Merge "Add caching for getDisplayInfo" into rvc-dev

core/java/android/hardware/display/DisplayManagerGlobal.java

@@ -18,6 +18,7 @@ package android.hardware.display;
 
 import android.annotation.NonNull;
 import android.annotation.Nullable;
+import android.app.PropertyInvalidatedCache;
 import android.compat.annotation.UnsupportedAppUsage;
 import android.content.Context;
 import android.content.pm.ParceledListSlice;
@@ -99,6 +100,20 @@ public final class DisplayManagerGlobal {
         }
     }
 
+    private PropertyInvalidatedCache<Integer, DisplayInfo> mDisplayCache =
+            new PropertyInvalidatedCache<Integer, DisplayInfo>(
+                8, // size of display cache
+                CACHE_KEY_DISPLAY_INFO_PROPERTY) {
+                @Override
+                protected DisplayInfo recompute(Integer id) {
+                    try {
+                        return mDm.getDisplayInfo(id);
+                    } catch (RemoteException ex) {
+                        throw ex.rethrowFromSystemServer();
+                    }
+                }
+            };
+
     /**
      * Gets an instance of the display manager global singleton.
      *
@@ -127,24 +142,21 @@ public final class DisplayManagerGlobal {
      */
     @UnsupportedAppUsage
     public DisplayInfo getDisplayInfo(int displayId) {
-        try {
         synchronized (mLock) {
-                DisplayInfo info;
+            DisplayInfo info = null;
-                if (USE_CACHE) {
+            if (mDisplayCache != null) {
-                    info = mDisplayInfoCache.get(displayId);
+                info = mDisplayCache.query(displayId);
-                    if (info != null) {
+            } else {
-                        return info;
+                try {
-                    }
-                }
-
                     info = mDm.getDisplayInfo(displayId);
+                } catch (RemoteException ex) {
+                    ex.rethrowFromSystemServer();
+                }
+            }
             if (info == null) {
                 return null;
             }
 
-                if (USE_CACHE) {
-                    mDisplayInfoCache.put(displayId, info);
-                }
             registerCallbackIfNeededLocked();
 
             if (DEBUG) {
@@ -152,9 +164,6 @@ public final class DisplayManagerGlobal {
             }
             return info;
         }
-        } catch (RemoteException ex) {
-            throw ex.rethrowFromSystemServer();
-        }
     }
 
     /**
@@ -777,4 +786,26 @@ public final class DisplayManagerGlobal {
             }
         }
     }
+
+    /**
+     * Name of the property containing a unique token which changes every time we update the
+     * system's display configuration.
+     */
+    public static final String CACHE_KEY_DISPLAY_INFO_PROPERTY =
+            "cache_key.display_info";
+
+    /**
+     * Invalidates the contents of the display info cache for all applications. Can only
+     * be called by system_server.
+     */
+    public static void invalidateLocalDisplayInfoCaches() {
+        PropertyInvalidatedCache.invalidateCache(CACHE_KEY_DISPLAY_INFO_PROPERTY);
+    }
+
+    /**
+     * Disables the binder call cache.
+     */
+    public void disableLocalDisplayInfoCaches() {
+        mDisplayCache = null;
+    }
 }

services/core/java/com/android/server/display/DisplayInfoProxy.java

@@ -0,0 +1,57 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.display;
+
+import android.annotation.Nullable;
+import android.hardware.display.DisplayManagerGlobal;
+import android.view.DisplayInfo;
+
+/**
+ * Class for wrapping access of DisplayInfo objects by LogicalDisplay so that we can appropriately
+ * invalidate caches when they change.
+ */
+public class DisplayInfoProxy {
+    private DisplayInfo mInfo;
+
+    public DisplayInfoProxy(@Nullable DisplayInfo info) {
+        mInfo = info;
+    }
+
+    /**
+     * Set the current {@link DisplayInfo}.
+     *
+     * The also automatically invalidates the display info caches across the entire system.
+     * @param info the new {@link DisplayInfo}.
+     */
+    public void set(@Nullable DisplayInfo info) {
+        mInfo = info;
+        DisplayManagerGlobal.invalidateLocalDisplayInfoCaches();
+    }
+
+    /**
+     * Returns the current {@link DisplayInfo}.
+     *
+     * This info <b>must</b> be treated as immutable. Modifying the returned object is undefined
+     * behavior that <b>will</b> result in inconsistent states across the system.
+     *
+     * @return the current {@link DisplayInfo}
+     */
+    @Nullable
+    public DisplayInfo get() {
+        return mInfo;
+    }
+}

services/core/java/com/android/server/display/DisplayManagerService.java

@@ -215,6 +215,7 @@ public final class DisplayManagerService extends SystemService {
     private final ArrayList<DisplayDevice> mDisplayDevices = new ArrayList<DisplayDevice>();
 
