Merge "Add support for calculation window size and tids" into main

10 files changed, 388 insertions, 216 deletions

diff --git a/core/api/current.txt b/core/api/current.txt
index 3af8e7e17dbd..55e1aeccd0fd 100644
--- a/core/api/current.txt
+++ b/core/api/current.txt
@@ -33612,9 +33612,14 @@ package android.os {
   @FlaggedApi("android.os.cpu_gpu_headrooms") public final class CpuHeadroomParams {
     ctor public CpuHeadroomParams();
     method public int getCalculationType();
+    method @IntRange(from=android.os.CpuHeadroomParams.CPU_HEADROOM_CALCULATION_WINDOW_MILLIS_MIN, to=android.os.CpuHeadroomParams.CPU_HEADROOM_CALCULATION_WINDOW_MILLIS_MAX) public long getCalculationWindowMillis();
     method public void setCalculationType(int);
+    method public void setCalculationWindowMillis(@IntRange(from=android.os.CpuHeadroomParams.CPU_HEADROOM_CALCULATION_WINDOW_MILLIS_MIN, to=android.os.CpuHeadroomParams.CPU_HEADROOM_CALCULATION_WINDOW_MILLIS_MAX) int);
+    method public void setTids(@NonNull int...);
     field public static final int CPU_HEADROOM_CALCULATION_TYPE_AVERAGE = 1; // 0x1
     field public static final int CPU_HEADROOM_CALCULATION_TYPE_MIN = 0; // 0x0
+    field public static final int CPU_HEADROOM_CALCULATION_WINDOW_MILLIS_MAX = 10000; // 0x2710
+    field public static final int CPU_HEADROOM_CALCULATION_WINDOW_MILLIS_MIN = 50; // 0x32
   }
 
   public final class CpuUsageInfo implements android.os.Parcelable {
@@ -33867,9 +33872,13 @@ package android.os {
   @FlaggedApi("android.os.cpu_gpu_headrooms") public final class GpuHeadroomParams {
     ctor public GpuHeadroomParams();
     method public int getCalculationType();
+    method @IntRange(from=android.os.GpuHeadroomParams.GPU_HEADROOM_CALCULATION_WINDOW_MILLIS_MIN, to=android.os.GpuHeadroomParams.GPU_HEADROOM_CALCULATION_WINDOW_MILLIS_MAX) public int getCalculationWindowMillis();
     method public void setCalculationType(int);
+    method public void setCalculationWindowMillis(@IntRange(from=android.os.GpuHeadroomParams.GPU_HEADROOM_CALCULATION_WINDOW_MILLIS_MIN, to=android.os.GpuHeadroomParams.GPU_HEADROOM_CALCULATION_WINDOW_MILLIS_MAX) int);
     field public static final int GPU_HEADROOM_CALCULATION_TYPE_AVERAGE = 1; // 0x1
     field public static final int GPU_HEADROOM_CALCULATION_TYPE_MIN = 0; // 0x0
+    field public static final int GPU_HEADROOM_CALCULATION_WINDOW_MILLIS_MAX = 10000; // 0x2710
+    field public static final int GPU_HEADROOM_CALCULATION_WINDOW_MILLIS_MIN = 50; // 0x32
   }
 
   public class Handler {
diff --git a/core/java/android/os/CpuHeadroomParams.java b/core/java/android/os/CpuHeadroomParams.java
index f0d4f7d8737f..8e78b7e355f9 100644
--- a/core/java/android/os/CpuHeadroomParams.java
+++ b/core/java/android/os/CpuHeadroomParams.java
@@ -18,10 +18,13 @@ package android.os;
 
 import android.annotation.FlaggedApi;
 import android.annotation.IntDef;
+import android.annotation.IntRange;
+import android.annotation.NonNull;
 import android.os.health.SystemHealthManager;
 
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
+import java.util.Arrays;
 
 /**
  * Headroom request params used by {@link SystemHealthManager#getCpuHeadroom(CpuHeadroomParams)}.
@@ -54,6 +57,16 @@ public final class CpuHeadroomParams {
     public static final int CPU_HEADROOM_CALCULATION_TYPE_AVERAGE = 1;
 
     /**
+     * Minimum CPU headroom calculation window size.
+     */
+    public static final int CPU_HEADROOM_CALCULATION_WINDOW_MILLIS_MIN = 50;
+
+    /**
+     * Maximum CPU headroom calculation window size.
+     */
+    public static final int CPU_HEADROOM_CALCULATION_WINDOW_MILLIS_MAX = 10000;
+
+    /**
      * Sets the headroom calculation type.
      * <p>
      *
@@ -83,6 +96,63 @@ public final class CpuHeadroomParams {
     }
 
     /**
+     * Sets the headroom calculation window size in milliseconds.
+     * <p>
+     *
+     * @param windowMillis the window size in milliseconds, ranged from
+     *                     [{@link #CPU_HEADROOM_CALCULATION_WINDOW_MILLIS_MIN},
+     *                     {@link #CPU_HEADROOM_CALCULATION_WINDOW_MILLIS_MAX}]. The smaller
+     *                     the value, the larger fluctuation in value should be expected. The
+     *                     default value can be retrieved from the
+     *                     {@link #getCalculationWindowMillis}. The device will try to use the
+     *                     closest feasible window size to this param.
+     * @throws IllegalArgumentException if the window size is not in allowed range.
+     */
+    public void setCalculationWindowMillis(
+            @IntRange(from = CPU_HEADROOM_CALCULATION_WINDOW_MILLIS_MIN, to =
+                    CPU_HEADROOM_CALCULATION_WINDOW_MILLIS_MAX) int windowMillis) {
+        if (windowMillis < CPU_HEADROOM_CALCULATION_WINDOW_MILLIS_MIN
+                || windowMillis > CPU_HEADROOM_CALCULATION_WINDOW_MILLIS_MAX) {
+            throw new IllegalArgumentException("Invalid calculation window: " + windowMillis);
+        }
+        mInternal.calculationWindowMillis = windowMillis;
+    }
+
+    /**
+     * Gets the headroom calculation window size in milliseconds.
+     * <p>
+     * This will return the default value chosen by the device if not set.
+     */
+    public @IntRange(from = CPU_HEADROOM_CALCULATION_WINDOW_MILLIS_MIN, to =
+            CPU_HEADROOM_CALCULATION_WINDOW_MILLIS_MAX) long getCalculationWindowMillis() {
+        return mInternal.calculationWindowMillis;
+    }
+
+    /**
+     * Sets the thread TIDs to track.
+     * <p>
+     * The TIDs should belong to the same of the process that will the headroom call. And they
+     * should not have different core affinity.
+     * <p>
+     * If not set, the headroom will be based on the PID of the process making the call.
+     *
+     * @param tids non-empty list of TIDs, maximum 5.
+     * @throws IllegalArgumentException if the list size is not in allowed range or TID is not
+     *                                  positive.
+     */
+    public void setTids(@NonNull int... tids) {
+        if (tids.length == 0 || tids.length > 5) {
+            throw new IllegalArgumentException("Invalid number of TIDs: " + tids.length);
+        }
+        for (int tid : tids) {
+            if (tid <= 0) {
+                throw new IllegalArgumentException("Invalid TID: " + tid);
+            }
+        }
+        mInternal.tids = Arrays.copyOf(tids, tids.length);
+    }
+
+    /**
      * @hide
      */
     public CpuHeadroomParamsInternal getInternal() {
diff --git a/core/java/android/os/CpuHeadroomParamsInternal.aidl b/core/java/android/os/CpuHeadroomParamsInternal.aidl
index 6cc4699a809e..d572f965579b 100644
--- a/core/java/android/os/CpuHeadroomParamsInternal.aidl
+++ b/core/java/android/os/CpuHeadroomParamsInternal.aidl
@@ -25,6 +25,8 @@ import android.hardware.power.CpuHeadroomParams;
 @JavaDerive(equals = true, toString = true)
 parcelable CpuHeadroomParamsInternal {
     boolean usesDeviceHeadroom = false;
+    int[] tids;
+    int calculationWindowMillis = 1000;
     CpuHeadroomParams.CalculationType calculationType = CpuHeadroomParams.CalculationType.MIN;
     CpuHeadroomParams.SelectionType selectionType = CpuHeadroomParams.SelectionType.ALL;
 }
diff --git a/core/java/android/os/GpuHeadroomParams.java b/core/java/android/os/GpuHeadroomParams.java
index efb2a28ad2b5..4dc98264e57b 100644
--- a/core/java/android/os/GpuHeadroomParams.java
+++ b/core/java/android/os/GpuHeadroomParams.java
@@ -18,6 +18,7 @@ package android.os;
 
