| /* |
| * Copyright (C) 2006 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; |
| |
| import static android.system.OsConstants.AF_UNIX; |
| import static android.system.OsConstants.SEEK_SET; |
| import static android.system.OsConstants.SOCK_STREAM; |
| import static android.system.OsConstants.SOCK_SEQPACKET; |
| import static android.system.OsConstants.S_ISLNK; |
| import static android.system.OsConstants.S_ISREG; |
| |
| import android.content.BroadcastReceiver; |
| import android.content.ContentProvider; |
| import android.os.MessageQueue.OnFileDescriptorEventListener; |
| import android.system.ErrnoException; |
| import android.system.Os; |
| import android.system.OsConstants; |
| import android.system.StructStat; |
| import android.util.Log; |
| |
| import dalvik.system.CloseGuard; |
| import libcore.io.IoUtils; |
| import libcore.io.Memory; |
| |
| import java.io.Closeable; |
| import java.io.File; |
| import java.io.FileDescriptor; |
| import java.io.FileInputStream; |
| import java.io.FileNotFoundException; |
| import java.io.FileOutputStream; |
| import java.io.IOException; |
| import java.io.InterruptedIOException; |
| import java.net.DatagramSocket; |
| import java.net.Socket; |
| import java.nio.ByteOrder; |
| |
| /** |
| * The FileDescriptor returned by {@link Parcel#readFileDescriptor}, allowing |
| * you to close it when done with it. |
| */ |
| public class ParcelFileDescriptor implements Parcelable, Closeable { |
| private static final String TAG = "ParcelFileDescriptor"; |
| |
| private final FileDescriptor mFd; |
| |
| /** |
| * Optional socket used to communicate close events, status at close, and |
| * detect remote process crashes. |
| */ |
| private FileDescriptor mCommFd; |
| |
| /** |
| * Wrapped {@link ParcelFileDescriptor}, if any. Used to avoid |
| * double-closing {@link #mFd}. |
| */ |
| private final ParcelFileDescriptor mWrapped; |
| |
| /** |
| * Maximum {@link #mStatusBuf} size; longer status messages will be |
| * truncated. |
| */ |
| private static final int MAX_STATUS = 1024; |
| |
| /** |
| * Temporary buffer used by {@link #readCommStatus(FileDescriptor, byte[])}, |
| * allocated on-demand. |
| */ |
| private byte[] mStatusBuf; |
| |
| /** |
| * Status read by {@link #checkError()}, or null if not read yet. |
| */ |
| private Status mStatus; |
| |
| private volatile boolean mClosed; |
| |
| private final CloseGuard mGuard = CloseGuard.get(); |
| |
| /** |
| * For use with {@link #open}: if {@link #MODE_CREATE} has been supplied and |
| * this file doesn't already exist, then create the file with permissions |
| * such that any application can read it. |
| * |
| * @deprecated Creating world-readable files is very dangerous, and likely |
| * to cause security holes in applications. It is strongly |
| * discouraged; instead, applications should use more formal |
| * mechanism for interactions such as {@link ContentProvider}, |
| * {@link BroadcastReceiver}, and {@link android.app.Service}. |
| * There are no guarantees that this access mode will remain on |
| * a file, such as when it goes through a backup and restore. |
| */ |
| @Deprecated |
| public static final int MODE_WORLD_READABLE = 0x00000001; |
| |
| /** |
| * For use with {@link #open}: if {@link #MODE_CREATE} has been supplied and |
| * this file doesn't already exist, then create the file with permissions |
| * such that any application can write it. |
| * |
| * @deprecated Creating world-writable files is very dangerous, and likely |
| * to cause security holes in applications. It is strongly |
| * discouraged; instead, applications should use more formal |
| * mechanism for interactions such as {@link ContentProvider}, |
| * {@link BroadcastReceiver}, and {@link android.app.Service}. |
| * There are no guarantees that this access mode will remain on |
| * a file, such as when it goes through a backup and restore. |
| */ |
| @Deprecated |
| public static final int MODE_WORLD_WRITEABLE = 0x00000002; |
| |
| /** |
| * For use with {@link #open}: open the file with read-only access. |
| */ |
| public static final int MODE_READ_ONLY = 0x10000000; |
| |
| /** |
