Merge changes Ice087a6f,I52fa9bd3,I1a375ab2 into main

* changes:
  Fix proto converter and support VUR.
  Overwrite enableVUR to false if not supported.
  Implement VUR in SubscriptionManager.
diff --git a/automotive/vehicle/TEST_MAPPING b/automotive/vehicle/TEST_MAPPING
index 02ad8bb..e1a90cb 100644
--- a/automotive/vehicle/TEST_MAPPING
+++ b/automotive/vehicle/TEST_MAPPING
@@ -51,6 +51,9 @@
           "include-filter": "com.android.car.hal.fakevhal.FakeVehicleStubUnitTest"
         }
       ]
+    },
+    {
+      "name": "VehicleHalProtoMessageConverterTest"
     }
   ]
 }
diff --git a/automotive/vehicle/aidl/impl/grpc/utils/proto_message_converter/src/ProtoMessageConverter.cpp b/automotive/vehicle/aidl/impl/grpc/utils/proto_message_converter/src/ProtoMessageConverter.cpp
index 6b789bb..491aa10 100644
--- a/automotive/vehicle/aidl/impl/grpc/utils/proto_message_converter/src/ProtoMessageConverter.cpp
+++ b/automotive/vehicle/aidl/impl/grpc/utils/proto_message_converter/src/ProtoMessageConverter.cpp
@@ -78,6 +78,7 @@
                 protoACfg->add_supported_enum_values(supportedEnumValue);
             }
         }
+        protoACfg->set_support_variable_update_rate(areaConfig.supportVariableUpdateRate);
     }
 }
 
@@ -100,9 +101,14 @@
                 .maxInt64Value = protoAcfg.max_int64_value(),
                 .minFloatValue = protoAcfg.min_float_value(),
                 .maxFloatValue = protoAcfg.max_float_value(),
+                .supportVariableUpdateRate = protoAcfg.support_variable_update_rate(),
         };
-        COPY_PROTOBUF_VEC_TO_VHAL_TYPE(protoAcfg, supported_enum_values, (&vehicleAreaConfig),
-                                       supportedEnumValues.value());
+        if (protoAcfg.supported_enum_values().size() != 0) {
+            vehicleAreaConfig.supportedEnumValues = std::vector<int64_t>();
+            COPY_PROTOBUF_VEC_TO_VHAL_TYPE(protoAcfg, supported_enum_values, (&vehicleAreaConfig),
+                                           supportedEnumValues.value());
+        }
+
         return vehicleAreaConfig;
     };
     CAST_COPY_PROTOBUF_VEC_TO_VHAL_TYPE(in, area_configs, out, areaConfigs, cast_to_acfg);
diff --git a/automotive/vehicle/aidl/impl/hardware/include/IVehicleHardware.h b/automotive/vehicle/aidl/impl/hardware/include/IVehicleHardware.h
index b813b11..f49d91b 100644
--- a/automotive/vehicle/aidl/impl/hardware/include/IVehicleHardware.h
+++ b/automotive/vehicle/aidl/impl/hardware/include/IVehicleHardware.h
@@ -117,18 +117,53 @@
         return std::chrono::nanoseconds(0);
     }
 
-    // A [propId, areaId] is newly subscribed or the update rate is changed.
+    // A [propId, areaId] is newly subscribed or the subscribe options are changed.
     //
-    // The 'options' contains the property ID, area ID and sample rate in Hz.
+    // The subscribe options contain sample rate in Hz or enable/disable variable update rate.
     //
-    // For continuous property, the sample rate is never 0 and indicates the new sample rate (or
-    // the initial sample rate if this property was not subscribed before).
+    // For continuous properties:
     //
-    // For on-change property, the sample rate is always 0 and must be ignored.
+    // The sample rate is never 0 and indicates the desired polling rate for this property. The
+    // sample rate is guaranteed to be within supported {@code minSampleRate} and
+    // {@code maxSampleRate} as specified in {@code VehiclePropConfig}.
+    //
+    // If the specified sample rate is not supported, e.g. vehicle bus only supports 5hz and 10hz
+    // polling rate but the sample rate is 8hz, impl must choose the higher polling rate (10hz).
+    //
+    // Whether variable update rate is enabled is specified by {@code enableVariableUpdateRate} in
+    // {@code SubscribeOptions}. If variable update rate is not supported for the
+    // [propId, areaId], impl must ignore this option and always treat it as disabled.
+    //
+    // If variable update rate is disabled/not supported, impl must report all the property events
+    // for this [propId, areaId] through {@code propertyChangeCallback} according to the sample
+    // rate. E.g. a sample rate of 10hz must generate at least 10 property change events per second.
+    //
+    // If variable update rate is enabled AND supported, impl must only report property events
+    // when the [propId, areaId]'s value or status changes (a.k.a same as on-change property).
+    // The sample rate still guides the polling rate, but duplicate property events must be dropped
+    // and not reported via {@code propertyChangeCallback}.
+    //
+    // Async property set error events are not affected by variable update rate and must always
+    // be reported.
+    //
+    // If the impl is always polling at {@code maxSampleRate} for all continuous [propId, areaId]s,
+    // and do not support variable update rate for any [propId, areaId], then this function can be a
+    // no-op.
+    //
+    // For on-change properties:
+    //
+    // The sample rate is always 0 and must be ignored. If the impl is always subscribing to all
+    // on-change properties, then this function can be no-op.
+    //
+    // For all properties:
+    //
+    // It is recommended to only deliver the subscribed property events to DefaultVehicleHal to
+    // improve performance. However, even if unsubscribed property events are delivered, they
+    // will be filtered out by DefaultVehicleHal.
     //
     // A subscription from VHAL client might not necessarily trigger this function.
     // DefaultVehicleHal will aggregate all the subscriptions from all the clients and notify
-    // IVehicleHardware if new subscriptions are required or sample rate is updated.
+    // IVehicleHardware if new subscriptions are required or subscribe options are updated.
     //
     // For example:
     // 1. VHAL initially have no subscriber for speed.
@@ -144,15 +179,6 @@
     // 5. The second subscriber is removed, 'unsubscribe' is called.
     //    The impl can optionally disable the polling for vehicle speed.
     //
-    // It is recommended to only deliver the subscribed property events to DefaultVehicleHal to
-    // improve performance. However, even if unsubscribed property events are delivered, they
-    // will be filtered out by DefaultVehicleHal.
-    //
-    // For continuous property, if the impl is always polling at {@code maxSampleRate} as specified
-    // in config, then this function can be a no-op.
-    //
-    // For on-change property, if the impl is always subscribing to all on-change properties, then
-    // this function can be no-op.
     virtual aidl::android::hardware::automotive::vehicle::StatusCode subscribe(
             [[maybe_unused]] aidl::android::hardware::automotive::vehicle::SubscribeOptions
                     options) {
diff --git a/automotive/vehicle/aidl/impl/vhal/include/SubscriptionManager.h b/automotive/vehicle/aidl/impl/vhal/include/SubscriptionManager.h
index 057da35..5053c96 100644
--- a/automotive/vehicle/aidl/impl/vhal/include/SubscriptionManager.h
+++ b/automotive/vehicle/aidl/impl/vhal/include/SubscriptionManager.h
@@ -36,20 +36,29 @@
 namespace automotive {
 namespace vehicle {
 