 import android.annotation.FlaggedApi;
 import android.annotation.IntDef;
+import android.annotation.IntRange;
 import android.os.health.SystemHealthManager;
 
 import java.lang.annotation.Retention;
@@ -54,6 +55,16 @@ public final class GpuHeadroomParams {
     public static final int GPU_HEADROOM_CALCULATION_TYPE_AVERAGE = 1;
 
     /**
+     * Minimum GPU headroom calculation window size.
+     */
+    public static final int GPU_HEADROOM_CALCULATION_WINDOW_MILLIS_MIN = 50;
+
+    /**
+     * Maximum GPU headroom calculation window size.
+     */
+    public static final int GPU_HEADROOM_CALCULATION_WINDOW_MILLIS_MAX = 10000;
+
+    /**
      * Sets the headroom calculation type.
      * <p>
      *
@@ -83,6 +94,39 @@ public final class GpuHeadroomParams {
     }
 
     /**
+     * Sets the headroom calculation window size in milliseconds.
+     * <p>
+     *
+     * @param windowMillis the window size in milliseconds, ranged from
+     *                     [{@link #GPU_HEADROOM_CALCULATION_WINDOW_MILLIS_MIN},
+     *                     {@link #GPU_HEADROOM_CALCULATION_WINDOW_MILLIS_MAX}]. The smaller
+     *                     the value, the larger fluctuation in value should be expected. The
+     *                     default value can be retrieved from the
+     *                     {@link #getCalculationWindowMillis}. If the device will try to use the
+     *                     closest feasible window size to this param.
+     * @throws IllegalArgumentException if the window is invalid.
+     */
+    public void setCalculationWindowMillis(
+            @IntRange(from = GPU_HEADROOM_CALCULATION_WINDOW_MILLIS_MIN, to =
+                    GPU_HEADROOM_CALCULATION_WINDOW_MILLIS_MAX) int windowMillis) {
+        if (windowMillis < GPU_HEADROOM_CALCULATION_WINDOW_MILLIS_MIN
+                || windowMillis > GPU_HEADROOM_CALCULATION_WINDOW_MILLIS_MAX) {
+            throw new IllegalArgumentException("Invalid calculation window: " + windowMillis);
+        }
+        mInternal.calculationWindowMillis = windowMillis;
+    }
+
+    /**
+     * Gets the headroom calculation window size in milliseconds.
+     * <p>
+     * This will return the default value chosen by the device if not set.
+     */
+    public @IntRange(from = GPU_HEADROOM_CALCULATION_WINDOW_MILLIS_MIN, to =
+            GPU_HEADROOM_CALCULATION_WINDOW_MILLIS_MAX) int getCalculationWindowMillis() {
+        return mInternal.calculationWindowMillis;
+    }
+
+    /**
      * @hide
      */
     public GpuHeadroomParamsInternal getInternal() {
diff --git a/core/java/android/os/GpuHeadroomParamsInternal.aidl b/core/java/android/os/GpuHeadroomParamsInternal.aidl
index 20309e7673f2..40d5d8e409ef 100644
--- a/core/java/android/os/GpuHeadroomParamsInternal.aidl
+++ b/core/java/android/os/GpuHeadroomParamsInternal.aidl
@@ -24,5 +24,6 @@ import android.hardware.power.GpuHeadroomParams;
  */
 @JavaDerive(equals = true, toString = true)
 parcelable GpuHeadroomParamsInternal {
+    int calculationWindowMillis = 1000;
     GpuHeadroomParams.CalculationType calculationType = GpuHeadroomParams.CalculationType.MIN;
 }
diff --git a/core/java/android/os/IHintManager.aidl b/core/java/android/os/IHintManager.aidl
index a043da9b7a36..f1936b5e0ff9 100644
--- a/core/java/android/os/IHintManager.aidl
+++ b/core/java/android/os/IHintManager.aidl
@@ -21,7 +21,9 @@ import android.os.CpuHeadroomParamsInternal;
 import android.os.GpuHeadroomParamsInternal;
 import android.os.IHintSession;
 import android.os.SessionCreationConfig;
+import android.hardware.power.CpuHeadroomResult;
 import android.hardware.power.ChannelConfig;
+import android.hardware.power.GpuHeadroomResult;
 import android.hardware.power.SessionConfig;
 import android.hardware.power.SessionTag;
 
@@ -53,9 +55,9 @@ interface IHintManager {
      */
     @nullable ChannelConfig getSessionChannel(in IBinder token);
     oneway void closeSessionChannel();
-    float[] getCpuHeadroom(in CpuHeadroomParamsInternal params);
+    @nullable CpuHeadroomResult getCpuHeadroom(in CpuHeadroomParamsInternal params);
     long getCpuHeadroomMinIntervalMillis();
-    float getGpuHeadroom(in GpuHeadroomParamsInternal params);
+    @nullable GpuHeadroomResult getGpuHeadroom(in GpuHeadroomParamsInternal params);
     long getGpuHeadroomMinIntervalMillis();
 
