libaudiohal: Make effect descriptors cache thread-safe
Due to legacy reasons, the code in the audio server assumes that
querying all effect descriptors is a cheap operation (stems from
pre-Treble times). Thus, the HIDL shim code needs to cache the
list of descriptors. It was assumed that the audio server code
queries effect descriptors under a lock, however recently it was
observed that it's not always the case (or it's not always the
same lock). To prevent races, access to the cache has been
serialized.
Bug: 243877224
Test: atest android.media.audio.cts.AudioEffectTest
Change-Id: Id5f3615074e540afca33a83d53d2b84634df89cf
diff --git a/media/libaudiohal/impl/EffectsFactoryHalHidl.cpp b/media/libaudiohal/impl/EffectsFactoryHalHidl.cpp
index d7217fc..3470380 100644
--- a/media/libaudiohal/impl/EffectsFactoryHalHidl.cpp
+++ b/media/libaudiohal/impl/EffectsFactoryHalHidl.cpp
@@ -17,6 +17,9 @@
#define LOG_TAG "EffectsFactoryHalHidl"
//#define LOG_NDEBUG 0
+#include <optional>
+#include <tuple>
+
#include <cutils/native_handle.h>
#include <UuidUtils.h>
@@ -38,51 +41,71 @@
using namespace ::android::hardware::audio::common::CPP_VERSION;
using namespace ::android::hardware::audio::effect::CPP_VERSION;
+class EffectDescriptorCache {
+ public:
+ using QueryResult = std::tuple<Return<void>, Result, hidl_vec<EffectDescriptor>>;
+ QueryResult queryAllDescriptors(IEffectsFactory* effectsFactory);
+ private:
+ std::mutex mLock;
+ std::optional<hidl_vec<EffectDescriptor>> mLastDescriptors; // GUARDED_BY(mLock)
+};
+
+EffectDescriptorCache::QueryResult EffectDescriptorCache::queryAllDescriptors(
+ IEffectsFactory* effectsFactory) {
+ {
+ std::lock_guard l(mLock);
+ if (mLastDescriptors.has_value()) {
+ return {::android::hardware::Void(), Result::OK, mLastDescriptors.value()};
+ }
+ }
+ Result retval = Result::NOT_INITIALIZED;
+ hidl_vec<EffectDescriptor> descriptors;
+ Return<void> ret = effectsFactory->getAllDescriptors(
+ [&](Result r, const hidl_vec<EffectDescriptor>& result) {
+ retval = r;
+ if (retval == Result::OK) {
+ descriptors = result;
+ }
+ });
+ if (ret.isOk() && retval == Result::OK) {
+ std::lock_guard l(mLock);
+ mLastDescriptors = descriptors;
+ }
+ return {std::move(ret), retval, std::move(descriptors)};
+}
+
EffectsFactoryHalHidl::EffectsFactoryHalHidl(sp<IEffectsFactory> effectsFactory)
- : EffectConversionHelperHidl("EffectsFactory") {
+ : EffectConversionHelperHidl("EffectsFactory"), mCache(new EffectDescriptorCache) {
ALOG_ASSERT(effectsFactory != nullptr, "Provided IEffectsFactory service is NULL");
mEffectsFactory = effectsFactory;
}
-status_t EffectsFactoryHalHidl::queryAllDescriptors() {
- if (mEffectsFactory == 0) return NO_INIT;
- Result retval = Result::NOT_INITIALIZED;
- Return<void> ret = mEffectsFactory->getAllDescriptors(
- [&](Result r, const hidl_vec<EffectDescriptor>& result) {
- retval = r;
- if (retval == Result::OK) {
- mLastDescriptors = result;
- }
- });
- if (ret.isOk()) {
- return retval == Result::OK ? OK : NO_INIT;
- }
- mLastDescriptors.resize(0);
- return processReturn(__FUNCTION__, ret);
-}
-
status_t EffectsFactoryHalHidl::queryNumberEffects(uint32_t *pNumEffects) {
- status_t queryResult = queryAllDescriptors();
- if (queryResult == OK) {
- *pNumEffects = mLastDescriptors.size();
+ if (mEffectsFactory == 0) return NO_INIT;
+ auto [ret, retval, descriptors] = mCache->queryAllDescriptors(mEffectsFactory.get());
+ if (ret.isOk() && retval == Result::OK) {
+ *pNumEffects = descriptors.size();
+ return OK;
+ } else if (ret.isOk()) {
+ return NO_INIT;
}
- return queryResult;
+ return processReturn(__FUNCTION__, ret);
}
status_t EffectsFactoryHalHidl::getDescriptor(
uint32_t index, effect_descriptor_t *pDescriptor) {
- // TODO: We need somehow to track the changes on the server side
- // or figure out how to convert everybody to query all the descriptors at once.
