| /* |
| * Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package sun.nio.ch; |
| |
| import java.io.FileDescriptor; |
| import java.io.IOException; |
| import java.nio.ByteBuffer; |
| |
| |
| /** |
| * File-descriptor based I/O utilities that are shared by NIO classes. |
| */ |
| |
| public class IOUtil { |
| |
| /** |
| * Max number of iovec structures that readv/writev supports |
| */ |
| static final int IOV_MAX; |
| |
| private IOUtil() { } // No instantiation |
| |
| static int write(FileDescriptor fd, ByteBuffer src, long position, |
| NativeDispatcher nd) |
| throws IOException |
| { |
| if (src instanceof DirectBuffer) |
| return writeFromNativeBuffer(fd, src, position, nd); |
| |
| // Substitute a native buffer |
| int pos = src.position(); |
| int lim = src.limit(); |
| assert (pos <= lim); |
| int rem = (pos <= lim ? lim - pos : 0); |
| ByteBuffer bb = Util.getTemporaryDirectBuffer(rem); |
| try { |
| bb.put(src); |
| bb.flip(); |
| // Do not update src until we see how many bytes were written |
| src.position(pos); |
| |
| int n = writeFromNativeBuffer(fd, bb, position, nd); |
| if (n > 0) { |
| // now update src |
| src.position(pos + n); |
| } |
| return n; |
| } finally { |
| Util.offerFirstTemporaryDirectBuffer(bb); |
| } |
| } |
| |
| private static int writeFromNativeBuffer(FileDescriptor fd, ByteBuffer bb, |
| long position, NativeDispatcher nd) |
| throws IOException |
| { |
| int pos = bb.position(); |
| int lim = bb.limit(); |
| assert (pos <= lim); |
| int rem = (pos <= lim ? lim - pos : 0); |
| |
| int written = 0; |
| if (rem == 0) |
| return 0; |
| if (position != -1) { |
| written = nd.pwrite(fd, |
| ((DirectBuffer)bb).address() + pos, |
| rem, position); |
| } else { |
| written = nd.write(fd, ((DirectBuffer)bb).address() + pos, rem); |
| } |
| if (written > 0) |
| bb.position(pos + written); |
| return written; |
| } |
| |
| static long write(FileDescriptor fd, ByteBuffer[] bufs, NativeDispatcher nd) |
| throws IOException |
| { |
| return write(fd, bufs, 0, bufs.length, nd); |
| } |
| |
| static long write(FileDescriptor fd, ByteBuffer[] bufs, int offset, int length, |
| NativeDispatcher nd) |
| throws IOException |
| { |
| IOVecWrapper vec = IOVecWrapper.get(length); |
| |
| boolean completed = false; |
| int iov_len = 0; |
| try { |
| |
| // Iterate over buffers to populate native iovec array. |
| int count = offset + length; |
| int i = offset; |
| while (i < count && iov_len < IOV_MAX) { |
| ByteBuffer buf = bufs[i]; |
| int pos = buf.position(); |
| int lim = buf.limit(); |
| assert (pos <= lim); |
| int rem = (pos <= lim ? lim - pos : 0); |
| if (rem > 0) { |
| vec.setBuffer(iov_len, buf, pos, rem); |
| |
| // allocate shadow buffer to ensure I/O is done with direct buffer |
| if (!(buf instanceof DirectBuffer)) { |
| ByteBuffer shadow = Util.getTemporaryDirectBuffer(rem); |
| shadow.put(buf); |
| shadow.flip(); |
| vec.setShadow(iov_len, shadow); |
| buf.position(pos); // temporarily restore position in user buffer |
| buf = shadow; |
| pos = shadow.position(); |
| } |
| |
| vec.putBase(iov_len, ((DirectBuffer)buf).address() + pos); |
| vec.putLen(iov_len, rem); |
| iov_len++; |
| } |
| i++; |
| } |
| if (iov_len == 0) |
| return 0L; |
| |
| long bytesWritten = nd.writev(fd, vec.address, iov_len); |
| |
| // Notify the buffers how many bytes were taken |
| long left = bytesWritten; |
| for (int j=0; j<iov_len; j++) { |
| if (left > 0) { |
| ByteBuffer buf = vec.getBuffer(j); |
| int pos = vec.getPosition(j); |
| int rem = vec.getRemaining(j); |
| int n = (left > rem) ? rem : (int)left; |
| buf.position(pos + n); |
| left -= n; |
| } |
| // return shadow buffers to buffer pool |
| ByteBuffer shadow = vec.getShadow(j); |
| if (shadow != null) |
| Util.offerLastTemporaryDirectBuffer(shadow); |
| vec.clearRefs(j); |
| } |
| |
| completed = true; |
| return bytesWritten; |
| |
| } finally { |
| // if an error occurred then clear refs to buffers and return any shadow |
| // buffers to cache |
| if (!completed) { |
| for (int j=0; j<iov_len; j++) { |
| ByteBuffer shadow = vec.getShadow(j); |
| if (shadow != null) |
| Util.offerLastTemporaryDirectBuffer(shadow); |
| vec.clearRefs(j); |
| } |
| } |
| } |
| } |
| |
| static int read(FileDescriptor fd, ByteBuffer dst, long position, |
| NativeDispatcher nd) |
| throws IOException |
| { |
| if (dst.isReadOnly()) |
| throw new IllegalArgumentException("Read-only buffer"); |
| if (dst instanceof DirectBuffer) |
| return readIntoNativeBuffer(fd, dst, position, nd); |
