diff options
Diffstat (limited to 'services/net/java/android/net/util/FdEventsReader.java')
| -rw-r--r-- | services/net/java/android/net/util/FdEventsReader.java | 254 |
1 files changed, 0 insertions, 254 deletions
diff --git a/services/net/java/android/net/util/FdEventsReader.java b/services/net/java/android/net/util/FdEventsReader.java deleted file mode 100644 index 8bbf449f6374..000000000000 --- a/services/net/java/android/net/util/FdEventsReader.java +++ /dev/null @@ -1,254 +0,0 @@ -/* - * Copyright (C) 2016 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.net.util; - -import static android.os.MessageQueue.OnFileDescriptorEventListener.EVENT_INPUT; -import static android.os.MessageQueue.OnFileDescriptorEventListener.EVENT_ERROR; - -import android.annotation.NonNull; -import android.annotation.Nullable; -import android.os.Handler; -import android.os.Looper; -import android.os.MessageQueue; -import android.system.ErrnoException; -import android.system.OsConstants; - -import libcore.io.IoUtils; - -import java.io.FileDescriptor; - - -/** - * This class encapsulates the mechanics of registering a file descriptor - * with a thread's Looper and handling read events (and errors). - * - * Subclasses MUST implement createFd() and SHOULD override handlePacket(). They MAY override - * onStop() and onStart(). - * - * Subclasses can expect a call life-cycle like the following: - * - * [1] when a client calls start(), createFd() is called, followed by the onStart() hook if all - * goes well. Implementations may override onStart() for additional initialization. - * - * [2] yield, waiting for read event or error notification: - * - * [a] readPacket() && handlePacket() - * - * [b] if (no error): - * goto 2 - * else: - * goto 3 - * - * [3] when a client calls stop(), the onStop() hook is called (unless already stopped or never - * started). Implementations may override onStop() for additional cleanup. - * - * The packet receive buffer is recycled on every read call, so subclasses - * should make any copies they would like inside their handlePacket() - * implementation. - * - * All public methods MUST only be called from the same thread with which - * the Handler constructor argument is associated. - * - * @hide - */ -public abstract class FdEventsReader<BufferType> { - private static final int FD_EVENTS = EVENT_INPUT | EVENT_ERROR; - private static final int UNREGISTER_THIS_FD = 0; - - @NonNull - private final Handler mHandler; - @NonNull - private final MessageQueue mQueue; - @NonNull - private final BufferType mBuffer; - @Nullable - private FileDescriptor mFd; - private long mPacketsReceived; - - protected static void closeFd(FileDescriptor fd) { - IoUtils.closeQuietly(fd); - } - - protected FdEventsReader(@NonNull Handler h, @NonNull BufferType buffer) { - mHandler = h; - mQueue = mHandler.getLooper().getQueue(); - mBuffer = buffer; - } - - public void start() { - if (onCorrectThread()) { - createAndRegisterFd(); - } else { - mHandler.post(() -> { - logError("start() called from off-thread", null); - createAndRegisterFd(); - }); - } - } - - public void stop() { - if (onCorrectThread()) { - unregisterAndDestroyFd(); - } else { - mHandler.post(() -> { - logError("stop() called from off-thread", null); - unregisterAndDestroyFd(); - }); - } - } - - @NonNull - public Handler getHandler() { return mHandler; } - - protected abstract int recvBufSize(@NonNull BufferType buffer); - - public int recvBufSize() { return recvBufSize(mBuffer); } - - /** - * Get the number of successful calls to {@link #readPacket(FileDescriptor, Object)}. - * - * <p>A call was successful if {@link #readPacket(FileDescriptor, Object)} returned a value > 0. - */ - public final long numPacketsReceived() { return mPacketsReceived; } - - /** - * Subclasses MUST create the listening socket here, including setting - * all desired socket options, interface or address/port binding, etc. - */ - @Nullable - protected abstract FileDescriptor createFd(); - - /** - * Implementations MUST return the bytes read or throw an Exception. - * - * <p>The caller may throw a {@link ErrnoException} with {@link OsConstants#EAGAIN} or - * {@link OsConstants#EINTR}, in which case {@link FdEventsReader} will ignore the buffer - * contents and respectively wait for further input or retry the read immediately. For all other - * exceptions, the {@link FdEventsReader} will be stopped with no more interactions with this - * method. - */ - protected abstract int readPacket(@NonNull FileDescriptor fd, @NonNull BufferType buffer) - throws Exception; - - /** - * Called by the main loop for every packet. Any desired copies of - * |recvbuf| should be made in here, as the underlying byte array is - * reused across all reads. - */ - protected void handlePacket(@NonNull BufferType recvbuf, int length) {} - - /** - * Called by the main loop to log errors. In some cases |e| may be null. - */ - protected void logError(@NonNull String msg, @Nullable Exception e) {} - - /** - * Called by start(), if successful, just prior to returning. - */ - protected void onStart() {} - - /** - * Called by stop() just prior to returning. - */ - protected void onStop() {} - - private void createAndRegisterFd() { - if (mFd != null) return; - - try { - mFd = createFd(); - if (mFd != null) { - // Force the socket to be non-blocking. - IoUtils.setBlocking(mFd, false); - } - } catch (Exception e) { - logError("Failed to create socket: ", e); - closeFd(mFd); - mFd = null; - } - - if (mFd == null) return; - - mQueue.addOnFileDescriptorEventListener( - mFd, - FD_EVENTS, - (fd, events) -> { - // Always call handleInput() so read/recvfrom are given - // a proper chance to encounter a meaningful errno and - // perhaps log a useful error message. - if (!isRunning() || !handleInput()) { - unregisterAndDestroyFd(); - return UNREGISTER_THIS_FD; - } - return FD_EVENTS; - }); - onStart(); - } - - private boolean isRunning() { return (mFd != null) && mFd.valid(); } - - // Keep trying to read until we get EAGAIN/EWOULDBLOCK or some fatal error. - private boolean handleInput() { - while (isRunning()) { - final int bytesRead; - - try { - bytesRead = readPacket(mFd, mBuffer); - if (bytesRead < 1) { - if (isRunning()) logError("Socket closed, exiting", null); - break; - } - mPacketsReceived++; - } catch (ErrnoException e) { - if (e.errno == OsConstants.EAGAIN) { - // We've read everything there is to read this time around. - return true; - } else if (e.errno == OsConstants.EINTR) { - continue; - } else { - if (isRunning()) logError("readPacket error: ", e); - break; - } - } catch (Exception e) { - if (isRunning()) logError("readPacket error: ", e); - break; - } - - try { - handlePacket(mBuffer, bytesRead); - } catch (Exception e) { - logError("handlePacket error: ", e); - break; - } - } - - return false; - } - - private void unregisterAndDestroyFd() { - if (mFd == null) return; - - mQueue.removeOnFileDescriptorEventListener(mFd); - closeFd(mFd); - mFd = null; - onStop(); - } - - private boolean onCorrectThread() { - return (mHandler.getLooper() == Looper.myLooper()); - } -} |