Migrate Tethering#dump to use runWithScissorsForDump
This change includes:
1. Refactor the logic in Tethering#dump into utils class.
2. Move the utils class to a common place which could be referenced
from other sub-modules.
3. Add @MonitorThreadLeak annotation to enforce
there is no thread leak problem.
Test: atest FrameworksNetTests NetworkStaticLibTests
Test: atest ConnectivityCoverageTests:com.android.networkstack.tethering.TetheringTest#testDumpTetheringLog
Test: adb shell dumpsys tethering (with hardcoded exception)
Fix: 312669345
Change-Id: Ia6fdfeeec2110afa0ec9e056e9db3843748845c3
diff --git a/Tethering/src/com/android/networkstack/tethering/Tethering.java b/Tethering/src/com/android/networkstack/tethering/Tethering.java
index 5022b40..552b105 100644
--- a/Tethering/src/com/android/networkstack/tethering/Tethering.java
+++ b/Tethering/src/com/android/networkstack/tethering/Tethering.java
@@ -136,6 +136,7 @@
import com.android.modules.utils.build.SdkLevel;
import com.android.net.module.util.BaseNetdUnsolicitedEventListener;
import com.android.net.module.util.CollectionUtils;
+import com.android.net.module.util.HandlerUtils;
import com.android.net.module.util.NetdUtils;
import com.android.net.module.util.SdkUtil.LateSdk;
import com.android.net.module.util.SharedLog;
@@ -161,11 +162,8 @@
import java.util.List;
import java.util.Objects;
import java.util.Set;
-import java.util.concurrent.CountDownLatch;
import java.util.concurrent.Executor;
import java.util.concurrent.RejectedExecutionException;
-import java.util.concurrent.TimeUnit;
-import java.util.concurrent.atomic.AtomicReference;
/**
*
@@ -2694,31 +2692,10 @@
return;
}
- final CountDownLatch latch = new CountDownLatch(1);
-
- // Don't crash the system if something in doDump throws an exception, but try to propagate
- // the exception to the caller.
- AtomicReference<RuntimeException> exceptionRef = new AtomicReference<>();
- mHandler.post(() -> {
- try {
- doDump(fd, writer, args);
- } catch (RuntimeException e) {
- exceptionRef.set(e);
- }
- latch.countDown();
- });
-
- try {
- if (!latch.await(DUMP_TIMEOUT_MS, TimeUnit.MILLISECONDS)) {
- writer.println("Dump timeout after " + DUMP_TIMEOUT_MS + "ms");
- return;
- }
- } catch (InterruptedException e) {
- exceptionRef.compareAndSet(null, new IllegalStateException("Dump interrupted", e));
+ if (!HandlerUtils.runWithScissorsForDump(mHandler, () -> doDump(fd, writer, args),
+ DUMP_TIMEOUT_MS)) {
+ writer.println("Dump timeout after " + DUMP_TIMEOUT_MS + "ms");
}
-
- final RuntimeException e = exceptionRef.get();
- if (e != null) throw e;
}
private void maybeDhcpLeasesChanged() {
diff --git a/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringTest.java b/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringTest.java
index 82b8845..750bfce 100644
--- a/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringTest.java
+++ b/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringTest.java
@@ -2810,12 +2810,10 @@
final FileDescriptor mockFd = mock(FileDescriptor.class);
final PrintWriter mockPw = mock(PrintWriter.class);
runUsbTethering(null);
- mLooper.startAutoDispatch();
mTethering.dump(mockFd, mockPw, new String[0]);
verify(mConfig).dump(any());
verify(mEntitleMgr).dump(any());
verify(mOffloadCtrl).dump(any());
- mLooper.stopAutoDispatch();
}
@Test
diff --git a/service/src/com/android/server/ConnectivityService.java b/service/src/com/android/server/ConnectivityService.java
index b4efa34..31b14ef 100755
--- a/service/src/com/android/server/ConnectivityService.java
+++ b/service/src/com/android/server/ConnectivityService.java
@@ -291,6 +291,7 @@
