Make network usage on the main thread fatal (Honeycomb+)

For apps targetting Honeycomb SDK or above, make network usage on the
main thread (aka event thread, Looper thread, UI thread) be fatal.

If an app is targetting a previous SDK version, they're grandfathered
into the older (lack of) rules.

Bug: 786847
Change-Id: Ia4ae77b8369567ee526c96b930d523bc722b0bc9

api/current.xml

@@ -138635,6 +138635,23 @@
 >
 </field>
 </class>
+<class name="NetworkOnMainThreadException"
+ extends="java.lang.RuntimeException"
+ abstract="false"
+ static="false"
+ final="false"
+ deprecated="not deprecated"
+ visibility="public"
+>
+<constructor name="NetworkOnMainThreadException"
+ type="android.os.NetworkOnMainThreadException"
+ static="false"
+ final="false"
+ deprecated="not deprecated"
+ visibility="public"
+>
+</constructor>
+</class>
 <class name="Parcel"
  extends="java.lang.Object"
  abstract="false"
@@ -141746,6 +141763,17 @@
  visibility="public"
 >
 </method>
+<method name="penaltyDeathOnNetwork"
+ return="android.os.StrictMode.ThreadPolicy.Builder"
+ abstract="false"
+ native="false"
+ synchronized="false"
+ static="false"
+ final="false"
+ deprecated="not deprecated"
+ visibility="public"
+>
+</method>
 <method name="penaltyDialog"
  return="android.os.StrictMode.ThreadPolicy.Builder"
  abstract="false"
@@ -245077,7 +245105,7 @@
  deprecated="not deprecated"
  visibility="public"
 >
-<parameter name="t" type="T">
+<parameter name="arg0" type="T">
 </parameter>
 </method>
 </interface>

core/java/android/app/ActivityThread.java

@@ -3187,6 +3187,17 @@ public final class ActivityThread {
             StrictMode.conditionallyEnableDebugLogging();
         }
 
+        /**
+         * For apps targetting SDK Honeycomb or later, we don't allow
+         * network usage on the main event loop / UI thread.
+         *
+         * Note to those grepping:  this is what ultimately throws
+         * NetworkOnMainThreadException ...
+         */
+        if (data.appInfo.targetSdkVersion > 9) {
+            StrictMode.enableDeathOnNetwork();
+        }
+
         /**
          * Switch this process to density compatibility mode if needed.
          */

core/java/android/os/NetworkOnMainThreadException.java

@@ -0,0 +1,32 @@
+/*
+ * Copyright (C) 2010 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 android.os;
+
+/**
+ * The exception that is thrown when an application attempts
+ * to perform a networking operation on its main thread.
+ *
+ * <p>This is only thrown for applications targeting the Honeycomb
+ * SDK or higher.  Applications targeting earlier SDK versions
+ * are allowed to do networking on their main event loop threads,
+ * but it's heavily discouraged.  See the document
+ * <a href="{@docRoot}guide/practices/design/responsiveness.html">
+ * Designing for Responsiveness</a>.
+ *
+ * <p>Also see {@link StrictMode}.
+ */
+public class NetworkOnMainThreadException extends RuntimeException {
+}

core/java/android/os/StrictMode.java

@@ -150,10 +150,19 @@ public final class StrictMode {
     public static final int PENALTY_DIALOG = 0x20;
 
     /**
+     * Death on any detected violation.
+     *
      * @hide
      */
     public static final int PENALTY_DEATH = 0x40;
 
+    /**
+     * Death just for detected network usage.
+     *
+     * @hide
+     */
+    public static final int PENALTY_DEATH_ON_NETWORK = 0x200;
+
     /**
      * @hide
      */
@@ -176,7 +185,8 @@ public final class StrictMode {
      * Mask of all the penalty bits.
      */
     private static final int PENALTY_MASK =
-            PENALTY_LOG | PENALTY_DIALOG | PENALTY_DEATH | PENALTY_DROPBOX | PENALTY_GATHER;
+            PENALTY_LOG | PENALTY_DIALOG | PENALTY_DEATH | PENALTY_DROPBOX | PENALTY_GATHER |
+            PENALTY_DEATH_ON_NETWORK;
 
     /**
      * The current VmPolicy in effect.
@@ -323,11 +333,27 @@ public final class StrictMode {
              * Crash the whole process on violation.  This penalty runs at
              * the end of all enabled penalties so you'll still get
              * see logging or other violations before the process dies.
+             *
+             * <p>Unlike {@link #penaltyDeathOnNetwork}, this applies
+             * to disk reads, disk writes, and network usage if their
+             * corresponding detect flags are set.
              */
             public Builder penaltyDeath() {
                 return enable(PENALTY_DEATH);
             }
 
+            /**
+             * Crash the whole process on any network usage.  Unlike
+             * {@link #penaltyDeath}, this penalty runs
+             * <em>before</em> anything else.  You must still have
+             * called {@link #detectNetwork} to enable this.
+             *
+             * <p>In the Honeycomb or later SDKs, this is on by default.
+             */
+            public Builder penaltyDeathOnNetwork() {
+                return enable(PENALTY_DEATH_ON_NETWORK);
+            }
+
             /**
              * Log detected violations to the system log.
              */
@@ -648,6 +674,18 @@ public final class StrictMode {
         return true;
     }
 
+    /**
+     * Used by the framework to make network usage on the main
+     * thread a fatal error.
+     *
+     * @hide
+     */
+    public static void enableDeathOnNetwork() {
+        int oldPolicy = getThreadPolicyMask();
+        int newPolicy = oldPolicy | DETECT_NETWORK | PENALTY_DEATH_ON_NETWORK;
+        setThreadPolicyMask(newPolicy);
+    }
+
     /**
      * Parses the BlockGuard policy mask out from the Exception's
      * getMessage() String value.  Kinda gross, but least
@@ -758,6 +796,9 @@ public final class StrictMode {
             if ((mPolicyMask & DETECT_NETWORK) == 0) {
                 return;
             }
+            if ((mPolicyMask & PENALTY_DEATH_ON_NETWORK) != 0) {
+                throw new NetworkOnMainThreadException();
+            }
             if (tooManyViolationsThisLoop()) {
                 return;
             }