author | robm |
Tue, 26 Jun 2012 13:27:26 +0100 | |
changeset 13149 | 27d52f97a5cc |
parent 12047 | 320a714614e9 |
child 16860 | 8fecebee12b0 |
permissions | -rw-r--r-- |
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/* |
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* Copyright (c) 1995, 2012, Oracle and/or its affiliates. All rights reserved. |
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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* |
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* This code is free software; you can redistribute it and/or modify it |
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* under the terms of the GNU General Public License version 2 only, as |
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* published by the Free Software Foundation. Oracle designates this |
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* particular file as subject to the "Classpath" exception as provided |
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* by Oracle in the LICENSE file that accompanied this code. |
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* |
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* This code is distributed in the hope that it will be useful, but WITHOUT |
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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* version 2 for more details (a copy is included in the LICENSE file that |
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* accompanied this code). |
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* |
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* You should have received a copy of the GNU General Public License version |
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* 2 along with this work; if not, write to the Free Software Foundation, |
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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* |
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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* or visit www.oracle.com if you need additional information or have any |
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* questions. |
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*/ |
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||
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package java.lang; |
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import java.io.BufferedInputStream; |
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import java.io.BufferedOutputStream; |
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import java.io.ByteArrayInputStream; |
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import java.io.FileDescriptor; |
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import java.io.FileInputStream; |
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import java.io.FileOutputStream; |
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import java.io.IOException; |
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import java.io.InputStream; |
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import java.io.OutputStream; |
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import java.util.Arrays; |
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import java.util.concurrent.Executors; |
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import java.util.concurrent.Executor; |
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import java.util.concurrent.ThreadFactory; |
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import java.util.concurrent.TimeUnit; |
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import java.security.AccessController; |
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import static java.security.AccessController.doPrivileged; |
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import java.security.PrivilegedAction; |
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import java.security.PrivilegedActionException; |
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import java.security.PrivilegedExceptionAction; |
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||
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/** |
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* java.lang.Process subclass in the UNIX environment. |
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* |
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* @author Mario Wolczko and Ross Knippel. |
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* @author Konstantin Kladko (ported to Bsd) |
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* @author Martin Buchholz |
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*/ |
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final class UNIXProcess extends Process { |
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private static final sun.misc.JavaIOFileDescriptorAccess fdAccess |
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= sun.misc.SharedSecrets.getJavaIOFileDescriptorAccess(); |
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private final int pid; |
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private int exitcode; |
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private boolean hasExited; |
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private /* final */ OutputStream stdin; |
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private /* final */ InputStream stdout; |
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private /* final */ InputStream stderr; |
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||
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/* this is for the reaping thread */ |
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private native int waitForProcessExit(int pid); |
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/** |
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* Create a process using fork(2) and exec(2). |
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* |
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* @param fds an array of three file descriptors. |
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* Indexes 0, 1, and 2 correspond to standard input, |
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* standard output and standard error, respectively. On |
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* input, a value of -1 means to create a pipe to connect |
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* child and parent processes. On output, a value which |
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* is not -1 is the parent pipe fd corresponding to the |
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* pipe which has been created. An element of this array |
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* is -1 on input if and only if it is <em>not</em> -1 on |
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* output. |
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* @return the pid of the subprocess |
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*/ |
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private native int forkAndExec(byte[] prog, |
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byte[] argBlock, int argc, |
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byte[] envBlock, int envc, |
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byte[] dir, |
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int[] fds, |
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boolean redirectErrorStream) |
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throws IOException; |
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/** |
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* The thread factory used to create "process reaper" daemon threads. |
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*/ |