     /**
diff --git a/core/java/android/os/health/SystemHealthManager.java b/core/java/android/os/health/SystemHealthManager.java
index 4db9bc333e2b..cd79e416531a 100644
--- a/core/java/android/os/health/SystemHealthManager.java
+++ b/core/java/android/os/health/SystemHealthManager.java
@@ -23,6 +23,8 @@ import android.annotation.Nullable;
 import android.annotation.SystemService;
 import android.compat.annotation.UnsupportedAppUsage;
 import android.content.Context;
+import android.hardware.power.CpuHeadroomResult;
+import android.hardware.power.GpuHeadroomResult;
 import android.os.BatteryStats;
 import android.os.Build;
 import android.os.Bundle;
@@ -110,15 +112,16 @@ public class SystemHealthManager {
     }
 
     /**
-     * Provides an estimate of global available CPU headroom of the calling thread.
+     * Provides an estimate of global available CPU headroom.
      * <p>
      *
      * @param  params params to customize the CPU headroom calculation, null to use default params.
-     * @return a single value a {@code Float.NaN} if it's temporarily unavailable.
+     * @return a single value headroom or a {@code Float.NaN} if it's temporarily unavailable.
      *         A valid value is ranged from [0, 100], where 0 indicates no more CPU resources can be
      *         granted.
-     * @throws UnsupportedOperationException if the API is unsupported or the request params can't
-     *         be served.
+     * @throws UnsupportedOperationException if the API is unsupported.
+     * @throws SecurityException if the TIDs of the params don't belong to the same process.
+     * @throws IllegalStateException if the TIDs of the params don't have the same affinity setting.
      */
     @FlaggedApi(android.os.Flags.FLAG_CPU_GPU_HEADROOMS)
     public @FloatRange(from = 0f, to = 100f) float getCpuHeadroom(
@@ -127,8 +130,12 @@ public class SystemHealthManager {
             throw new UnsupportedOperationException();
         }
         try {
-            return mHintManager.getCpuHeadroom(
-                    params != null ? params.getInternal() : new CpuHeadroomParamsInternal())[0];
+            final CpuHeadroomResult ret = mHintManager.getCpuHeadroom(
+                    params != null ? params.getInternal() : new CpuHeadroomParamsInternal());
+            if (ret == null || ret.getTag() != CpuHeadroomResult.globalHeadroom) {
+                return Float.NaN;
+            }
+            return ret.getGlobalHeadroom();
         } catch (RemoteException re) {
             throw re.rethrowFromSystemServer();
         }
@@ -144,8 +151,7 @@ public class SystemHealthManager {
      * @return a single value headroom or a {@code Float.NaN} if it's temporarily unavailable.
      *         A valid value is ranged from [0, 100], where 0 indicates no more GPU resources can be
      *         granted.
-     * @throws UnsupportedOperationException if the API is unsupported or the request params can't
-     *         be served.
+     * @throws UnsupportedOperationException if the API is unsupported.
      */
     @FlaggedApi(android.os.Flags.FLAG_CPU_GPU_HEADROOMS)
     public @FloatRange(from = 0f, to = 100f) float getGpuHeadroom(
@@ -154,8 +160,12 @@ public class SystemHealthManager {
             throw new UnsupportedOperationException();
         }
         try {
-            return mHintManager.getGpuHeadroom(
+            final GpuHeadroomResult ret = mHintManager.getGpuHeadroom(
                     params != null ? params.getInternal() : new GpuHeadroomParamsInternal());
+            if (ret == null || ret.getTag() != GpuHeadroomResult.globalHeadroom) {
+                return Float.NaN;
+            }
+            return ret.getGlobalHeadroom();
         } catch (RemoteException re) {
             throw re.rethrowFromSystemServer();
         }
diff --git a/native/android/tests/performance_hint/PerformanceHintNativeTest.cpp b/native/android/tests/performance_hint/PerformanceHintNativeTest.cpp
index c5fb80840b84..b00658052bde 100644
--- a/native/android/tests/performance_hint/PerformanceHintNativeTest.cpp
+++ b/native/android/tests/performance_hint/PerformanceHintNativeTest.cpp
@@ -73,13 +73,13 @@ public:
     MOCK_METHOD(ScopedAStatus, closeSessionChannel, (), (override));
     MOCK_METHOD(ScopedAStatus, getCpuHeadroom,
                 (const ::aidl::android::os::CpuHeadroomParamsInternal& in_params,
-                 std::vector<float>* _aidl_return),
+                 std::optional<hal::CpuHeadroomResult>* _aidl_return),
                 (override));
     MOCK_METHOD(ScopedAStatus, getCpuHeadroomMinIntervalMillis, (int64_t* _aidl_return),
                 (override));
     MOCK_METHOD(ScopedAStatus, getGpuHeadroom,
                 (const ::aidl::android::os::GpuHeadroomParamsInternal& in_params,
-                 float* _aidl_return),
+                 std::optional<hal::GpuHeadroomResult>* _aidl_return),
                 (override));
     MOCK_METHOD(ScopedAStatus, getGpuHeadroomMinIntervalMillis, (int64_t* _aidl_return),
                 (override));
diff --git a/services/core/java/com/android/server/power/hint/HintManagerService.java b/services/core/java/com/android/server/power/hint/HintManagerService.java
index 71f67d82dbec..aba15c83f907 100644
--- a/services/core/java/com/android/server/power/hint/HintManagerService.java
+++ b/services/core/java/com/android/server/power/hint/HintManagerService.java
@@ -34,7 +34,9 @@ import android.content.pm.ApplicationInfo;
 import android.content.pm.PackageManager;
 import android.hardware.power.ChannelConfig;
 import android.hardware.power.CpuHeadroomParams;
+import android.hardware.power.CpuHeadroomResult;
 import android.hardware.power.GpuHeadroomParams;
+import android.hardware.power.GpuHeadroomResult;
 import android.hardware.power.IPower;
 import android.hardware.power.SessionConfig;
 import android.hardware.power.SessionTag;
@@ -79,6 +81,7 @@ import java.io.PrintWriter;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashMap;
+import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import java.util.NoSuchElementException;
@@ -96,10 +99,10 @@ public final class HintManagerService extends SystemService {
 
     private static final int EVENT_CLEAN_UP_UID = 3;
     @VisibleForTesting  static final int CLEAN_UP_UID_DELAY_MILLIS = 1000;
+    // The minimum interval between the headroom calls as rate limiting.
     private static final int DEFAULT_GPU_HEADROOM_INTERVAL_MILLIS = 1000;
     private static final int DEFAULT_CPU_HEADROOM_INTERVAL_MILLIS = 1000;
     private static final int HEADROOM_INTERVAL_UNSUPPORTED = -1;
-    @VisibleForTesting static final int DEFAULT_HEADROOM_PID = -1;
 
