diff options
Diffstat (limited to 'services/audioflinger/MonoPipe.cpp')
| -rw-r--r-- | services/audioflinger/MonoPipe.cpp | 71 |
1 files changed, 55 insertions, 16 deletions
diff --git a/services/audioflinger/MonoPipe.cpp b/services/audioflinger/MonoPipe.cpp index 6efb8b1..f3fc19a 100644 --- a/services/audioflinger/MonoPipe.cpp +++ b/services/audioflinger/MonoPipe.cpp @@ -20,6 +20,7 @@ #include <cutils/atomic.h> #include <cutils/compiler.h> #include <utils/Log.h> +#include <utils/Trace.h> #include "MonoPipe.h" #include "roundup.h" @@ -32,6 +33,9 @@ MonoPipe::MonoPipe(size_t reqFrames, NBAIO_Format format, bool writeCanBlock) : mBuffer(malloc(mMaxFrames * Format_frameSize(format))), mFront(0), mRear(0), + mWriteTsValid(false), + // mWriteTs + mSetpoint((reqFrames * 11) / 16), mWriteCanBlock(writeCanBlock) { } @@ -87,40 +91,75 @@ ssize_t MonoPipe::write(const void *buffer, size_t count) count -= written; buffer = (char *) buffer + (written << mBitShift); // Simulate blocking I/O by sleeping at different rates, depending on a throttle. - // The throttle tries to keep the pipe about 11/16 full on average, with a slight jitter. + // 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 <= mReqFrames / 4) { + if (filled <= mSetpoint / 2) { // pipe is (nearly) empty, fill quickly ns = written * ( 500000000 / Format_sampleRate(mFormat)); - } else if (filled <= mReqFrames / 2) { - // pipe is normal, fill at slightly faster rate + } else if (filled <= (mSetpoint * 3) / 4) { + // pipe is below setpoint, fill at slightly faster rate ns = written * ( 750000000 / Format_sampleRate(mFormat)); - } else if (filled <= (mReqFrames * 5) / 8) { - // pipe is normal, fill at nominal rate + } else if (filled <= (mSetpoint * 5) / 4) { + // pipe is at setpoint, fill at nominal rate ns = written * (1000000000 / Format_sampleRate(mFormat)); - } else if (filled <= (mReqFrames * 3) / 4) { - // pipe is normal, fill at slightly slower rate - ns = written * (1100000000 / 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 (nearly) full, fill slowly - ns = written * (1250000000 / Format_sampleRate(mFormat)); + // pipe is severely overflowing + ns = written * (1750000000 / Format_sampleRate(mFormat)); } } else { - ns = mReqFrames * (250000000 / Format_sampleRate(mFormat)); + ns = count * (1350000000 / Format_sampleRate(mFormat)); } if (ns > 999999999) { ns = 999999999; } - struct timespec sleep; - sleep.tv_sec = 0; - sleep.tv_nsec = ns; - nanosleep(&sleep, NULL); + 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; + 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, 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; +} + } // namespace android |