1 /* 2 * Copyright (C) 2009 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 #ifndef ANDROID_RS_LOCKLESS_FIFO_H 18 #define ANDROID_RS_LOCKLESS_FIFO_H 19 20 21 #include "rsUtils.h" 22 #include "rsSignal.h" 23 24 namespace android { 25 namespace renderscript { 26 27 28 // A simple FIFO to be used as a producer / consumer between two 29 // threads. One is writer and one is reader. The common cases 30 // will not require locking. It is not threadsafe for multiple 31 // readers or writers by design. 32 33 class LocklessCommandFifo { 34 public: 35 bool init(uint32_t size); 36 void shutdown(); 37 void setTimoutCallback(void (*)(void *), void *, uint64_t timeout); 38 39 void printDebugData() const; 40 41 LocklessCommandFifo(); 42 ~LocklessCommandFifo(); 43 44 protected: 45 uint8_t * volatile mPut; 46 uint8_t * volatile mGet; 47 uint8_t * mBuffer; 48 uint8_t * mEnd; 49 uint8_t mSize; 50 bool mInShutdown; 51 bool mInitialized; 52 53 Signal mSignalToWorker; 54 Signal mSignalToControl; 55 56 public: 57 void * reserve(uint32_t bytes); 58 void commit(uint32_t command, uint32_t bytes); 59 void commitSync(uint32_t command, uint32_t bytes); 60 61 void flush(); 62 bool wait(uint64_t timeout = 0); 63 64 const void * get(uint32_t *command, uint32_t *bytesData, uint64_t timeout = 0); 65 void next(); 66 67 void makeSpace(uint32_t bytes); 68 bool makeSpaceNonBlocking(uint32_t bytes); 69 70 bool isEmpty() const; 71 uint32_t getFreeSpace() const; 72 73 private: 74 void dumpState(const char *) const; 75 76 void (*mTimeoutCallback)(void *); 77 void * mTimeoutCallbackData; 78 uint64_t mTimeoutWait; 79 }; 80 81 82 } 83 } 84 #endif 85