| * For use with {@link #open}: open the file with write-only access. |
| */ |
| public static final int MODE_WRITE_ONLY = 0x20000000; |
| |
| /** |
| * For use with {@link #open}: open the file with read and write access. |
| */ |
| public static final int MODE_READ_WRITE = 0x30000000; |
| |
| /** |
| * For use with {@link #open}: create the file if it doesn't already exist. |
| */ |
| public static final int MODE_CREATE = 0x08000000; |
| |
| /** |
| * For use with {@link #open}: erase contents of file when opening. |
| */ |
| public static final int MODE_TRUNCATE = 0x04000000; |
| |
| /** |
| * For use with {@link #open}: append to end of file while writing. |
| */ |
| public static final int MODE_APPEND = 0x02000000; |
| |
| /** |
| * Create a new ParcelFileDescriptor wrapped around another descriptor. By |
| * default all method calls are delegated to the wrapped descriptor. |
| */ |
| public ParcelFileDescriptor(ParcelFileDescriptor wrapped) { |
| // We keep a strong reference to the wrapped PFD, and rely on its |
| // finalizer to trigger CloseGuard. All calls are delegated to wrapper. |
| mWrapped = wrapped; |
| mFd = null; |
| mCommFd = null; |
| mClosed = true; |
| } |
| |
| /** {@hide} */ |
| public ParcelFileDescriptor(FileDescriptor fd) { |
| this(fd, null); |
| } |
| |
| /** {@hide} */ |
| public ParcelFileDescriptor(FileDescriptor fd, FileDescriptor commChannel) { |
| if (fd == null) { |
| throw new NullPointerException("FileDescriptor must not be null"); |
| } |
| mWrapped = null; |
| mFd = fd; |
| mCommFd = commChannel; |
| mGuard.open("close"); |
| } |
| |
| /** |
| * Create a new ParcelFileDescriptor accessing a given file. |
| * |
| * @param file The file to be opened. |
| * @param mode The desired access mode, must be one of |
| * {@link #MODE_READ_ONLY}, {@link #MODE_WRITE_ONLY}, or |
| * {@link #MODE_READ_WRITE}; may also be any combination of |
| * {@link #MODE_CREATE}, {@link #MODE_TRUNCATE}, |
| * {@link #MODE_WORLD_READABLE}, and |
| * {@link #MODE_WORLD_WRITEABLE}. |
| * @return a new ParcelFileDescriptor pointing to the given file. |
| * @throws FileNotFoundException if the given file does not exist or can not |
| * be opened with the requested mode. |
| * @see #parseMode(String) |
| */ |
| public static ParcelFileDescriptor open(File file, int mode) throws FileNotFoundException { |
| final FileDescriptor fd = openInternal(file, mode); |
| if (fd == null) return null; |
| |
| return new ParcelFileDescriptor(fd); |
| } |
| |
| /** |
| * Create a new ParcelFileDescriptor accessing a given file. |
| * |
| * @param file The file to be opened. |
| * @param mode The desired access mode, must be one of |
| * {@link #MODE_READ_ONLY}, {@link #MODE_WRITE_ONLY}, or |
| * {@link #MODE_READ_WRITE}; may also be any combination of |
| * {@link #MODE_CREATE}, {@link #MODE_TRUNCATE}, |
| * {@link #MODE_WORLD_READABLE}, and |
| * {@link #MODE_WORLD_WRITEABLE}. |
| * @param handler to call listener from; must not be null. |
| * @param listener to be invoked when the returned descriptor has been |
| * closed; must not be null. |
| * @return a new ParcelFileDescriptor pointing to the given file. |
| * @throws FileNotFoundException if the given file does not exist or can not |
| * be opened with the requested mode. |
| * @see #parseMode(String) |
| */ |
| public static ParcelFileDescriptor open(File file, int mode, Handler handler, |
| final OnCloseListener listener) throws IOException { |
| if (handler == null) { |
| throw new IllegalArgumentException("Handler must not be null"); |
| } |
| if (listener == null) { |
| throw new IllegalArgumentException("Listener must not be null"); |
| } |
| |
| final FileDescriptor fd = openInternal(file, mode); |
| if (fd == null) return null; |
| |
| final FileDescriptor[] comm = createCommSocketPair(); |
| final ParcelFileDescriptor pfd = new ParcelFileDescriptor(fd, comm[0]); |
| final MessageQueue queue = handler.getLooper().getQueue(); |
| queue.addOnFileDescriptorEventListener(comm[1], |
| OnFileDescriptorEventListener.EVENT_INPUT, new OnFileDescriptorEventListener() { |
| @Override |
| public int onFileDescriptorEvents(FileDescriptor fd, int events) { |
