ojluni/src/main/java/sun/tools/attach/BsdVirtualMachine.java - platform/libcore - Git at Google

 /*
  * Copyright (c) 2005, 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 sun.tools.attach;

 import com.sun.tools.attach.VirtualMachine;
 import com.sun.tools.attach.AgentLoadException;
 import com.sun.tools.attach.AttachNotSupportedException;
 import com.sun.tools.attach.spi.AttachProvider;
 import java.io.InputStream;
 import java.io.IOException;
 import java.io.File;
 import java.util.Properties;

 /*
  * Bsd implementation of HotSpotVirtualMachine
  */
 public class BsdVirtualMachine extends HotSpotVirtualMachine {
     // "tmpdir" is used as a global well-known location for the files
     // .java_pid<pid>. and .attach_pid<pid>. It is important that this
     // location is the same for all processes, otherwise the tools
     // will not be able to find all Hotspot processes.
     // This is intentionally not the same as java.io.tmpdir, since
     // the latter can be changed by the user.
     // Any changes to this needs to be synchronized with HotSpot.
     private static final String tmpdir;

     // The patch to the socket file created by the target VM
     String path;

     /**
      * Attaches to the target VM
      */
     BsdVirtualMachine(AttachProvider provider, String vmid)
         throws AttachNotSupportedException, IOException
     {
         super(provider, vmid);

         // This provider only understands pids
         int pid;
         try {
             pid = Integer.parseInt(vmid);
         } catch (NumberFormatException x) {
             throw new AttachNotSupportedException("Invalid process identifier");
         }

         // Find the socket file. If not found then we attempt to start the
         // attach mechanism in the target VM by sending it a QUIT signal.
         // Then we attempt to find the socket file again.
         path = findSocketFile(pid);
         if (path == null) {
             File f = new File(tmpdir, ".attach_pid" + pid);
             createAttachFile(f.getPath());
             try {
                 sendQuitTo(pid);

                 // give the target VM time to start the attach mechanism
                 int i = 0;
                 long delay = 200;
                 int retries = (int)(attachTimeout() / delay);
                 do {
                     try {
                         Thread.sleep(delay);
                     } catch (InterruptedException x) { }
                     path = findSocketFile(pid);
                     i++;
                 } while (i <= retries && path == null);
                 if (path == null) {
                     throw new AttachNotSupportedException(
                         "Unable to open socket file: target process not responding " +
                         "or HotSpot VM not loaded");
                 }
             } finally {
                 f.delete();
             }
         }

         // Check that the file owner/permission to avoid attaching to
         // bogus process
         checkPermissions(path);

         // Check that we can connect to the process
         // - this ensures we throw the permission denied error now rather than
         // later when we attempt to enqueue a command.
         int s = socket();
         try {
             connect(s, path);
         } finally {
             close(s);
         }
     }

     /**
      * Detach from the target VM
      */
     public void detach() throws IOException {
         synchronized (this) {
             if (this.path != null) {
                 this.path = null;
             }
         }
     }

     // protocol version
     private final static String PROTOCOL_VERSION = "1";

     // known errors
     private final static int ATTACH_ERROR_BADVERSION = 101;

     /**
      * Execute the given command in the target VM.
      */
     InputStream execute(String cmd, Object ... args) throws AgentLoadException, IOException {
         assert args.length <= 3;                // includes null

         // did we detach?
         String p;
         synchronized (this) {
             if (this.path == null) {
                 throw new IOException("Detached from target VM");
             }
             p = this.path;
         }

         // create UNIX socket
         int s = socket();

         // connect to target VM
         try {
             connect(s, p);
         } catch (IOException x) {
             close(s);
             throw x;
         }

         IOException ioe = null;

         // connected - write request
         // <ver> <cmd> <args...>
         try {
             writeString(s, PROTOCOL_VERSION);
             writeString(s, cmd);

             for (int i=0; i<3; i++) {
                 if (i < args.length && args[i] != null) {
                     writeString(s, (String)args[i]);
                 } else {
                     writeString(s, "");
                 }
             }
         } catch (IOException x) {
             ioe = x;
         }


         // Create an input stream to read reply
         SocketInputStream sis = new SocketInputStream(s);

         // Read the command completion status
         int completionStatus;
         try {
             completionStatus = readInt(sis);
         } catch (IOException x) {
             sis.close();
             if (ioe != null) {
                 throw ioe;
             } else {
                 throw x;
             }
         }

         if (completionStatus != 0) {
             sis.close();

             // In the event of a protocol mismatch then the target VM
             // returns a known error so that we can throw a reasonable
             // error.
             if (completionStatus == ATTACH_ERROR_BADVERSION) {
                 throw new IOException("Protocol mismatch with target VM");
             }

