java/lang/UNIXProcess.java.solaris

	UNIXProcess.java.solaris revision 25
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff/*
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff * Copyright 1995-2008 Sun Microsystems, Inc.  All Rights Reserved.
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff *
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff * This code is free software; you can redistribute it and/or modify it
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff * under the terms of the GNU General Public License version 2 only, as
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff * published by the Free Software Foundation.  Sun designates this
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff * particular file as subject to the "Classpath" exception as provided
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff * by Sun in the LICENSE file that accompanied this code.
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff *
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff * This code is distributed in the hope that it will be useful, but WITHOUT
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff * version 2 for more details (a copy is included in the LICENSE file that
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff * accompanied this code).
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff *
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff * You should have received a copy of the GNU General Public License version
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff * 2 along with this work; if not, write to the Free Software Foundation,
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff *
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff * CA 95054 USA or visit www.sun.com if you need additional information or
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff * have any questions.
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff */
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloffpackage java.lang;
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff
8658209f33f5c6670cdeac3004cefc1938d1df17Andi Egloffimport java.io.*;
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff/* java.lang.Process subclass in the UNIX environment.
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff *
e5c203467ee4398ae81a6adb63da7477451b2e77Laszlo Hordos * @author Mario Wolczko and Ross Knippel.
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff */
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff
e13366e235a3af3029b751bc89f419ec1615fe30Andi Eglofffinal class UNIXProcess extends Process {
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff    private static final sun.misc.JavaIOFileDescriptorAccess fdAccess
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff        = sun.misc.SharedSecrets.getJavaIOFileDescriptorAccess();
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff    private final int pid;
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff    private int exitcode;
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff    private boolean hasExited;
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff    private OutputStream stdin_stream;
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff    private InputStream stdout_stream;
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff    private DeferredCloseInputStream stdout_inner_stream;
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff    private InputStream stderr_stream;
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff    /* this is for the reaping thread */
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff    private native int waitForProcessExit(int pid);
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff    /**
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff     * Create a process using fork(2) and exec(2).
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff     *
35cd0f38c7b43c813f9d4e5be555c5f9406fae2eAndi Egloff     * @param std_fds array of file descriptors.  Indexes 0, 1, and
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff     *        2 correspond to standard input, standard output and
f572d33ed141953335fe796ca36d818146af68efLaszlo Hordos     *        standard error, respectively.  On input, a value of -1
f572d33ed141953335fe796ca36d818146af68efLaszlo Hordos     *        means to create a pipe to connect child and parent
f572d33ed141953335fe796ca36d818146af68efLaszlo Hordos     *        processes.  On output, a value which is not -1 is the
f572d33ed141953335fe796ca36d818146af68efLaszlo Hordos     *        parent pipe fd corresponding to the pipe which has
f572d33ed141953335fe796ca36d818146af68efLaszlo Hordos     *        been created.  An element of this array is -1 on input
f572d33ed141953335fe796ca36d818146af68efLaszlo Hordos     *        if and only if it is <em>not</em> -1 on output.
f572d33ed141953335fe796ca36d818146af68efLaszlo Hordos     * @return the pid of the subprocess
f572d33ed141953335fe796ca36d818146af68efLaszlo Hordos     */
ee62c64ead29d0f9db8846e4a137b4e928245fd4Andi Egloff    private native int forkAndExec(byte[] prog,
ee62c64ead29d0f9db8846e4a137b4e928245fd4Andi Egloff                                   byte[] argBlock, int argc,
ee62c64ead29d0f9db8846e4a137b4e928245fd4Andi Egloff                                   byte[] envBlock, int envc,
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff                                   byte[] dir,
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff                                   int[] std_fds,
d2f952a00b334781659435acb1f084d1e564294bAndi Egloff                                   boolean redirectErrorStream)
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff        throws IOException;
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff
7eb845c4ebff52285787cca49968a4637146e6c4Andi Egloff    UNIXProcess(final byte[] prog,
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff                final byte[] argBlock, int argc,
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff                final byte[] envBlock, int envc,
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff                final byte[] dir,
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff                final int[] std_fds,
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff                final boolean redirectErrorStream)
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff    throws IOException {
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff        pid = forkAndExec(prog,
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff                          argBlock, argc,
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff                          envBlock, envc,
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff                          dir,
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff                          std_fds,
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff                          redirectErrorStream);
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff
e13366e235a3af3029b751bc89f419ec1615fe30Andi Egloff        java.security.AccessController.doPrivileged(
f572d33ed141953335fe796ca36d818146af68efLaszlo Hordos        new java.security.PrivilegedAction<Void>() { public Void run() {
dedea1c74ef770604ee181088cedc7bd891486baAndi Egloff            if (std_fds[0] == -1)
660a40ad15749d74efa0dd4ef12cb8781c570e22Laszlo Hordos                stdin_stream = new ProcessBuilder.NullOutputStream();
35a69e16f6cf17f17cf311efec806bda5e89ff2fLaszlo Hordos            else {
dedea1c74ef770604ee181088cedc7bd891486baAndi Egloff                FileDescriptor stdin_fd = new FileDescriptor();
dedea1c74ef770604ee181088cedc7bd891486baAndi Egloff                fdAccess.set(stdin_fd, std_fds[0]);
dedea1c74ef770604ee181088cedc7bd891486baAndi Egloff                stdin_stream = new BufferedOutputStream(
35a69e16f6cf17f17cf311efec806bda5e89ff2fLaszlo Hordos                    new FileOutputStream(stdin_fd));
dedea1c74ef770604ee181088cedc7bd891486baAndi Egloff            }
d0ffcfdbe57afaf2adba4ef3134ba519c3e2b05fAndi Egloff
            if (std_fds[1] == -1)
                stdout_stream = new ProcessBuilder.NullInputStream();
            else {
                FileDescriptor stdout_fd = new FileDescriptor();
                fdAccess.set(stdout_fd, std_fds[1]);
                stdout_inner_stream = new DeferredCloseInputStream(stdout_fd);
                stdout_stream = new BufferedInputStream(stdout_inner_stream);
            }

