--- a/jdk/src/java.base/unix/classes/java/lang/UNIXProcess.java Wed Jan 28 16:45:33 2015 -0800
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,836 +0,0 @@
-/*
- * Copyright (c) 1995, 2014, 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.EnumSet;
-import java.util.Locale;
-import java.util.Set;
-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 Linux and Bsd)
- * @author Martin Buchholz
- * @author Volker Simonis (ported to AIX)
- */
-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;
-
- // only used on Solaris
- private /* final */ DeferredCloseInputStream stdout_inner_stream;
-
- private static enum LaunchMechanism {
- // order IS important!
- FORK,
- POSIX_SPAWN,
- VFORK
- }
-
- private static enum Platform {
-
- LINUX(LaunchMechanism.VFORK, LaunchMechanism.FORK),
-
- BSD(LaunchMechanism.POSIX_SPAWN, LaunchMechanism.FORK),
-
- SOLARIS(LaunchMechanism.POSIX_SPAWN, LaunchMechanism.FORK),
-
- AIX(LaunchMechanism.POSIX_SPAWN, LaunchMechanism.FORK);
-
- final LaunchMechanism defaultLaunchMechanism;
- final Set<LaunchMechanism> validLaunchMechanisms;
-
- Platform(LaunchMechanism ... launchMechanisms) {
- this.defaultLaunchMechanism = launchMechanisms[0];
- this.validLaunchMechanisms =
- EnumSet.copyOf(Arrays.asList(launchMechanisms));
- }
-
- @SuppressWarnings("fallthrough")
- private String helperPath(String javahome, String osArch) {
- switch (this) {
- case SOLARIS:
- if (osArch.equals("x86")) { osArch = "i386"; }
- else if (osArch.equals("x86_64")) { osArch = "amd64"; }
- // fall through...
- case LINUX:
- case AIX:
- return javahome + "/lib/" + osArch + "/jspawnhelper";
-
- case BSD:
- return javahome + "/lib/jspawnhelper";
-
- default:
- throw new AssertionError("Unsupported platform: " + this);
- }
- }
-
- String helperPath() {
- return AccessController.doPrivileged(
- (PrivilegedAction<String>) () ->
- helperPath(System.getProperty("java.home"),
- System.getProperty("os.arch"))
- );
- }
-
- LaunchMechanism launchMechanism() {
- return AccessController.doPrivileged(
- (PrivilegedAction<LaunchMechanism>) () -> {
- String s = System.getProperty(
- "jdk.lang.Process.launchMechanism");
- LaunchMechanism lm;
- if (s == null) {
- lm = defaultLaunchMechanism;
- s = lm.name().toLowerCase(Locale.ENGLISH);
- } else {
- try {
- lm = LaunchMechanism.valueOf(
- s.toUpperCase(Locale.ENGLISH));
- } catch (IllegalArgumentException e) {
- lm = null;
- }
- }
- if (lm == null || !validLaunchMechanisms.contains(lm)) {
- throw new Error(
- s + " is not a supported " +
- "process launch mechanism on this platform."
- );
- }
- return lm;
- }
- );
- }
-
- static Platform get() {
- String osName = AccessController.doPrivileged(
- (PrivilegedAction<String>) () -> System.getProperty("os.name")
- );
-
- if (osName.equals("Linux")) { return LINUX; }
- if (osName.contains("OS X")) { return BSD; }
- if (osName.equals("SunOS")) { return SOLARIS; }
- if (osName.equals("AIX")) { return AIX; }
-
- throw new Error(osName + " is not a supported OS platform.");
- }
- }
-
- private static final Platform platform = Platform.get();
- private static final LaunchMechanism launchMechanism = platform.launchMechanism();
- private static final byte[] helperpath = toCString(platform.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;
- }
-
- /* this is for the reaping thread */
- private native int waitForProcessExit(int pid);
-
- /**
- * Creates a process. Depending on the {@code mode} flag, this is done by
- * one of the following mechanisms:
- * <pre>
- * 1 - fork(2) and exec(2)
- * 2 - posix_spawn(3P)
- * 3 - vfork(2) and exec(2)
- *
- * (4 - clone(2) and exec(2) - obsolete and currently disabled in native code)
- * </pre>
- * @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 pool of "process reaper" daemon threads.
- */
- private static final Executor processReaperExecutor =
- doPrivileged((PrivilegedAction<Executor>) () -> {
-
- ThreadGroup tg = Thread.currentThread().getThreadGroup();
- while (tg.getParent() != null) tg = tg.getParent();
- ThreadGroup systemThreadGroup = tg;
-
- ThreadFactory threadFactory = grimReaper -> {
- // Our thread stack requirement is quite modest.