 
     @VisibleForTesting final long mHintSessionPreferredRate;
@@ -184,73 +187,77 @@ public final class HintManagerService extends SystemService {
     private static final String PROPERTY_SF_ENABLE_CPU_HINT = "debug.sf.enable_adpf_cpu_hint";
     private static final String PROPERTY_HWUI_ENABLE_HINT_MANAGER = "debug.hwui.use_hint_manager";
     private static final String PROPERTY_USE_HAL_HEADROOMS = "persist.hms.use_hal_headrooms";
+    private static final String PROPERTY_CHECK_HEADROOM_TID = "persist.hms.check_headroom_tid";
 
     private Boolean mFMQUsesIntegratedEventFlag = false;
 
     private final Object mCpuHeadroomLock = new Object();
 
-    private static class CpuHeadroomCacheItem {
-        long mExpiredTimeMillis;
-        CpuHeadroomParamsInternal mParams;
-        float[] mHeadroom;
-        long mPid;
 
-        CpuHeadroomCacheItem(long expiredTimeMillis, CpuHeadroomParamsInternal params,
-                float[] headroom, long pid) {
-            mExpiredTimeMillis = expiredTimeMillis;
-            mParams = params;
-            mPid = pid;
-            mHeadroom = headroom;
-        }
+    // this cache tracks the expiration time of the items and performs cleanup on lookup
+    private static class HeadroomCache<K, V> {
+        final List<HeadroomCacheItem> mItemList;
+        final Map<K, HeadroomCacheItem> mKeyItemMap;
+        final long mItemExpDurationMillis;
+
+        class HeadroomCacheItem {
+            long mExpTime;
+            K mKey;
+            V mValue;
 
-        private boolean match(CpuHeadroomParamsInternal params, long pid) {
-            if (mParams == null && params == null) return true;
-            if (mParams != null) {
-                return mParams.equals(params) && pid == mPid;
+            HeadroomCacheItem(K k, V v) {
+                mExpTime = System.currentTimeMillis() + mItemExpDurationMillis;
+                mKey = k;
+                mValue = v;
             }
-            return false;
-        }
 
-        private boolean isExpired() {
-            return System.currentTimeMillis() > mExpiredTimeMillis;
+            boolean isExpired() {
+                return mExpTime <= System.currentTimeMillis();
+            }
         }
-    }
-
-    @GuardedBy("mCpuHeadroomLock")
-    private final List<CpuHeadroomCacheItem> mCpuHeadroomCache;
-    private final long mCpuHeadroomIntervalMillis;
-
-    private final Object mGpuHeadroomLock = new Object();
 
-    private static class GpuHeadroomCacheItem {
-        long mExpiredTimeMillis;
-        GpuHeadroomParamsInternal mParams;
-        float mHeadroom;
-
-        GpuHeadroomCacheItem(long expiredTimeMillis, GpuHeadroomParamsInternal params,
-                float headroom) {
-            mExpiredTimeMillis = expiredTimeMillis;
-            mParams = params;
-            mHeadroom = headroom;
+        void add(K key, V value) {
+            if (mKeyItemMap.containsKey(key)) {
+                final HeadroomCacheItem item = mKeyItemMap.get(key);
+                mItemList.remove(item);
+            }
+            final HeadroomCacheItem item = new HeadroomCacheItem(key, value);
+            mItemList.add(item);
+            mKeyItemMap.put(key, item);
         }
 
-        private boolean match(GpuHeadroomParamsInternal params) {
-            if (mParams == null && params == null) return true;
-            if (mParams != null) {
-                return mParams.equals(params);
+        V get(K key) {
+            while (!mItemList.isEmpty() && mItemList.getFirst().isExpired()) {
+                mKeyItemMap.remove(mItemList.removeFirst().mKey);
             }
-            return false;
+            final HeadroomCacheItem item = mKeyItemMap.get(key);
+            if (item == null) {
+                return null;
+            }
+            return item.mValue;
         }
 
-        private boolean isExpired() {
-            return System.currentTimeMillis() > mExpiredTimeMillis;
+        HeadroomCache(int size, long expDurationMillis) {
+            mItemList = new LinkedList<>();
+            mKeyItemMap = new ArrayMap<>(size);
+            mItemExpDurationMillis = expDurationMillis;
         }
     }
 
+    @GuardedBy("mCpuHeadroomLock")
+    private final HeadroomCache<CpuHeadroomParams, CpuHeadroomResult> mCpuHeadroomCache;
+    private final long mCpuHeadroomIntervalMillis;
+
+    private final Object mGpuHeadroomLock = new Object();
+
     @GuardedBy("mGpuHeadroomLock")
-    private final List<GpuHeadroomCacheItem> mGpuHeadroomCache;
+    private final HeadroomCache<GpuHeadroomParams, GpuHeadroomResult> mGpuHeadroomCache;
     private final long mGpuHeadroomIntervalMillis;
 
+    // these are set to default values in CpuHeadroomParamsInternal and GpuHeadroomParamsInternal
+    private final int mDefaultCpuHeadroomCalculationWindowMillis;
+    private final int mDefaultGpuHeadroomCalculationWindowMillis;
+
     @VisibleForTesting
     final IHintManager.Stub mService = new BinderService();
 
@@ -303,26 +310,31 @@ public final class HintManagerService extends SystemService {
             }
         }
         mCpuHeadroomIntervalMillis = cpuHeadroomIntervalMillis;
+        mDefaultCpuHeadroomCalculationWindowMillis =
+                new CpuHeadroomParamsInternal().calculationWindowMillis;
+        mDefaultGpuHeadroomCalculationWindowMillis =
+                new GpuHeadroomParamsInternal().calculationWindowMillis;
         mGpuHeadroomIntervalMillis = gpuHeadroomIntervalMillis;
         if (mCpuHeadroomIntervalMillis > 0) {
-            mCpuHeadroomCache = new ArrayList<>(4);
+            mCpuHeadroomCache = new HeadroomCache<>(2, mCpuHeadroomIntervalMillis);
         } else {
             mCpuHeadroomCache = null;
         }
         if (mGpuHeadroomIntervalMillis > 0) {
-            mGpuHeadroomCache = new ArrayList<>(2);
+            mGpuHeadroomCache = new HeadroomCache<>(2, mGpuHeadroomIntervalMillis);
         } else {
             mGpuHeadroomCache = null;
         }
     }
 
     private long checkCpuHeadroomSupport() {
+        final CpuHeadroomParams params = new CpuHeadroomParams();
+        params.tids = new int[]{Process.myPid()};
         try {
             synchronized (mCpuHeadroomLock) {
-                final CpuHeadroomParams defaultParams = new CpuHeadroomParams();
-                defaultParams.pid = Process.myPid();
-                float[] ret = mPowerHal.getCpuHeadroom(defaultParams);
-                if (ret != null && ret.length > 0) {
+                final CpuHeadroomResult ret = mPowerHal.getCpuHeadroom(params);
+                if (ret != null && ret.getTag() == CpuHeadroomResult.globalHeadroom
+                        && !Float.isNaN(ret.getGlobalHeadroom())) {
                     return Math.max(
                             DEFAULT_CPU_HEADROOM_INTERVAL_MILLIS,
                             mPowerHal.getCpuHeadroomMinIntervalMillis());
@@ -330,27 +342,29 @@ public final class HintManagerService extends SystemService {
             }
 
