Home | History | Annotate | Download | only in src 
      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 ThreadPool.h ThreadPool interface */
     18 
     19 /** Kind of closure */
     20 
     21 typedef enum {
     22     CLOSURE_KIND_PPI,   // void *, void *, int
     23     CLOSURE_KIND_PPII,  // void *, void *, int, int
     24     CLOSURE_KIND_PIIPP  // void *, int, int, void *, void *
     25 } ClosureKind;
     26 
     27 /** Closure handlers */
     28 
     29 typedef void (*ClosureHandler_generic)(void *p1, void *p2, void *p3, int i1, int i2);
     30 typedef void (*ClosureHandler_ppi)    (void *p1, void *p2, int i1);
     31 typedef void (*ClosureHandler_ppii)   (void *p1, void *p2, int i1, int i2);
     32 typedef void (*ClosureHandler_piipp)  (void *p1, int i1, int i2, void *p2, void *p3);
     33 
     34 /** \brief Closure represents a deferred computation */
     35 
     36 typedef struct {
     37     union {
     38         ClosureHandler_ppi mHandler_ppi;
     39         ClosureHandler_ppii mHandler_ppii;
     40         ClosureHandler_piipp mHandler_piipp;
     41     } mHandler;
     42     ClosureKind mKind;
     43     void *mContext1;
     44     void *mContext2;
     45     void *mContext3;
     46     int mParameter1;
     47     int mParameter2;
     48 } Closure;
     49 
     50 /** \brief ThreadPool manages a pool of worker threads that execute Closures */
     51 
     52 typedef struct {
     53     unsigned mInitialized; ///< Indicates which of the following 3 fields are initialized
     54     pthread_mutex_t mMutex;
     55     pthread_cond_t mCondNotFull;    ///< Signalled when a client thread could be unblocked
     56     pthread_cond_t mCondNotEmpty;   ///< Signalled when a worker thread could be unblocked
     57     SLboolean mShutdown;   ///< Whether shutdown of thread pool has been requested
     58     unsigned mWaitingNotFull;   ///< Number of client threads waiting to enqueue
     59     unsigned mWaitingNotEmpty;  ///< Number of worker threads waiting to dequeue
     60     unsigned mMaxClosures;  ///< Number of slots in circular buffer for closures, not counting spare
     61     unsigned mMaxThreads;   ///< Number of worker threads
     62     Closure **mClosureArray;    ///< The circular buffer of closures
     63     Closure **mClosureFront, **mClosureRear;
     64     /// Saves a malloc in the typical case
     65 #define CLOSURE_TYPICAL 15
     66     Closure *mClosureTypical[CLOSURE_TYPICAL+1];
     67     pthread_t *mThreadArray;    ///< The worker threads
     68 #ifdef ANDROID
     69 // Note: if you set THREAD_TYPICAL to a non-zero value because you
     70 // want to use asynchronous callbacks, be aware that any value greater
     71 // than 1 can result in out-of-order callbacks on a given player, in the
     72 // current implementation.  Thus you should probably configure 1 total or
     73 // change the implementation so that it uses at most 1 thread per player.
     74 #if defined(USE_ASYNCHRONOUS_PLAY_CALLBACK) || \
     75         defined(USE_ASYNCHRONOUS_STREAMCBEVENT_PROPERTYCHANGE_CALLBACK)
     76 #define THREAD_TYPICAL 1
     77 #else
     78 #define THREAD_TYPICAL 0
     79 #endif
     80 #else // !ANDROID
     81 #define THREAD_TYPICAL 4
     82 #endif
     83     pthread_t mThreadTypical[THREAD_TYPICAL];
     84 } ThreadPool;
     85 
     86 extern SLresult ThreadPool_init(ThreadPool *tp, unsigned maxClosures, unsigned maxThreads);
     87 extern void ThreadPool_deinit(ThreadPool *tp);
     88 extern SLresult ThreadPool_add(ThreadPool *tp, ClosureKind kind,
     89         ClosureHandler_generic,
     90         void *cntxt1, void *cntxt2, void *cntxt3, int param1, int param2);
     91 extern Closure *ThreadPool_remove(ThreadPool *tp);
     92 extern SLresult ThreadPool_add_ppi(ThreadPool *tp, ClosureHandler_ppi handler,
     93         void *cntxt1, void *cntxt2, int param1);
     94 extern SLresult ThreadPool_add_ppii(ThreadPool *tp, ClosureHandler_ppii handler,
     95         void *cntxt1, void *cntxt2, int param1, int param2);
     96 extern SLresult ThreadPool_add_piipp(ThreadPool *tp, ClosureHandler_piipp handler,
     97         void *cntxt1, int param1, int param2, void *cntxt2, void *cntxt3);
     98