import com.android.net.module.util.BpfUtils;
import com.android.net.module.util.CollectionUtils;
import com.android.net.module.util.DeviceConfigUtils;
+import com.android.net.module.util.HandlerUtils;
import com.android.net.module.util.InterfaceParams;
import com.android.net.module.util.LinkPropertiesUtils.CompareOrUpdateResult;
import com.android.net.module.util.LinkPropertiesUtils.CompareResult;
@@ -315,7 +316,6 @@
import com.android.server.connectivity.DnsManager.PrivateDnsValidationUpdate;
import com.android.server.connectivity.DscpPolicyTracker;
import com.android.server.connectivity.FullScore;
-import com.android.server.connectivity.HandlerUtils;
import com.android.server.connectivity.InvalidTagException;
import com.android.server.connectivity.KeepaliveResourceUtil;
import com.android.server.connectivity.KeepaliveTracker;
@@ -1280,7 +1280,7 @@
LocalPriorityDump() {}
private void dumpHigh(FileDescriptor fd, PrintWriter pw) {
- if (!HandlerUtils.runWithScissors(mHandler, () -> {
+ if (!HandlerUtils.runWithScissorsForDump(mHandler, () -> {
doDump(fd, pw, new String[]{DIAG_ARG});
doDump(fd, pw, new String[]{SHORT_ARG});
}, DUMPSYS_DEFAULT_TIMEOUT_MS)) {
@@ -1289,7 +1289,7 @@
}
private void dumpNormal(FileDescriptor fd, PrintWriter pw, String[] args) {
- if (!HandlerUtils.runWithScissors(mHandler, () -> doDump(fd, pw, args),
+ if (!HandlerUtils.runWithScissorsForDump(mHandler, () -> doDump(fd, pw, args),
DUMPSYS_DEFAULT_TIMEOUT_MS)) {
pw.println("dumpNormal timeout");
}
diff --git a/service/src/com/android/server/connectivity/HandlerUtils.java b/service/src/com/android/server/connectivity/HandlerUtils.java
deleted file mode 100644
index 997ecbf..0000000
--- a/service/src/com/android/server/connectivity/HandlerUtils.java
+++ /dev/null
@@ -1,139 +0,0 @@
-/*
- * Copyright (C) 2023 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 com.android.server.connectivity;
-
-import android.annotation.NonNull;
-import android.os.Handler;
-import android.os.Looper;
-import android.os.SystemClock;
-
-/**
- * Helper class for Handler related utilities.
- *
- * @hide
- */
-public class HandlerUtils {
- // Note: @hide methods copied from android.os.Handler
- /**
- * Runs the specified task synchronously.
- * <p>
- * If the current thread is the same as the handler thread, then the runnable
- * runs immediately without being enqueued. Otherwise, posts the runnable
- * to the handler and waits for it to complete before returning.
- * </p><p>
- * This method is dangerous! Improper use can result in deadlocks.
- * Never call this method while any locks are held or use it in a
- * possibly re-entrant manner.
- * </p><p>
- * This method is occasionally useful in situations where a background thread
- * must synchronously await completion of a task that must run on the
- * handler's thread. However, this problem is often a symptom of bad design.
- * Consider improving the design (if possible) before resorting to this method.
- * </p><p>
- * One example of where you might want to use this method is when you just
- * set up a Handler thread and need to perform some initialization steps on
- * it before continuing execution.
- * </p><p>
- * If timeout occurs then this method returns <code>false</code> but the runnable
- * will remain posted on the handler and may already be in progress or
- * complete at a later time.
- * </p><p>
- * When using this method, be sure to use {@link Looper#quitSafely} when
- * quitting the looper. Otherwise {@link #runWithScissors} may hang indefinitely.
- * (TODO: We should fix this by making MessageQueue aware of blocking runnables.)