             // Special-case the "load" command so that the right exception is
             // thrown.
             if (cmd.equals("load")) {
                 throw new AgentLoadException("Failed to load agent library");
             } else {
                 throw new IOException("Command failed in target VM");
             }
         }

         // Return the input stream so that the command output can be read
         return sis;
     }

     /*
      * InputStream for the socket connection to get target VM
      */
     private class SocketInputStream extends InputStream {
         int s;

         public SocketInputStream(int s) {
             this.s = s;
         }

         public synchronized int read() throws IOException {
             byte b[] = new byte[1];
             int n = this.read(b, 0, 1);
             if (n == 1) {
                 return b[0] & 0xff;
             } else {
                 return -1;
             }
         }

         public synchronized int read(byte[] bs, int off, int len) throws IOException {
             if ((off < 0) || (off > bs.length) || (len < 0) ||
                 ((off + len) > bs.length) || ((off + len) < 0)) {
                 throw new IndexOutOfBoundsException();
             } else if (len == 0)
                 return 0;

             return BsdVirtualMachine.read(s, bs, off, len);
         }

         public void close() throws IOException {
             BsdVirtualMachine.close(s);
         }
     }

     // Return the socket file for the given process.
     // Checks temp directory for .java_pid<pid>.
     private String findSocketFile(int pid) {
         String fn = ".java_pid" + pid;
         File f = new File(tmpdir, fn);
         return f.exists() ? f.getPath() : null;
     }

     /*
      * Write/sends the given to the target VM. String is transmitted in
      * UTF-8 encoding.
      */
     private void writeString(int fd, String s) throws IOException {
         if (s.length() > 0) {
             byte b[];
             try {
                 b = s.getBytes("UTF-8");
             } catch (java.io.UnsupportedEncodingException x) {
                 throw new InternalError();
             }
             BsdVirtualMachine.write(fd, b, 0, b.length);
         }
         byte b[] = new byte[1];
         b[0] = 0;
         write(fd, b, 0, 1);
     }


     //-- native methods

     static native void sendQuitTo(int pid) throws IOException;

     static native void checkPermissions(String path) throws IOException;

     static native int socket() throws IOException;

     static native void connect(int fd, String path) throws IOException;

     static native void close(int fd) throws IOException;

     static native int read(int fd, byte buf[], int off, int bufLen) throws IOException;

     static native void write(int fd, byte buf[], int off, int bufLen) throws IOException;

     static native void createAttachFile(String path);

     static native String getTempDir();

     static {
         System.loadLibrary("attach");
         tmpdir = getTempDir();
     }
 }
	/*
	* Copyright (c) 2005, 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 sun.tools.attach;

	import com.sun.tools.attach.VirtualMachine;
	import com.sun.tools.attach.AgentLoadException;
	import com.sun.tools.attach.AttachNotSupportedException;
	import com.sun.tools.attach.spi.AttachProvider;
	import java.io.InputStream;
	import java.io.IOException;
	import java.io.File;
	import java.util.Properties;

	/*
	* Bsd implementation of HotSpotVirtualMachine
	*/
	public class BsdVirtualMachine extends HotSpotVirtualMachine {
	// "tmpdir" is used as a global well-known location for the files
	// .java_pid<pid>. and .attach_pid<pid>. It is important that this
	// location is the same for all processes, otherwise the tools
	// will not be able to find all Hotspot processes.
	// This is intentionally not the same as java.io.tmpdir, since
	// the latter can be changed by the user.
	// Any changes to this needs to be synchronized with HotSpot.
	private static final String tmpdir;

	// The patch to the socket file created by the target VM
	String path;

	/**
	* Attaches to the target VM
	*/
	BsdVirtualMachine(AttachProvider provider, String vmid)
	throws AttachNotSupportedException, IOException
	{
	super(provider, vmid);

	// This provider only understands pids
	int pid;
	try {
	pid = Integer.parseInt(vmid);
	} catch (NumberFormatException x) {
	throw new AttachNotSupportedException("Invalid process identifier");
	}

	// Find the socket file. If not found then we attempt to start the
	// attach mechanism in the target VM by sending it a QUIT signal.
	// Then we attempt to find the socket file again.
	path = findSocketFile(pid);
	if (path == null) {
	File f = new File(tmpdir, ".attach_pid" + pid);
	createAttachFile(f.getPath());
	try {
	sendQuitTo(pid);

	// give the target VM time to start the attach mechanism
	int i = 0;
	long delay = 200;
	int retries = (int)(attachTimeout() / delay);
	do {
	try {
	Thread.sleep(delay);
	} catch (InterruptedException x) { }
	path = findSocketFile(pid);
	i++;
	} while (i <= retries && path == null);
	if (path == null) {
	throw new AttachNotSupportedException(
	"Unable to open socket file: target process not responding " +
	"or HotSpot VM not loaded");
	}
	} finally {
	f.delete();
	}
	}

