| /* |
| * Copyright (C) 2012 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #include <inttypes.h> |
| |
| #define LOG_TAG "MonoPipe" |
| //#define LOG_NDEBUG 0 |
| |
| #include <cutils/atomic.h> |
| #include <cutils/compiler.h> |
| #include <utils/Log.h> |
| #include <utils/Trace.h> |
| #include <media/AudioBufferProvider.h> |
| #include <media/nbaio/MonoPipe.h> |
| #include <audio_utils/roundup.h> |
| |
| |
| namespace android { |
| |
| MonoPipe::MonoPipe(size_t reqFrames, const NBAIO_Format& format, bool writeCanBlock) : |
| NBAIO_Sink(format), |
| mReqFrames(reqFrames), |
| mMaxFrames(roundup(reqFrames)), |
| mBuffer(malloc(mMaxFrames * Format_frameSize(format))), |
| mFront(0), |
| mRear(0), |
| mWriteTsValid(false), |
| // mWriteTs |
| mSetpoint((reqFrames * 11) / 16), |
| mWriteCanBlock(writeCanBlock), |
| mIsShutdown(false), |
| // mTimestampShared |
| mTimestampMutator(&mTimestampShared), |
| mTimestampObserver(&mTimestampShared) |
| { |
| } |
| |
| MonoPipe::~MonoPipe() |
| { |
| free(mBuffer); |
| } |
| |
| ssize_t MonoPipe::availableToWrite() const |
| { |
| if (CC_UNLIKELY(!mNegotiated)) { |
| return NEGOTIATE; |
| } |
| // uses mMaxFrames not mReqFrames, so allows "over-filling" the pipe beyond requested limit |
| ssize_t ret = mMaxFrames - (mRear - android_atomic_acquire_load(&mFront)); |
| ALOG_ASSERT((0 <= ret) && (ret <= mMaxFrames)); |
| return ret; |
| } |
| |
| ssize_t MonoPipe::write(const void *buffer, size_t count) |
| { |
| if (CC_UNLIKELY(!mNegotiated)) { |
| return NEGOTIATE; |
| } |
| size_t totalFramesWritten = 0; |
| while (count > 0) { |
| // can't return a negative value, as we already checked for !mNegotiated |
| size_t avail = availableToWrite(); |
| size_t written = avail; |
| if (CC_LIKELY(written > count)) { |
| written = count; |
| } |
| size_t rear = mRear & (mMaxFrames - 1); |
| size_t part1 = mMaxFrames - rear; |
| if (part1 > written) { |
| part1 = written; |
| } |
| if (CC_LIKELY(part1 > 0)) { |
| memcpy((char *) mBuffer + (rear * mFrameSize), buffer, part1 * mFrameSize); |
| if (CC_UNLIKELY(rear + part1 == mMaxFrames)) { |
| size_t part2 = written - part1; |
| if (CC_LIKELY(part2 > 0)) { |
| memcpy(mBuffer, (char *) buffer + (part1 * mFrameSize), part2 * mFrameSize); |
| } |
| } |
| android_atomic_release_store(written + mRear, &mRear); |
| totalFramesWritten += written; |
| } |
| if (!mWriteCanBlock || mIsShutdown) { |
| break; |
| } |
| count -= written; |
| buffer = (char *) buffer + (written * mFrameSize); |
| // Simulate blocking I/O by sleeping at different rates, depending on a throttle. |
| // The throttle tries to keep the mean pipe depth near the setpoint, with a slight jitter. |
| uint32_t ns; |
| if (written > 0) { |
| size_t filled = (mMaxFrames - avail) + written; |
| // FIXME cache these values to avoid re-computation |
| if (filled <= mSetpoint / 2) { |
| // pipe is (nearly) empty, fill quickly |
| ns = written * ( 500000000 / Format_sampleRate(mFormat)); |
| } else if (filled <= (mSetpoint * 3) / 4) { |
| // pipe is below setpoint, fill at slightly faster rate |
| ns = written * ( 750000000 / Format_sampleRate(mFormat)); |
| } else if (filled <= (mSetpoint * 5) / 4) { |
| // pipe is at setpoint, fill at nominal rate |
| ns = written * (1000000000 / Format_sampleRate(mFormat)); |
| } else if (filled <= (mSetpoint * 3) / 2) { |
| // pipe is above setpoint, fill at slightly slower rate |
| ns = written * (1150000000 / Format_sampleRate(mFormat)); |
| } else if (filled <= (mSetpoint * 7) / 4) { |
| // pipe is overflowing, fill slowly |
| ns = written * (1350000000 / Format_sampleRate(mFormat)); |
| } else { |
| // pipe is severely overflowing |
| ns = written * (1750000000 / Format_sampleRate(mFormat)); |
| } |
| } else { |
| ns = count * (1350000000 / Format_sampleRate(mFormat)); |
| } |
| if (ns > 999999999) { |
| ns = 999999999; |
| } |
| struct timespec nowTs; |
| bool nowTsValid = !clock_gettime(CLOCK_MONOTONIC, &nowTs); |
| // deduct the elapsed time since previous write() completed |
| if (nowTsValid && mWriteTsValid) { |
| time_t sec = nowTs.tv_sec - mWriteTs.tv_sec; |
| long nsec = nowTs.tv_nsec - mWriteTs.tv_nsec; |
| ALOGE_IF(sec < 0 || (sec == 0 && nsec < 0), |
| "clock_gettime(CLOCK_MONOTONIC) failed: was %ld.%09ld but now %ld.%09ld", |
| mWriteTs.tv_sec, mWriteTs.tv_nsec, nowTs.tv_sec, nowTs.tv_nsec); |
| if (nsec < 0) { |
| --sec; |
| nsec += 1000000000; |
| } |
| if (sec == 0) { |
| if ((long) ns > nsec) { |
| ns -= nsec; |
| } else { |
| ns = 0; |
| } |
| } |
| } |
| if (ns > 0) { |
| const struct timespec req = {0, static_cast<long>(ns)}; |
| nanosleep(&req, NULL); |
| } |
| // record the time that this write() completed |
| if (nowTsValid) { |
| mWriteTs = nowTs; |
| if ((mWriteTs.tv_nsec += ns) >= 1000000000) { |
| mWriteTs.tv_nsec -= 1000000000; |
| ++mWriteTs.tv_sec; |
| } |
| } |
| mWriteTsValid = nowTsValid; |
| } |
| mFramesWritten += totalFramesWritten; |
| return totalFramesWritten; |
| } |
| |
| void MonoPipe::setAvgFrames(size_t setpoint) |
| { |
| mSetpoint = setpoint; |
| } |
| |
| void MonoPipe::shutdown(bool newState) |
| { |
| mIsShutdown = newState; |
| } |
| |
| bool MonoPipe::isShutdown() |
| { |
| return mIsShutdown; |
| } |
| |
| status_t MonoPipe::getTimestamp(ExtendedTimestamp ×tamp) |
| { |
| ExtendedTimestamp ets; |
| if (mTimestampObserver.poll(ets)) { |
| timestamp.mPosition[ExtendedTimestamp::LOCATION_KERNEL] = |
| ets.mPosition[ExtendedTimestamp::LOCATION_KERNEL]; |
| timestamp.mTimeNs[ExtendedTimestamp::LOCATION_KERNEL] = |
| ets.mTimeNs[ExtendedTimestamp::LOCATION_KERNEL]; |
| return OK; |
| } |
| return INVALID_OPERATION; |
| } |
| |
| } // namespace android |