1010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten/* 2010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten * Copyright (C) 2012 The Android Open Source Project 3010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten * 4010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten * Licensed under the Apache License, Version 2.0 (the "License"); 5010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten * you may not use this file except in compliance with the License. 6010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten * You may obtain a copy of the License at 7010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten * 8010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten * http://www.apache.org/licenses/LICENSE-2.0 9010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten * 10010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten * Unless required by applicable law or agreed to in writing, software 11010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten * distributed under the License is distributed on an "AS IS" BASIS, 12010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten * See the License for the specific language governing permissions and 14010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten * limitations under the License. 15010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten */ 16010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 17010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten#define LOG_TAG "Pipe" 18010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten//#define LOG_NDEBUG 0 19010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 20010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten#include <cutils/atomic.h> 21010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten#include <cutils/compiler.h> 22010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten#include <utils/Log.h> 232dd4bdd715f586d4d30cf90cc6fc2bbfbce60fe0Glenn Kasten#include <media/nbaio/Pipe.h> 242dd4bdd715f586d4d30cf90cc6fc2bbfbce60fe0Glenn Kasten#include <media/nbaio/roundup.h> 25010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 26010662326b9c43c703725f933e95e0897f8a6bddGlenn Kastennamespace android { 27010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 28010662326b9c43c703725f933e95e0897f8a6bddGlenn KastenPipe::Pipe(size_t maxFrames, NBAIO_Format format) : 29010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten NBAIO_Sink(format), 30010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten mMaxFrames(roundup(maxFrames)), 31010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten mBuffer(malloc(mMaxFrames * Format_frameSize(format))), 32010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten mRear(0), 33010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten mReaders(0) 34010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten{ 35010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten} 36010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 37010662326b9c43c703725f933e95e0897f8a6bddGlenn KastenPipe::~Pipe() 38010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten{ 39010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten ALOG_ASSERT(android_atomic_acquire_load(&mReaders) == 0); 40010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten free(mBuffer); 41010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten} 42010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 43010662326b9c43c703725f933e95e0897f8a6bddGlenn Kastenssize_t Pipe::write(const void *buffer, size_t count) 44010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten{ 45010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // count == 0 is unlikely and not worth checking for 46010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten if (CC_UNLIKELY(!mNegotiated)) { 47010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten return NEGOTIATE; 48010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten } 49010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten // write() is not multi-thread safe w.r.t. itself, so no mutex or atomic op needed to read mRear 50010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten size_t rear = mRear & (mMaxFrames - 1); 51010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten size_t written = mMaxFrames - rear; 52010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten if (CC_LIKELY(written > count)) { 53010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten written = count; 54010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten } 55010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten memcpy((char *) mBuffer + (rear << mBitShift), buffer, written << mBitShift); 56010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten if (CC_UNLIKELY(rear + written == mMaxFrames)) { 57010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten if (CC_UNLIKELY((count -= written) > rear)) { 58010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten count = rear; 59010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten } 60010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten if (CC_LIKELY(count > 0)) { 61010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten memcpy(mBuffer, (char *) buffer + (written << mBitShift), count << mBitShift); 62010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten written += count; 63010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten } 64010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten } 65010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten android_atomic_release_store(written + mRear, &mRear); 66010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten mFramesWritten += written; 67010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten return written; 68010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten} 69010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten 70010662326b9c43c703725f933e95e0897f8a6bddGlenn Kasten} // namespace android 71