+// A structure to represent subscription config for one subscription client.
+struct SubConfig {
+    float sampleRateHz;
+    bool enableVur;
+};
+
 // A class to represent all the subscription configs for a continuous [propId, areaId].
 class ContSubConfigs final {
   public:
     using ClientIdType = const AIBinder*;
 
-    void addClient(const ClientIdType& clientId, float sampleRateHz);
+    void addClient(const ClientIdType& clientId, float sampleRateHz, bool enableVur);
     void removeClient(const ClientIdType& clientId);
     float getMaxSampleRateHz() const;
+    bool isVurEnabled() const;
+    bool isVurEnabledForClient(const ClientIdType& clientId);
 
   private:
     float mMaxSampleRateHz = 0.;
-    std::unordered_map<ClientIdType, float> mSampleRateHzByClient;
+    bool mEnableVur;
+    std::unordered_map<ClientIdType, SubConfig> mConfigByClient;
 
-    void refreshMaxSampleRateHz();
+    void refreshCombinedConfig();
 };
 
 // A thread-safe subscription manager that manages all VHAL subscriptions.
@@ -58,6 +67,7 @@
     using ClientIdType = const AIBinder*;
     using CallbackType =
             std::shared_ptr<aidl::android::hardware::automotive::vehicle::IVehicleCallback>;
+    using VehiclePropValue = aidl::android::hardware::automotive::vehicle::VehiclePropValue;
 
     explicit SubscriptionManager(IVehicleHardware* vehicleHardware);
     ~SubscriptionManager();
@@ -92,11 +102,8 @@
     // For a list of updated properties, returns a map that maps clients subscribing to
     // the updated properties to a list of updated values. This would only return on-change property
     // clients that should be informed for the given updated values.
-    std::unordered_map<CallbackType,
-                       std::vector<aidl::android::hardware::automotive::vehicle::VehiclePropValue>>
-    getSubscribedClients(
-            std::vector<aidl::android::hardware::automotive::vehicle::VehiclePropValue>&&
-                    updatedValues);
+    std::unordered_map<CallbackType, std::vector<VehiclePropValue>> getSubscribedClients(
+            std::vector<VehiclePropValue>&& updatedValues);
 
     // For a list of set property error events, returns a map that maps clients subscribing to the
     // properties to a list of errors for each client.
@@ -116,6 +123,21 @@
 
     IVehicleHardware* mVehicleHardware;
 
+    struct VehiclePropValueHashPropIdAreaId {
+        inline size_t operator()(const VehiclePropValue& vehiclePropValue) const {
+            size_t res = 0;
+            hashCombine(res, vehiclePropValue.prop);
+            hashCombine(res, vehiclePropValue.areaId);
+            return res;
+        }
+    };
+
+    struct VehiclePropValueEqualPropIdAreaId {
+        inline bool operator()(const VehiclePropValue& left, const VehiclePropValue& right) const {
+            return left.prop == right.prop && left.areaId == right.areaId;
+        }
+    };
+
     mutable std::mutex mLock;
     std::unordered_map<PropIdAreaId, std::unordered_map<ClientIdType, CallbackType>,
                        PropIdAreaIdHash>
@@ -124,10 +146,15 @@
             mSubscribedPropsByClient GUARDED_BY(mLock);
     std::unordered_map<PropIdAreaId, ContSubConfigs, PropIdAreaIdHash> mContSubConfigsByPropIdArea
             GUARDED_BY(mLock);
+    std::unordered_map<CallbackType,
+                       std::unordered_set<VehiclePropValue, VehiclePropValueHashPropIdAreaId,
+                                          VehiclePropValueEqualPropIdAreaId>>
+            mContSubValuesByCallback GUARDED_BY(mLock);
 
     VhalResult<void> addContinuousSubscriberLocked(const ClientIdType& clientId,
                                                    const PropIdAreaId& propIdAreaId,
-                                                   float sampleRateHz) REQUIRES(mLock);
+                                                   float sampleRateHz, bool enableVur)
+            REQUIRES(mLock);
     VhalResult<void> addOnChangeSubscriberLocked(const PropIdAreaId& propIdAreaId) REQUIRES(mLock);
     // Removes the subscription client for the continuous [propId, areaId].
     VhalResult<void> removeContinuousSubscriberLocked(const ClientIdType& clientId,
@@ -147,6 +174,9 @@
     // Checks whether the manager is empty. For testing purpose.
     bool isEmpty();
 