	// Check that the file owner/permission to avoid attaching to
	// bogus process
	checkPermissions(path);

	// Check that we can connect to the process
	// - this ensures we throw the permission denied error now rather than
	// later when we attempt to enqueue a command.
	int s = socket();
	try {
	connect(s, path);
	} finally {
	close(s);
	}
	}

	/**
	* Detach from the target VM
	*/
	public void detach() throws IOException {
	synchronized (this) {
	if (this.path != null) {
	this.path = null;
	}
	}
	}

	// protocol version
	private final static String PROTOCOL_VERSION = "1";

	// known errors
	private final static int ATTACH_ERROR_BADVERSION = 101;

	/**
	* Execute the given command in the target VM.
	*/
	InputStream execute(String cmd, Object ... args) throws AgentLoadException, IOException {
	assert args.length <= 3; // includes null

	// did we detach?
	String p;
	synchronized (this) {
	if (this.path == null) {
	throw new IOException("Detached from target VM");
	}
	p = this.path;
	}

	// create UNIX socket
	int s = socket();

	// connect to target VM
	try {
	connect(s, p);
	} catch (IOException x) {
	close(s);
	throw x;
	}

	IOException ioe = null;

	// connected - write request
	// <ver> <cmd> <args...>
	try {
	writeString(s, PROTOCOL_VERSION);
	writeString(s, cmd);

	for (int i=0; i<3; i++) {
	if (i < args.length && args[i] != null) {
	writeString(s, (String)args[i]);
	} else {
	writeString(s, "");
	}
	}
	} catch (IOException x) {
	ioe = x;
	}


	// Create an input stream to read reply
	SocketInputStream sis = new SocketInputStream(s);

	// Read the command completion status
	int completionStatus;
	try {
	completionStatus = readInt(sis);
	} catch (IOException x) {
	sis.close();
	if (ioe != null) {
	throw ioe;
	} else {
	throw x;
	}
	}

	if (completionStatus != 0) {
	sis.close();

	// In the event of a protocol mismatch then the target VM
	// returns a known error so that we can throw a reasonable
	// error.
	if (completionStatus == ATTACH_ERROR_BADVERSION) {
	throw new IOException("Protocol mismatch with target VM");
	}

	// Special-case the "load" command so that the right exception is
	// thrown.
	if (cmd.equals("load")) {
	throw new AgentLoadException("Failed to load agent library");
	} else {
	throw new IOException("Command failed in target VM");
	}
	}

	// Return the input stream so that the command output can be read
	return sis;
	}

	/*
	* InputStream for the socket connection to get target VM
	*/
	private class SocketInputStream extends InputStream {
	int s;

	public SocketInputStream(int s) {
	this.s = s;
	}

	public synchronized int read() throws IOException {
	byte b[] = new byte[1];
	int n = this.read(b, 0, 1);
	if (n == 1) {
	return b[0] & 0xff;
	} else {
	return -1;
	}
	}

	public synchronized int read(byte[] bs, int off, int len) throws IOException {
	if ((off < 0) \|\| (off > bs.length) \|\| (len < 0) \|\|
	((off + len) > bs.length) \|\| ((off + len) < 0)) {
	throw new IndexOutOfBoundsException();
	} else if (len == 0)
	return 0;

	return BsdVirtualMachine.read(s, bs, off, len);
	}

	public void close() throws IOException {
	BsdVirtualMachine.close(s);
	}
	}

	// Return the socket file for the given process.
	// Checks temp directory for .java_pid<pid>.
	private String findSocketFile(int pid) {
	String fn = ".java_pid" + pid;
	File f = new File(tmpdir, fn);
	return f.exists() ? f.getPath() : null;
	}

	/*
	* Write/sends the given to the target VM. String is transmitted in
	* UTF-8 encoding.
	*/
	private void writeString(int fd, String s) throws IOException {
	if (s.length() > 0) {
	byte b[];
	try {
	b = s.getBytes("UTF-8");
	} catch (java.io.UnsupportedEncodingException x) {
	throw new InternalError();
	}
	BsdVirtualMachine.write(fd, b, 0, b.length);
	}
	byte b[] = new byte[1];
	b[0] = 0;
	write(fd, b, 0, 1);
	}


	//-- native methods

	static native void sendQuitTo(int pid) throws IOException;

	static native void checkPermissions(String path) throws IOException;

	static native int socket() throws IOException;

	static native void connect(int fd, String path) throws IOException;

	static native void close(int fd) throws IOException;

	static native int read(int fd, byte buf[], int off, int bufLen) throws IOException;

	static native void write(int fd, byte buf[], int off, int bufLen) throws IOException;

	static native void createAttachFile(String path);

	static native String getTempDir();

	static {
	System.loadLibrary("attach");
	tmpdir = getTempDir();
	}
	}