if (pDescriptor == nullptr) {
return BAD_VALUE;
}
- if (mLastDescriptors.size() == 0) {
- status_t queryResult = queryAllDescriptors();
- if (queryResult != OK) return queryResult;
+ if (mEffectsFactory == 0) return NO_INIT;
+ auto [ret, retval, descriptors] = mCache->queryAllDescriptors(mEffectsFactory.get());
+ if (ret.isOk() && retval == Result::OK) {
+ if (index >= descriptors.size()) return NAME_NOT_FOUND;
+ EffectUtils::effectDescriptorToHal(descriptors[index], pDescriptor);
+ } else if (ret.isOk()) {
+ return NO_INIT;
}
- if (index >= mLastDescriptors.size()) return NAME_NOT_FOUND;
- EffectUtils::effectDescriptorToHal(mLastDescriptors[index], pDescriptor);
- return OK;
+ return processReturn(__FUNCTION__, ret);
}
status_t EffectsFactoryHalHidl::getDescriptor(
@@ -114,21 +137,15 @@
if (pEffectType == nullptr || descriptors == nullptr) {
return BAD_VALUE;
}
+ if (mEffectsFactory == 0) return NO_INIT;
- uint32_t numEffects = 0;
- status_t status = queryNumberEffects(&numEffects);
- if (status != NO_ERROR) {
- ALOGW("%s error %d from FactoryHal queryNumberEffects", __func__, status);
- return status;
+ auto [ret, retval, hidlDescs] = mCache->queryAllDescriptors(mEffectsFactory.get());
+ if (!ret.isOk() || retval != Result::OK) {
+ return processReturn(__FUNCTION__, ret, retval);
}
-
- for (uint32_t i = 0; i < numEffects; i++) {
+ for (const auto& hidlDesc : hidlDescs) {
effect_descriptor_t descriptor;
- status = getDescriptor(i, &descriptor);
- if (status != NO_ERROR) {
- ALOGW("%s error %d from FactoryHal getDescriptor", __func__, status);
- continue;
- }
+ EffectUtils::effectDescriptorToHal(hidlDesc, &descriptor);
if (memcmp(&descriptor.type, pEffectType, sizeof(effect_uuid_t)) == 0) {
descriptors->push_back(descriptor);
}
diff --git a/media/libaudiohal/impl/EffectsFactoryHalHidl.h b/media/libaudiohal/impl/EffectsFactoryHalHidl.h
index e1882e1..7ccddc6 100644
--- a/media/libaudiohal/impl/EffectsFactoryHalHidl.h
+++ b/media/libaudiohal/impl/EffectsFactoryHalHidl.h
@@ -17,6 +17,8 @@
#ifndef ANDROID_HARDWARE_EFFECTS_FACTORY_HAL_HIDL_H
#define ANDROID_HARDWARE_EFFECTS_FACTORY_HAL_HIDL_H
+#include <memory>
+
#include PATH(android/hardware/audio/effect/FILE_VERSION/IEffectsFactory.h)
#include <media/audiohal/EffectsFactoryHalInterface.h>
@@ -28,6 +30,8 @@
using ::android::hardware::hidl_vec;
using namespace ::android::hardware::audio::effect::CPP_VERSION;
+class EffectDescriptorCache;
+
class EffectsFactoryHalHidl : public EffectsFactoryHalInterface, public EffectConversionHelperHidl
{
public:
@@ -63,9 +67,7 @@
private:
sp<IEffectsFactory> mEffectsFactory;
- hidl_vec<EffectDescriptor> mLastDescriptors;
-
- status_t queryAllDescriptors();
+ std::unique_ptr<EffectDescriptorCache> mCache;
};
} // namespace effect