| Status status = null; |
| if ((events & OnFileDescriptorEventListener.EVENT_INPUT) != 0) { |
| final byte[] buf = new byte[MAX_STATUS]; |
| status = readCommStatus(fd, buf); |
| } else if ((events & OnFileDescriptorEventListener.EVENT_ERROR) != 0) { |
| status = new Status(Status.DEAD); |
| } |
| if (status != null) { |
| queue.removeOnFileDescriptorEventListener(fd); |
| IoUtils.closeQuietly(fd); |
| listener.onClose(status.asIOException()); |
| return 0; |
| } |
| return EVENT_INPUT; |
| } |
| }); |
| |
| return pfd; |
| } |
| |
| private static FileDescriptor openInternal(File file, int mode) throws FileNotFoundException { |
| if ((mode & MODE_READ_WRITE) == 0) { |
| throw new IllegalArgumentException( |
| "Must specify MODE_READ_ONLY, MODE_WRITE_ONLY, or MODE_READ_WRITE"); |
| } |
| |
| final String path = file.getPath(); |
| return Parcel.openFileDescriptor(path, mode); |
| } |
| |
| /** |
| * Create a new ParcelFileDescriptor that is a dup of an existing |
| * FileDescriptor. This obeys standard POSIX semantics, where the |
| * new file descriptor shared state such as file position with the |
| * original file descriptor. |
| */ |
| public static ParcelFileDescriptor dup(FileDescriptor orig) throws IOException { |
| try { |
| final FileDescriptor fd = Os.dup(orig); |
| return new ParcelFileDescriptor(fd); |
| } catch (ErrnoException e) { |
| throw e.rethrowAsIOException(); |
| } |
| } |
| |
| /** |
| * Create a new ParcelFileDescriptor that is a dup of the existing |
| * FileDescriptor. This obeys standard POSIX semantics, where the |
| * new file descriptor shared state such as file position with the |
| * original file descriptor. |
| */ |
| public ParcelFileDescriptor dup() throws IOException { |
| if (mWrapped != null) { |
| return mWrapped.dup(); |
| } else { |
| return dup(getFileDescriptor()); |
| } |
| } |
| |
| /** |
| * Create a new ParcelFileDescriptor from a raw native fd. The new |
| * ParcelFileDescriptor holds a dup of the original fd passed in here, |
| * so you must still close that fd as well as the new ParcelFileDescriptor. |
| * |
| * @param fd The native fd that the ParcelFileDescriptor should dup. |
| * |
| * @return Returns a new ParcelFileDescriptor holding a FileDescriptor |
| * for a dup of the given fd. |
| */ |
| public static ParcelFileDescriptor fromFd(int fd) throws IOException { |
| final FileDescriptor original = new FileDescriptor(); |
| original.setInt$(fd); |
| |
| try { |
| final FileDescriptor dup = Os.dup(original); |
| return new ParcelFileDescriptor(dup); |
| } catch (ErrnoException e) { |
| throw e.rethrowAsIOException(); |
| } |
| } |
| |
| /** |
| * Take ownership of a raw native fd in to a new ParcelFileDescriptor. |
| * The returned ParcelFileDescriptor now owns the given fd, and will be |
| * responsible for closing it. You must not close the fd yourself. |
| * |
| * @param fd The native fd that the ParcelFileDescriptor should adopt. |
| * |
| * @return Returns a new ParcelFileDescriptor holding a FileDescriptor |
| * for the given fd. |
| */ |
| public static ParcelFileDescriptor adoptFd(int fd) { |
| final FileDescriptor fdesc = new FileDescriptor(); |
| fdesc.setInt$(fd); |
| |
| return new ParcelFileDescriptor(fdesc); |
| } |
| |
| /** |
| * Create a new ParcelFileDescriptor from the specified Socket. The new |
| * ParcelFileDescriptor holds a dup of the original FileDescriptor in |
| * the Socket, so you must still close the Socket as well as the new |
| * ParcelFileDescriptor. |
| * |
| * @param socket The Socket whose FileDescriptor is used to create |
| * a new ParcelFileDescriptor. |
| * |
| * @return A new ParcelFileDescriptor with the FileDescriptor of the |
| * specified Socket. |
| */ |
| public static ParcelFileDescriptor fromSocket(Socket socket) { |
| FileDescriptor fd = socket.getFileDescriptor$(); |
| return fd != null ? new ParcelFileDescriptor(fd) : null; |
| } |
| |
| /** |
| * Create a new ParcelFileDescriptor from the specified DatagramSocket. |
| * |
| * @param datagramSocket The DatagramSocket whose FileDescriptor is used |
| * to create a new ParcelFileDescriptor. |
| * |