- Thread t = new Thread(systemThreadGroup, grimReaper,
- "process reaper", 32768);
- t.setDaemon(true);
- // A small attempt (probably futile) to avoid priority inversion
- t.setPriority(Thread.MAX_PRIORITY);
- return t;
- };
-
- return Executors.newCachedThreadPool(threadFactory);
- });
-
- 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.ordinal() + 1,
- helperpath,
- prog,
- argBlock, argc,
- envBlock, envc,
- dir,
- fds,
- redirectErrorStream);
-
- try {
- doPrivileged((PrivilegedExceptionAction<Void>) () -> {
- 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 {
- switch (platform) {
- case LINUX:
- case BSD:
- 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(() -> {
- int exitcode = waitForProcessExit(pid);
-
- synchronized (this) {
- this.exitcode = exitcode;
- this.hasExited = true;
- this.notifyAll();
- }
-
- if (stdout instanceof ProcessPipeInputStream)
- ((ProcessPipeInputStream) stdout).processExited();
-
- if (stderr instanceof ProcessPipeInputStream)
- ((ProcessPipeInputStream) stderr).processExited();
-
- if (stdin instanceof ProcessPipeOutputStream)
- ((ProcessPipeOutputStream) stdin).processExited();
- });
- break;
-
- case SOLARIS:
- stdin = (fds[0] == -1) ?
- ProcessBuilder.NullOutputStream.INSTANCE :
- new BufferedOutputStream(
- new FileOutputStream(newFileDescriptor(fds[0])));
-
- stdout = (fds[1] == -1) ?
- ProcessBuilder.NullInputStream.INSTANCE :
- new BufferedInputStream(
- stdout_inner_stream =
- new DeferredCloseInputStream(
- newFileDescriptor(fds[1])));
-
- stderr = (fds[2] == -1) ?
- ProcessBuilder.NullInputStream.INSTANCE :
- new DeferredCloseInputStream(newFileDescriptor(fds[2]));
-
- /*
- * For each subprocess forked a corresponding reaper task
- * is submitted. That task is the only thread which waits
- * for the subprocess to terminate and it doesn't hold any
- * locks while doing so. This design allows waitFor() and
- * exitStatus() to be safely executed in parallel (and they
- * need no native code).
- */
- processReaperExecutor.execute(() -> {
- int exitcode = waitForProcessExit(pid);
-
- synchronized (this) {
- this.exitcode = exitcode;
- this.hasExited = true;
- this.notifyAll();
- }
- });
- break;
-
- case AIX:
- stdin = (fds[0] == -1) ?
- ProcessBuilder.NullOutputStream.INSTANCE :
- new ProcessPipeOutputStream(fds[0]);
-
- stdout = (fds[1] == -1) ?
- ProcessBuilder.NullInputStream.INSTANCE :
- new DeferredCloseProcessPipeInputStream(fds[1]);
-
- stderr = (fds[2] == -1) ?
- ProcessBuilder.NullInputStream.INSTANCE :
- new DeferredCloseProcessPipeInputStream(fds[2]);
-
- processReaperExecutor.execute(() -> {
- int exitcode = waitForProcessExit(pid);
-
- synchronized (this) {
- this.exitcode = exitcode;
- this.hasExited = true;
- this.notifyAll();
- }
-
- if (stdout instanceof DeferredCloseProcessPipeInputStream)
- ((DeferredCloseProcessPipeInputStream) stdout).processExited();
-
- if (stderr instanceof DeferredCloseProcessPipeInputStream)
- ((DeferredCloseProcessPipeInputStream) stderr).processExited();
-
- if (stdin instanceof ProcessPipeOutputStream)
- ((ProcessPipeOutputStream) stdin).processExited();
- });
- break;
-
- default: throw new AssertionError("Unsupported platform: " + platform);
- }
- }
-
- 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 remainingNanos = unit.toNanos(timeout);
- long deadline = System.nanoTime() + remainingNanos;
-
- do {
- // Round up to next millisecond
- wait(TimeUnit.NANOSECONDS.toMillis(remainingNanos + 999_999L));
- if (hasExited) {
- return true;
- }
- remainingNanos = deadline - System.nanoTime();
- } while (remainingNanos > 0);
- 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) {
- switch (platform) {
- case LINUX:
- case BSD:
- case AIX:
- // 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) {}
- break;
-
- case SOLARIS:
- // 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();
- if (stdout_inner_stream != null)
- stdout_inner_stream.closeDeferred(stdout);
- if (stderr instanceof DeferredCloseInputStream)
- ((DeferredCloseInputStream) stderr)
- .closeDeferred(stderr);
- } catch (IOException e) {
- // ignore
- }
- }
- break;
-
- default: throw new AssertionError("Unsupported platform: " + platform);
- }
- }
-
- public void destroy() {
- destroy(false);
- }
-
- @Override
- public Process destroyForcibly() {
- destroy(true);
- return this;
- }
-
- @Override
- public long getPid() {
- return pid;
- }
-
- @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.
- */
- private 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.
- */
- private 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;
- }
- }
- }
-
- // A FileInputStream that supports the deferment of the actual close
- // operation until the last pending I/O operation on the stream has
- // finished. This is required on Solaris because we must close the stdin
- // and stdout streams in the destroy method in order to reclaim the
- // underlying file descriptors. Doing so, however, causes any thread
- // currently blocked in a read on one of those streams to receive an
- // IOException("Bad file number"), which is incompatible with historical
- // behavior. By deferring the close we allow any pending reads to see -1
- // (EOF) as they did before.