         } catch (UnsupportedOperationException e) {
-            Slog.w(TAG, "getCpuHeadroom HAL API is not supported", e);
+            Slog.w(TAG, "getCpuHeadroom HAL API is not supported, params: " + params, e);
         } catch (RemoteException e) {
-            Slog.e(TAG, "getCpuHeadroom HAL API fails, disabling the API", e);
+            Slog.e(TAG, "getCpuHeadroom HAL API fails, disabling the API, params: " + params, e);
         }
         return HEADROOM_INTERVAL_UNSUPPORTED;
     }
 
     private long checkGpuHeadroomSupport() {
+        final GpuHeadroomParams params = new GpuHeadroomParams();
         try {
             synchronized (mGpuHeadroomLock) {
-                float ret = mPowerHal.getGpuHeadroom(new GpuHeadroomParams());
-                if (!Float.isNaN(ret)) {
+                final GpuHeadroomResult ret = mPowerHal.getGpuHeadroom(params);
+                if (ret != null && ret.getTag() == GpuHeadroomResult.globalHeadroom && !Float.isNaN(
+                        ret.getGlobalHeadroom())) {
                     return Math.max(
                             DEFAULT_GPU_HEADROOM_INTERVAL_MILLIS,
                             mPowerHal.getGpuHeadroomMinIntervalMillis());
                 }
             }
         } catch (UnsupportedOperationException e) {
-            Slog.w(TAG, "getGpuHeadroom HAL API is not supported", e);
+            Slog.w(TAG, "getGpuHeadroom HAL API is not supported, params: " + params, e);
         } catch (RemoteException e) {
-            Slog.e(TAG, "getGpuHeadroom HAL API fails, disabling the API", e);
+            Slog.e(TAG, "getGpuHeadroom HAL API fails, disabling the API, params: " + params, e);
         }
         return HEADROOM_INTERVAL_UNSUPPORTED;
     }
@@ -1445,109 +1459,98 @@ public final class HintManagerService extends SystemService {
         }
 
         @Override
-        public float[] getCpuHeadroom(@Nullable CpuHeadroomParamsInternal params) {
+        public CpuHeadroomResult getCpuHeadroom(@NonNull CpuHeadroomParamsInternal params) {
             if (mCpuHeadroomIntervalMillis <= 0) {
                 throw new UnsupportedOperationException();
             }
-            CpuHeadroomParams halParams = new CpuHeadroomParams();
-            halParams.pid = Binder.getCallingPid();
-            if (params != null) {
-                halParams.calculationType = params.calculationType;
-                halParams.selectionType = params.selectionType;
-                if (params.usesDeviceHeadroom) {
-                    halParams.pid = DEFAULT_HEADROOM_PID;
-                }
-            }
-            synchronized (mCpuHeadroomLock) {
-                while (!mCpuHeadroomCache.isEmpty()) {
-                    if (mCpuHeadroomCache.getFirst().isExpired()) {
-                        mCpuHeadroomCache.removeFirst();
-                    } else {
-                        break;
+            final CpuHeadroomParams halParams = new CpuHeadroomParams();
+            halParams.tids = new int[]{Binder.getCallingPid()};
+            halParams.calculationType = params.calculationType;
+            halParams.calculationWindowMillis = params.calculationWindowMillis;
+            halParams.selectionType = params.selectionType;
+            if (params.usesDeviceHeadroom) {
+                halParams.tids = new int[]{};
+            } else if (params.tids != null && params.tids.length > 0) {
+                if (params.tids.length > 5) {
+                    throw new IllegalArgumentException(
+                            "More than 5 TIDs is requested: " + params.tids.length);
+                }
+                if (SystemProperties.getBoolean(PROPERTY_CHECK_HEADROOM_TID, true)) {
+                    final int tgid = Process.getThreadGroupLeader(Binder.getCallingPid());
+                    for (int tid : params.tids) {
+                        if (Process.getThreadGroupLeader(tid) != tgid) {
+                            throw new SecurityException("TID " + tid
+                                    + " doesn't belong to the calling process with pid "
+                                    + tgid);
+                        }
                     }
                 }
-                for (int i = 0; i < mCpuHeadroomCache.size(); ++i) {
-                    final CpuHeadroomCacheItem item = mCpuHeadroomCache.get(i);
-                    if (item.match(params, halParams.pid)) {
-                        item.mExpiredTimeMillis =
-                                System.currentTimeMillis() + mCpuHeadroomIntervalMillis;
-                        mCpuHeadroomCache.remove(i);
-                        mCpuHeadroomCache.add(item);
-                        return item.mHeadroom;
-                    }
+                halParams.tids = params.tids;
+            }
+            if (halParams.calculationWindowMillis
+                    == mDefaultCpuHeadroomCalculationWindowMillis) {
+                synchronized (mCpuHeadroomLock) {
+                    final CpuHeadroomResult res = mCpuHeadroomCache.get(halParams);
+                    if (res != null) return res;
                 }
             }
             // return from HAL directly
             try {
-                float[] headroom = mPowerHal.getCpuHeadroom(halParams);
-                if (headroom == null || headroom.length == 0) {
-                    Slog.wtf(TAG,
-                            "CPU headroom from Power HAL is invalid: " + Arrays.toString(headroom));
-                    return new float[]{Float.NaN};
-                }
-                synchronized (mCpuHeadroomLock) {
-                    mCpuHeadroomCache.add(new CpuHeadroomCacheItem(
-                            System.currentTimeMillis() + mCpuHeadroomIntervalMillis,
-                            params, headroom, halParams.pid
-                    ));
+                final CpuHeadroomResult result = mPowerHal.getCpuHeadroom(halParams);
+                if (result == null) {
+                    Slog.wtf(TAG, "CPU headroom from Power HAL is invalid");
+                    return null;
+                }
+                if (halParams.calculationWindowMillis
+                        == mDefaultCpuHeadroomCalculationWindowMillis) {
+                    synchronized (mCpuHeadroomLock) {
+                        mCpuHeadroomCache.add(halParams, result);
+                    }
                 }
-                return headroom;
-
+                return result;
             } catch (RemoteException e) {
-                return new float[]{Float.NaN};
+                Slog.e(TAG, "Failed to get CPU headroom from Power HAL", e);
+                return null;
             }
         }
 