| * @return A new ParcelFileDescriptor with the FileDescriptor of the |
| * specified DatagramSocket. |
| */ |
| public static ParcelFileDescriptor fromDatagramSocket(DatagramSocket datagramSocket) { |
| FileDescriptor fd = datagramSocket.getFileDescriptor$(); |
| return fd != null ? new ParcelFileDescriptor(fd) : null; |
| } |
| |
| /** |
| * Create two ParcelFileDescriptors structured as a data pipe. The first |
| * ParcelFileDescriptor in the returned array is the read side; the second |
| * is the write side. |
| */ |
| public static ParcelFileDescriptor[] createPipe() throws IOException { |
| try { |
| final FileDescriptor[] fds = Os.pipe(); |
| return new ParcelFileDescriptor[] { |
| new ParcelFileDescriptor(fds[0]), |
| new ParcelFileDescriptor(fds[1]) }; |
| } catch (ErrnoException e) { |
| throw e.rethrowAsIOException(); |
| } |
| } |
| |
| /** |
| * Create two ParcelFileDescriptors structured as a data pipe. The first |
| * ParcelFileDescriptor in the returned array is the read side; the second |
| * is the write side. |
| * <p> |
| * The write end has the ability to deliver an error message through |
| * {@link #closeWithError(String)} which can be handled by the read end |
| * calling {@link #checkError()}, usually after detecting an EOF. |
| * This can also be used to detect remote crashes. |
| */ |
| public static ParcelFileDescriptor[] createReliablePipe() throws IOException { |
| try { |
| final FileDescriptor[] comm = createCommSocketPair(); |
| final FileDescriptor[] fds = Os.pipe(); |
| return new ParcelFileDescriptor[] { |
| new ParcelFileDescriptor(fds[0], comm[0]), |
| new ParcelFileDescriptor(fds[1], comm[1]) }; |
| } catch (ErrnoException e) { |
| throw e.rethrowAsIOException(); |
| } |
| } |
| |
| /** |
| * Create two ParcelFileDescriptors structured as a pair of sockets |
| * connected to each other. The two sockets are indistinguishable. |
| */ |
| public static ParcelFileDescriptor[] createSocketPair() throws IOException { |
| return createSocketPair(SOCK_STREAM); |
| } |
| |
| /** |
| * @hide |
| */ |
| public static ParcelFileDescriptor[] createSocketPair(int type) throws IOException { |
| try { |
| final FileDescriptor fd0 = new FileDescriptor(); |
| final FileDescriptor fd1 = new FileDescriptor(); |
| Os.socketpair(AF_UNIX, type, 0, fd0, fd1); |
| return new ParcelFileDescriptor[] { |
| new ParcelFileDescriptor(fd0), |
| new ParcelFileDescriptor(fd1) }; |
| } catch (ErrnoException e) { |
| throw e.rethrowAsIOException(); |
| } |
| } |
| |
| /** |
| * Create two ParcelFileDescriptors structured as a pair of sockets |
| * connected to each other. The two sockets are indistinguishable. |
| * <p> |
| * Both ends have the ability to deliver an error message through |
| * {@link #closeWithError(String)} which can be detected by the other end |
| * calling {@link #checkError()}, usually after detecting an EOF. |
| * This can also be used to detect remote crashes. |
| */ |
| public static ParcelFileDescriptor[] createReliableSocketPair() throws IOException { |
| return createReliableSocketPair(SOCK_STREAM); |
| } |
| |
| /** |
| * @hide |
| */ |
| public static ParcelFileDescriptor[] createReliableSocketPair(int type) throws IOException { |
| try { |
| final FileDescriptor[] comm = createCommSocketPair(); |
| final FileDescriptor fd0 = new FileDescriptor(); |
| final FileDescriptor fd1 = new FileDescriptor(); |
| Os.socketpair(AF_UNIX, type, 0, fd0, fd1); |
| return new ParcelFileDescriptor[] { |
| new ParcelFileDescriptor(fd0, comm[0]), |
| new ParcelFileDescriptor(fd1, comm[1]) }; |
| } catch (ErrnoException e) { |
| throw e.rethrowAsIOException(); |
| } |
| } |
| |
| private static FileDescriptor[] createCommSocketPair() throws IOException { |
| try { |
| // Use SOCK_SEQPACKET so that we have a guarantee that the status |
| // is written and read atomically as one unit and is not split |
| // across multiple IO operations. |
| final FileDescriptor comm1 = new FileDescriptor(); |
| final FileDescriptor comm2 = new FileDescriptor(); |
| Os.socketpair(AF_UNIX, SOCK_SEQPACKET, 0, comm1, comm2); |
| IoUtils.setBlocking(comm1, false); |