            if (std_fds[2] == -1)
                stderr_stream = new ProcessBuilder.NullInputStream();
            else {
                FileDescriptor stderr_fd = new FileDescriptor();
                fdAccess.set(stderr_fd, std_fds[2]);
                stderr_stream = new DeferredCloseInputStream(stderr_fd);
            }

            return null; }});

        /*
         * For each subprocess forked a corresponding reaper thread
         * is started.  That thread 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).
         */

        java.security.AccessController.doPrivileged(
            new java.security.PrivilegedAction<Void>() { public Void run() {
                Thread t = new Thread("process reaper") {
                    public void run() {
                        int res = waitForProcessExit(pid);
                        synchronized (UNIXProcess.this) {
                            hasExited = true;
                            exitcode = res;
                            UNIXProcess.this.notifyAll();
                        }
                    }
                };
                t.setDaemon(true);
                t.start();
                return null; }});
    }

    public OutputStream getOutputStream() {
        return stdin_stream;
    }

    public InputStream getInputStream() {
        return stdout_stream;
    }

    public InputStream getErrorStream() {
        return stderr_stream;
    }

    public synchronized int waitFor() throws InterruptedException {
        while (!hasExited) {
            wait();
        }
        return exitcode;
    }

    public synchronized int exitValue() {
        if (!hasExited) {
            throw new IllegalThreadStateException("process hasn't exited");
        }
        return exitcode;
    }

    private static native void destroyProcess(int pid);
    public synchronized void destroy() {
        // 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.
        if (!hasExited)
            destroyProcess(pid);
        try {
            stdin_stream.close();
            if (stdout_inner_stream != null)
                stdout_inner_stream.closeDeferred(stdout_stream);
            if (stderr_stream instanceof DeferredCloseInputStream)
                ((DeferredCloseInputStream) stderr_stream)
                    .closeDeferred(stderr_stream);
        } catch (IOException e) {
            // ignore
        }
    }

    // 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
    {

        private 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();
            }
        }

    }

    /* This routine initializes JNI field offsets for the class */
    private static native void initIDs();

    static {
        initIDs();
    }
}