         @Override
-        public float getGpuHeadroom(@Nullable GpuHeadroomParamsInternal params) {
+        public GpuHeadroomResult getGpuHeadroom(@NonNull GpuHeadroomParamsInternal params) {
             if (mGpuHeadroomIntervalMillis <= 0) {
                 throw new UnsupportedOperationException();
             }
-            GpuHeadroomParams halParams = new GpuHeadroomParams();
-            if (params != null) {
-                halParams.calculationType = params.calculationType;
-            }
-            synchronized (mGpuHeadroomLock) {
-                while (!mGpuHeadroomCache.isEmpty()) {
-                    if (mGpuHeadroomCache.getFirst().isExpired()) {
-                        mGpuHeadroomCache.removeFirst();
-                    } else {
-                        break;
-                    }
-                }
-                for (int i = 0; i < mGpuHeadroomCache.size(); ++i) {
-                    final GpuHeadroomCacheItem item = mGpuHeadroomCache.get(i);
-                    if (item.match(params)) {
-                        item.mExpiredTimeMillis =
-                                System.currentTimeMillis() + mGpuHeadroomIntervalMillis;
-                        mGpuHeadroomCache.remove(i);
-                        mGpuHeadroomCache.add(item);
-                        return item.mHeadroom;
-                    }
+            final GpuHeadroomParams halParams = new GpuHeadroomParams();
+            halParams.calculationType = params.calculationType;
+            halParams.calculationWindowMillis = params.calculationWindowMillis;
+            if (halParams.calculationWindowMillis
+                    == mDefaultGpuHeadroomCalculationWindowMillis) {
+                synchronized (mGpuHeadroomLock) {
+                    final GpuHeadroomResult res = mGpuHeadroomCache.get(halParams);
+                    if (res != null) return res;
                 }
             }
             // return from HAL directly
             try {
-                float headroom = mPowerHal.getGpuHeadroom(halParams);
-                if (Float.isNaN(headroom)) {
-                    Slog.wtf(TAG,
-                            "GPU headroom from Power HAL is NaN");
-                    return Float.NaN;
-                }
-                synchronized (mGpuHeadroomLock) {
-                    mGpuHeadroomCache.add(new GpuHeadroomCacheItem(
-                            System.currentTimeMillis() + mGpuHeadroomIntervalMillis,
-                            params, headroom
-                    ));
+                final GpuHeadroomResult headroom = mPowerHal.getGpuHeadroom(halParams);
+                if (headroom == null) {
+                    Slog.wtf(TAG, "GPU headroom from Power HAL is invalid");
+                    return null;
+                }
+                if (halParams.calculationWindowMillis
+                        == mDefaultGpuHeadroomCalculationWindowMillis) {
+                    synchronized (mGpuHeadroomLock) {
+                        mGpuHeadroomCache.add(halParams, headroom);
+                    }
                 }
                 return headroom;
             } catch (RemoteException e) {
-                return Float.NaN;
+                Slog.e(TAG, "Failed to get GPU headroom from Power HAL", e);
+                return null;
             }
         }
 
         @Override
-        public long getCpuHeadroomMinIntervalMillis() throws RemoteException {
+        public long getCpuHeadroomMinIntervalMillis() {
             if (mCpuHeadroomIntervalMillis <= 0) {
                 throw new UnsupportedOperationException();
             }
@@ -1555,7 +1558,7 @@ public final class HintManagerService extends SystemService {
         }
 
         @Override
-        public long getGpuHeadroomMinIntervalMillis() throws RemoteException {
+        public long getGpuHeadroomMinIntervalMillis() {
             if (mGpuHeadroomIntervalMillis <= 0) {
                 throw new UnsupportedOperationException();
             }
@@ -1591,17 +1594,23 @@ public final class HintManagerService extends SystemService {
                 CpuHeadroomParamsInternal params = new CpuHeadroomParamsInternal();
                 params.selectionType = CpuHeadroomParams.SelectionType.ALL;
                 params.usesDeviceHeadroom = true;
-                pw.println("CPU headroom: " + Arrays.toString(getCpuHeadroom(params)));
+                CpuHeadroomResult ret = getCpuHeadroom(params);
+                pw.println("CPU headroom: " + (ret == null ? "N/A" : ret.getGlobalHeadroom()));
                 params = new CpuHeadroomParamsInternal();
                 params.selectionType = CpuHeadroomParams.SelectionType.PER_CORE;
                 params.usesDeviceHeadroom = true;
-                pw.println("CPU headroom per core: " + Arrays.toString(getCpuHeadroom(params)));
+                ret = getCpuHeadroom(params);
+                pw.println("CPU headroom per core: " + (ret == null ? "N/A"
+                        : Arrays.toString(ret.getPerCoreHeadroom())));
             } catch (Exception e) {
+                Slog.d(TAG, "Failed to dump CPU headroom", e);
                 pw.println("CPU headroom: N/A");
             }
             try {
-                pw.println("GPU headroom: " + getGpuHeadroom(null));
+                GpuHeadroomResult ret = getGpuHeadroom(new GpuHeadroomParamsInternal());
+                pw.println("GPU headroom: " + (ret == null ? "N/A" : ret.getGlobalHeadroom()));
             } catch (Exception e) {
+                Slog.d(TAG, "Failed to dump GPU headroom", e);
                 pw.println("GPU headroom: N/A");
             }
         }
diff --git a/services/tests/performancehinttests/src/com/android/server/power/hint/HintManagerServiceTest.java b/services/tests/performancehinttests/src/com/android/server/power/hint/HintManagerServiceTest.java
index e631cb66eaf7..313c01d5ce58 100644
--- a/services/tests/performancehinttests/src/com/android/server/power/hint/HintManagerServiceTest.java
+++ b/services/tests/performancehinttests/src/com/android/server/power/hint/HintManagerServiceTest.java
@@ -18,7 +18,6 @@ package com.android.server.power.hint;
 
 
 import static com.android.server.power.hint.HintManagerService.CLEAN_UP_UID_DELAY_MILLIS;
-import static com.android.server.power.hint.HintManagerService.DEFAULT_HEADROOM_PID;
 
 import static com.google.common.truth.Truth.assertThat;
 
@@ -53,7 +52,9 @@ import android.hardware.common.fmq.MQDescriptor;
 import android.hardware.power.ChannelConfig;
 import android.hardware.power.ChannelMessage;
 import android.hardware.power.CpuHeadroomParams;
+import android.hardware.power.CpuHeadroomResult;
 import android.hardware.power.GpuHeadroomParams;
+import android.hardware.power.GpuHeadroomResult;
 import android.hardware.power.IPower;
 import android.hardware.power.SessionConfig;
 import android.hardware.power.SessionTag;
@@ -1251,67 +1252,98 @@ public class HintManagerServiceTest {
         CpuHeadroomParams halParams1 = new CpuHeadroomParams();
         halParams1.calculationType = CpuHeadroomParams.CalculationType.MIN;
         halParams1.selectionType = CpuHeadroomParams.SelectionType.ALL;
-        halParams1.pid = Process.myPid();
+        halParams1.tids = new int[]{Process.myPid()};
 
