Avoid holding lock while calling callback.
Avoid holding lock while calling property store
OnValueChangeCallback. This might cause dead lock if
VehiclePropertyStore is accessed within the callback.
Test: atest VehiclePropertyStoreTest
Bug: 306511577
Change-Id: I5e29e9715d4429ccde5145af385a363bac548af7
diff --git a/automotive/vehicle/aidl/impl/utils/common/include/VehiclePropertyStore.h b/automotive/vehicle/aidl/impl/utils/common/include/VehiclePropertyStore.h
index 3d25cd3..b74dff5 100644
--- a/automotive/vehicle/aidl/impl/utils/common/include/VehiclePropertyStore.h
+++ b/automotive/vehicle/aidl/impl/utils/common/include/VehiclePropertyStore.h
@@ -92,7 +92,7 @@
// used as the key.
void registerProperty(
const aidl::android::hardware::automotive::vehicle::VehiclePropConfig& config,
- TokenFunction tokenFunc = nullptr);
+ TokenFunction tokenFunc = nullptr) EXCLUDES(mLock);
// Stores provided value. Returns error if config wasn't registered. If 'updateStatus' is
// true, the 'status' in 'propValue' would be stored. Otherwise, if this is a new value,
@@ -102,44 +102,47 @@
// 'EventMode' controls whether the 'OnValueChangeCallback' will be called for this operation.
VhalResult<void> writeValue(VehiclePropValuePool::RecyclableType propValue,
bool updateStatus = false,
- EventMode mode = EventMode::ON_VALUE_CHANGE);
+ EventMode mode = EventMode::ON_VALUE_CHANGE) EXCLUDES(mLock);
// Remove a given property value from the property store. The 'propValue' would be used to
// generate the key for the value to remove.
void removeValue(
- const aidl::android::hardware::automotive::vehicle::VehiclePropValue& propValue);
+ const aidl::android::hardware::automotive::vehicle::VehiclePropValue& propValue)
+ EXCLUDES(mLock);
// Remove all the values for the property.
- void removeValuesForProperty(int32_t propId);
+ void removeValuesForProperty(int32_t propId) EXCLUDES(mLock);
// Read all the stored values.
- std::vector<VehiclePropValuePool::RecyclableType> readAllValues() const;
+ std::vector<VehiclePropValuePool::RecyclableType> readAllValues() const EXCLUDES(mLock);
// Read all the values for the property.
- ValuesResultType readValuesForProperty(int32_t propId) const;
+ ValuesResultType readValuesForProperty(int32_t propId) const EXCLUDES(mLock);
// Read the value for the requested property. Returns {@code StatusCode::NOT_AVAILABLE} if the
// value has not been set yet. Returns {@code StatusCode::INVALID_ARG} if the property is
// not configured.
ValueResultType readValue(
- const aidl::android::hardware::automotive::vehicle::VehiclePropValue& request) const;
+ const aidl::android::hardware::automotive::vehicle::VehiclePropValue& request) const
+ EXCLUDES(mLock);
// Read the value for the requested property. Returns {@code StatusCode::NOT_AVAILABLE} if the
// value has not been set yet. Returns {@code StatusCode::INVALID_ARG} if the property is
// not configured.
- ValueResultType readValue(int32_t prop, int32_t area = 0, int64_t token = 0) const;
+ ValueResultType readValue(int32_t prop, int32_t area = 0, int64_t token = 0) const
+ EXCLUDES(mLock);
// Get all property configs.
std::vector<aidl::android::hardware::automotive::vehicle::VehiclePropConfig> getAllConfigs()
- const;
+ const EXCLUDES(mLock);
// Get the property config for the requested property.
android::base::Result<const aidl::android::hardware::automotive::vehicle::VehiclePropConfig*,
VhalError>
- getConfig(int32_t propId) const;
+ getConfig(int32_t propId) const EXCLUDES(mLock);
// Set a callback that would be called when a property value has been updated.
- void setOnValueChangeCallback(const OnValueChangeCallback& callback);
+ void setOnValueChangeCallback(const OnValueChangeCallback& callback) EXCLUDES(mLock);
inline std::shared_ptr<VehiclePropValuePool> getValuePool() { return mValuePool; }
diff --git a/automotive/vehicle/aidl/impl/utils/common/src/VehiclePropertyStore.cpp b/automotive/vehicle/aidl/impl/utils/common/src/VehiclePropertyStore.cpp
index 646dc0e..3fd2aa8 100644
--- a/automotive/vehicle/aidl/impl/utils/common/src/VehiclePropertyStore.cpp
+++ b/automotive/vehicle/aidl/impl/utils/common/src/VehiclePropertyStore.cpp
@@ -108,51 +108,62 @@
VhalResult<void> VehiclePropertyStore::writeValue(VehiclePropValuePool::RecyclableType propValue,
bool updateStatus,
VehiclePropertyStore::EventMode eventMode) {
- std::scoped_lock<std::mutex> g(mLock);
-
- int32_t propId = propValue->prop;
-
- VehiclePropertyStore::Record* record = getRecordLocked(propId);
- if (record == nullptr) {
- return StatusError(StatusCode::INVALID_ARG) << "property: " << propId << " not registered";
- }
-
- if (!isGlobalProp(propId) && getAreaConfig(*propValue, record->propConfig) == nullptr) {
- return StatusError(StatusCode::INVALID_ARG)
- << "no config for property: " << propId << " area: " << propValue->areaId;
- }
-
- VehiclePropertyStore::RecordId recId = getRecordIdLocked(*propValue, *record);
bool valueUpdated = true;
- if (auto it = record->values.find(recId); it != record->values.end()) {
- const VehiclePropValue* valueToUpdate = it->second.get();
- int64_t oldTimestamp = valueToUpdate->timestamp;
- VehiclePropertyStatus oldStatus = valueToUpdate->status;
- // propValue is outdated and drops it.
