commit 51f220dac29f3b988b668893f29f78c4c9a33473
author Sunny Goyal <sunnygoyal@google.com> Wed May 29 11:05:30 2019 -0700
committer Sunny Goyal <sunnygoyal@google.com> Wed May 29 11:07:10 2019 -0700
tree e03c340b01687524f9274e3c5a2ffa2c0d8a934d
parent 5860288fc85dd45cd58e85be5454c8191bd38e23

Fixing ANR when loader task could run while helding the lock object

During AppWidgetRestoredReceiver, we call forceReload from worker thread
which in turn starts the loader while holding mLock. This causes other
loader calls on UI thread to cause ANR

Bug: 133651528
Change-Id: Iabf983c4319bd6e6ef88e74fe6076289294454f9

src/com/android/launcher3/LauncherModel.java

diff --git a/src/com/android/launcher3/LauncherModel.java b/src/com/android/launcher3/LauncherModel.java
index e7b4ff4..ac392a6 100644
--- a/src/com/android/launcher3/LauncherModel.java
+++ b/src/com/android/launcher3/LauncherModel.java
@@ -165,17 +165,6 @@
         mBgAllAppsList = new AllAppsList(iconCache, appFilter);
     }
 
-    /** Runs the specified runnable immediately if called from the worker thread, otherwise it is
-     * posted on the worker thread handler. */
-    private static void runOnWorkerThread(Runnable r) {
-        if (sWorkerThread.getThreadId() == Process.myTid()) {
-            r.run();
-        } else {
-            // If we are not on the worker thread, then post to the worker handler
-            sWorker.post(r);
-        }
-    }
-
     public void setPackageState(PackageInstallInfo installInfo) {
         enqueueModelUpdateTask(new PackageInstallStateChangedTask(installInfo));
     }
@@ -400,7 +389,10 @@
         synchronized (mLock) {
             stopLoader();
             mLoaderTask = new LoaderTask(mApp, mBgAllAppsList, sBgDataModel, results);
-            runOnWorkerThread(mLoaderTask);
+
+            // Always post the loader task, instead of running directly (even on same thread) so
+            // that we exit any nested synchronized blocks
+            sWorker.post(mLoaderTask);
         }
     }
 
@@ -505,7 +497,13 @@
 
     public void enqueueModelUpdateTask(ModelUpdateTask task) {
         task.init(mApp, this, sBgDataModel, mBgAllAppsList, mUiExecutor);
-        runOnWorkerThread(task);
+
+        if (sWorkerThread.getThreadId() == Process.myTid()) {
+            task.run();
+        } else {
+            // If we are not on the worker thread, then post to the worker handler
+            sWorker.post(task);
+        }
     }
 
     /**