     // List of all logical displays indexed by logical display id.
+    // Any modification to mLogicalDisplays must invalidate the DisplayManagerGlobal cache.
     private final SparseArray<LogicalDisplay> mLogicalDisplays =
             new SparseArray<LogicalDisplay>();
     private int mNextNonDefaultDisplayId = Display.DEFAULT_DISPLAY + 1;
@@ -373,6 +374,10 @@ public final class DisplayManagerService extends SystemService {
         }
         mHandler.sendEmptyMessage(MSG_REGISTER_DEFAULT_DISPLAY_ADAPTERS);
 
+        // If there was a runtime restart then we may have stale caches left around, so we need to
+        // make sure to invalidate them upon every start.
+        DisplayManagerGlobal.invalidateLocalDisplayInfoCaches();
+
         publishBinderService(Context.DISPLAY_SERVICE, new BinderService(),
                 true /*allowIsolated*/);
         publishLocalService(DisplayManagerInternal.class, new LocalService());
@@ -1005,9 +1010,17 @@ public final class DisplayManagerService extends SystemService {
         if (displayId == Display.DEFAULT_DISPLAY) {
             recordTopInsetLocked(display);
         }
+        // We don't bother invalidating the display info caches here because any changes to the
+        // display info will trigger a cache invalidation inside of LogicalDisplay before we hit
+        // this point.
         sendDisplayEventLocked(displayId, DisplayManagerGlobal.EVENT_DISPLAY_CHANGED);
     }
 
+    private void handleLogicalDisplayRemoved(int displayId) {
+        DisplayManagerGlobal.invalidateLocalDisplayInfoCaches();
+        sendDisplayEventLocked(displayId, DisplayManagerGlobal.EVENT_DISPLAY_REMOVED);
+    }
+
     private void applyGlobalDisplayStateLocked(List<Runnable> workQueue) {
         final int count = mDisplayDevices.size();
         for (int i = 0; i < count; i++) {
@@ -1066,6 +1079,7 @@ public final class DisplayManagerService extends SystemService {
         }
 
         mLogicalDisplays.put(displayId, display);
+        DisplayManagerGlobal.invalidateLocalDisplayInfoCaches();
 
         // Wake up waitForDefaultDisplay.
         if (isDefault) {
@@ -1206,7 +1220,7 @@ public final class DisplayManagerService extends SystemService {
             display.updateLocked(mDisplayDevices);
             if (!display.isValidLocked()) {
                 mLogicalDisplays.removeAt(i);
-                sendDisplayEventLocked(displayId, DisplayManagerGlobal.EVENT_DISPLAY_REMOVED);
+                handleLogicalDisplayRemoved(displayId);
                 changed = true;
             } else if (!mTempDisplayInfo.equals(display.getDisplayInfoLocked())) {
                 handleLogicalDisplayChanged(displayId, display);

services/core/java/com/android/server/display/LogicalDisplay.java

@@ -77,7 +77,7 @@ final class LogicalDisplay {
      * needs to be updated.
      * @see #getDisplayInfoLocked()
      */
-    private DisplayInfo mInfo;
+    private final DisplayInfoProxy mInfo = new DisplayInfoProxy(null);
 
