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8071481: (Process) Merge UNIXProcess.java into ProcessImpl.java

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Simplify source files for Unix Process implementation

Reviewed-by: plevart, chegar
This commit is contained in:
Roger Riggs 2015-01-26 10:55:27 -05:00
parent 6a34176e9c
commit aa6b19f38e
6 changed files with 815 additions and 869 deletions
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10
jdk/make/mapfiles/libjava/mapfile-vers
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@ -1,5 +1,5 @@
#
# Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
# Copyright (c) 1997, 2015, 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
@ -214,10 +214,10 @@ SUNWprivate_1.1 {
Java_java_lang_Throwable_fillInStackTrace;
Java_java_lang_Throwable_getStackTraceDepth;
Java_java_lang_Throwable_getStackTraceElement;
Java_java_lang_UNIXProcess_init;
Java_java_lang_UNIXProcess_waitForProcessExit;
Java_java_lang_UNIXProcess_forkAndExec;
Java_java_lang_UNIXProcess_destroyProcess;
Java_java_lang_ProcessImpl_init;
Java_java_lang_ProcessImpl_waitForProcessExit;
Java_java_lang_ProcessImpl_forkAndExec;
Java_java_lang_ProcessImpl_destroyProcess;
Java_java_nio_Bits_copyFromShortArray;
Java_java_nio_Bits_copyToShortArray;
Java_java_nio_Bits_copyFromIntArray;

822
jdk/src/java.base/unix/classes/java/lang/ProcessImpl.java
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@ -1,5 +1,5 @@
/*
* Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2003, 2015, 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
@ -25,24 +25,156 @@
package java.lang;
import java.io.IOException;
import java.lang.ProcessBuilder.Redirect;
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.lang.ProcessBuilder.Redirect;
import java.lang.ProcessBuilder.Redirect;
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;
/**
* This class is for the exclusive use of ProcessBuilder.start() to
* create new processes.
* This java.lang.Process subclass in the UNIX environment is for the exclusive use of
* ProcessBuilder.start() to create new processes.
*
* @author Mario Wolczko and Ross Knippel.
* @author Konstantin Kladko (ported to Linux and Bsd)
* @author Martin Buchholz
* @author Volker Simonis (ported to AIX)
* @since 1.5
*/
final class ProcessImpl {
final class ProcessImpl extends Process {
private static final sun.misc.JavaIOFileDescriptorAccess fdAccess
= sun.misc.SharedSecrets.getJavaIOFileDescriptorAccess();
private ProcessImpl() {} // Not instantiable
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());
/* this is for the reaping thread */
private native int waitForProcessExit(int pid);
private static byte[] toCString(String s) {
if (s == null)
@ -50,8 +182,8 @@ final class ProcessImpl {
byte[] bytes = s.getBytes();
byte[] result = new byte[bytes.length + 1];
System.arraycopy(bytes, 0,
result, 0,
bytes.length);
result, 0,
bytes.length);
result[result.length-1] = (byte)0;
return result;
}
@ -62,7 +194,7 @@ final class ProcessImpl {
String dir,
ProcessBuilder.Redirect[] redirects,
boolean redirectErrorStream)
throws IOException
throws IOException
{
assert cmdarray != null && cmdarray.length > 0;
@ -112,7 +244,7 @@ final class ProcessImpl {
std_fds[1] = 1;
else {
f1 = new FileOutputStream(redirects[1].file(),
redirects[1].append());
redirects[1].append());
std_fds[1] = fdAccess.get(f1.getFD());
}
@ -122,18 +254,18 @@ final class ProcessImpl {
std_fds[2] = 2;
else {
f2 = new FileOutputStream(redirects[2].file(),
redirects[2].append());
redirects[2].append());
std_fds[2] = fdAccess.get(f2.getFD());
}
}
return new UNIXProcess
(toCString(cmdarray[0]),
argBlock, args.length,
envBlock, envc[0],
toCString(dir),
std_fds,
redirectErrorStream);
return new ProcessImpl
(toCString(cmdarray[0]),
argBlock, args.length,
envBlock, envc[0],
toCString(dir),
std_fds,
redirectErrorStream);
} finally {
// In theory, close() can throw IOException
// (although it is rather unlikely to happen here)
@ -144,4 +276,654 @@ final class ProcessImpl {
}
}
}
/**
* 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);
});
private ProcessImpl(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;
}
}
}
}
}

836
jdk/src/java.base/unix/classes/java/lang/UNIXProcess.java
View File

@ -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;
}
}
}
}
}

10
jdk/src/java.base/unix/native/libjava/UNIXProcess_md.c → jdk/src/java.base/unix/native/libjava/ProcessImpl_md.c
View File

@ -1,5 +1,5 @@
/*
* Copyright (c) 1995, 2013, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 1995, 2015, 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
@ -203,7 +203,7 @@ effectivePathv(JNIEnv *env)
}
JNIEXPORT void JNICALL
Java_java_lang_UNIXProcess_init(JNIEnv *env, jclass clazz)
Java_java_lang_ProcessImpl_init(JNIEnv *env, jclass clazz)
{
parentPathv = effectivePathv(env);
CHECK_NULL(parentPathv);
@ -230,7 +230,7 @@ Java_java_lang_UNIXProcess_init(JNIEnv *env, jclass clazz)
/* Block until a child process exits and return its exit code.
Note, can only be called once for any given pid. */
JNIEXPORT jint JNICALL
Java_java_lang_UNIXProcess_waitForProcessExit(JNIEnv* env,
Java_java_lang_ProcessImpl_waitForProcessExit(JNIEnv* env,
jobject junk,
jint pid)
{
@ -562,7 +562,7 @@ startChild(JNIEnv *env, jobject process, ChildStuff *c, const char *helperpath)
}
JNIEXPORT jint JNICALL
Java_java_lang_UNIXProcess_forkAndExec(JNIEnv *env,
Java_java_lang_ProcessImpl_forkAndExec(JNIEnv *env,
jobject process,
jint mode,
jbyteArray helperpath,
@ -714,7 +714,7 @@ Java_java_lang_UNIXProcess_forkAndExec(JNIEnv *env,
}
JNIEXPORT void JNICALL
Java_java_lang_UNIXProcess_destroyProcess(JNIEnv *env,
Java_java_lang_ProcessImpl_destroyProcess(JNIEnv *env,
jobject junk,
jint pid,
jboolean force)

4
jdk/src/java.base/unix/native/libjava/childproc.h
View File

@ -1,5 +1,5 @@
/*
* Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2013, 2015, 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
@ -79,7 +79,7 @@ extern char **environ;
} while((_result == -1) && (errno == EINTR)); \
} while(0)
/* These numbers must be the same as the Enum in UNIXProcess.java
/* These numbers must be the same as the Enum in ProcessImpl.java
* Must be a better way of doing this.
*/
#define MODE_FORK 1

2
jdk/test/java/lang/ProcessBuilder/Basic.java
View File

@ -2042,7 +2042,7 @@ public class Basic {
final Object deferred;
Class<?> c = s.getClass();
if (c.getName().equals(
"java.lang.UNIXProcess$DeferredCloseInputStream"))
"java.lang.ProcessImpl$DeferredCloseInputStream"))
{
deferred = s;
} else {