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      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
     20 extern void object_lock_exclusive_(IObject *thiz, const char *file, int line);
     21 extern void object_unlock_exclusive_(IObject *thiz, const char *file, int line);
     22 extern void object_unlock_exclusive_attributes_(IObject *thiz, unsigned attr,
     23     const char *file, int line);
     24 extern void object_cond_wait_(IObject *thiz, const char *file, int line);
     25 #else
     26 extern void object_lock_exclusive(IObject *thiz);
     27 extern void object_unlock_exclusive(IObject *thiz);
     28 extern void object_unlock_exclusive_attributes(IObject *thiz, unsigned attr);
     29 extern void object_cond_wait(IObject *thiz);
     30 #endif
     31 extern void object_cond_signal(IObject *thiz);
     32 extern 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