         CpuHeadroomParamsInternal params2 = new CpuHeadroomParamsInternal();
         params2.usesDeviceHeadroom = true;
-        params2.calculationType = CpuHeadroomParams.CalculationType.AVERAGE;
+        params2.calculationType = CpuHeadroomParams.CalculationType.MIN;
         params2.selectionType = CpuHeadroomParams.SelectionType.PER_CORE;
         CpuHeadroomParams halParams2 = new CpuHeadroomParams();
-        halParams2.calculationType = CpuHeadroomParams.CalculationType.AVERAGE;
+        halParams2.calculationType = CpuHeadroomParams.CalculationType.MIN;
         halParams2.selectionType = CpuHeadroomParams.SelectionType.PER_CORE;
-        halParams2.pid = DEFAULT_HEADROOM_PID;
+        halParams2.tids = new int[]{};
+
+        CpuHeadroomParamsInternal params3 = new CpuHeadroomParamsInternal();
+        params3.calculationType = CpuHeadroomParams.CalculationType.AVERAGE;
+        params3.selectionType = CpuHeadroomParams.SelectionType.ALL;
+        CpuHeadroomParams halParams3 = new CpuHeadroomParams();
+        halParams3.calculationType = CpuHeadroomParams.CalculationType.AVERAGE;
+        halParams3.selectionType = CpuHeadroomParams.SelectionType.ALL;
+        halParams3.tids = new int[]{Process.myPid()};
+
+        // this params should not be cached as the window is not default
+        CpuHeadroomParamsInternal params4 = new CpuHeadroomParamsInternal();
+        params4.calculationWindowMillis = 123;
+        CpuHeadroomParams halParams4 = new CpuHeadroomParams();
+        halParams4.calculationType = CpuHeadroomParams.CalculationType.MIN;
+        halParams4.selectionType = CpuHeadroomParams.SelectionType.ALL;
+        halParams4.calculationWindowMillis = 123;
+        halParams4.tids = new int[]{Process.myPid()};
 
-        float[] headroom1 = new float[] {0.1f};
-        when(mIPowerMock.getCpuHeadroom(eq(halParams1))).thenReturn(headroom1);
-        float[] headroom2 = new float[] {0.1f, 0.5f};
-        when(mIPowerMock.getCpuHeadroom(eq(halParams2))).thenReturn(headroom2);
+        float headroom1 = 0.1f;
+        CpuHeadroomResult halRet1 = CpuHeadroomResult.globalHeadroom(headroom1);
+        when(mIPowerMock.getCpuHeadroom(eq(halParams1))).thenReturn(halRet1);
+        float[] headroom2 = new float[] {0.2f, 0.2f};
+        CpuHeadroomResult halRet2 = CpuHeadroomResult.perCoreHeadroom(headroom2);
+        when(mIPowerMock.getCpuHeadroom(eq(halParams2))).thenReturn(halRet2);
+        float headroom3 = 0.3f;
+        CpuHeadroomResult halRet3 = CpuHeadroomResult.globalHeadroom(headroom3);
+        when(mIPowerMock.getCpuHeadroom(eq(halParams3))).thenReturn(halRet3);
+        float headroom4 = 0.4f;
+        CpuHeadroomResult halRet4 = CpuHeadroomResult.globalHeadroom(headroom4);
+        when(mIPowerMock.getCpuHeadroom(eq(halParams4))).thenReturn(halRet4);
 
         HintManagerService service = createService();
         clearInvocations(mIPowerMock);
 
         service.getBinderServiceInstance().getCpuHeadroomMinIntervalMillis();
         verify(mIPowerMock, times(0)).getCpuHeadroomMinIntervalMillis();
-        service.getBinderServiceInstance().getCpuHeadroom(params1);
+        assertEquals(halRet1, service.getBinderServiceInstance().getCpuHeadroom(params1));
         verify(mIPowerMock, times(1)).getCpuHeadroom(eq(halParams1));
-        service.getBinderServiceInstance().getCpuHeadroom(params2);
+        assertEquals(halRet2, service.getBinderServiceInstance().getCpuHeadroom(params2));
         verify(mIPowerMock, times(1)).getCpuHeadroom(eq(halParams2));
+        assertEquals(halRet3, service.getBinderServiceInstance().getCpuHeadroom(params3));
+        verify(mIPowerMock, times(1)).getCpuHeadroom(eq(halParams3));
+        assertEquals(halRet4, service.getBinderServiceInstance().getCpuHeadroom(params4));
+        verify(mIPowerMock, times(1)).getCpuHeadroom(eq(halParams4));
 
         // verify cache is working
         clearInvocations(mIPowerMock);
-        assertArrayEquals(headroom1, service.getBinderServiceInstance().getCpuHeadroom(params1),
-                0.01f);
-        assertArrayEquals(headroom2, service.getBinderServiceInstance().getCpuHeadroom(params2),
-                0.01f);
-        verify(mIPowerMock, times(0)).getCpuHeadroom(any());
+        assertEquals(halRet1, service.getBinderServiceInstance().getCpuHeadroom(params1));
+        assertEquals(halRet2, service.getBinderServiceInstance().getCpuHeadroom(params2));
+        assertEquals(halRet3, service.getBinderServiceInstance().getCpuHeadroom(params3));
+        assertEquals(halRet4, service.getBinderServiceInstance().getCpuHeadroom(params4));
+        verify(mIPowerMock, times(1)).getCpuHeadroom(any());
+        verify(mIPowerMock, times(0)).getCpuHeadroom(eq(halParams1));
+        verify(mIPowerMock, times(0)).getCpuHeadroom(eq(halParams2));
+        verify(mIPowerMock, times(0)).getCpuHeadroom(eq(halParams3));
+        verify(mIPowerMock, times(1)).getCpuHeadroom(eq(halParams4));
 
         // after 1 more second it should be served with cache still
         Thread.sleep(1000);
         clearInvocations(mIPowerMock);
-        assertArrayEquals(headroom1, service.getBinderServiceInstance().getCpuHeadroom(params1),
-                0.01f);
-        assertArrayEquals(headroom2, service.getBinderServiceInstance().getCpuHeadroom(params2),
-                0.01f);
-        verify(mIPowerMock, times(0)).getCpuHeadroom(any());
-
-        // after 1.5 more second it should be served with cache still as timer reset
-        Thread.sleep(1500);
-        clearInvocations(mIPowerMock);
-        assertArrayEquals(headroom1, service.getBinderServiceInstance().getCpuHeadroom(params1),
-                0.01f);
-        assertArrayEquals(headroom2, service.getBinderServiceInstance().getCpuHeadroom(params2),
-                0.01f);
-        verify(mIPowerMock, times(0)).getCpuHeadroom(any());
+        assertEquals(halRet1, service.getBinderServiceInstance().getCpuHeadroom(params1));
+        assertEquals(halRet2, service.getBinderServiceInstance().getCpuHeadroom(params2));
+        assertEquals(halRet3, service.getBinderServiceInstance().getCpuHeadroom(params3));
+        assertEquals(halRet4, service.getBinderServiceInstance().getCpuHeadroom(params4));
+        verify(mIPowerMock, times(1)).getCpuHeadroom(any());
+        verify(mIPowerMock, times(0)).getCpuHeadroom(eq(halParams1));
+        verify(mIPowerMock, times(0)).getCpuHeadroom(eq(halParams2));
+        verify(mIPowerMock, times(0)).getCpuHeadroom(eq(halParams3));
+        verify(mIPowerMock, times(1)).getCpuHeadroom(eq(halParams4));
 
