.h>
35 
36 #define CK_HP_STACK_SLOTS_COUNT 1
37 #define CK_HP_STACK_SLOTS_SIZE  sizeof(void *)
38 
39 CK_CC_INLINE static void
40 ck_hp_stack_push_mpmc(struct ck_stack *target, struct ck_stack_entry *entry)
41 {
42 
43 	ck_stack_push_upmc(target, entry);
44 	return;
45 }
46 
47 CK_CC_INLINE static bool
48 ck_hp_stack_trypush_mpmc(struct ck_stack *target, struct ck_stack_entry *entry)
49 {
50 
51 	return ck_stack_trypush_upmc(target, entry);
52 }
53 
54 CK_CC_INLINE static struct ck_stack_entry *
55 ck_hp_stack_pop_mpmc(ck_hp_record_t *record, struct ck_stack *target)
56 {
57 	struct ck_stack_entry *entry, *update;
58 
59 	do {
60 		entry = ck_pr_load_ptr(&target->head);
61 		if (entry == NULL)
62 			return NULL;
63 
64 		ck_hp_set_fence(record, 0, entry);
65 	} while (entry != ck_pr_load_ptr(&target->head));
66 
67 	while (ck_pr_cas_ptr_value(&target->head, entry, entry->next, &entry) == false) {
68 		if (entry == NULL)
69 			return NULL;
70 
71 		ck_hp_set_fence(record, 0, entry);
72 
73 		update = ck_pr_load_ptr(&target->head);
74 		while (entry != update) {
75 			ck_hp_set_fence(record, 0, update);
76 			entry = update;
77 			update = ck_pr_load_ptr(&target->head);
78 			if (update == NULL)
79 				return NULL;
80 		}
81 	}
82 
83 	return entry;
84 }
85 
86 CK_CC_INLINE static bool
87 ck_hp_stack_trypop_mpmc(ck_hp_record_t *record, struct ck_stack *target, struct ck_stack_entry **r)
88 {
89 	struct ck_stack_entry *entry;
90 
91 	entry = ck_pr_load_ptr(&target->head);
92 	if (entry == NULL)
93 		return false;
94 
95 	ck_hp_set_fence(record, 0, entry);
96 	if (entry != ck_pr_load_ptr(&target->head))
97 		goto leave;
98 
99 	if (ck_pr_cas_ptr_value(&target->head, entry, entry->next, &entry) == false)
100 		goto leave;
101 
102 	*r = entry;
103 	return true;
104 
105 leave:
106 	ck_hp_set(record, 0, NULL);
107 	return false;
108 }
109 
110 #endif /* CK_HP_STACK_H */
111