From a6574308c74192f4e22b823353ca8c80d1c9cb71 Mon Sep 17 00:00:00 2001
From: Lee Shombert <shombert@google.com>
Date: Mon, 30 Dec 2019 11:54:37 -0800
Subject: [PATCH] Binder caches for Bluetooth

* A cache for isOffloadedFilteringSupported().

* A cache for getProfileConnectionState().

Bug: 140788621

Test: A special build that puts the PropertyInvalidatedCache in
verification mode was loaded on the device.  Then one iteration of MPTS
was executed.  No cache inconsistencies were found and no SELinux
violations (associated with the binder cache) were found.  The number of
cache misses was approximately 15% of the total binder calls.  A second
test was run in which bluetooth headphones were connected and
disconnected.  Then bluetooth itself was disabled and then enabled.  The
caches were invalidated as expected and no errors were uncovered.

Change-Id: Icfad1071725e2d1e320fd252a49f0c4ae8ce6ad0
---
 .../android/bluetooth/BluetoothAdapter.java   | 93 ++++++++++++++-----
 1 file changed, 71 insertions(+), 22 deletions(-)

diff --git a/core/java/android/bluetooth/BluetoothAdapter.java b/core/java/android/bluetooth/BluetoothAdapter.java
index 587c92e014c48..66bfcbd27ca61 100644
--- a/core/java/android/bluetooth/BluetoothAdapter.java
+++ b/core/java/android/bluetooth/BluetoothAdapter.java
@@ -1970,6 +1970,38 @@ public final class BluetoothAdapter {
         }
     }
 
+    private static final String BLUETOOTH_FILTERING_CACHE_PROPERTY =
+            "cache_key.bluetooth.is_offloaded_filtering_supported";
+    private final PropertyInvalidatedCache<Void, Boolean> mBluetoothFilteringCache =
+            new PropertyInvalidatedCache<Void, Boolean>(
+                8, BLUETOOTH_FILTERING_CACHE_PROPERTY) {
+                @Override
+                protected Boolean recompute(Void query) {
+                    try {
+                        mServiceLock.readLock().lock();
+                        if (mService != null) {
+                            return mService.isOffloadedFilteringSupported();
+                        }
+                    } catch (RemoteException e) {
+                        Log.e(TAG, "failed to get isOffloadedFilteringSupported, error: ", e);
+                    } finally {
+                        mServiceLock.readLock().unlock();
+                    }
+                    return false;
+
+                }
+            };
+
+    /** @hide */
+    public void disableIsOffloadedFilteringSupportedCache() {
+        mBluetoothFilteringCache.disableLocal();
+    }
+
+    /** @hide */
+    public static void invalidateIsOffloadedFilteringSupportedCache() {
+        PropertyInvalidatedCache.invalidateCache(BLUETOOTH_FILTERING_CACHE_PROPERTY);
+    }
+
     /**
      * Return true if offloaded filters are supported
      *
@@ -1979,17 +2011,7 @@ public final class BluetoothAdapter {
         if (!getLeAccess()) {
             return false;
         }
-        try {
-            mServiceLock.readLock().lock();
-            if (mService != null) {
-                return mService.isOffloadedFilteringSupported();
-            }
-        } catch (RemoteException e) {
-            Log.e(TAG, "failed to get isOffloadedFilteringSupported, error: ", e);
-        } finally {
-            mServiceLock.readLock().unlock();
-        }
-        return false;
+        return mBluetoothFilteringCache.query(null);
     }
 
     /**
@@ -2361,6 +2383,43 @@ public final class BluetoothAdapter {
         return BluetoothAdapter.STATE_DISCONNECTED;
     }
 
+    private static final String BLUETOOTH_PROFILE_CACHE_PROPERTY =
+            "cache_key.bluetooth.get_profile_connection_state";
+    private final PropertyInvalidatedCache<Integer, Integer>
+            mGetProfileConnectionStateCache =
+            new PropertyInvalidatedCache<Integer, Integer>(
+                8, BLUETOOTH_PROFILE_CACHE_PROPERTY) {
+                @Override
+                protected Integer recompute(Integer query) {
+                    try {
+                        mServiceLock.readLock().lock();
+                        if (mService != null) {
+                            return mService.getProfileConnectionState(query);
+                        }
+                    } catch (RemoteException e) {
+                        Log.e(TAG, "getProfileConnectionState:", e);
+                    } finally {
+                        mServiceLock.readLock().unlock();
+                    }
+                    return BluetoothProfile.STATE_DISCONNECTED;
+                }
+                @Override
+                public String queryToString(Integer query) {
+                    return String.format("getProfileConnectionState(profile=\"%d\")",
+                                         query);
+                }
+            };
+
+    /** @hide */
+    public void disableGetProfileConnectionStateCache() {
+        mGetProfileConnectionStateCache.disableLocal();
+    }
+
+    /** @hide */
+    public static void invalidateGetProfileConnectionStateCache() {
+        PropertyInvalidatedCache.invalidateCache(BLUETOOTH_PROFILE_CACHE_PROPERTY);
+    }
+
     /**
      * Get the current connection state of a profile.
      * This function can be used to check whether the local Bluetooth adapter
@@ -2378,17 +2437,7 @@ public final class BluetoothAdapter {
         if (getState() != STATE_ON) {
             return BluetoothProfile.STATE_DISCONNECTED;
         }
-        try {
-            mServiceLock.readLock().lock();
-            if (mService != null) {
-                return mService.getProfileConnectionState(profile);
-            }
-        } catch (RemoteException e) {
-            Log.e(TAG, "getProfileConnectionState:", e);
-        } finally {
-            mServiceLock.readLock().unlock();
-        }
-        return BluetoothProfile.STATE_DISCONNECTED;
+        return mGetProfileConnectionStateCache.query(new Integer(profile));
     }
 
     /**