| /* |
| * Copyright (c) 1995, 2012, 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 java.lang; |
| |
| import java.io.BufferedInputStream; |
| import java.io.BufferedOutputStream; |
| import java.io.ByteArrayInputStream; |
| import java.io.FileDescriptor; |
| import java.io.FileInputStream; |
| import java.io.FileOutputStream; |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.io.OutputStream; |
| import java.util.Arrays; |
| import java.util.concurrent.Executors; |
| import java.util.concurrent.Executor; |
| import java.util.concurrent.ThreadFactory; |
| import java.util.concurrent.TimeUnit; |
| import java.security.AccessController; |
| import static java.security.AccessController.doPrivileged; |
| import java.security.PrivilegedAction; |
| import java.security.PrivilegedActionException; |
| import java.security.PrivilegedExceptionAction; |
| |
| /** |
| * java.lang.Process subclass in the UNIX environment. |
| * |
| * @author Mario Wolczko and Ross Knippel. |
| * @author Konstantin Kladko (ported to Bsd) |
| * @author Martin Buchholz |
| */ |
| final class UNIXProcess extends Process { |
| private static final sun.misc.JavaIOFileDescriptorAccess fdAccess |
| = sun.misc.SharedSecrets.getJavaIOFileDescriptorAccess(); |
| |
| private final int pid; |
| private int exitcode; |
| private boolean hasExited; |
| |
| private /* final */ OutputStream stdin; |
| private /* final */ InputStream stdout; |
| private /* final */ InputStream stderr; |
| |
| private static enum LaunchMechanism { |
| FORK(1), |
| POSIX_SPAWN(2); |
| |
| private int value; |
| LaunchMechanism(int x) {value = x;} |
| }; |
| |
| /* On BSD, the default is to spawn */ |
| private static final LaunchMechanism launchMechanism; |
| private static byte[] helperpath; |
| |
| private static byte[] toCString(String s) { |
| if (s == null) |
| return null; |
| byte[] bytes = s.getBytes(); |
| byte[] result = new byte[bytes.length + 1]; |
| System.arraycopy(bytes, 0, |
| result, 0, |
| bytes.length); |
| result[result.length-1] = (byte)0; |
| return result; |
| } |
| |
| static { |
| launchMechanism = AccessController.doPrivileged( |
| new PrivilegedAction<LaunchMechanism>() |
| { |
| public LaunchMechanism run() { |
| String javahome = System.getProperty("java.home"); |
| |
| helperpath = toCString(javahome + "/lib/jspawnhelper"); |
| String s = System.getProperty( |
| "jdk.lang.Process.launchMechanism", "posix_spawn"); |
| |
| try { |
| return LaunchMechanism.valueOf(s.toUpperCase()); |
| } catch (IllegalArgumentException e) { |
| throw new Error(s + " is not a supported " + |
| "process launch mechanism on this platform."); |
| } |
| } |
| }); |
| } |
| |
| /* this is for the reaping thread */ |
| private native int waitForProcessExit(int pid); |
| |
| /** |
| * Create a process. Depending on the mode flag, this is done by |
| * one of the following mechanisms. |
| * - fork(2) and exec(2) |
| * - posix_spawn(2) |
| * |
| * @param fds an array of three file descriptors. |
| * Indexes 0, 1, and 2 correspond to standard input, |
| * standard output and standard error, respectively. On |
| * input, a value of -1 means to create a pipe to connect |
| * child and parent processes. On output, a value which |
| * is not -1 is the parent pipe fd corresponding to the |
| * pipe which has been created. An element of this array |
| * is -1 on input if and only if it is <em>not</em> -1 on |
| * output. |
| * @return the pid of the subprocess |
| */ |
| private native int forkAndExec(int mode, byte[] helperpath, |
| byte[] prog, |
| byte[] argBlock, int argc, |
| byte[] envBlock, int envc, |
| byte[] dir, |
| int[] fds, |
| boolean redirectErrorStream) |
| throws IOException; |
| |
| /** |
| * The thread factory used to create "process reaper" daemon threads. |
| */ |
| private static class ProcessReaperThreadFactory implements ThreadFactory { |