| IoUtils.setBlocking(comm2, false); |
| return new FileDescriptor[] { comm1, comm2 }; |
| } catch (ErrnoException e) { |
| throw e.rethrowAsIOException(); |
| } |
| } |
| |
| /** |
| * @hide Please use createPipe() or ContentProvider.openPipeHelper(). |
| * Gets a file descriptor for a read-only copy of the given data. |
| * |
| * @param data Data to copy. |
| * @param name Name for the shared memory area that may back the file descriptor. |
| * This is purely informative and may be {@code null}. |
| * @return A ParcelFileDescriptor. |
| * @throws IOException if there is an error while creating the shared memory area. |
| */ |
| @Deprecated |
| public static ParcelFileDescriptor fromData(byte[] data, String name) throws IOException { |
| if (data == null) return null; |
| MemoryFile file = new MemoryFile(name, data.length); |
| if (data.length > 0) { |
| file.writeBytes(data, 0, 0, data.length); |
| } |
| file.deactivate(); |
| FileDescriptor fd = file.getFileDescriptor(); |
| return fd != null ? new ParcelFileDescriptor(fd) : null; |
| } |
| |
| /** |
| * Converts a string representing a file mode, such as "rw", into a bitmask suitable for use |
| * with {@link #open}. |
| * <p> |
| * @param mode The string representation of the file mode. |
| * @return A bitmask representing the given file mode. |
| * @throws IllegalArgumentException if the given string does not match a known file mode. |
| */ |
| public static int parseMode(String mode) { |
| final int modeBits; |
| if ("r".equals(mode)) { |
| modeBits = ParcelFileDescriptor.MODE_READ_ONLY; |
| } else if ("w".equals(mode) || "wt".equals(mode)) { |
| modeBits = ParcelFileDescriptor.MODE_WRITE_ONLY |
| | ParcelFileDescriptor.MODE_CREATE |
| | ParcelFileDescriptor.MODE_TRUNCATE; |
| } else if ("wa".equals(mode)) { |
| modeBits = ParcelFileDescriptor.MODE_WRITE_ONLY |
| | ParcelFileDescriptor.MODE_CREATE |
| | ParcelFileDescriptor.MODE_APPEND; |
| } else if ("rw".equals(mode)) { |
| modeBits = ParcelFileDescriptor.MODE_READ_WRITE |
| | ParcelFileDescriptor.MODE_CREATE; |
| } else if ("rwt".equals(mode)) { |
| modeBits = ParcelFileDescriptor.MODE_READ_WRITE |
| | ParcelFileDescriptor.MODE_CREATE |
| | ParcelFileDescriptor.MODE_TRUNCATE; |
| } else { |
| throw new IllegalArgumentException("Bad mode '" + mode + "'"); |
| } |
| return modeBits; |
| } |
| |
| /** |
| * Retrieve the actual FileDescriptor associated with this object. |
| * |
| * @return Returns the FileDescriptor associated with this object. |
| */ |
| public FileDescriptor getFileDescriptor() { |
| if (mWrapped != null) { |
| return mWrapped.getFileDescriptor(); |
| } else { |
| return mFd; |
| } |
| } |
| |
| /** |
| * Return the total size of the file representing this fd, as determined by |
| * {@code stat()}. Returns -1 if the fd is not a file. |
| */ |
| public long getStatSize() { |
| if (mWrapped != null) { |
| return mWrapped.getStatSize(); |
| } else { |
| try { |
| final StructStat st = Os.fstat(mFd); |
| if (S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)) { |
| return st.st_size; |
| } else { |
| return -1; |
| } |
| } catch (ErrnoException e) { |
| Log.w(TAG, "fstat() failed: " + e); |
| return -1; |
| } |
| } |
| } |
| |
| /** |
| * This is needed for implementing AssetFileDescriptor.AutoCloseOutputStream, |
| * and I really don't think we want it to be public. |
| * @hide |
| */ |
| public long seekTo(long pos) throws IOException { |
| if (mWrapped != null) { |
| return mWrapped.seekTo(pos); |
| } else { |
| try { |
| return Os.lseek(mFd, pos, SEEK_SET); |
| } catch (ErrnoException e) { |
| throw e.rethrowAsIOException(); |
| } |
| } |
| } |
| |
| /** |
| * Return the native fd int for this ParcelFileDescriptor. The |
| * ParcelFileDescriptor still owns the fd, and it still must be closed |
| * through this API. |
| */ |
| public int getFd() { |
| if (mWrapped != null) { |
| return mWrapped.getFd(); |
| } else { |
| if (mClosed) { |
| throw new IllegalStateException("Already closed"); |
| } |
| return mFd.getInt$(); |
| } |
| } |
| |
| /** |
| * Return the native fd int for this ParcelFileDescriptor and detach it from |