+    bool isValueUpdatedLocked(const CallbackType& callback, const VehiclePropValue& value)
+            REQUIRES(mLock);
+
     // Get the interval in nanoseconds accroding to sample rate.
     static android::base::Result<int64_t> getIntervalNanos(float sampleRateHz);
 };
diff --git a/automotive/vehicle/aidl/impl/vhal/src/DefaultVehicleHal.cpp b/automotive/vehicle/aidl/impl/vhal/src/DefaultVehicleHal.cpp
index 111a6ec..d85cc09 100644
--- a/automotive/vehicle/aidl/impl/vhal/src/DefaultVehicleHal.cpp
+++ b/automotive/vehicle/aidl/impl/vhal/src/DefaultVehicleHal.cpp
@@ -695,7 +695,39 @@
         if (config.changeMode == VehiclePropertyChangeMode::CONTINUOUS) {
             optionCopy.sampleRate = getDefaultSampleRateHz(
                     optionCopy.sampleRate, config.minSampleRate, config.maxSampleRate);
-            continuousSubscriptions.push_back(std::move(optionCopy));
+            if (!optionCopy.enableVariableUpdateRate) {
+                continuousSubscriptions.push_back(std::move(optionCopy));
+            } else {
+                // If clients enables to VUR, we need to check whether VUR is supported for the
+                // specific [propId, areaId] and overwrite the option to disable if not supported.
+                std::vector<int32_t> areasVurEnabled;
+                std::vector<int32_t> areasVurDisabled;
+                for (int32_t areaId : optionCopy.areaIds) {
+                    const VehicleAreaConfig* areaConfig = getAreaConfig(propId, areaId, config);
+                    if (areaConfig == nullptr) {
+                        areasVurDisabled.push_back(areaId);
+                        continue;
+                    }
+                    if (!areaConfig->supportVariableUpdateRate) {
+                        areasVurDisabled.push_back(areaId);
+                        continue;
+                    }
+                    areasVurEnabled.push_back(areaId);
+                }
+                if (!areasVurEnabled.empty()) {
+                    SubscribeOptions optionVurEnabled = optionCopy;
+                    optionVurEnabled.areaIds = areasVurEnabled;
+                    optionVurEnabled.enableVariableUpdateRate = true;
+                    continuousSubscriptions.push_back(std::move(optionVurEnabled));
+                }
+
+                if (!areasVurDisabled.empty()) {
+                    // We use optionCopy for areas with VUR disabled.
+                    optionCopy.areaIds = areasVurDisabled;
+                    optionCopy.enableVariableUpdateRate = false;
+                    continuousSubscriptions.push_back(std::move(optionCopy));
+                }
+            }
         } else {
             onChangeSubscriptions.push_back(std::move(optionCopy));
         }
diff --git a/automotive/vehicle/aidl/impl/vhal/src/SubscriptionManager.cpp b/automotive/vehicle/aidl/impl/vhal/src/SubscriptionManager.cpp
index a7c797b..29d81a7 100644
--- a/automotive/vehicle/aidl/impl/vhal/src/SubscriptionManager.cpp
+++ b/automotive/vehicle/aidl/impl/vhal/src/SubscriptionManager.cpp
@@ -42,11 +42,13 @@
 
 constexpr float ONE_SECOND_IN_NANOS = 1'000'000'000.;
 
-SubscribeOptions newSubscribeOptions(int32_t propId, int32_t areaId, float sampleRateHz) {
+SubscribeOptions newSubscribeOptions(int32_t propId, int32_t areaId, float sampleRateHz,
+                                     bool enableVur) {
     SubscribeOptions subscribedOptions;
     subscribedOptions.propId = propId;
     subscribedOptions.areaIds = {areaId};
     subscribedOptions.sampleRate = sampleRateHz;
+    subscribedOptions.enableVariableUpdateRate = enableVur;
 
     return subscribedOptions;
 }
@@ -79,32 +81,50 @@
     return intervalNanos;
 }
 
-void ContSubConfigs::refreshMaxSampleRateHz() {
+void ContSubConfigs::refreshCombinedConfig() {
     float maxSampleRateHz = 0.;
+    bool enableVur = true;
     // This is not called frequently so a brute-focre is okay. More efficient way exists but this
     // is simpler.
-    for (const auto& [_, sampleRateHz] : mSampleRateHzByClient) {
-        if (sampleRateHz > maxSampleRateHz) {
-            maxSampleRateHz = sampleRateHz;
+    for (const auto& [_, subConfig] : mConfigByClient) {
+        if (subConfig.sampleRateHz > maxSampleRateHz) {
+            maxSampleRateHz = subConfig.sampleRateHz;
+        }
+        if (!subConfig.enableVur) {
+            // If one client does not enable variable update rate, we cannot enable variable update
+            // rate in IVehicleHardware.
+            enableVur = false;
         }
     }
     mMaxSampleRateHz = maxSampleRateHz;
+    mEnableVur = enableVur;
 }
 
-void ContSubConfigs::addClient(const ClientIdType& clientId, float sampleRateHz) {
-    mSampleRateHzByClient[clientId] = sampleRateHz;
-    refreshMaxSampleRateHz();
+void ContSubConfigs::addClient(const ClientIdType& clientId, float sampleRateHz, bool enableVur) {
+    mConfigByClient[clientId] = {
+            .sampleRateHz = sampleRateHz,
+            .enableVur = enableVur,
+    };
+    refreshCombinedConfig();
 }
 
 void ContSubConfigs::removeClient(const ClientIdType& clientId) {
-    mSampleRateHzByClient.erase(clientId);
-    refreshMaxSampleRateHz();
+    mConfigByClient.erase(clientId);
+    refreshCombinedConfig();
 }
 
 float ContSubConfigs::getMaxSampleRateHz() const {
     return mMaxSampleRateHz;
 }
 