     // The display device that this logical display is based on and which
     // determines the base metrics that it uses.
@@ -141,26 +141,27 @@ final class LogicalDisplay {
      * the data changes.
      */
     public DisplayInfo getDisplayInfoLocked() {
-        if (mInfo == null) {
+        if (mInfo.get() == null) {
-            mInfo = new DisplayInfo();
+            DisplayInfo info = new DisplayInfo();
-            mInfo.copyFrom(mBaseDisplayInfo);
+            info.copyFrom(mBaseDisplayInfo);
             if (mOverrideDisplayInfo != null) {
-                mInfo.appWidth = mOverrideDisplayInfo.appWidth;
+                info.appWidth = mOverrideDisplayInfo.appWidth;
-                mInfo.appHeight = mOverrideDisplayInfo.appHeight;
+                info.appHeight = mOverrideDisplayInfo.appHeight;
-                mInfo.smallestNominalAppWidth = mOverrideDisplayInfo.smallestNominalAppWidth;
+                info.smallestNominalAppWidth = mOverrideDisplayInfo.smallestNominalAppWidth;
-                mInfo.smallestNominalAppHeight = mOverrideDisplayInfo.smallestNominalAppHeight;
+                info.smallestNominalAppHeight = mOverrideDisplayInfo.smallestNominalAppHeight;
-                mInfo.largestNominalAppWidth = mOverrideDisplayInfo.largestNominalAppWidth;
+                info.largestNominalAppWidth = mOverrideDisplayInfo.largestNominalAppWidth;
-                mInfo.largestNominalAppHeight = mOverrideDisplayInfo.largestNominalAppHeight;
+                info.largestNominalAppHeight = mOverrideDisplayInfo.largestNominalAppHeight;
-                mInfo.logicalWidth = mOverrideDisplayInfo.logicalWidth;
+                info.logicalWidth = mOverrideDisplayInfo.logicalWidth;
-                mInfo.logicalHeight = mOverrideDisplayInfo.logicalHeight;
+                info.logicalHeight = mOverrideDisplayInfo.logicalHeight;
-                mInfo.rotation = mOverrideDisplayInfo.rotation;
+                info.rotation = mOverrideDisplayInfo.rotation;
-                mInfo.displayCutout = mOverrideDisplayInfo.displayCutout;
+                info.displayCutout = mOverrideDisplayInfo.displayCutout;
-                mInfo.logicalDensityDpi = mOverrideDisplayInfo.logicalDensityDpi;
+                info.logicalDensityDpi = mOverrideDisplayInfo.logicalDensityDpi;
-                mInfo.physicalXDpi = mOverrideDisplayInfo.physicalXDpi;
+                info.physicalXDpi = mOverrideDisplayInfo.physicalXDpi;
-                mInfo.physicalYDpi = mOverrideDisplayInfo.physicalYDpi;
+                info.physicalYDpi = mOverrideDisplayInfo.physicalYDpi;
             }
+            mInfo.set(info);
         }
-        return mInfo;
+        return mInfo.get();
     }
 
     /**
@@ -181,17 +182,16 @@ final class LogicalDisplay {
         if (info != null) {
             if (mOverrideDisplayInfo == null) {
                 mOverrideDisplayInfo = new DisplayInfo(info);
-                mInfo = null;
+                mInfo.set(null);
                 return true;
-            }
+            } else if (!mOverrideDisplayInfo.equals(info)) {
-            if (!mOverrideDisplayInfo.equals(info)) {
                 mOverrideDisplayInfo.copyFrom(info);
-                mInfo = null;
+                mInfo.set(null);
                 return true;
             }
         } else if (mOverrideDisplayInfo != null) {
             mOverrideDisplayInfo = null;
-            mInfo = null;
+            mInfo.set(null);
             return true;
         }
         return false;
@@ -306,7 +306,7 @@ final class LogicalDisplay {
             mBaseDisplayInfo.displayId = mDisplayId;
 
             mPrimaryDisplayDeviceInfo = deviceInfo;
-            mInfo = null;
+            mInfo.set(null);
         }
     }
 
@@ -327,6 +327,7 @@ final class LogicalDisplay {
     private static Rect getMaskingInsets(DisplayDeviceInfo deviceInfo) {
         boolean maskCutout = (deviceInfo.flags & DisplayDeviceInfo.FLAG_MASK_DISPLAY_CUTOUT) != 0;
         if (maskCutout && deviceInfo.displayCutout != null) {
+            // getSafeInsets is fixed at creation time and cannot change
             return deviceInfo.displayCutout.getSafeInsets();
         } else {
             return new Rect();