| * the object here. You are now responsible for closing the fd in native |
| * code. |
| * <p> |
| * You should not detach when the original creator of the descriptor is |
| * expecting a reliable signal through {@link #close()} or |
| * {@link #closeWithError(String)}. |
| * |
| * @see #canDetectErrors() |
| */ |
| public int detachFd() { |
| if (mWrapped != null) { |
| return mWrapped.detachFd(); |
| } else { |
| if (mClosed) { |
| throw new IllegalStateException("Already closed"); |
| } |
| final int fd = getFd(); |
| Parcel.clearFileDescriptor(mFd); |
| writeCommStatusAndClose(Status.DETACHED, null); |
| mClosed = true; |
| mGuard.close(); |
| releaseResources(); |
| return fd; |
| } |
| } |
| |
| /** |
| * Close the ParcelFileDescriptor. This implementation closes the underlying |
| * OS resources allocated to represent this stream. |
| * |
| * @throws IOException |
| * If an error occurs attempting to close this ParcelFileDescriptor. |
| */ |
| @Override |
| public void close() throws IOException { |
| if (mWrapped != null) { |
| try { |
| mWrapped.close(); |
| } finally { |
| releaseResources(); |
| } |
| } else { |
| closeWithStatus(Status.OK, null); |
| } |
| } |
| |
| /** |
| * Close the ParcelFileDescriptor, informing any peer that an error occurred |
| * while processing. If the creator of this descriptor is not observing |
| * errors, it will close normally. |
| * |
| * @param msg describing the error; must not be null. |
| */ |
| public void closeWithError(String msg) throws IOException { |
| if (mWrapped != null) { |
| try { |
| mWrapped.closeWithError(msg); |
| } finally { |
| releaseResources(); |
| } |
| } else { |
| if (msg == null) { |
| throw new IllegalArgumentException("Message must not be null"); |
| } |
| closeWithStatus(Status.ERROR, msg); |
| } |
| } |
| |
| private void closeWithStatus(int status, String msg) { |
| if (mClosed) return; |
| mClosed = true; |
| mGuard.close(); |
| // Status MUST be sent before closing actual descriptor |
| writeCommStatusAndClose(status, msg); |
| IoUtils.closeQuietly(mFd); |
| releaseResources(); |
| } |
| |
| /** |
| * Called when the fd is being closed, for subclasses to release any other resources |
| * associated with it, such as acquired providers. |
| * @hide |
| */ |
| public void releaseResources() { |
| } |
| |
| private byte[] getOrCreateStatusBuffer() { |
| if (mStatusBuf == null) { |
| mStatusBuf = new byte[MAX_STATUS]; |
| } |
| return mStatusBuf; |
| } |
| |
| private void writeCommStatusAndClose(int status, String msg) { |
| if (mCommFd == null) { |
| // Not reliable, or someone already sent status |
| if (msg != null) { |
| Log.w(TAG, "Unable to inform peer: " + msg); |
| } |
| return; |
| } |
| |
| if (status == Status.DETACHED) { |
| Log.w(TAG, "Peer expected signal when closed; unable to deliver after detach"); |
| } |
| |
| try { |
| if (status == Status.SILENCE) return; |
| |
| // Since we're about to close, read off any remote status. It's |
| // okay to remember missing here. |
| mStatus = readCommStatus(mCommFd, getOrCreateStatusBuffer()); |
| |
| // Skip writing status when other end has already gone away. |
| if (mStatus != null) return; |
| |
| try { |
| final byte[] buf = getOrCreateStatusBuffer(); |
| int writePtr = 0; |
| |
| Memory.pokeInt(buf, writePtr, status, ByteOrder.BIG_ENDIAN); |
| writePtr += 4; |
| |
| if (msg != null) { |
| final byte[] rawMsg = msg.getBytes(); |
| final int len = Math.min(rawMsg.length, buf.length - writePtr); |
| System.arraycopy(rawMsg, 0, buf, writePtr, len); |
| writePtr += len; |
| } |
| |
| // Must write the entire status as a single operation. |
| Os.write(mCommFd, buf, 0, writePtr); |
| } catch (ErrnoException e) { |
| // Reporting status is best-effort |
| Log.w(TAG, "Failed to report status: " + e); |
| } catch (InterruptedIOException e) { |
| // Reporting status is best-effort |
| Log.w(TAG, "Failed to report status: " + e); |
| } |
| |
| } finally { |
| IoUtils.closeQuietly(mCommFd); |
| mCommFd = null; |
| } |
| } |
| |
| private static Status readCommStatus(FileDescriptor comm, byte[] buf) { |
| try { |
| // Must read the entire status as a single operation. |