| private final static ThreadGroup group = getRootThreadGroup(); |
| |
| private static ThreadGroup getRootThreadGroup() { |
| return doPrivileged(new PrivilegedAction<ThreadGroup> () { |
| public ThreadGroup run() { |
| ThreadGroup root = Thread.currentThread().getThreadGroup(); |
| while (root.getParent() != null) |
| root = root.getParent(); |
| return root; |
| }}); |
| } |
| |
| public Thread newThread(Runnable grimReaper) { |
| // Our thread stack requirement is quite modest. |
| Thread t = new Thread(group, grimReaper, "process reaper", 32768); |
| t.setDaemon(true); |
| // A small attempt (probably futile) to avoid priority inversion |
| t.setPriority(Thread.MAX_PRIORITY); |
| return t; |
| } |
| } |
| |
| /** |
| * The thread pool of "process reaper" daemon threads. |
| */ |
| private static final Executor processReaperExecutor = |
| doPrivileged(new PrivilegedAction<Executor>() { |
| public Executor run() { |
| return Executors.newCachedThreadPool |
| (new ProcessReaperThreadFactory()); |
| }}); |
| |
| UNIXProcess(final byte[] prog, |
| final byte[] argBlock, final int argc, |
| final byte[] envBlock, final int envc, |
| final byte[] dir, |
| final int[] fds, |
| final boolean redirectErrorStream) |
| throws IOException { |
| |
| pid = forkAndExec(launchMechanism.value, |
| helperpath, |
| prog, |
| argBlock, argc, |
| envBlock, envc, |
| dir, |
| fds, |
| redirectErrorStream); |
| |
| try { |
| doPrivileged(new PrivilegedExceptionAction<Void>() { |
| public Void run() throws IOException { |
| initStreams(fds); |
| return null; |
| }}); |
| } catch (PrivilegedActionException ex) { |
| throw (IOException) ex.getException(); |
| } |
| } |
| |
| static FileDescriptor newFileDescriptor(int fd) { |
| FileDescriptor fileDescriptor = new FileDescriptor(); |
| fdAccess.set(fileDescriptor, fd); |
| return fileDescriptor; |
| } |
| |
| void initStreams(int[] fds) throws IOException { |
| stdin = (fds[0] == -1) ? |
| ProcessBuilder.NullOutputStream.INSTANCE : |
| new ProcessPipeOutputStream(fds[0]); |
| |
| stdout = (fds[1] == -1) ? |
| ProcessBuilder.NullInputStream.INSTANCE : |
| new ProcessPipeInputStream(fds[1]); |
| |
| stderr = (fds[2] == -1) ? |
| ProcessBuilder.NullInputStream.INSTANCE : |
| new ProcessPipeInputStream(fds[2]); |
| |
| processReaperExecutor.execute(new Runnable() { |
| public void run() { |
| int exitcode = waitForProcessExit(pid); |
| UNIXProcess.this.processExited(exitcode); |
| }}); |
| } |
| |
| void processExited(int exitcode) { |
| synchronized (this) { |
| this.exitcode = exitcode; |
| hasExited = true; |
| notifyAll(); |
| } |
| |
| if (stdout instanceof ProcessPipeInputStream) |
| ((ProcessPipeInputStream) stdout).processExited(); |
| |
| if (stderr instanceof ProcessPipeInputStream) |
| ((ProcessPipeInputStream) stderr).processExited(); |
| |
| if (stdin instanceof ProcessPipeOutputStream) |
| ((ProcessPipeOutputStream) stdin).processExited(); |
| } |
| |
| public OutputStream getOutputStream() { |
| return stdin; |
| } |
| |
| public InputStream getInputStream() { |
| return stdout; |
| } |
| |
| public InputStream getErrorStream() { |
| return stderr; |
| } |
| |
| public synchronized int waitFor() throws InterruptedException { |
| while (!hasExited) { |
| wait(); |
| } |
| return exitcode; |
| } |
| |
| @Override |
| public synchronized boolean waitFor(long timeout, TimeUnit unit) |
| throws InterruptedException |
| { |
| if (hasExited) return true; |
| if (timeout <= 0) return false; |
| |
| long timeoutAsNanos = unit.toNanos(timeout); |
| long startTime = System.nanoTime(); |
| long rem = timeoutAsNanos; |
| |
| while (!hasExited && (rem > 0)) { |
| wait(Math.max(TimeUnit.NANOSECONDS.toMillis(rem), 1)); |
| rem = timeoutAsNanos - (System.nanoTime() - startTime); |
| } |
| return hasExited; |