- * </p>
- *
- * @param h The target handler.
- * @param r The Runnable that will be executed synchronously.
- * @param timeout The timeout in milliseconds, or 0 to wait indefinitely.
- *
- * @return Returns true if the Runnable was successfully executed.
- * Returns false on failure, usually because the
- * looper processing the message queue is exiting.
- *
- * @hide This method is prone to abuse and should probably not be in the API.
- * If we ever do make it part of the API, we might want to rename it to something
- * less funny like runUnsafe().
- */
- public static boolean runWithScissors(@NonNull Handler h, @NonNull Runnable r, long timeout) {
- if (r == null) {
- throw new IllegalArgumentException("runnable must not be null");
- }
- if (timeout < 0) {
- throw new IllegalArgumentException("timeout must be non-negative");
- }
-
- if (Looper.myLooper() == h.getLooper()) {
- r.run();
- return true;
- }
-
- BlockingRunnable br = new BlockingRunnable(r);
- return br.postAndWait(h, timeout);
- }
-
- private static final class BlockingRunnable implements Runnable {
- private final Runnable mTask;
- private boolean mDone;
-
- BlockingRunnable(Runnable task) {
- mTask = task;
- }
-
- @Override
- public void run() {
- try {
- mTask.run();
- } finally {
- synchronized (this) {
- mDone = true;
- notifyAll();
- }
- }
- }
-
- public boolean postAndWait(Handler handler, long timeout) {
- if (!handler.post(this)) {
- return false;
- }
-
- synchronized (this) {
- if (timeout > 0) {
- final long expirationTime = SystemClock.uptimeMillis() + timeout;
- while (!mDone) {
- long delay = expirationTime - SystemClock.uptimeMillis();
- if (delay <= 0) {
- return false; // timeout
- }
- try {
- wait(delay);
- } catch (InterruptedException ex) {
- }
- }
- } else {
- while (!mDone) {
- try {
- wait();
- } catch (InterruptedException ex) {
- }
- }
- }
- }
- return true;
- }
- }
-}
diff --git a/staticlibs/Android.bp b/staticlibs/Android.bp
index 9f1debc..04eb15c 100644
--- a/staticlibs/Android.bp
+++ b/staticlibs/Android.bp
@@ -43,6 +43,7 @@
"device/com/android/net/module/util/SharedLog.java",
"device/com/android/net/module/util/SocketUtils.java",
"device/com/android/net/module/util/FeatureVersions.java",
+ "device/com/android/net/module/util/HandlerUtils.java",
// This library is used by system modules, for which the system health impact of Kotlin
// has not yet been evaluated. Annotations may need jarjar'ing.
// "src_devicecommon/**/*.kt",
diff --git a/staticlibs/device/com/android/net/module/util/HandlerUtils.java b/staticlibs/device/com/android/net/module/util/HandlerUtils.java
new file mode 100644
index 0000000..c620368
--- /dev/null
+++ b/staticlibs/device/com/android/net/module/util/HandlerUtils.java
@@ -0,0 +1,105 @@
+/*
+ * Copyright (C) 2023 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 com.android.net.module.util;
+
+import android.annotation.NonNull;
+import android.os.Handler;
+import android.os.Looper;
+
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicReference;
+
+/**
+ * Helper class for Handler related utilities.
+ *
+ * @hide
+ */
+public class HandlerUtils {
+ /**
+ * Runs the specified task synchronously for dump method.
+ * <p>
+ * If the current thread is the same as the handler thread, then the runnable
+ * runs immediately without being enqueued. Otherwise, posts the runnable
+ * to the handler and waits for it to complete before returning.
+ * </p><p>
+ * This method is dangerous! Improper use can result in deadlocks.
+ * Never call this method while any locks are held or use it in a
+ * possibly re-entrant manner.
+ * </p><p>
+ * This method is made to let dump method access members on the handler thread to
+ * avoid concurrent access problems or races.