| final int n = Os.read(comm, buf, 0, buf.length); |
| if (n == 0) { |
| // EOF means they're dead |
| return new Status(Status.DEAD); |
| } else { |
| final int status = Memory.peekInt(buf, 0, ByteOrder.BIG_ENDIAN); |
| if (status == Status.ERROR) { |
| final String msg = new String(buf, 4, n - 4); |
| return new Status(status, msg); |
| } |
| return new Status(status); |
| } |
| } catch (ErrnoException e) { |
| if (e.errno == OsConstants.EAGAIN) { |
| // Remote is still alive, but no status written yet |
| return null; |
| } else { |
| Log.d(TAG, "Failed to read status; assuming dead: " + e); |
| return new Status(Status.DEAD); |
| } |
| } catch (InterruptedIOException e) { |
| Log.d(TAG, "Failed to read status; assuming dead: " + e); |
| return new Status(Status.DEAD); |
| } |
| } |
| |
| /** |
| * Indicates if this ParcelFileDescriptor can communicate and detect remote |
| * errors/crashes. |
| * |
| * @see #checkError() |
| */ |
| public boolean canDetectErrors() { |
| if (mWrapped != null) { |
| return mWrapped.canDetectErrors(); |
| } else { |
| return mCommFd != null; |
| } |
| } |
| |
| /** |
| * Detect and throw if the other end of a pipe or socket pair encountered an |
| * error or crashed. This allows a reader to distinguish between a valid EOF |
| * and an error/crash. |
| * <p> |
| * If this ParcelFileDescriptor is unable to detect remote errors, it will |
| * return silently. |
| * |
| * @throws IOException for normal errors. |
| * @throws FileDescriptorDetachedException |
| * if the remote side called {@link #detachFd()}. Once detached, the remote |
| * side is unable to communicate any errors through |
| * {@link #closeWithError(String)}. |
| * @see #canDetectErrors() |
| */ |
| public void checkError() throws IOException { |
| if (mWrapped != null) { |
| mWrapped.checkError(); |
| } else { |
| if (mStatus == null) { |
| if (mCommFd == null) { |
| Log.w(TAG, "Peer didn't provide a comm channel; unable to check for errors"); |
| return; |
| } |
| |
| // Try reading status; it might be null if nothing written yet. |
| // Either way, we keep comm open to write our status later. |
| mStatus = readCommStatus(mCommFd, getOrCreateStatusBuffer()); |
| } |
| |
| if (mStatus == null || mStatus.status == Status.OK) { |
| // No status yet, or everything is peachy! |
| return; |
| } else { |
| throw mStatus.asIOException(); |
| } |
| } |
| } |
| |
| /** |
| * An InputStream you can create on a ParcelFileDescriptor, which will |
| * take care of calling {@link ParcelFileDescriptor#close |
| * ParcelFileDescriptor.close()} for you when the stream is closed. |
| */ |
| public static class AutoCloseInputStream extends FileInputStream { |
| private final ParcelFileDescriptor mPfd; |
| |
| public AutoCloseInputStream(ParcelFileDescriptor pfd) { |
| super(pfd.getFileDescriptor()); |
| mPfd = pfd; |
| } |
| |
| @Override |
| public void close() throws IOException { |
| try { |
| mPfd.close(); |
| } finally { |
| super.close(); |
| } |
| } |
| } |
| |
| /** |
| * An OutputStream you can create on a ParcelFileDescriptor, which will |
| * take care of calling {@link ParcelFileDescriptor#close |
| * ParcelFileDescriptor.close()} for you when the stream is closed. |
| */ |
| public static class AutoCloseOutputStream extends FileOutputStream { |
| private final ParcelFileDescriptor mPfd; |
| |
| public AutoCloseOutputStream(ParcelFileDescriptor pfd) { |
| super(pfd.getFileDescriptor()); |
| mPfd = pfd; |
| } |
| |
| @Override |
| public void close() throws IOException { |
| try { |
| mPfd.close(); |
| } finally { |
| super.close(); |
| } |
| } |
| } |
| |
| @Override |
| public String toString() { |
| if (mWrapped != null) { |
| return mWrapped.toString(); |
| } else { |
| return "{ParcelFileDescriptor: " + mFd + "}"; |
| } |
| } |
| |
| @Override |
| protected void finalize() throws Throwable { |
| if (mWrapped != null) { |
| releaseResources(); |
| } |
| if (mGuard != null) { |
| mGuard.warnIfOpen(); |
| } |
| try { |
| if (!mClosed) { |
| closeWithStatus(Status.LEAKED, null); |
| } |
| } finally { |
| super.finalize(); |
| } |
| } |
| |
| @Override |
| public int describeContents() { |
