Merge "Only allow completion callback to be run once for PIs" into sc-qpr1-dev am: b53041d1eb am: 0a0cb88bba

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/15890710

Change-Id: Ie1420e0065a763cfed304be1b116d8718f5544a2

services/core/java/com/android/server/location/provider/LocationProviderManager.java

@@ -243,15 +243,24 @@ public class LocationProviderManager extends
                 intent.putExtra(KEY_LOCATIONS, locationResult.asList().toArray(new Location[0]));
             }
 
+            // send() SHOULD only run the completion callback if it completes successfully. however,
+            // b/199464864 (which could not be fixed in the S timeframe) means that it's possible
+            // for send() to throw an exception AND run the completion callback. if this happens, we
+            // would over-release the wakelock... we take matters into our own hands to ensure that
+            // the completion callback can only be run if send() completes successfully. this means
+            // the completion callback may be run inline - but as we've never specified what thread
+            // the callback is run on, this is fine.
+            GatedCallback gatedCallback = new GatedCallback(onCompleteCallback);
+
             mPendingIntent.send(
                     mContext,
                     0,
                     intent,
-                    onCompleteCallback != null ? (pI, i, rC, rD, rE) -> onCompleteCallback.run()
+                    (pI, i, rC, rD, rE) -> gatedCallback.run(),
-                            : null,
                     null,
                     null,
                     options.toBundle());
+            gatedCallback.allow();
         }
 
         @Override
@@ -2734,4 +2743,49 @@ public class LocationProviderManager extends
             }
         }
     }
+
+    private static class GatedCallback implements Runnable {
+
+        private @Nullable Runnable mCallback;
+
+        @GuardedBy("this")
+        private boolean mGate;
+        @GuardedBy("this")
+        private boolean mRun;
+
+        GatedCallback(Runnable callback) {
+            mCallback = callback;
+        }
+
+        public void allow() {
+            Runnable callback = null;
+            synchronized (this) {
+                mGate = true;
+                if (mRun && mCallback != null) {
+                    callback = mCallback;
+                    mCallback = null;
+                }
+            }
+
+            if (callback != null) {
+                callback.run();
+            }
+        }
+
+        @Override
+        public void run() {
+            Runnable callback = null;
+            synchronized (this) {
+                mRun = true;
+                if (mGate && mCallback != null) {
+                    callback = mCallback;
+                    mCallback = null;
+                }
+            }
+
+            if (callback != null) {
+                callback.run();
+            }
+        }
+    }
 }