1 /******************************************************************************
2 *
3 * Copyright (C) 2014 Google, Inc.
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at:
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 *
17 ******************************************************************************/
18
19 #define LOG_TAG "bt_classic_peer"
20
21 #include "device/include/classic/peer.h"
22
23 #include <assert.h>
24 #include <cutils/log.h>
25 #include <pthread.h>
26 #include <stdbool.h>
27
28 #include "btcore/include/module.h"
29 #include "osi/include/allocator.h"
30 #include "osi/include/future.h"
31 #include "osi/include/hash_map.h"
32 #include "osi/include/osi.h"
33
34 struct classic_peer_t {
35 bt_bdaddr_t address;
36 };
37
38 static const size_t number_of_address_buckets = 42;
39
40 static bool initialized;
41 static pthread_mutex_t bag_of_peers_lock;
42 static hash_map_t *peers_by_address;
43
44 static bool bdaddr_equality_fn(const void *x, const void *y);
45
46 // Module lifecycle functions
47
init(void)48 static future_t *init(void) {
49 peers_by_address = hash_map_new(
50 number_of_address_buckets,
51 hash_function_bdaddr,
52 NULL,
53 osi_free,
54 bdaddr_equality_fn);
55
56 pthread_mutex_init(&bag_of_peers_lock, NULL);
57
58 initialized = true;
59 return NULL;
60 }
61
clean_up(void)62 static future_t *clean_up(void) {
63 initialized = false;
64
65 hash_map_free(peers_by_address);
66 peers_by_address = NULL;
67
68 pthread_mutex_destroy(&bag_of_peers_lock);
69 return NULL;
70 }
71
72 EXPORT_SYMBOL const module_t classic_peer_module = {
73 .name = CLASSIC_PEER_MODULE,
74 .init = init,
75 .start_up = NULL,
76 .shut_down = NULL,
77 .clean_up = clean_up,
78 .dependencies = {
79 NULL
80 }
81 };
82
83 // Interface functions
84
classic_peer_by_address(bt_bdaddr_t * address)85 classic_peer_t *classic_peer_by_address(bt_bdaddr_t *address) {
86 assert(initialized);
87 assert(address != NULL);
88
89 classic_peer_t *peer = hash_map_get(peers_by_address, address);
90
91 if (!peer) {
92 pthread_mutex_lock(&bag_of_peers_lock);
93
94 // Make sure it didn't get added in the meantime
95 peer = hash_map_get(peers_by_address, address);
96 if (peer)
97 goto done;
98
99 // Splice in a new peer struct on behalf of the caller.
100 peer = osi_calloc(sizeof(classic_peer_t));
101 peer->address = *address;
102 hash_map_set(peers_by_address, &peer->address, peer);
103
104 pthread_mutex_unlock(&bag_of_peers_lock);
105 }
106
107 done:
108 return peer;
109 }
110
classic_peer_get_address(classic_peer_t * peer)111 const bt_bdaddr_t *classic_peer_get_address(classic_peer_t *peer) {
112 assert(peer != NULL);
113 return &peer->address;
114 }
115
116 // Internal functions
117
118 // Wrapper for bdaddr_equals used in the hash map of peers by address
bdaddr_equality_fn(const void * x,const void * y)119 static bool bdaddr_equality_fn(const void *x, const void *y) {
120 return bdaddr_equals((bt_bdaddr_t *)x, (bt_bdaddr_t *)y);
121 }
122