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private static class ProcessReaperThreadFactory implements ThreadFactory { |
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private final static ThreadGroup group = getRootThreadGroup(); |
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private static ThreadGroup getRootThreadGroup() { |
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return doPrivileged(new PrivilegedAction<ThreadGroup> () { |
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public ThreadGroup run() { |
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ThreadGroup root = Thread.currentThread().getThreadGroup(); |
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while (root.getParent() != null) |
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root = root.getParent(); |
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return root; |
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}}); |
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} |
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public Thread newThread(Runnable grimReaper) { |
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// Our thread stack requirement is quite modest. |
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Thread t = new Thread(group, grimReaper, "process reaper", 32768); |
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t.setDaemon(true); |
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// A small attempt (probably futile) to avoid priority inversion |
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t.setPriority(Thread.MAX_PRIORITY); |
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return t; |
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} |
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} |
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/** |
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* The thread pool of "process reaper" daemon threads. |
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*/ |
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private static final Executor processReaperExecutor = |
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doPrivileged(new PrivilegedAction<Executor>() { |
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public Executor run() { |
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return Executors.newCachedThreadPool |
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(new ProcessReaperThreadFactory()); |
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}}); |
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||
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UNIXProcess(final byte[] prog, |
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final byte[] argBlock, final int argc, |
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final byte[] envBlock, final int envc, |
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final byte[] dir, |
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final int[] fds, |
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final boolean redirectErrorStream) |
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throws IOException { |
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pid = forkAndExec(prog, |
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argBlock, argc, |
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envBlock, envc, |
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dir, |
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fds, |
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redirectErrorStream); |
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try { |
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doPrivileged(new PrivilegedExceptionAction<Void>() { |
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public Void run() throws IOException { |
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initStreams(fds); |
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return null; |
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}}); |
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} catch (PrivilegedActionException ex) { |
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throw (IOException) ex.getException(); |
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} |
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} |
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static FileDescriptor newFileDescriptor(int fd) { |
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FileDescriptor fileDescriptor = new FileDescriptor(); |
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fdAccess.set(fileDescriptor, fd); |
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return fileDescriptor; |
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} |
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void initStreams(int[] fds) throws IOException { |
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stdin = (fds[0] == -1) ? |
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ProcessBuilder.NullOutputStream.INSTANCE : |
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new ProcessPipeOutputStream(fds[0]); |
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stdout = (fds[1] == -1) ? |
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ProcessBuilder.NullInputStream.INSTANCE : |
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new ProcessPipeInputStream(fds[1]); |
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stderr = (fds[2] == -1) ? |
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ProcessBuilder.NullInputStream.INSTANCE : |
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new ProcessPipeInputStream(fds[2]); |
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processReaperExecutor.execute(new Runnable() { |
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public void run() { |
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int exitcode = waitForProcessExit(pid); |
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UNIXProcess.this.processExited(exitcode); |
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}}); |
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} |
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void processExited(int exitcode) { |
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synchronized (this) { |
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this.exitcode = exitcode; |
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hasExited = true; |
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notifyAll(); |
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} |
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||
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if (stdout instanceof ProcessPipeInputStream) |
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((ProcessPipeInputStream) stdout).processExited(); |
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if (stderr instanceof ProcessPipeInputStream) |
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((ProcessPipeInputStream) stderr).processExited(); |
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if (stdin instanceof ProcessPipeOutputStream) |
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((ProcessPipeOutputStream) stdin).processExited(); |
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} |
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||
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public OutputStream getOutputStream() { |
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return stdin; |
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} |
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public InputStream getInputStream() { |
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return stdout; |
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} |
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public InputStream getErrorStream() { |
