diff options
Diffstat (limited to 'third_party/libwebrtc/build/android/incremental_install/java/org/chromium/incrementalinstall/LockFile.java')
-rw-r--r-- | third_party/libwebrtc/build/android/incremental_install/java/org/chromium/incrementalinstall/LockFile.java | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/third_party/libwebrtc/build/android/incremental_install/java/org/chromium/incrementalinstall/LockFile.java b/third_party/libwebrtc/build/android/incremental_install/java/org/chromium/incrementalinstall/LockFile.java new file mode 100644 index 0000000000..19d1f7624e --- /dev/null +++ b/third_party/libwebrtc/build/android/incremental_install/java/org/chromium/incrementalinstall/LockFile.java @@ -0,0 +1,129 @@ +// Copyright 2015 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +package org.chromium.incrementalinstall; + +import android.util.Log; + +import java.io.File; +import java.io.FileOutputStream; +import java.io.IOException; +import java.nio.channels.FileLock; +import java.util.concurrent.Callable; + +/** + * Helpers for dealing with .lock files used during install / first run. + */ +final class LockFile { + private static final String TAG = "incrementalinstall"; + + private final File mFile; + private final FileOutputStream mOutputStream; + private final FileLock mFileLock; + + private LockFile(File file, FileOutputStream outputStream, FileLock fileLock) { + mFile = file; + mOutputStream = outputStream; + mFileLock = fileLock; + } + + /** + * Clears the lock file by writing to it (making it non-zero in length); + */ + static void clearInstallerLock(File lockFile) throws IOException { + Log.i(TAG, "Clearing " + lockFile); + // On Android M+, we can't delete files in /data/local/tmp, so we write to it instead. + FileOutputStream os = new FileOutputStream(lockFile); + os.write(1); + os.close(); + } + + /** + * Waits for the given file to be non-zero in length. + */ + static void waitForInstallerLock(final File file, long timeoutMs) { + pollingWait(new Callable<Boolean>() { + @Override public Boolean call() { + return !installerLockExists(file); + } + }, file, timeoutMs); + } + + /** + * Waits for the given file to be non-zero in length. + */ + private static void pollingWait(Callable<Boolean> func, File file, long timeoutMs) { + long pollIntervalMs = 200; + for (int i = 0; i < timeoutMs / pollIntervalMs; i++) { + try { + if (func.call()) { + if (i > 0) { + Log.i(TAG, "Finished waiting on lock file: " + file); + } + return; + } else if (i == 0) { + Log.i(TAG, "Waiting on lock file: " + file); + } + } catch (Exception e) { + throw new RuntimeException(e); + } + try { + Thread.sleep(pollIntervalMs); + } catch (InterruptedException e) { + // Should never happen. + } + } + throw new RuntimeException("Timed out waiting for lock file: " + file); + } + + /** + * Returns whether the given lock file is missing or is in the locked state. + */ + static boolean installerLockExists(File file) { + return !file.exists() || file.length() == 0; + } + + /** + * Attempts to acquire a lock for the given file. + * @return Returns the FileLock if it was acquired, or null otherwise. + */ + static LockFile acquireRuntimeLock(File file) { + try { + FileOutputStream outputStream = new FileOutputStream(file); + FileLock lock = outputStream.getChannel().tryLock(); + if (lock != null) { + Log.i(TAG, "Created lock file: " + file); + return new LockFile(file, outputStream, lock); + } + outputStream.close(); + } catch (IOException e) { + // Do nothing. We didn't get the lock. + Log.w(TAG, "Exception trying to acquire lock " + file, e); + } + return null; + } + + /** + * Waits for the given file to not exist. + */ + static void waitForRuntimeLock(final File file, long timeoutMs) { + pollingWait(new Callable<Boolean>() { + @Override public Boolean call() { + return !file.exists(); + } + }, file, timeoutMs); + } + + /** + * Releases and deletes the lock file. + */ + void release() throws IOException { + Log.i(TAG, "Deleting lock file: " + mFile); + mFileLock.release(); + mOutputStream.close(); + if (!mFile.delete()) { + throw new IOException("Failed to delete lock file: " + mFile); + } + } +} |