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src/java.base/share/classes/sun/nio/ch/IOUtil.java
449 строк
15 KB
Alan Bateman
8200256: java/nio/channels/AsynchronousChannelGroup/Basic.java fails intermittently
27 мар 2018, 21:29
27 мар 2018, 21:29
704b2cc
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/* * Copyright (c) 2000, 2018, 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 { return write(fd, src, position, false, -1, nd); } static int write(FileDescriptor fd, ByteBuffer src, long position, boolean directIO, int alignment, NativeDispatcher nd) throws IOException { if (src instanceof DirectBuffer) { return writeFromNativeBuffer(fd, src, position, directIO, alignment, 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; if (directIO) { Util.checkRemainingBufferSizeAligned(rem, alignment); bb = Util.getTemporaryAlignedDirectBuffer(rem, alignment); } else { 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, directIO, alignment, 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, boolean directIO, int alignment, NativeDispatcher nd) throws IOException { int pos = bb.position(); int lim = bb.limit(); assert (pos <= lim); int rem = (pos <= lim ? lim - pos : 0); if (directIO) { Util.checkBufferPositionAligned(bb, pos, alignment); Util.checkRemainingBufferSizeAligned(rem, alignment); } 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, false, -1, nd); } static long write(FileDescriptor fd, ByteBuffer[] bufs, int offset, int length, NativeDispatcher nd) throws IOException { return write(fd, bufs, offset, length, false, -1, nd); } static long write(FileDescriptor fd, ByteBuffer[] bufs, int offset, int length, boolean directIO, int alignment, 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 (directIO) Util.checkRemainingBufferSizeAligned(rem, alignment); 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; if (directIO) shadow = Util.getTemporaryAlignedDirectBuffer(rem, alignment); else 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 { return read(fd, dst, position, false, -1, nd); } static int read(FileDescriptor fd, ByteBuffer dst, long position, boolean directIO, int alignment, NativeDispatcher nd) throws IOException { if (dst.isReadOnly()) throw new IllegalArgumentException("Read-only buffer"); if (dst instanceof DirectBuffer) return readIntoNativeBuffer(fd, dst, position, directIO, alignment, nd); // Substitute a native buffer ByteBuffer bb; int rem = dst.remaining(); if (directIO) { Util.checkRemainingBufferSizeAligned(rem, alignment); bb = Util.getTemporaryAlignedDirectBuffer(rem, alignment); } else { bb = Util.getTemporaryDirectBuffer(rem); } try { int n = readIntoNativeBuffer(fd, bb, position, directIO, alignment,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, boolean directIO, int alignment, NativeDispatcher nd) throws IOException { int pos = bb.position(); int lim = bb.limit(); assert (pos <= lim); int rem = (pos <= lim ? lim - pos : 0); if (directIO) { Util.checkBufferPositionAligned(bb, pos, alignment); Util.checkRemainingBufferSizeAligned(rem, alignment); } 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, false, -1, nd); } static long read(FileDescriptor fd, ByteBuffer[] bufs, int offset, int length, NativeDispatcher nd) throws IOException { return read(fd, bufs, offset, length, false, -1, nd); } static long read(FileDescriptor fd, ByteBuffer[] bufs, int offset, int length, boolean directIO, int alignment, 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 (directIO) Util.checkRemainingBufferSizeAligned(rem, alignment); 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; if (directIO) { shadow = Util.getTemporaryAlignedDirectBuffer(rem, alignment); } else { 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) throws IOException; static native int write1(int fd, byte b) throws IOException; /** * Read and discard all bytes. */ static native boolean drain(int fd) throws IOException; /** * Read and discard at most one byte * @return the number of bytes read or IOS_INTERRUPTED */ static native int drain1(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(); } }