+bool ContSubConfigs::isVurEnabled() const {
+    return mEnableVur;
+}
+
+bool ContSubConfigs::isVurEnabledForClient(const ClientIdType& clientId) {
+    return mConfigByClient[clientId].enableVur;
+}
+
 VhalResult<void> SubscriptionManager::addOnChangeSubscriberLocked(
         const PropIdAreaId& propIdAreaId) {
     if (mClientsByPropIdAreaId.find(propIdAreaId) != mClientsByPropIdAreaId.end()) {
@@ -115,7 +135,7 @@
     int32_t propId = propIdAreaId.propId;
     int32_t areaId = propIdAreaId.areaId;
     if (auto status = mVehicleHardware->subscribe(
-                newSubscribeOptions(propId, areaId, /*updateRateHz=*/0));
+                newSubscribeOptions(propId, areaId, /*updateRateHz=*/0, /*enableVur*/ false));
         status != StatusCode::OK) {
         return StatusError(status)
                << StringPrintf("failed subscribe for prop: %s, areaId: %" PRId32,
@@ -125,10 +145,11 @@
 }
 
 VhalResult<void> SubscriptionManager::addContinuousSubscriberLocked(
-        const ClientIdType& clientId, const PropIdAreaId& propIdAreaId, float sampleRateHz) {
+        const ClientIdType& clientId, const PropIdAreaId& propIdAreaId, float sampleRateHz,
+        bool enableVur) {
     // Make a copy so that we don't modify 'mContSubConfigsByPropIdArea' on failure cases.
     ContSubConfigs newConfig = mContSubConfigsByPropIdArea[propIdAreaId];
-    newConfig.addClient(clientId, sampleRateHz);
+    newConfig.addClient(clientId, sampleRateHz, enableVur);
     return updateContSubConfigsLocked(propIdAreaId, newConfig);
 }
 
@@ -159,24 +180,27 @@
 
 VhalResult<void> SubscriptionManager::updateContSubConfigsLocked(const PropIdAreaId& propIdAreaId,
                                                                  const ContSubConfigs& newConfig) {
-    if (newConfig.getMaxSampleRateHz() ==
-        mContSubConfigsByPropIdArea[propIdAreaId].getMaxSampleRateHz()) {
+    const auto& oldConfig = mContSubConfigsByPropIdArea[propIdAreaId];
+    float newRateHz = newConfig.getMaxSampleRateHz();
+    float oldRateHz = oldConfig.getMaxSampleRateHz();
+    if (newRateHz == oldRateHz && newConfig.isVurEnabled() == oldConfig.isVurEnabled()) {
         mContSubConfigsByPropIdArea[propIdAreaId] = newConfig;
         return {};
     }
-    float newRateHz = newConfig.getMaxSampleRateHz();
     int32_t propId = propIdAreaId.propId;
     int32_t areaId = propIdAreaId.areaId;
-    if (auto status = mVehicleHardware->updateSampleRate(propId, areaId, newRateHz);
-        status != StatusCode::OK) {
-        return StatusError(status)
-               << StringPrintf("failed to update sample rate for prop: %s, areaId: %" PRId32
-                               ", sample rate: %f HZ",
-                               propIdToString(propId).c_str(), areaId, newRateHz);
+    if (newRateHz != oldRateHz) {
+        if (auto status = mVehicleHardware->updateSampleRate(propId, areaId, newRateHz);
+            status != StatusCode::OK) {
+            return StatusError(status)
+                   << StringPrintf("failed to update sample rate for prop: %s, areaId: %" PRId32
+                                   ", sample rate: %f HZ",
+                                   propIdToString(propId).c_str(), areaId, newRateHz);
+        }
     }
     if (newRateHz != 0) {
-        if (auto status =
-                    mVehicleHardware->subscribe(newSubscribeOptions(propId, areaId, newRateHz));
+        if (auto status = mVehicleHardware->subscribe(
+                    newSubscribeOptions(propId, areaId, newRateHz, newConfig.isVurEnabled()));
             status != StatusCode::OK) {
             return StatusError(status) << StringPrintf(
                            "failed subscribe for prop: %s, areaId"
@@ -228,7 +252,8 @@
             };
             VhalResult<void> result;
             if (isContinuousProperty) {
-                result = addContinuousSubscriberLocked(clientId, propIdAreaId, option.sampleRate);
+                result = addContinuousSubscriberLocked(clientId, propIdAreaId, option.sampleRate,
+                                                       option.enableVariableUpdateRate);
             } else {
                 result = addOnChangeSubscriberLocked(propIdAreaId);
             }
@@ -324,6 +349,34 @@
     return {};
 }
 
+bool SubscriptionManager::isValueUpdatedLocked(const std::shared_ptr<IVehicleCallback>& callback,
+                                               const VehiclePropValue& value) {
+    const auto& it = mContSubValuesByCallback[callback].find(value);
+    if (it == mContSubValuesByCallback[callback].end()) {
+        mContSubValuesByCallback[callback].insert(value);
+        return true;
+    }
+
+    if (it->timestamp > value.timestamp) {
+        ALOGE("The updated property value: %s is outdated, ignored", value.toString().c_str());
+        return false;
+    }
+
+    if (it->value == value.value && it->status == value.status) {
+        // Even though the property value is the same, we need to store the new property event to
+        // update the timestamp.
+        mContSubValuesByCallback[callback].insert(value);
+        ALOGD("The updated property value for propId: %" PRId32 ", areaId: %" PRId32
+              " has the "
+              "same value and status, ignored if VUR is enabled",
+              it->prop, it->areaId);
+        return false;
+    }
+
+    mContSubValuesByCallback[callback].insert(value);
+    return true;
+}
+
 std::unordered_map<std::shared_ptr<IVehicleCallback>, std::vector<VehiclePropValue>>
 SubscriptionManager::getSubscribedClients(std::vector<VehiclePropValue>&& updatedValues) {
     std::scoped_lock<std::mutex> lockGuard(mLock);
@@ -338,8 +391,18 @@
             continue;
         }
 