- if (oldTimestamp > propValue->timestamp) {
+ VehiclePropValue updatedValue;
+ OnValueChangeCallback onValueChangeCallback = nullptr;
+ {
+ std::scoped_lock<std::mutex> g(mLock);
+
+ int32_t propId = propValue->prop;
+
+ VehiclePropertyStore::Record* record = getRecordLocked(propId);
+ if (record == nullptr) {
return StatusError(StatusCode::INVALID_ARG)
- << "outdated timestamp: " << propValue->timestamp;
- }
- if (!updateStatus) {
- propValue->status = oldStatus;
+ << "property: " << propId << " not registered";
}
- valueUpdated = (valueToUpdate->value != propValue->value ||
- valueToUpdate->status != propValue->status ||
- valueToUpdate->prop != propValue->prop ||
- valueToUpdate->areaId != propValue->areaId);
- } else if (!updateStatus) {
- propValue->status = VehiclePropertyStatus::AVAILABLE;
+ if (!isGlobalProp(propId) && getAreaConfig(*propValue, record->propConfig) == nullptr) {
+ return StatusError(StatusCode::INVALID_ARG)
+ << "no config for property: " << propId << " area ID: " << propValue->areaId;
+ }
+
+ VehiclePropertyStore::RecordId recId = getRecordIdLocked(*propValue, *record);
+ if (auto it = record->values.find(recId); it != record->values.end()) {
+ const VehiclePropValue* valueToUpdate = it->second.get();
+ int64_t oldTimestampNanos = valueToUpdate->timestamp;
+ VehiclePropertyStatus oldStatus = valueToUpdate->status;
+ // propValue is outdated and drops it.
+ if (oldTimestampNanos > propValue->timestamp) {
+ return StatusError(StatusCode::INVALID_ARG)
+ << "outdated timestampNanos: " << propValue->timestamp;
+ }
+ if (!updateStatus) {
+ propValue->status = oldStatus;
+ }
+
+ valueUpdated = (valueToUpdate->value != propValue->value ||
+ valueToUpdate->status != propValue->status ||
+ valueToUpdate->prop != propValue->prop ||
+ valueToUpdate->areaId != propValue->areaId);
+ } else if (!updateStatus) {
+ propValue->status = VehiclePropertyStatus::AVAILABLE;
+ }
+
+ record->values[recId] = std::move(propValue);
+
+ if (eventMode == EventMode::NEVER) {
+ return {};
+ }
+ updatedValue = *(record->values[recId]);
+ if (mOnValueChangeCallback == nullptr) {
+ return {};
+ }
+ onValueChangeCallback = mOnValueChangeCallback;
}
- record->values[recId] = std::move(propValue);
-
- if (eventMode == EventMode::NEVER) {
- return {};
- }
-
- if ((eventMode == EventMode::ALWAYS || valueUpdated) && mOnValueChangeCallback != nullptr) {
- mOnValueChangeCallback(*(record->values[recId]));
+ // Invoke the callback outside the lock to prevent dead-lock.
+ if (eventMode == EventMode::ALWAYS || valueUpdated) {
+ onValueChangeCallback(updatedValue);
}
return {};
}
diff --git a/automotive/vehicle/aidl/impl/utils/common/test/VehiclePropertyStoreTest.cpp b/automotive/vehicle/aidl/impl/utils/common/test/VehiclePropertyStoreTest.cpp
index fea5034..625652e 100644
--- a/automotive/vehicle/aidl/impl/utils/common/test/VehiclePropertyStoreTest.cpp
+++ b/automotive/vehicle/aidl/impl/utils/common/test/VehiclePropertyStoreTest.cpp
@@ -509,6 +509,24 @@
ASSERT_EQ(updatedValue.prop, INVALID_PROP_ID);
}
+TEST_F(VehiclePropertyStoreTest, testPropertyChangeCallbackUseVehiclePropertyStore_noDeadLock) {
+ VehiclePropValue fuelCapacity = {
+ .prop = toInt(VehicleProperty::INFO_FUEL_CAPACITY),
+ .value = {.floatValues = {1.0}},
+ };
+
+ std::vector<VehiclePropConfig> configs;
+
+ mStore->setOnValueChangeCallback(
+ [this, &configs]([[maybe_unused]] const VehiclePropValue& value) {
+ configs = mStore->getAllConfigs();
+ });
+
+ ASSERT_RESULT_OK(mStore->writeValue(mValuePool->obtain(fuelCapacity), /*updateStatus=*/true,
+ VehiclePropertyStore::EventMode::ALWAYS));
+ ASSERT_EQ(configs.size(), static_cast<size_t>(2));
+}
+
} // namespace vehicle
} // namespace automotive
} // namespace hardware