| // Copyright 2012 The Chromium Authors |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| package org.chromium.base; |
| |
| import android.os.Handler; |
| import android.os.Looper; |
| import android.os.Process; |
| |
| import org.jni_zero.CalledByNative; |
| |
| import org.chromium.base.task.PostTask; |
| import org.chromium.base.task.TaskTraits; |
| |
| import java.util.concurrent.Callable; |
| import java.util.concurrent.ExecutionException; |
| import java.util.concurrent.FutureTask; |
| |
| /** Helper methods to deal with threading related tasks. */ |
| public class ThreadUtils { |
| |
| private static final Object sLock = new Object(); |
| |
| private static volatile boolean sWillOverride; |
| |
| private static volatile Handler sUiThreadHandler; |
| |
| private static boolean sThreadAssertsDisabledForTesting; |
| |
| /** |
| * A helper object to ensure that interactions with a particular object only happens on a |
| * particular thread. |
| * |
| * Example: |
| * <pre> |
| * {@code |
| * class Foo { |
| * // Valid thread is set during construction here. |
| * private final ThreadChecker mThreadChecker = new ThreadChecker(); |
| * |
| * public void doFoo() { |
| * mThreadChecker.assertOnValidThread(); |
| * } |
| * } |
| * } |
| * </pre> |
| */ |
| public static class ThreadChecker { |
| private final long mThreadId = Process.myTid(); |
| |
| /** |
| * Asserts that the current thread is the same as the one the ThreadChecker was constructed |
| * on. |
| */ |
| public void assertOnValidThread() { |
| assert sThreadAssertsDisabledForTesting || mThreadId == Process.myTid() |
| : "Must only be used on a single thread."; |
| } |
| } |
| |
| public static void setWillOverrideUiThread() { |
| sWillOverride = true; |
| assert sUiThreadHandler == null; |
| } |
| |
| public static void clearUiThreadForTesting() { |
| sWillOverride = false; |
| PostTask.resetUiThreadForTesting(); // IN-TEST |
| sUiThreadHandler = null; |
| } |
| |
| public static void setUiThread(Looper looper) { |
| assert looper != null; |
| synchronized (sLock) { |
| if (sUiThreadHandler == null) { |
| Handler uiThreadHandler = new Handler(looper); |
| // Set up the UI Thread TaskExecutor before signaling readiness. |
| PostTask.onUiThreadReady(uiThreadHandler); |
| // volatile write signals readiness since other threads read it without acquiring |
| // sLock. |
| sUiThreadHandler = uiThreadHandler; |
| // Must come after PostTask is initialized since it uses PostTask. |
| TraceEvent.onUiThreadReady(); |
| } else if (sUiThreadHandler.getLooper() != looper) { |
| throw new RuntimeException( |
| "UI thread looper is already set to " |
| + sUiThreadHandler.getLooper() |
| + " (Main thread looper is " |
| + Looper.getMainLooper() |
| + "), cannot set to new looper " |
| + looper); |
| } |
| } |
| } |
| |
| public static Handler getUiThreadHandler() { |
| if (sUiThreadHandler != null) return sUiThreadHandler; |
| |
| if (sWillOverride) { |
| throw new RuntimeException("Did not yet override the UI thread"); |
| } |
| setUiThread(Looper.getMainLooper()); |
| return sUiThreadHandler; |
| } |
| |
| /** |
| * Run the supplied Runnable on the main thread. The method will block until the Runnable |
| * completes. |
| * |
| * Note that non-test usage of this function is heavily discouraged. For non-tests, use |
| * callbacks rather than blocking threads. |
| * |
| * @param r The Runnable to run. |
| */ |
| public static void runOnUiThreadBlocking(final Runnable r) { |
| PostTask.runSynchronously(TaskTraits.UI_DEFAULT, r); |
| } |
| |
| /** |
| * Run the supplied Callable on the main thread, wrapping any exceptions in a RuntimeException. |
| * The method will block until the Callable completes. |
| * |
| * Note that non-test usage of this function is heavily discouraged. For non-tests, use |
| * callbacks rather than blocking threads. |
| * |
| * @param c The Callable to run |
| * @return The result of the callable |
| */ |
| public static <T> T runOnUiThreadBlockingNoException(Callable<T> c) { |
| try { |
| return runOnUiThreadBlocking(c); |
| } catch (ExecutionException e) { |
| throw new RuntimeException("Error occurred waiting for callable", e); |
| } |
| } |
| |
| /** |
| * Run the supplied Callable on the main thread, The method will block until the Callable |
| * completes. |
| * |
| * Note that non-test usage of this function is heavily discouraged. For non-tests, use |
| * callbacks rather than blocking threads. |
| * |
| * @param c The Callable to run |
| * @return The result of the callable |
| * @throws ExecutionException c's exception |
| */ |
| public static <T> T runOnUiThreadBlocking(Callable<T> c) throws ExecutionException { |
| return PostTask.runSynchronously(TaskTraits.UI_DEFAULT, c); |