-        for (const auto& [_, client] : mClientsByPropIdAreaId[propIdAreaId]) {
-            clients[client].push_back(value);
+        for (const auto& [client, callback] : mClientsByPropIdAreaId[propIdAreaId]) {
+            auto& subConfigs = mContSubConfigsByPropIdArea[propIdAreaId];
+            // If client wants VUR (and VUR is supported as checked in DefaultVehicleHal), it is
+            // possible that VUR is not enabled in IVehicleHardware because another client does not
+            // enable VUR. We will implement VUR filtering here for the client that enables it.
+            if (subConfigs.isVurEnabledForClient(client) && !subConfigs.isVurEnabled()) {
+                if (isValueUpdatedLocked(callback, value)) {
+                    clients[callback].push_back(value);
+                }
+            } else {
+                clients[callback].push_back(value);
+            }
         }
     }
     return clients;
diff --git a/automotive/vehicle/aidl/impl/vhal/test/DefaultVehicleHalTest.cpp b/automotive/vehicle/aidl/impl/vhal/test/DefaultVehicleHalTest.cpp
index e775612..7195d97 100644
--- a/automotive/vehicle/aidl/impl/vhal/test/DefaultVehicleHalTest.cpp
+++ b/automotive/vehicle/aidl/impl/vhal/test/DefaultVehicleHalTest.cpp
@@ -98,12 +98,22 @@
 constexpr int32_t READ_ONLY_PROP = 10006 + 0x10000000 + 0x01000000 + 0x00400000;
 // VehiclePropertyGroup:SYSTEM,VehicleArea:GLOBAL,VehiclePropertyType:INT32
 constexpr int32_t WRITE_ONLY_PROP = 10007 + 0x10000000 + 0x01000000 + 0x00400000;
+// VehiclePropertyGroup:SYSTEM,VehicleArea:GLOBAL,VehiclePropertyType:INT32
+constexpr int32_t GLOBAL_CONTINUOUS_PROP_NO_VUR = 10008 + 0x10000000 + 0x01000000 + 0x00400000;
 
 int32_t testInt32VecProp(size_t i) {
     // VehiclePropertyGroup:SYSTEM,VehicleArea:GLOBAL,VehiclePropertyType:INT32_VEC
     return static_cast<int32_t>(i) + 0x10000000 + 0x01000000 + 0x00410000;
 }
 
+std::string toString(const std::vector<SubscribeOptions>& options) {
+    std::string optionsStr;
+    for (const auto& option : options) {
+        optionsStr += option.toString() + "\n";
+    }
+    return optionsStr;
+}
+
 struct PropConfigCmp {
     bool operator()(const VehiclePropConfig& a, const VehiclePropConfig& b) const {
         return (a.prop < b.prop);
@@ -245,8 +255,18 @@
                 .changeMode = VehiclePropertyChangeMode::ON_CHANGE,
         });
         // A global continuous property.
+        testConfigs.push_back(VehiclePropConfig{.prop = GLOBAL_CONTINUOUS_PROP,
+                                                .access = VehiclePropertyAccess::READ_WRITE,
+                                                .changeMode = VehiclePropertyChangeMode::CONTINUOUS,
+                                                .minSampleRate = 0.0,
+                                                .maxSampleRate = 100.0,
+                                                .areaConfigs = {{
+                                                        .areaId = 0,
+                                                        .supportVariableUpdateRate = true,
+                                                }}});
+        // A global continuous property that does not support VUR.
         testConfigs.push_back(VehiclePropConfig{
-                .prop = GLOBAL_CONTINUOUS_PROP,
+                .prop = GLOBAL_CONTINUOUS_PROP_NO_VUR,
                 .access = VehiclePropertyAccess::READ_WRITE,
                 .changeMode = VehiclePropertyChangeMode::CONTINUOUS,
                 .minSampleRate = 0.0,
@@ -286,11 +306,13 @@
                                         .areaId = toInt(VehicleAreaWindow::ROW_1_LEFT),
                                         .minInt32Value = 0,
                                         .maxInt32Value = 100,
+                                        .supportVariableUpdateRate = true,
                                 },
                                 {
                                         .areaId = toInt(VehicleAreaWindow::ROW_1_RIGHT),
                                         .minInt32Value = 0,
                                         .maxInt32Value = 100,
+                                        .supportVariableUpdateRate = false,
                                 },
                         },
         });
@@ -1352,6 +1374,62 @@
     EXPECT_EQ(countClients(), static_cast<size_t>(1));
 }
 
+TEST_F(DefaultVehicleHalTest, testSubscribeContinuous_propNotSupportVur) {
+    std::vector<SubscribeOptions> options = {
+            {
+                    .propId = GLOBAL_CONTINUOUS_PROP,
+                    .sampleRate = 20.0,
+                    .enableVariableUpdateRate = true,
+            },
+            {
+                    .propId = GLOBAL_CONTINUOUS_PROP_NO_VUR,
+                    .sampleRate = 30.0,
+                    .enableVariableUpdateRate = true,
+            },
+    };
+
+    auto status = getClient()->subscribe(getCallbackClient(), options, 0);
+
+    ASSERT_TRUE(status.isOk()) << "subscribe failed: " << status.getMessage();
+    auto receivedSubscribeOptions = getHardware()->getSubscribeOptions();
+    ASSERT_THAT(receivedSubscribeOptions, UnorderedElementsAre(
+                                                  SubscribeOptions{
+                                                          .propId = GLOBAL_CONTINUOUS_PROP,
+                                                          .areaIds = {0},
+                                                          .enableVariableUpdateRate = true,
+                                                          .sampleRate = 20.0,
+                                                  },
+                                                  SubscribeOptions{
+                                                          .propId = GLOBAL_CONTINUOUS_PROP_NO_VUR,
+                                                          .areaIds = {0},
+                                                          .enableVariableUpdateRate = false,
+                                                          .sampleRate = 30.0,
+                                                  }))
+            << "received unexpected subscribe options: " << toString(receivedSubscribeOptions);
+}
+
+TEST_F(DefaultVehicleHalTest, testSubscribeContinuous_propSupportVurNotEnabled) {
+    std::vector<SubscribeOptions> options = {
+            {
+                    .propId = GLOBAL_CONTINUOUS_PROP,
+                    .sampleRate = 20.0,
+                    .enableVariableUpdateRate = false,
+            },
+    };
+
+    auto status = getClient()->subscribe(getCallbackClient(), options, 0);
+
+    ASSERT_TRUE(status.isOk()) << "subscribe failed: " << status.getMessage();
+    auto receivedSubscribeOptions = getHardware()->getSubscribeOptions();
+    ASSERT_THAT(receivedSubscribeOptions, UnorderedElementsAre(SubscribeOptions{
+                                                  .propId = GLOBAL_CONTINUOUS_PROP,
+                                                  .areaIds = {0},
+                                                  .enableVariableUpdateRate = false,
+                                                  .sampleRate = 20.0,
+                                          }))
+            << "received unexpected subscribe options: " << toString(receivedSubscribeOptions);
+}
+
 TEST_F(DefaultVehicleHalTest, testSubscribeAreaContinuous) {
     std::vector<SubscribeOptions> options = {
             {
@@ -1404,6 +1482,44 @@
     ASSERT_GE(rightCount, static_cast<size_t>(5));
 }
 