- //
- private static class DeferredCloseInputStream extends FileInputStream
- {
- DeferredCloseInputStream(FileDescriptor fd) {
- super(fd);
- }
-
- private Object lock = new Object(); // For the following fields
- private boolean closePending = false;
- private int useCount = 0;
- private InputStream streamToClose;
-
- private void raise() {
- synchronized (lock) {
- useCount++;
- }
- }
-
- private void lower() throws IOException {
- synchronized (lock) {
- useCount--;
- if (useCount == 0 && closePending) {
- streamToClose.close();
- }
- }
- }
-
- // stc is the actual stream to be closed; it might be this object, or
- // it might be an upstream object for which this object is downstream.
- //
- private void closeDeferred(InputStream stc) throws IOException {
- synchronized (lock) {
- if (useCount == 0) {
- stc.close();
- } else {
- closePending = true;
- streamToClose = stc;
- }
- }
- }
-
- public void close() throws IOException {
- synchronized (lock) {
- useCount = 0;
- closePending = false;
- }
- super.close();
- }
-
- public int read() throws IOException {
- raise();
- try {
- return super.read();
- } finally {
- lower();
- }
- }
-
- public int read(byte[] b) throws IOException {
- raise();
- try {
- return super.read(b);
- } finally {
- lower();
- }
- }
-
- public int read(byte[] b, int off, int len) throws IOException {
- raise();
- try {
- return super.read(b, off, len);
- } finally {
- lower();
- }
- }
-
- public long skip(long n) throws IOException {
- raise();
- try {
- return super.skip(n);
- } finally {
- lower();
- }
- }
-
- public int available() throws IOException {
- raise();
- try {
- return super.available();
- } finally {
- lower();
- }
- }
- }
-
- /**
- * 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.
- *
- * On AIX this is especially tricky, because the 'close()' system call
- * will block if another thread is at the same time blocked in a file
- * operation (e.g. 'read()') on the same file descriptor. We therefore
- * combine 'ProcessPipeInputStream' approach used on Linux and Bsd
- * with the DeferredCloseInputStream approach used on Solaris. This means
- * that every potentially blocking operation on the file descriptor
- * increments a counter before it is executed and decrements it once it
- * finishes. The 'close()' operation will only be executed if there are
- * no pending operations. Otherwise it is deferred after the last pending
- * operation has finished.
- *
- */
- private static class DeferredCloseProcessPipeInputStream
- extends BufferedInputStream {
-
- private final Object closeLock = new Object();
- private int useCount = 0;
- private boolean closePending = false;
-
- DeferredCloseProcessPipeInputStream(int fd) {
- super(new FileInputStream(newFileDescriptor(fd)));
- }
-
- private InputStream drainInputStream(InputStream in)
- throws IOException {
- int n = 0;
- int j;
- byte[] a = null;
- synchronized (closeLock) {
- if (buf == null) // asynchronous close()?
- return null; // discard
- j = in.available();
- }
- while (j > 0) {
- a = (a == null) ? new byte[j] : Arrays.copyOf(a, n + j);
- synchronized (closeLock) {
- if (buf == null) // asynchronous close()?
- return null; // discard
- n += in.read(a, n, j);
- j = in.available();
- }
- }
- return (a == null) ?
- ProcessBuilder.NullInputStream.INSTANCE :
- new ByteArrayInputStream(n == a.length ? a : Arrays.copyOf(a, n));
- }
-
- /** Called by the process reaper thread when the process exits. */
- synchronized void processExited() {
- try {
- InputStream in = this.in;
- if (in != null) {
- InputStream stragglers = drainInputStream(in);
- in.close();
- this.in = stragglers;
- }
- } catch (IOException ignored) { }
- }
-
- private void raise() {
- synchronized (closeLock) {
- useCount++;
- }
- }
-
- private void lower() throws IOException {
- synchronized (closeLock) {
- useCount--;
- if (useCount == 0 && closePending) {
- closePending = false;
- super.close();
- }
- }
- }
-
- @Override
- public int read() throws IOException {
- raise();
- try {
- return super.read();
- } finally {
- lower();
- }
- }
-
- @Override
- public int read(byte[] b) throws IOException {
- raise();
- try {
- return super.read(b);
- } finally {
- lower();
- }
- }
-
- @Override
- public int read(byte[] b, int off, int len) throws IOException {
- raise();
- try {
- return super.read(b, off, len);
- } finally {
- lower();
- }
- }
-
- @Override
- public long skip(long n) throws IOException {
- raise();
- try {
- return super.skip(n);
- } finally {
- lower();
- }
- }
-
- @Override
- public int available() throws IOException {
- raise();
- try {
- return super.available();
- } finally {
- lower();
- }
- }
-
- @Override
- public void close() throws IOException {
- // BufferedInputStream#close() is not synchronized unlike most other
- // methods. Synchronizing helps avoid racing with drainInputStream().
- synchronized (closeLock) {
- if (useCount == 0) {
- super.close();
- }
- else {
- closePending = true;
- }
- }
- }
- }
-}