Merge "Frameworks: Handle exceptions in SystemProperties callbacks"

core/java/android/os/SystemProperties.java

@@ -189,7 +189,12 @@ public class SystemProperties {
             }
             ArrayList<Runnable> callbacks = new ArrayList<Runnable>(sChangeCallbacks);
             for (int i=0; i<callbacks.size(); i++) {
-                callbacks.get(i).run();
+                try {
+                    callbacks.get(i).run();
+                } catch (Throwable t) {
+                    Log.wtf(TAG, "Exception in SystemProperties change callback", t);
+                    // Ignore and try to go on.
+                }
             }
         }
     }

core/jni/android_os_SystemProperties.cpp

@@ -124,6 +124,12 @@ void do_report_sysprop_change() {
         if (sVM->GetEnv((void **)&env, JNI_VERSION_1_4) >= 0) {
             //ALOGI("Java SystemProperties: calling %p", sCallChangeCallbacks);
             env->CallStaticVoidMethod(sClazz, sCallChangeCallbacks);
+            // There should not be any exceptions. But we must guarantee
+            // there are none on return.
+            if (env->ExceptionCheck()) {
+                env->ExceptionClear();
+                LOG(ERROR) << "Exception pending after sysprop_change!";
+            }
         }
     }
 }

core/tests/systemproperties/src/android/os/SystemPropertiesTest.java

@@ -16,6 +16,9 @@
 
 package android.os;
 
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+
 import junit.framework.TestCase;
 
 import android.os.SystemProperties;
@@ -141,4 +144,48 @@ public class SystemPropertiesTest extends TestCase {
         } catch (NullPointerException npe) {
         }
     }
+
+    @SmallTest
+    public void testCallbacks() {
+        // Latches are not really necessary, but are easy to use.
+        final CountDownLatch wait1 = new CountDownLatch(1);
+        final CountDownLatch wait2 = new CountDownLatch(1);
+
+        Runnable r1 = new Runnable() {
+            boolean done = false;
+            @Override
+            public void run() {
+                if (done) {
+                    return;
+                }
+                done = true;
+
+                wait1.countDown();
+                throw new RuntimeException("test");
+            }
+        };
+
+        Runnable r2 = new Runnable() {
+            @Override
+            public void run() {
+                wait2.countDown();
+            }
+        };
+
+        SystemProperties.addChangeCallback(r1);
+        SystemProperties.addChangeCallback(r2);
+
+        SystemProperties.reportSyspropChanged();
+
+        try {
+            assertTrue(wait1.await(5, TimeUnit.SECONDS));
+        } catch (InterruptedException e) {
+            fail("InterruptedException");
+        }
+        try {
+            assertTrue(wait2.await(5, TimeUnit.SECONDS));
+        } catch (InterruptedException e) {
+            fail("InterruptedException");
+        }
+    }
 }