+TEST_F(DefaultVehicleHalTest, testAreaContinuous_areaNotSupportVur) {
+    std::vector<SubscribeOptions> options = {
+            {
+                    .propId = AREA_CONTINUOUS_PROP,
+                    .sampleRate = 20.0,
+                    .areaIds = {toInt(VehicleAreaWindow::ROW_1_LEFT)},
+                    .enableVariableUpdateRate = true,
+            },
+            {
+                    .propId = AREA_CONTINUOUS_PROP,
+                    .sampleRate = 10.0,
+                    .areaIds = {toInt(VehicleAreaWindow::ROW_1_RIGHT)},
+                    .enableVariableUpdateRate = true,
+            },
+    };
+
+    auto status = getClient()->subscribe(getCallbackClient(), options, 0);
+
+    ASSERT_TRUE(status.isOk()) << "subscribe failed: " << status.getMessage();
+    auto receivedSubscribeOptions = getHardware()->getSubscribeOptions();
+    ASSERT_THAT(receivedSubscribeOptions,
+                UnorderedElementsAre(
+                        SubscribeOptions{
+                                .propId = AREA_CONTINUOUS_PROP,
+                                .sampleRate = 20.0,
+                                .areaIds = {toInt(VehicleAreaWindow::ROW_1_LEFT)},
+                                .enableVariableUpdateRate = true,
+                        },
+                        SubscribeOptions{
+                                .propId = AREA_CONTINUOUS_PROP,
+                                .sampleRate = 10.0,
+                                .areaIds = {toInt(VehicleAreaWindow::ROW_1_RIGHT)},
+                                // Area2 actually does not support VUR.
+                                .enableVariableUpdateRate = false,
+                        }))
+            << "received unexpected subscribe options: " << toString(receivedSubscribeOptions);
+}
+
 TEST_F(DefaultVehicleHalTest, testUnsubscribeOnChange) {
     std::vector<SubscribeOptions> options = {
             {
diff --git a/automotive/vehicle/aidl/impl/vhal/test/MockVehicleHardware.cpp b/automotive/vehicle/aidl/impl/vhal/test/MockVehicleHardware.cpp
index b64c0d7..db15c89 100644
--- a/automotive/vehicle/aidl/impl/vhal/test/MockVehicleHardware.cpp
+++ b/automotive/vehicle/aidl/impl/vhal/test/MockVehicleHardware.cpp
@@ -90,6 +90,10 @@
 }
 
 StatusCode MockVehicleHardware::subscribe(SubscribeOptions options) {
+    {
+        std::scoped_lock<std::mutex> lockGuard(mLock);
+        mSubscribeOptions.push_back(options);
+    }
     for (int32_t areaId : options.areaIds) {
         if (auto status = subscribePropIdAreaId(options.propId, areaId, options.sampleRate);
             status != StatusCode::OK) {
@@ -99,6 +103,16 @@
     return StatusCode::OK;
 }
 
+std::vector<SubscribeOptions> MockVehicleHardware::getSubscribeOptions() {
+    std::scoped_lock<std::mutex> lockGuard(mLock);
+    return mSubscribeOptions;
+}
+
+void MockVehicleHardware::clearSubscribeOptions() {
+    std::scoped_lock<std::mutex> lockGuard(mLock);
+    mSubscribeOptions.clear();
+}
+
 StatusCode MockVehicleHardware::subscribePropIdAreaId(int32_t propId, int32_t areaId,
                                                       float sampleRateHz) {
     if (sampleRateHz == 0) {
diff --git a/automotive/vehicle/aidl/impl/vhal/test/MockVehicleHardware.h b/automotive/vehicle/aidl/impl/vhal/test/MockVehicleHardware.h
index e0d2d66..eeca582 100644
--- a/automotive/vehicle/aidl/impl/vhal/test/MockVehicleHardware.h
+++ b/automotive/vehicle/aidl/impl/vhal/test/MockVehicleHardware.h
@@ -95,6 +95,9 @@
 
     std::set<std::pair<int32_t, int32_t>> getSubscribedOnChangePropIdAreaIds();
     std::set<std::pair<int32_t, int32_t>> getSubscribedContinuousPropIdAreaIds();
+    std::vector<aidl::android::hardware::automotive::vehicle::SubscribeOptions>
+    getSubscribeOptions();
+    void clearSubscribeOptions();
 
   private:
     mutable std::mutex mLock;
@@ -121,6 +124,8 @@
             mGetValueResponder GUARDED_BY(mLock);
     std::chrono::nanoseconds mEventBatchingWindow GUARDED_BY(mLock) = std::chrono::nanoseconds(0);
     std::set<std::pair<int32_t, int32_t>> mSubOnChangePropIdAreaIds GUARDED_BY(mLock);
+    std::vector<aidl::android::hardware::automotive::vehicle::SubscribeOptions> mSubscribeOptions
+            GUARDED_BY(mLock);
 
     template <class ResultType>
     aidl::android::hardware::automotive::vehicle::StatusCode returnResponse(
diff --git a/automotive/vehicle/aidl/impl/vhal/test/SubscriptionManagerTest.cpp b/automotive/vehicle/aidl/impl/vhal/test/SubscriptionManagerTest.cpp
index 049ca8b..aa5f003 100644
--- a/automotive/vehicle/aidl/impl/vhal/test/SubscriptionManagerTest.cpp
+++ b/automotive/vehicle/aidl/impl/vhal/test/SubscriptionManagerTest.cpp
@@ -43,10 +43,12 @@
 using ::aidl::android::hardware::automotive::vehicle::SetValueResults;
 using ::aidl::android::hardware::automotive::vehicle::SubscribeOptions;
 using ::aidl::android::hardware::automotive::vehicle::VehiclePropErrors;
+using ::aidl::android::hardware::automotive::vehicle::VehiclePropertyStatus;
 using ::aidl::android::hardware::automotive::vehicle::VehiclePropValue;
 using ::aidl::android::hardware::automotive::vehicle::VehiclePropValues;
 using ::ndk::ScopedAStatus;
 using ::ndk::SpAIBinder;
+using ::testing::Contains;
 using ::testing::ElementsAre;
 using ::testing::UnorderedElementsAre;
 
