xref: /freebsd/sys/contrib/ck/src/ck_array.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
1 /*
2  * Copyright 2013-2015 Samy Al Bahra
3  * Copyright 2013-2014 AppNexus, Inc.
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include <ck_array.h>
29 #include <ck_cc.h>
30 #include <ck_pr.h>
31 #include <ck_stdbool.h>
32 #include <ck_string.h>
33 
34 static struct _ck_array *
35 ck_array_create(struct ck_malloc *allocator, unsigned int length)
36 {
37 	struct _ck_array *active;
38 
39 	active = allocator->malloc(sizeof(struct _ck_array) + sizeof(void *) * length);
40 	if (active == NULL)
41 		return NULL;
42 
43 	active->n_committed = 0;
44 	active->length = length;
45 
46 	return active;
47 }
48 
49 bool
50 ck_array_init(struct ck_array *array, unsigned int mode, struct ck_malloc *allocator, unsigned int length)
51 {
52 	struct _ck_array *active;
53 
54 	(void)mode;
55 
56 	if (allocator->realloc == NULL ||
57 	    allocator->malloc == NULL ||
58 	    allocator->free == NULL ||
59 	    length == 0)
60 		return false;
61 
62 	active = ck_array_create(allocator, length);
63 	if (active == NULL)
64 		return false;
65 
66 	array->n_entries = 0;
67 	array->allocator = allocator;
68 	array->active = active;
69 	array->transaction = NULL;
70 	return true;
71 }
72 
73 bool
74 ck_array_put(struct ck_array *array, void *value)
75 {
76 	struct _ck_array *target;
77 	unsigned int size;
78 
79 	/*
80 	 * If no transaction copy has been necessary, attempt to do in-place
81 	 * modification of the array.
82 	 */
83 	if (array->transaction == NULL) {
84 		target = array->active;
85 
86 		if (array->n_entries == target->length) {
87 			size = target->length << 1;
88 
89 			target = array->allocator->realloc(target,
90 			    sizeof(struct _ck_array) + sizeof(void *) * array->n_entries,
91 			    sizeof(struct _ck_array) + sizeof(void *) * size,
92 			    true);
93 
94 			if (target == NULL)
95 				return false;
96 
97 			ck_pr_store_uint(&target->length, size);
98 
99 			/* Serialize with respect to contents. */
100 			ck_pr_fence_store();
101 			ck_pr_store_ptr(&array->active, target);
102 		}
103 
104 		target->values[array->n_entries++] = value;
105 		return true;
106 	}
107 
108 	target = array->transaction;
109 	if (array->n_entries == target->length) {
110 		size = target->length << 1;
111 
112 		target = array->allocator->realloc(target,
113 		    sizeof(struct _ck_array) + sizeof(void *) * array->n_entries,
114 		    sizeof(struct _ck_array) + sizeof(void *) * size,
115 		    true);
116 
117 		if (target == NULL)
118 			return false;
119 
120 		target->length = size;
121 		array->transaction = target;
122 	}
123 
124 	target->values[array->n_entries++] = value;
125 	return false;
126 }
127 
128 int
129 ck_array_put_unique(struct ck_array *array, void *value)
130 {
131 	unsigned int i, limit;
132 	void **v;
133 
134 	limit = array->n_entries;
135 	if (array->transaction != NULL) {
136 		v = array->transaction->values;
137 	} else {
138 		v = array->active->values;
139 	}
140 
141 	for (i = 0; i < limit; i++) {
142 		if (v[i] == value)
143 			return 1;
144 	}
145 
146 	return -!ck_array_put(array, value);
147 }
148 
149 bool
150 ck_array_remove(struct ck_array *array, void *value)
151 {
152 	struct _ck_array *target;
153 	unsigned int i;
154 
155 	if (array->transaction != NULL) {
156 		target = array->transaction;
157 
158 		for (i = 0; i < array->n_entries; i++) {
159 			if (target->values[i] == value) {
160 				target->values[i] = target->values[--array->n_entries];
161 				return true;
162 			}
163 		}
164 
165 		return false;
166 	}
167 
168 	target = array->active;
169 
170 	for (i = 0; i < array->n_entries; i++) {
171 		if (target->values[i] == value)
172 			break;
173 	}
174 
175 	if (i == array->n_entries)
176 		return false;
177 
178 	/* If there are pending additions, immediately eliminate the operation. */
179 	if (target->n_committed != array->n_entries) {
180 		ck_pr_store_ptr(&target->values[i], target->values[--array->n_entries]);
181 		return true;
182 	}
183 
184 	/*
185 	 * The assumption is that these allocations are small to begin with.
186 	 * If there is no immediate opportunity for transaction, allocate a
187 	 * transactional array which will be applied upon commit time.
188 	 */
189 	target = ck_array_create(array->allocator, array->n_entries);
190 	if (target == NULL)
191 		return false;
192 
193 	memcpy(target->values, array->active->values, sizeof(void *) * array->n_entries);
194 	target->length = array->n_entries;
195 	target->n_committed = array->n_entries;
196 	target->values[i] = target->values[--array->n_entries];
197 
198 	array->transaction = target;
199 	return true;
200 }
201 
202 bool
203 ck_array_commit(ck_array_t *array)
204 {
205 	struct _ck_array *m = array->transaction;
206 
207 	if (m != NULL) {
208 		struct _ck_array *p;
209 
210 		m->n_committed = array->n_entries;
211 		ck_pr_fence_store();
212 		p = array->active;
213 		ck_pr_store_ptr(&array->active, m);
214 		array->allocator->free(p, sizeof(struct _ck_array) +
215 		    p->length * sizeof(void *), true);
216 		array->transaction = NULL;
217 
218 		return true;
219 	}
220 
221 	ck_pr_fence_store();
222 	ck_pr_store_uint(&array->active->n_committed, array->n_entries);
223 	return true;
224 }
225 
226 void
227 ck_array_deinit(struct ck_array *array, bool defer)
228 {
229 
230 	array->allocator->free(array->active,
231 	    sizeof(struct _ck_array) + sizeof(void *) * array->active->length, defer);
232 
233 	if (array->transaction != NULL) {
234 		array->allocator->free(array->transaction,
235 		    sizeof(struct _ck_array) + sizeof(void *) * array->transaction->length, defer);
236 	}
237 
238 	array->transaction = array->active = NULL;
239 	return;
240 }
241