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return stderr; |
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} |
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public synchronized int waitFor() throws InterruptedException { |
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while (!hasExited) { |
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wait(); |
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} |
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return exitcode; |
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} |
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@Override |
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public synchronized boolean waitFor(long timeout, TimeUnit unit) |
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throws InterruptedException |
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{ |
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if (hasExited) return true; |
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if (timeout <= 0) return false; |
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long timeoutAsNanos = unit.toNanos(timeout); |
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long startTime = System.nanoTime(); |
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long rem = timeoutAsNanos; |
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while (!hasExited && (rem > 0)) { |
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wait(Math.max(TimeUnit.NANOSECONDS.toMillis(rem), 1)); |
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rem = timeoutAsNanos - (System.nanoTime() - startTime); |
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} |
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return hasExited; |
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} |
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public synchronized int exitValue() { |
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if (!hasExited) { |
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throw new IllegalThreadStateException("process hasn't exited"); |
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} |
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return exitcode; |
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} |
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private static native void destroyProcess(int pid, boolean force); |
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private void destroy(boolean force) { |
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// There is a risk that pid will be recycled, causing us to |
244 |
// kill the wrong process! So we only terminate processes |
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// that appear to still be running. Even with this check, |
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// there is an unavoidable race condition here, but the window |
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// is very small, and OSes try hard to not recycle pids too |
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// soon, so this is quite safe. |
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synchronized (this) { |
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if (!hasExited) |
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destroyProcess(pid, force); |
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} |
253 |
try { stdin.close(); } catch (IOException ignored) {} |
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try { stdout.close(); } catch (IOException ignored) {} |
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try { stderr.close(); } catch (IOException ignored) {} |
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} |
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||
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public void destroy() { |
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destroy(false); |
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} |
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|
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@Override |
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public Process destroyForcibly() { |
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destroy(true); |
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return this; |
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} |
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|
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@Override |
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public synchronized boolean isAlive() { |
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return !hasExited; |
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} |
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|
12047 | 273 |
/* This routine initializes JNI field offsets for the class */ |
274 |
private static native void initIDs(); |
|
275 |
||
276 |
static { |
|
277 |
initIDs(); |
|
278 |
} |
|
279 |
||
280 |
/** |
|
281 |
* A buffered input stream for a subprocess pipe file descriptor |
|
282 |
* that allows the underlying file descriptor to be reclaimed when |
|
283 |
* the process exits, via the processExited hook. |
|
284 |
* |
|
285 |
* This is tricky because we do not want the user-level InputStream to be |
|
286 |
* closed until the user invokes close(), and we need to continue to be |
|
287 |
* able to read any buffered data lingering in the OS pipe buffer. |
|
288 |
*/ |
|
289 |
static class ProcessPipeInputStream extends BufferedInputStream { |
|
290 |
ProcessPipeInputStream(int fd) { |
|
291 |
super(new FileInputStream(newFileDescriptor(fd))); |
|
292 |
} |
|
293 |
||
294 |
private static byte[] drainInputStream(InputStream in) |
|
295 |
throws IOException { |
|
296 |
if (in == null) return null; |
|
297 |
int n = 0; |
|
298 |
int j; |
|
299 |
byte[] a = null; |
|
300 |
while ((j = in.available()) > 0) { |
|
301 |
a = (a == null) ? new byte[j] : Arrays.copyOf(a, n + j); |
|
302 |
n += in.read(a, n, j); |
|
303 |
} |
|
304 |
return (a == null || n == a.length) ? a : Arrays.copyOf(a, n); |
|
305 |
} |
|
306 |
||
307 |
/** Called by the process reaper thread when the process exits. */ |
|
308 |
synchronized void processExited() { |
|
309 |
// Most BufferedInputStream methods are synchronized, but close() |
|
310 |
// is not, and so we have to handle concurrent racing close(). |
|
311 |
try { |
|
312 |
InputStream in = this.in; |
|
313 |
if (in != null) { |
|
314 |
byte[] stragglers = drainInputStream(in); |
|
315 |
in.close(); |
|
316 |
this.in = (stragglers == null) ? |
|
317 |
ProcessBuilder.NullInputStream.INSTANCE : |
|
318 |
new ByteArrayInputStream(stragglers); |
|
319 |
if (buf == null) // asynchronous close()? |
|
320 |
this.in = null; |
|
321 |
} |
|
322 |
} catch (IOException ignored) { |
|
323 |
// probably an asynchronous close(). |
|
324 |
} |
|
325 |
} |
|
326 |
} |
|
327 |
||
328 |
/** |
|
329 |
* A buffered output stream for a subprocess pipe file descriptor |
|
330 |
* that allows the underlying file descriptor to be reclaimed when |
|
331 |
* the process exits, via the processExited hook. |
|
332 |
*/ |
|
333 |
static class ProcessPipeOutputStream extends BufferedOutputStream { |
|
334 |
ProcessPipeOutputStream(int fd) { |
|
335 |
super(new FileOutputStream(newFileDescriptor(fd))); |
|
336 |
} |
|
337 |
||
338 |
/** Called by the process reaper thread when the process exits. */ |
|
339 |
synchronized void processExited() { |
|
340 |
OutputStream out = this.out; |
|
341 |
if (out != null) { |
|
342 |
try { |
|
343 |
out.close(); |
|
344 |
} catch (IOException ignored) { |
|
345 |
// We know of no reason to get an IOException, but if |
|
346 |
// we do, there's nothing else to do but carry on. |
|
347 |
} |
|
348 |
this.out = ProcessBuilder.NullOutputStream.INSTANCE; |
|
349 |
} |
|
350 |
} |
|
351 |
} |
|
352 |
} |