         // after 2+ seconds it should be served from HAL as it exceeds 2000 millis interval
-        Thread.sleep(2100);
+        Thread.sleep(1100);
         clearInvocations(mIPowerMock);
-        assertArrayEquals(headroom1, service.getBinderServiceInstance().getCpuHeadroom(params1),
-                0.01f);
-        assertArrayEquals(headroom2, service.getBinderServiceInstance().getCpuHeadroom(params2),
-                0.01f);
+        assertEquals(halRet1, service.getBinderServiceInstance().getCpuHeadroom(params1));
+        assertEquals(halRet2, service.getBinderServiceInstance().getCpuHeadroom(params2));
+        assertEquals(halRet3, service.getBinderServiceInstance().getCpuHeadroom(params3));
+        assertEquals(halRet4, service.getBinderServiceInstance().getCpuHeadroom(params4));
+        verify(mIPowerMock, times(4)).getCpuHeadroom(any());
         verify(mIPowerMock, times(1)).getCpuHeadroom(eq(halParams1));
         verify(mIPowerMock, times(1)).getCpuHeadroom(eq(halParams2));
+        verify(mIPowerMock, times(1)).getCpuHeadroom(eq(halParams3));
+        verify(mIPowerMock, times(1)).getCpuHeadroom(eq(halParams4));
     }
 
     @Test
@@ -1322,59 +1354,52 @@ public class HintManagerServiceTest {
         halParams1.calculationType = GpuHeadroomParams.CalculationType.MIN;
 
         GpuHeadroomParamsInternal params2 = new GpuHeadroomParamsInternal();
+        params2.calculationType = GpuHeadroomParams.CalculationType.AVERAGE;
+        params2.calculationWindowMillis = 123;
         GpuHeadroomParams halParams2 = new GpuHeadroomParams();
-        params2.calculationType =
-                halParams2.calculationType = GpuHeadroomParams.CalculationType.AVERAGE;
+        halParams2.calculationType = GpuHeadroomParams.CalculationType.AVERAGE;
+        halParams2.calculationWindowMillis = 123;
 
         float headroom1 = 0.1f;
-        when(mIPowerMock.getGpuHeadroom(eq(halParams1))).thenReturn(headroom1);
+        GpuHeadroomResult halRet1 = GpuHeadroomResult.globalHeadroom(headroom1);
+        when(mIPowerMock.getGpuHeadroom(eq(halParams1))).thenReturn(halRet1);
         float headroom2 = 0.2f;
-        when(mIPowerMock.getGpuHeadroom(eq(halParams2))).thenReturn(headroom2);
+        GpuHeadroomResult halRet2 = GpuHeadroomResult.globalHeadroom(headroom2);
+        when(mIPowerMock.getGpuHeadroom(eq(halParams2))).thenReturn(halRet2);
         HintManagerService service = createService();
         clearInvocations(mIPowerMock);
 
         service.getBinderServiceInstance().getGpuHeadroomMinIntervalMillis();
         verify(mIPowerMock, times(0)).getGpuHeadroomMinIntervalMillis();
-        assertEquals(headroom1, service.getBinderServiceInstance().getGpuHeadroom(params1),
-                0.01f);
-        assertEquals(headroom2, service.getBinderServiceInstance().getGpuHeadroom(params2),
-                0.01f);
+        assertEquals(halRet1, service.getBinderServiceInstance().getGpuHeadroom(params1));
+        assertEquals(halRet2, service.getBinderServiceInstance().getGpuHeadroom(params2));
+        verify(mIPowerMock, times(2)).getGpuHeadroom(any());
         verify(mIPowerMock, times(1)).getGpuHeadroom(eq(halParams1));
         verify(mIPowerMock, times(1)).getGpuHeadroom(eq(halParams2));
 
         // verify cache is working
         clearInvocations(mIPowerMock);
-        assertEquals(headroom1, service.getBinderServiceInstance().getGpuHeadroom(params1),
-                0.01f);
-        assertEquals(headroom2, service.getBinderServiceInstance().getGpuHeadroom(params2),
-                0.01f);
-        verify(mIPowerMock, times(0)).getGpuHeadroom(any());
+        assertEquals(halRet1, service.getBinderServiceInstance().getGpuHeadroom(params1));
+        assertEquals(halRet2, service.getBinderServiceInstance().getGpuHeadroom(params2));
+        verify(mIPowerMock, times(1)).getGpuHeadroom(any());
+        verify(mIPowerMock, times(0)).getGpuHeadroom(eq(halParams1));
+        verify(mIPowerMock, times(1)).getGpuHeadroom(eq(halParams2));
 
         // after 1 more second it should be served with cache still
         Thread.sleep(1000);
         clearInvocations(mIPowerMock);
-        assertEquals(headroom1, service.getBinderServiceInstance().getGpuHeadroom(params1),
-                0.01f);
-        assertEquals(headroom2, service.getBinderServiceInstance().getGpuHeadroom(params2),
-                0.01f);
-        verify(mIPowerMock, times(0)).getGpuHeadroom(any());
-
-        // after 1.5 more second it should be served with cache still as timer reset
-        Thread.sleep(1500);
-        clearInvocations(mIPowerMock);
-        assertEquals(headroom1, service.getBinderServiceInstance().getGpuHeadroom(params1),
-                0.01f);
-        assertEquals(headroom2, service.getBinderServiceInstance().getGpuHeadroom(params2),
-                0.01f);
-        verify(mIPowerMock, times(0)).getGpuHeadroom(any());
+        assertEquals(halRet1, service.getBinderServiceInstance().getGpuHeadroom(params1));
+        assertEquals(halRet2, service.getBinderServiceInstance().getGpuHeadroom(params2));
+        verify(mIPowerMock, times(1)).getGpuHeadroom(any());
+        verify(mIPowerMock, times(0)).getGpuHeadroom(eq(halParams1));
+        verify(mIPowerMock, times(1)).getGpuHeadroom(eq(halParams2));
 
         // after 2+ seconds it should be served from HAL as it exceeds 2000 millis interval
-        Thread.sleep(2100);
+        Thread.sleep(1100);
         clearInvocations(mIPowerMock);
-        assertEquals(headroom1, service.getBinderServiceInstance().getGpuHeadroom(params1),
-                0.01f);
-        assertEquals(headroom2, service.getBinderServiceInstance().getGpuHeadroom(params2),
-                0.01f);
+        assertEquals(halRet1, service.getBinderServiceInstance().getGpuHeadroom(params1));
+        assertEquals(halRet2, service.getBinderServiceInstance().getGpuHeadroom(params2));
+        verify(mIPowerMock, times(2)).getGpuHeadroom(any());
         verify(mIPowerMock, times(1)).getGpuHeadroom(eq(halParams1));
         verify(mIPowerMock, times(1)).getGpuHeadroom(eq(halParams2));
     }