| } |
| |
| /** |
| * Run the supplied FutureTask on the main thread. The method will block only if the current |
| * thread is the main thread. |
| * |
| * @param task The FutureTask to run |
| * @return The queried task (to aid inline construction) |
| */ |
| public static <T> FutureTask<T> runOnUiThread(FutureTask<T> task) { |
| PostTask.runOrPostTask(TaskTraits.UI_DEFAULT, task); |
| return task; |
| } |
| |
| /** |
| * Run the supplied Callable on the main thread. The method will block only if the current |
| * thread is the main thread. |
| * |
| * @param c The Callable to run |
| * @return A FutureTask wrapping the callable to retrieve results |
| */ |
| public static <T> FutureTask<T> runOnUiThread(Callable<T> c) { |
| return runOnUiThread(new FutureTask<T>(c)); |
| } |
| |
| /** |
| * Run the supplied Runnable on the main thread. The method will block only if the current |
| * thread is the main thread. |
| * |
| * @param r The Runnable to run |
| */ |
| public static void runOnUiThread(Runnable r) { |
| PostTask.runOrPostTask(TaskTraits.UI_DEFAULT, r); |
| } |
| |
| /** |
| * Post the supplied FutureTask to run on the main thread. The method will not block, even if |
| * called on the UI thread. |
| * |
| * @param task The FutureTask to run |
| * @return The queried task (to aid inline construction) |
| */ |
| public static <T> FutureTask<T> postOnUiThread(FutureTask<T> task) { |
| PostTask.postTask(TaskTraits.UI_DEFAULT, task); |
| return task; |
| } |
| |
| /** |
| * Post the supplied Runnable to run on the main thread. The method will not block, even if |
| * called on the UI thread. |
| * |
| * @param r The Runnable to run |
| */ |
| public static void postOnUiThread(Runnable r) { |
| PostTask.postTask(TaskTraits.UI_DEFAULT, r); |
| } |
| |
| /** |
| * Post the supplied Runnable to run on the main thread after the given amount of time. The |
| * method will not block, even if called on the UI thread. |
| * |
| * @param r The Runnable to run |
| * @param delayMillis The delay in milliseconds until the Runnable will be run |
| */ |
| public static void postOnUiThreadDelayed(Runnable r, long delayMillis) { |
| PostTask.postDelayedTask(TaskTraits.UI_DEFAULT, r, delayMillis); |
| } |
| |
| /** |
| * Throw an exception (when DCHECKs are enabled) if currently not running on the UI thread. |
| * |
| * Can be disabled by setThreadAssertsDisabledForTesting(true). |
| */ |
| public static void assertOnUiThread() { |
| if (sThreadAssertsDisabledForTesting) return; |
| |
| assert runningOnUiThread() : "Must be called on the UI thread."; |
| } |
| |
| /** |
| * Throw an exception (regardless of build) if currently not running on the UI thread. |
| * |
| * Can be disabled by setThreadAssertsEnabledForTesting(false). |
| * |
| * @see #assertOnUiThread() |
| */ |
| public static void checkUiThread() { |
| if (!sThreadAssertsDisabledForTesting && !runningOnUiThread()) { |
| throw new IllegalStateException("Must be called on the UI thread."); |
| } |
| } |
| |
| /** |
| * Throw an exception (when DCHECKs are enabled) if currently running on the UI thread. |
| * |
| * Can be disabled by setThreadAssertsDisabledForTesting(true). |
| */ |
| public static void assertOnBackgroundThread() { |
| if (sThreadAssertsDisabledForTesting) return; |
| |
| assert !runningOnUiThread() : "Must be called on a thread other than UI."; |
| } |
| |
| /** |
| * Disables thread asserts. |
| * |
| * Can be used by tests where code that normally runs multi-threaded is going to run |
| * single-threaded for the test (otherwise asserts that are valid in production would fail in |
| * those tests). |
| */ |
| public static void setThreadAssertsDisabledForTesting(boolean disabled) { |
| sThreadAssertsDisabledForTesting = disabled; |
| ResettersForTesting.register(() -> sThreadAssertsDisabledForTesting = false); |
| } |
| |
| /** |
| * @return true iff the current thread is the main (UI) thread. |
| */ |
| public static boolean runningOnUiThread() { |
| return getUiThreadHandler().getLooper() == Looper.myLooper(); |
| } |
| |
| public static Looper getUiThreadLooper() { |
| return getUiThreadHandler().getLooper(); |
| } |
| |
| /** Set thread priority to audio. */ |
| @CalledByNative |
| public static void setThreadPriorityAudio(int tid) { |
| Process.setThreadPriority(tid, Process.THREAD_PRIORITY_AUDIO); |
| } |
| |
| /** |
| * Checks whether Thread priority is THREAD_PRIORITY_AUDIO or not. |
| * @param tid Thread id. |
| * @return true for THREAD_PRIORITY_AUDIO and false otherwise. |
| */ |
| @CalledByNative |
| private static boolean isThreadPriorityAudio(int tid) { |
| return Process.getThreadPriority(tid) == Process.THREAD_PRIORITY_AUDIO; |
| } |
| } |