| if (mWrapped != null) { |
| return mWrapped.describeContents(); |
| } else { |
| return Parcelable.CONTENTS_FILE_DESCRIPTOR; |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| * If {@link Parcelable#PARCELABLE_WRITE_RETURN_VALUE} is set in flags, |
| * the file descriptor will be closed after a copy is written to the Parcel. |
| */ |
| @Override |
| public void writeToParcel(Parcel out, int flags) { |
| if (mWrapped != null) { |
| try { |
| mWrapped.writeToParcel(out, flags); |
| } finally { |
| releaseResources(); |
| } |
| } else { |
| if (mCommFd != null) { |
| out.writeInt(1); |
| out.writeFileDescriptor(mFd); |
| out.writeFileDescriptor(mCommFd); |
| } else { |
| out.writeInt(0); |
| out.writeFileDescriptor(mFd); |
| } |
| if ((flags & PARCELABLE_WRITE_RETURN_VALUE) != 0 && !mClosed) { |
| // Not a real close, so emit no status |
| closeWithStatus(Status.SILENCE, null); |
| } |
| } |
| } |
| |
| public static final Parcelable.Creator<ParcelFileDescriptor> CREATOR |
| = new Parcelable.Creator<ParcelFileDescriptor>() { |
| @Override |
| public ParcelFileDescriptor createFromParcel(Parcel in) { |
| int hasCommChannel = in.readInt(); |
| final FileDescriptor fd = in.readRawFileDescriptor(); |
| FileDescriptor commChannel = null; |
| if (hasCommChannel != 0) { |
| commChannel = in.readRawFileDescriptor(); |
| } |
| return new ParcelFileDescriptor(fd, commChannel); |
| } |
| |
| @Override |
| public ParcelFileDescriptor[] newArray(int size) { |
| return new ParcelFileDescriptor[size]; |
| } |
| }; |
| |
| /** |
| * Callback indicating that a ParcelFileDescriptor has been closed. |
| */ |
| public interface OnCloseListener { |
| /** |
| * Event indicating the ParcelFileDescriptor to which this listener was |
| * attached has been closed. |
| * |
| * @param e error state, or {@code null} if closed cleanly. |
| * If the close event was the result of |
| * {@link ParcelFileDescriptor#detachFd()}, this will be a |
| * {@link FileDescriptorDetachedException}. After detach the |
| * remote side may continue reading/writing to the underlying |
| * {@link FileDescriptor}, but they can no longer deliver |
| * reliable close/error events. |
| */ |
| public void onClose(IOException e); |
| } |
| |
| /** |
| * Exception that indicates that the file descriptor was detached. |
| */ |
| public static class FileDescriptorDetachedException extends IOException { |
| |
| private static final long serialVersionUID = 0xDe7ac4edFdL; |
| |
| public FileDescriptorDetachedException() { |
| super("Remote side is detached"); |
| } |
| } |
| |
| /** |
| * Internal class representing a remote status read by |
| * {@link ParcelFileDescriptor#readCommStatus(FileDescriptor, byte[])}. |
| */ |
| private static class Status { |
| /** Special value indicating remote side died. */ |
| public static final int DEAD = -2; |
| /** Special value indicating no status should be written. */ |
| public static final int SILENCE = -1; |
| |
| /** Remote reported that everything went better than expected. */ |
| public static final int OK = 0; |
| /** Remote reported error; length and message follow. */ |
| public static final int ERROR = 1; |
| /** Remote reported {@link #detachFd()} and went rogue. */ |
| public static final int DETACHED = 2; |
| /** Remote reported their object was finalized. */ |
| public static final int LEAKED = 3; |
| |
| public final int status; |
| public final String msg; |
| |
| public Status(int status) { |
| this(status, null); |
| } |
| |
| public Status(int status, String msg) { |
| this.status = status; |
| this.msg = msg; |
| } |
| |
| public IOException asIOException() { |
| switch (status) { |
| case DEAD: |
| return new IOException("Remote side is dead"); |
| case OK: |
| return null; |
| case ERROR: |
| return new IOException("Remote error: " + msg); |
| case DETACHED: |
| return new FileDescriptorDetachedException(); |
| case LEAKED: |
| return new IOException("Remote side was leaked"); |
| default: |
| return new IOException("Unknown status: " + status); |
| } |
| } |
| |
| @Override |
| public String toString() { |
| return "{" + status + ": " + msg + "}"; |
| } |
| } |
| } |
