1 /*
2  * Copyright (c) 2014, Linaro Limited
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 are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright notice,
9  * this list of conditions and the following disclaimer.
10  *
11  * 2. Redistributions in binary form must reproduce the above copyright notice,
12  * this list of conditions and the following disclaimer in the documentation
13  * and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
16  * AND 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 COPYRIGHT HOLDER OR CONTRIBUTORS BE
19  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
20  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
21  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
22  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
23  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
24  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
25  * POSSIBILITY OF SUCH DAMAGE.
26  */
27 #ifndef HANDLE_H
28 #define HANDLE_H
29 
30 #include <stdint.h>
31 #include <pthread.h>
32 
33 struct handle_db {
34 	void **ptrs;
35 	size_t max_ptrs;
36 	pthread_mutex_t *mu;
37 };
38 
39 #define HANDLE_DB_INITIALIZER { NULL, 0, NULL }
40 #define HANDLE_DB_INITIALIZER_WITH_MUTEX(mu) { NULL, 0, (mu) }
41 
42 /*
43  * Assigns a mutex for the database. If mu != NULL the mutex will be
44  * acquired before each access to the database and released when
45  * the operation is done.
46  */
47 void handle_db_set_mutex(struct handle_db *db, pthread_mutex_t *mu);
48 
49 /*
50  * Frees all internal data structures of the database, but does not free
51  * the db pointer. The database is safe to reuse after it's destroyed, it
52  * just be empty again. The assigned mutex is also preserved.
53  */
54 void handle_db_destroy(struct handle_db *db);
55 
56 /*
57  * Allocates a new handle and assigns the supplied pointer to it,
58  * ptr must not be NULL.
59  * The function returns
60  * >= 0 on success and
61  * -1 on failure
62  */
63 int handle_get(struct handle_db *db, void *ptr);
64 
65 /*
66  * Deallocates a handle. Returns the assiciated pointer of the handle
67  * the the handle was valid or NULL if it's invalid.
68  */
69 void *handle_put(struct handle_db *db, int handle);
70 
71 /*
72  * Returns the assiciated pointer of the handle if the handle is a valid
73  * handle.
74  * Returns NULL on failure.
75  */
76 void *handle_lookup(struct handle_db *db, int handle);
77 
78 void handle_foreach_put(struct handle_db *db,
79 			void (*cb)(int handle, void *ptr, void *arg),
80 			void *arg);
81 
82 #endif /*HANDLE_H*/
83