@@ -518,6 +520,257 @@
     ASSERT_FALSE(SubscriptionManager::checkSampleRateHz(0));
 }
 
+TEST_F(SubscriptionManagerTest, testSubscribe_enableVur) {
+    std::vector<SubscribeOptions> options = {{
+            .propId = 0,
+            .areaIds = {0},
+            .sampleRate = 10.0,
+            .enableVariableUpdateRate = true,
+    }};
+
+    auto result = getManager()->subscribe(getCallbackClient(), options, true);
+    ASSERT_TRUE(result.ok()) << "failed to subscribe: " << result.error().message();
+
+    ASSERT_THAT(getHardware()->getSubscribeOptions(), ElementsAre(options[0]));
+}
+
+TEST_F(SubscriptionManagerTest, testSubscribe_VurStateChange) {
+    std::vector<SubscribeOptions> options = {{
+            .propId = 0,
+            .areaIds = {0},
+            .sampleRate = 10.0,
+            .enableVariableUpdateRate = true,
+    }};
+
+    auto result = getManager()->subscribe(getCallbackClient(), options, true);
+    ASSERT_TRUE(result.ok()) << "failed to subscribe: " << result.error().message();
+
+    ASSERT_THAT(getHardware()->getSubscribeOptions(), ElementsAre(options[0]));
+
+    getHardware()->clearSubscribeOptions();
+    result = getManager()->subscribe(getCallbackClient(), options, true);
+    ASSERT_TRUE(result.ok()) << "failed to subscribe: " << result.error().message();
+
+    ASSERT_TRUE(getHardware()->getSubscribeOptions().empty());
+
+    std::vector<SubscribeOptions> newOptions = {{
+            .propId = 0,
+            .areaIds = {0},
+            .sampleRate = 10.0,
+            .enableVariableUpdateRate = false,
+    }};
+    result = getManager()->subscribe(getCallbackClient(), newOptions, true);
+    ASSERT_TRUE(result.ok()) << "failed to subscribe: " << result.error().message();
+
+    ASSERT_THAT(getHardware()->getSubscribeOptions(), ElementsAre(newOptions[0]));
+}
+
+TEST_F(SubscriptionManagerTest, testSubscribe_enableVur_filterUnchangedEvents) {
+    SpAIBinder binder1 = ndk::SharedRefBase::make<PropertyCallback>()->asBinder();
+    std::shared_ptr<IVehicleCallback> client1 = IVehicleCallback::fromBinder(binder1);
+    SpAIBinder binder2 = ndk::SharedRefBase::make<PropertyCallback>()->asBinder();
+    std::shared_ptr<IVehicleCallback> client2 = IVehicleCallback::fromBinder(binder2);
+    SubscribeOptions client1Option = {
+            .propId = 0,
+            .areaIds = {0},
+            .sampleRate = 10.0,
+            .enableVariableUpdateRate = false,
+    };
+    auto result = getManager()->subscribe(client1, {client1Option}, true);
+    ASSERT_TRUE(result.ok()) << "failed to subscribe: " << result.error().message();
+
+    ASSERT_THAT(getHardware()->getSubscribeOptions(), UnorderedElementsAre(client1Option));
+
+    getHardware()->clearSubscribeOptions();
+    SubscribeOptions client2Option = {
+            .propId = 0,
+            .areaIds = {0, 1},
+            .sampleRate = 20.0,
+            .enableVariableUpdateRate = true,
+    };
+
+    result = getManager()->subscribe(client2, {client2Option}, true);
+    ASSERT_TRUE(result.ok()) << "failed to subscribe: " << result.error().message();
+
+    ASSERT_THAT(getHardware()->getSubscribeOptions(),
+                UnorderedElementsAre(
+                        SubscribeOptions{
+                                .propId = 0,
+                                .areaIds = {0},
+                                .sampleRate = 20.0,
+                                // This is enabled for client2, but disabled for client1.
+                                .enableVariableUpdateRate = false,
+                        },
+                        SubscribeOptions{
+                                .propId = 0,
+                                .areaIds = {1},
+                                .sampleRate = 20.0,
+                                .enableVariableUpdateRate = true,
+                        }));
+
+    std::vector<VehiclePropValue> propertyEvents = {{
+                                                            .prop = 0,
+                                                            .areaId = 0,
+                                                            .value = {.int32Values = {0}},
+                                                            .timestamp = 1,
+                                                    },
+                                                    {
+                                                            .prop = 0,
+                                                            .areaId = 1,
+                                                            .value = {.int32Values = {1}},
+                                                            .timestamp = 1,
+                                                    }};
+    auto clients =
+            getManager()->getSubscribedClients(std::vector<VehiclePropValue>(propertyEvents));
+
+    ASSERT_THAT(clients[client1], UnorderedElementsAre(propertyEvents[0]));
+    ASSERT_THAT(clients[client2], UnorderedElementsAre(propertyEvents[0], propertyEvents[1]));
+
+    // If the same property events happen again with a new timestamp.
+    // VUR is disabled for client1, enabled for client2.
+    clients = getManager()->getSubscribedClients({{
+            .prop = 0,
+            .areaId = 0,
+            .value = {.int32Values = {0}},
+            .timestamp = 2,
+    }});
+
+    ASSERT_FALSE(clients.find(client1) == clients.end())
+            << "Must not filter out property events if VUR is not enabled";
+    ASSERT_TRUE(clients.find(client2) == clients.end())
+            << "Must filter out property events if VUR is enabled";
+}
+
+TEST_F(SubscriptionManagerTest, testSubscribe_enableVur_mustNotFilterStatusChange) {