| |
| // Substitute a native buffer |
| ByteBuffer bb = Util.getTemporaryDirectBuffer(dst.remaining()); |
| try { |
| int n = readIntoNativeBuffer(fd, bb, position, nd); |
| bb.flip(); |
| if (n > 0) |
| dst.put(bb); |
| return n; |
| } finally { |
| Util.offerFirstTemporaryDirectBuffer(bb); |
| } |
| } |
| |
| private static int readIntoNativeBuffer(FileDescriptor fd, ByteBuffer bb, |
| long position, NativeDispatcher nd) |
| throws IOException |
| { |
| int pos = bb.position(); |
| int lim = bb.limit(); |
| assert (pos <= lim); |
| int rem = (pos <= lim ? lim - pos : 0); |
| |
| if (rem == 0) |
| return 0; |
| int n = 0; |
| if (position != -1) { |
| n = nd.pread(fd, ((DirectBuffer)bb).address() + pos, |
| rem, position); |
| } else { |
| n = nd.read(fd, ((DirectBuffer)bb).address() + pos, rem); |
| } |
| if (n > 0) |
| bb.position(pos + n); |
| return n; |
| } |
| |
| static long read(FileDescriptor fd, ByteBuffer[] bufs, NativeDispatcher nd) |
| throws IOException |
| { |
| return read(fd, bufs, 0, bufs.length, nd); |
| } |
| |
| static long read(FileDescriptor fd, ByteBuffer[] bufs, int offset, int length, |
| NativeDispatcher nd) |
| throws IOException |
| { |
| IOVecWrapper vec = IOVecWrapper.get(length); |
| |
| boolean completed = false; |
| int iov_len = 0; |
| try { |
| |
| // Iterate over buffers to populate native iovec array. |
| int count = offset + length; |
| int i = offset; |
| while (i < count && iov_len < IOV_MAX) { |
| ByteBuffer buf = bufs[i]; |
| if (buf.isReadOnly()) |
| throw new IllegalArgumentException("Read-only buffer"); |
| int pos = buf.position(); |
| int lim = buf.limit(); |
| assert (pos <= lim); |
| int rem = (pos <= lim ? lim - pos : 0); |
| |
| if (rem > 0) { |
| vec.setBuffer(iov_len, buf, pos, rem); |
| |
| // allocate shadow buffer to ensure I/O is done with direct buffer |
| if (!(buf instanceof DirectBuffer)) { |
| ByteBuffer shadow = Util.getTemporaryDirectBuffer(rem); |
| vec.setShadow(iov_len, shadow); |
| buf = shadow; |
| pos = shadow.position(); |
| } |
| |
| vec.putBase(iov_len, ((DirectBuffer)buf).address() + pos); |
| vec.putLen(iov_len, rem); |
| iov_len++; |
| } |
| i++; |
| } |
| if (iov_len == 0) |
| return 0L; |
| |
| long bytesRead = nd.readv(fd, vec.address, iov_len); |
| |
| // Notify the buffers how many bytes were read |
| long left = bytesRead; |
| for (int j=0; j<iov_len; j++) { |
| ByteBuffer shadow = vec.getShadow(j); |
| if (left > 0) { |
| ByteBuffer buf = vec.getBuffer(j); |
| int rem = vec.getRemaining(j); |
| int n = (left > rem) ? rem : (int)left; |
| if (shadow == null) { |
| int pos = vec.getPosition(j); |
| buf.position(pos + n); |
| } else { |
| shadow.limit(shadow.position() + n); |
| buf.put(shadow); |
| } |
| left -= n; |
| } |
| if (shadow != null) |
| Util.offerLastTemporaryDirectBuffer(shadow); |
| vec.clearRefs(j); |
| } |
| |
| completed = true; |
| return bytesRead; |
| |
| } finally { |
| // if an error occurred then clear refs to buffers and return any shadow |
| // buffers to cache |
| if (!completed) { |
| for (int j=0; j<iov_len; j++) { |
| ByteBuffer shadow = vec.getShadow(j); |
| if (shadow != null) |
| Util.offerLastTemporaryDirectBuffer(shadow); |
| vec.clearRefs(j); |
| } |
| } |
| } |
| } |
| |
| public static FileDescriptor newFD(int i) { |
| FileDescriptor fd = new FileDescriptor(); |
| setfdVal(fd, i); |
| return fd; |
| } |
| |
| static native boolean randomBytes(byte[] someBytes); |
| |
| /** |
| * Returns two file descriptors for a pipe encoded in a long. |
| * The read end of the pipe is returned in the high 32 bits, |
| * while the write end is returned in the low 32 bits. |
| */ |
| static native long makePipe(boolean blocking); |
| |
| static native boolean drain(int fd) throws IOException; |
| |
| public static native void configureBlocking(FileDescriptor fd, |
| boolean blocking) |
| throws IOException; |
| |
| public static native int fdVal(FileDescriptor fd); |
| |
| static native void setfdVal(FileDescriptor fd, int value); |
| |
| static native int fdLimit(); |
| |
| static native int iovMax(); |
| |
| static native void initIDs(); |
| |
| /** |
| * Used to trigger loading of native libraries |
| */ |
| public static void load() { } |
| |
| static { |
| java.security.AccessController.doPrivileged( |
| new java.security.PrivilegedAction<Void>() { |
| public Void run() { |
| System.loadLibrary("net"); |
| System.loadLibrary("nio"); |
| return null; |
| } |
| }); |
| |
| initIDs(); |
| |
| IOV_MAX = iovMax(); |
| } |
| |
| } |