+ * </p><p>
+ * If timeout occurs then this method returns <code>false</code> but the runnable
+ * will remain posted on the handler and may already be in progress or
+ * complete at a later time.
+ * </p><p>
+ * When using this method, be sure to use {@link Looper#quitSafely} when
+ * quitting the looper. Otherwise {@link #runWithScissorsForDump} may hang indefinitely.
+ * (TODO: We should fix this by making MessageQueue aware of blocking runnables.)
+ * </p>
+ *
+ * @param h The target handler.
+ * @param r The Runnable that will be executed synchronously.
+ * @param timeout The timeout in milliseconds, or 0 to not wait at all.
+ *
+ * @return Returns true if the Runnable was successfully executed.
+ * Returns false on failure, usually because the
+ * looper processing the message queue is exiting.
+ *
+ * @hide
+ */
+ public static boolean runWithScissorsForDump(@NonNull Handler h, @NonNull Runnable r,
+ long timeout) {
+ if (r == null) {
+ throw new IllegalArgumentException("runnable must not be null");
+ }
+ if (timeout < 0) {
+ throw new IllegalArgumentException("timeout must be non-negative");
+ }
+ if (Looper.myLooper() == h.getLooper()) {
+ r.run();
+ return true;
+ }
+
+ final CountDownLatch latch = new CountDownLatch(1);
+
+ // Don't crash in the handler if something in the runnable throws an exception,
+ // but try to propagate the exception to the caller.
+ AtomicReference<RuntimeException> exceptionRef = new AtomicReference<>();
+ h.post(() -> {
+ try {
+ r.run();
+ } catch (RuntimeException e) {
+ exceptionRef.set(e);
+ }
+ latch.countDown();
+ });
+
+ try {
+ if (!latch.await(timeout, TimeUnit.MILLISECONDS)) {
+ return false;
+ }
+ } catch (InterruptedException e) {
+ exceptionRef.compareAndSet(null, new IllegalStateException("Thread interrupted", e));
+ }
+
+ final RuntimeException e = exceptionRef.get();
+ if (e != null) throw e;
+ return true;
+ }
+}
diff --git a/tests/unit/java/com/android/server/HandlerUtilsTest.kt b/staticlibs/tests/unit/src/com/android/net/module/util/HandlerUtilsTest.kt
similarity index 90%
rename from tests/unit/java/com/android/server/HandlerUtilsTest.kt
rename to staticlibs/tests/unit/src/com/android/net/module/util/HandlerUtilsTest.kt
index 62bb651..f2c902f 100644
--- a/tests/unit/java/com/android/server/HandlerUtilsTest.kt
+++ b/staticlibs/tests/unit/src/com/android/net/module/util/HandlerUtilsTest.kt
@@ -14,11 +14,11 @@
* limitations under the License.
*/
-package com.android.server
+package com.android.net.module.util
import android.os.HandlerThread
-import com.android.server.connectivity.HandlerUtils
import com.android.testutils.DevSdkIgnoreRunner
+import com.android.testutils.DevSdkIgnoreRunner.MonitorThreadLeak
import kotlin.test.assertEquals
import kotlin.test.assertTrue
import org.junit.After
@@ -27,6 +27,8 @@
const val THREAD_BLOCK_TIMEOUT_MS = 1000L
const val TEST_REPEAT_COUNT = 100
+
+@MonitorThreadLeak
@RunWith(DevSdkIgnoreRunner::class)
class HandlerUtilsTest {
val handlerThread = HandlerThread("HandlerUtilsTestHandlerThread").also {
@@ -39,7 +41,7 @@
// Repeat the test a fair amount of times to ensure that it does not pass by chance.
repeat(TEST_REPEAT_COUNT) {
var result = false
- HandlerUtils.runWithScissors(handler, {
+ HandlerUtils.runWithScissorsForDump(handler, {
assertEquals(Thread.currentThread(), handlerThread)
result = true
}, THREAD_BLOCK_TIMEOUT_MS)