+    SpAIBinder binder1 = ndk::SharedRefBase::make<PropertyCallback>()->asBinder();
+    std::shared_ptr<IVehicleCallback> client1 = IVehicleCallback::fromBinder(binder1);
+    SpAIBinder binder2 = ndk::SharedRefBase::make<PropertyCallback>()->asBinder();
+    std::shared_ptr<IVehicleCallback> client2 = IVehicleCallback::fromBinder(binder2);
+    SubscribeOptions client1Option = {
+            .propId = 0,
+            .areaIds = {0},
+            .sampleRate = 10.0,
+            .enableVariableUpdateRate = false,
+    };
+    auto result = getManager()->subscribe(client1, {client1Option}, true);
+    ASSERT_TRUE(result.ok()) << "failed to subscribe: " << result.error().message();
+
+    ASSERT_THAT(getHardware()->getSubscribeOptions(), UnorderedElementsAre(client1Option));
+
+    getHardware()->clearSubscribeOptions();
+    SubscribeOptions client2Option = {
+            .propId = 0,
+            .areaIds = {0, 1},
+            .sampleRate = 20.0,
+            .enableVariableUpdateRate = true,
+    };
+
+    result = getManager()->subscribe(client2, {client2Option}, true);
+    ASSERT_TRUE(result.ok()) << "failed to subscribe: " << result.error().message();
+
+    ASSERT_THAT(getHardware()->getSubscribeOptions(),
+                UnorderedElementsAre(
+                        SubscribeOptions{
+                                .propId = 0,
+                                .areaIds = {0},
+                                .sampleRate = 20.0,
+                                // This is enabled for client2, but disabled for client1.
+                                .enableVariableUpdateRate = false,
+                        },
+                        SubscribeOptions{
+                                .propId = 0,
+                                .areaIds = {1},
+                                .sampleRate = 20.0,
+                                .enableVariableUpdateRate = true,
+                        }));
+
+    VehiclePropValue propValue1 = {
+            .prop = 0,
+            .areaId = 0,
+            .value = {.int32Values = {0}},
+            .timestamp = 1,
+    };
+    auto clients = getManager()->getSubscribedClients(std::vector<VehiclePropValue>({propValue1}));
+
+    ASSERT_THAT(clients[client1], UnorderedElementsAre(propValue1));
+
+    // A new event with the same value, but different status must not be filtered out.
+    VehiclePropValue propValue2 = {
+            .prop = 0,
+            .areaId = 0,
+            .value = {.int32Values = {0}},
+            .status = VehiclePropertyStatus::UNAVAILABLE,
+            .timestamp = 2,
+    };
+    clients = getManager()->getSubscribedClients({propValue2});
+
+    ASSERT_THAT(clients[client1], UnorderedElementsAre(propValue2))
+            << "Must not filter out property events that has status change";
+}
+
+TEST_F(SubscriptionManagerTest, testSubscribe_enableVur_timestampUpdated_filterOutdatedEvent) {
+    SpAIBinder binder1 = ndk::SharedRefBase::make<PropertyCallback>()->asBinder();
+    std::shared_ptr<IVehicleCallback> client1 = IVehicleCallback::fromBinder(binder1);
+    SpAIBinder binder2 = ndk::SharedRefBase::make<PropertyCallback>()->asBinder();
+    std::shared_ptr<IVehicleCallback> client2 = IVehicleCallback::fromBinder(binder2);
+    std::vector<SubscribeOptions> options = {{
+            .propId = 0,
+            .areaIds = {0},
+            .sampleRate = 10.0,
+            .enableVariableUpdateRate = true,
+    }};
+
+    // client1 subscribe with VUR enabled.
+    auto result = getManager()->subscribe(client1, options, true);
+    ASSERT_TRUE(result.ok()) << "failed to subscribe: " << result.error().message();
+
+    // Let client2 subscribe with VUR disabled so that we enabled VUR in DefaultVehicleHal layer.
+    result = getManager()->subscribe(client2,
+                                     {{
+                                             .propId = 0,
+                                             .areaIds = {0},
+                                             .sampleRate = 10.0,
+                                             .enableVariableUpdateRate = false,
+                                     }},
+                                     true);
+    ASSERT_TRUE(result.ok()) << "failed to subscribe: " << result.error().message();
+
+    VehiclePropValue value0 = {
+            .prop = 0,
+            .areaId = 0,
+            .value = {.int32Values = {0}},
+            .timestamp = 1,
+    };
+    auto clients = getManager()->getSubscribedClients({value0});
+
+    ASSERT_THAT(clients[client1], UnorderedElementsAre(value0));
+
+    // A new event with the same value arrived. This must update timestamp to 3.
+    VehiclePropValue value1 = {
+            .prop = 0,
+            .areaId = 0,
+            .value = {.int32Values = {0}},
+            .timestamp = 3,
+    };
+    clients = getManager()->getSubscribedClients({value1});
+
+    ASSERT_TRUE(clients.find(client1) == clients.end())
+            << "Must filter out duplicate property events if VUR is enabled";
+
+    // The latest timestamp is 3, so even though the value is not the same, this is outdated and
+    // must be ignored.
+    VehiclePropValue value2 = {
+            .prop = 0,
+            .areaId = 0,
+            .value = {.int32Values = {1}},
+            .timestamp = 2,
+    };
+    clients = getManager()->getSubscribedClients({value1});
+
+    ASSERT_TRUE(clients.find(client1) == clients.end())
+            << "Must filter out outdated property events if VUR is enabled";
+}
+
 }  // namespace vehicle
 }  // namespace automotive
 }  // namespace hardware