locks.h revision bcc5c7225e3b7a1dbf2e9e830987f69167acf06f 
1/*
2 * Copyright (C) 2010 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17/** \file locks.h Mutual exclusion and condition variables */
18
19#ifdef USE_DEBUG
20extern void object_lock_exclusive_(IObject *thiz, const char *file, int line);
21extern void object_unlock_exclusive_(IObject *thiz, const char *file, int line);
22extern void object_unlock_exclusive_attributes_(IObject *thiz, unsigned attr,
23    const char *file, int line);
24extern void object_cond_wait_(IObject *thiz, const char *file, int line);
25#else
26extern void object_lock_exclusive(IObject *thiz);
27extern void object_unlock_exclusive(IObject *thiz);
28extern void object_unlock_exclusive_attributes(IObject *thiz, unsigned attr);
29extern void object_cond_wait(IObject *thiz);
30#endif
31extern void object_cond_signal(IObject *thiz);
32extern void object_cond_broadcast(IObject *thiz);
33
34#ifdef USE_DEBUG
35#define object_lock_exclusive(thiz) object_lock_exclusive_((thiz), __FILE__, __LINE__)
36#define object_unlock_exclusive(thiz) object_unlock_exclusive_((thiz), __FILE__, __LINE__)
37#define object_unlock_exclusive_attributes(thiz, attr) \
38    object_unlock_exclusive_attributes_((thiz), (attr), __FILE__, __LINE__)
39#define object_cond_wait(thiz) object_cond_wait_((thiz), __FILE__, __LINE__)
40#endif
41
42// Currently shared locks are implemented as exclusive, but don't count on it
43
44#define object_lock_shared(thiz)   object_lock_exclusive(thiz)
45#define object_unlock_shared(thiz) object_unlock_exclusive(thiz)
46
47// Currently interface locks are actually on whole object, but don't count on it.
48// These operations are undefined on IObject, as it lacks an mThis.
49// If you have an IObject, then use the object_ functions instead.
50
51#define interface_lock_exclusive(thiz)   object_lock_exclusive(InterfaceToIObject(thiz))
52#define interface_unlock_exclusive(thiz) object_unlock_exclusive(InterfaceToIObject(thiz))
53#define interface_unlock_exclusive_attributes(thiz, attr) \
54    object_unlock_exclusive_attributes(InterfaceToIObject(thiz), (attr))
55#define interface_lock_shared(thiz)      object_lock_shared(InterfaceToIObject(thiz))
56#define interface_unlock_shared(thiz)    object_unlock_shared(InterfaceToIObject(thiz))
57#define interface_cond_wait(thiz)        object_cond_wait(InterfaceToIObject(thiz))
58#define interface_cond_signal(thiz)      object_cond_signal(InterfaceToIObject(thiz))
59#define interface_cond_broadcast(thiz)   object_cond_broadcast(InterfaceToIObject(thiz))
60
61// Peek and poke are an optimization for small atomic fields that don't "matter".
62// Don't use for struct, as struct copy might not be atomic.
63// On uniprocessor they can be no-ops, on SMP they could be memory barriers but locks are easier.
64
65#define object_lock_peek(thiz)      object_lock_shared(thiz)
66#define object_unlock_peek(thiz)    object_unlock_shared(thiz)
67#define interface_lock_poke(thiz)   interface_lock_exclusive(thiz)
68#define interface_unlock_poke(thiz) interface_unlock_exclusive(thiz)
69#define interface_lock_peek(thiz)   interface_lock_shared(thiz)
70#define interface_unlock_peek(thiz) interface_unlock_shared(thiz)
71