| } |
| |
| public synchronized int exitValue() { |
| if (!hasExited) { |
| throw new IllegalThreadStateException("process hasn't exited"); |
| } |
| return exitcode; |
| } |
| |
| private static native void destroyProcess(int pid, boolean force); |
| private void destroy(boolean force) { |
| // There is a risk that pid will be recycled, causing us to |
| // kill the wrong process! So we only terminate processes |
| // that appear to still be running. Even with this check, |
| // there is an unavoidable race condition here, but the window |
| // is very small, and OSes try hard to not recycle pids too |
| // soon, so this is quite safe. |
| synchronized (this) { |
| if (!hasExited) |
| destroyProcess(pid, force); |
| } |
| try { stdin.close(); } catch (IOException ignored) {} |
| try { stdout.close(); } catch (IOException ignored) {} |
| try { stderr.close(); } catch (IOException ignored) {} |
| } |
| |
| public void destroy() { |
| destroy(false); |
| } |
| |
| @Override |
| public Process destroyForcibly() { |
| destroy(true); |
| return this; |
| } |
| |
| @Override |
| public synchronized boolean isAlive() { |
| return !hasExited; |
| } |
| |
| private static native void init(); |
| |
| static { |
| init(); |
| } |
| |
| /** |
| * A buffered input stream for a subprocess pipe file descriptor |
| * that allows the underlying file descriptor to be reclaimed when |
| * the process exits, via the processExited hook. |
| * |
| * This is tricky because we do not want the user-level InputStream to be |
| * closed until the user invokes close(), and we need to continue to be |
| * able to read any buffered data lingering in the OS pipe buffer. |
| */ |
| static class ProcessPipeInputStream extends BufferedInputStream { |
| private final Object closeLock = new Object(); |
| |
| ProcessPipeInputStream(int fd) { |
| super(new FileInputStream(newFileDescriptor(fd))); |
| } |
| private static byte[] drainInputStream(InputStream in) |
| throws IOException { |
| int n = 0; |
| int j; |
| byte[] a = null; |
| while ((j = in.available()) > 0) { |
| a = (a == null) ? new byte[j] : Arrays.copyOf(a, n + j); |
| n += in.read(a, n, j); |
| } |
| return (a == null || n == a.length) ? a : Arrays.copyOf(a, n); |
| } |
| |
| /** Called by the process reaper thread when the process exits. */ |
| synchronized void processExited() { |
| synchronized (closeLock) { |
| try { |
| InputStream in = this.in; |
| // this stream is closed if and only if: in == null |
| if (in != null) { |
| byte[] stragglers = drainInputStream(in); |
| in.close(); |
| this.in = (stragglers == null) ? |
| ProcessBuilder.NullInputStream.INSTANCE : |
| new ByteArrayInputStream(stragglers); |
| } |
| } catch (IOException ignored) {} |
| } |
| } |
| |
| @Override |
| public void close() throws IOException { |
| // BufferedInputStream#close() is not synchronized unlike most other methods. |
| // Synchronizing helps avoid race with processExited(). |
| synchronized (closeLock) { |
| super.close(); |
| } |
| } |
| } |
| |
| /** |
| * A buffered output stream for a subprocess pipe file descriptor |
| * that allows the underlying file descriptor to be reclaimed when |
| * the process exits, via the processExited hook. |
| */ |
| static class ProcessPipeOutputStream extends BufferedOutputStream { |
| ProcessPipeOutputStream(int fd) { |
| super(new FileOutputStream(newFileDescriptor(fd))); |
| } |
| |
| /** Called by the process reaper thread when the process exits. */ |
| synchronized void processExited() { |
| OutputStream out = this.out; |
| if (out != null) { |
| try { |
| out.close(); |
| } catch (IOException ignored) { |
| // We know of no reason to get an IOException, but if |
| // we do, there's nothing else to do but carry on. |
| } |
| this.out = ProcessBuilder.NullOutputStream.INSTANCE; |
| } |
| } |
| } |
| } |