Fix race in AudioSystem::getInputBufferSize
It was caching the recording parameters without a mutex.
Change-Id: Ic4b9f621cbc080d224c2233cf3ca3454fc0f19bd
diff --git a/media/libmedia/AudioSystem.cpp b/media/libmedia/AudioSystem.cpp
index f7f129c..caa3d30 100644
--- a/media/libmedia/AudioSystem.cpp
+++ b/media/libmedia/AudioSystem.cpp
@@ -38,7 +38,7 @@
DefaultKeyedVector<int, audio_io_handle_t> AudioSystem::gStreamOutputMap(0);
DefaultKeyedVector<audio_io_handle_t, AudioSystem::OutputDescriptor *> AudioSystem::gOutputs(0);
-// Cached values for recording queries
+// Cached values for recording queries, all protected by gLock
uint32_t AudioSystem::gPrevInSamplingRate = 16000;
int AudioSystem::gPrevInFormat = AUDIO_FORMAT_PCM_16_BIT;
int AudioSystem::gPrevInChannelCount = 1;
@@ -301,22 +301,27 @@
status_t AudioSystem::getInputBufferSize(uint32_t sampleRate, int format, int channelCount,
size_t* buffSize)
{
+ gLock.lock();
// Do we have a stale gInBufferSize or are we requesting the input buffer size for new values
- if ((gInBuffSize == 0) || (sampleRate != gPrevInSamplingRate) || (format != gPrevInFormat)
+ size_t inBuffSize = gInBuffSize;
+ if ((inBuffSize == 0) || (sampleRate != gPrevInSamplingRate) || (format != gPrevInFormat)
|| (channelCount != gPrevInChannelCount)) {
+ gLock.unlock();
+ const sp<IAudioFlinger>& af = AudioSystem::get_audio_flinger();
+ if (af == 0) {
+ return PERMISSION_DENIED;
+ }
+ inBuffSize = af->getInputBufferSize(sampleRate, format, channelCount);
+ gLock.lock();
// save the request params
gPrevInSamplingRate = sampleRate;
gPrevInFormat = format;
gPrevInChannelCount = channelCount;
- gInBuffSize = 0;
- const sp<IAudioFlinger>& af = AudioSystem::get_audio_flinger();
- if (af == 0) {
- return PERMISSION_DENIED;
- }
- gInBuffSize = af->getInputBufferSize(sampleRate, format, channelCount);
+ gInBuffSize = inBuffSize;
}
- *buffSize = gInBuffSize;
+ gLock.unlock();
+ *buffSize = inBuffSize;
return NO_ERROR;
}