31 import java.io.RandomAccessFile;

    31 import java.io.RandomAccessFile;

    32 import java.nio.channels.ClosedChannelException;

    32 import java.nio.channels.ClosedChannelException;

    33 import java.nio.channels.FileChannel;

    33 import java.nio.channels.FileChannel;

    34 import java.nio.channels.FileLock;

    34 import java.nio.channels.FileLock;

    35 import java.nio.channels.FileLockInterruptionException;

    35 import java.nio.channels.FileLockInterruptionException;

    36 import com.sun.tools.sjavac.Log;

    37 import com.sun.tools.sjavac.Log;

    37 

    38 

    38 /**

    39 /**

    39  * The PortFile class mediates access to a short binary file containing the tcp/ip port (for the localhost)

    40  * The PortFile class mediates access to a short binary file containing the tcp/ip port (for the localhost)

    40  * and a cookie necessary for the server answering on that port. The file can be locked using file system

    41  * and a cookie necessary for the server answering on that port. The file can be locked using file system

    41  * primitives to avoid race conditions when several javac clients are started at the same. Note that file

    42  * primitives to avoid race conditions when several javac clients are started at the same. Note that file

    42  * system locking is not always supported on a all operating systems and/or file systems.

    43  * system locking is not always supported on a all operating systems and/or file systems.

    43  *

    44  *

    48  */

    49  */

    50 

    51 

    51     // Port file format:

    52     // Port file format:

    52     // byte ordering: high byte first = big endian

    53     // byte ordering: high byte first = big endian

    53     // Magic nr, 4 byte int, first in file.

    54     // Magic nr, 4 byte int, first in file.

    54     private final static int magicNr = 0x1174;

    55     private final static int magicNr = 0x1174;

    70 

    71 

    71     /**

    72     /**

    72      * Create a new portfile.

    73      * Create a new portfile.

    73      * @param filename is the path to the file.

    74      * @param filename is the path to the file.

    74      */

    75      */

    77         filename = fn;

    77         filename = fn;

    78         file = new File(filename);

    78         file = new File(filename);

    79         stopFile = new File(filename+".stop");

    79         stopFile = new File(filename+".stop");

    80         rwfile = new RandomAccessFile(file, "rw");

    80         rwfile = new RandomAccessFile(file, "rw");

    81         // The rwfile should only be readable by the owner of the process

    81         // The rwfile should only be readable by the owner of the process

    86     }

    86     }

    87 

    87 

    88     /**

    88     /**

    89      * Lock the port file.

    89      * Lock the port file.

    90      */

    90      */

    92         lock = channel.lock();

    92         lock = channel.lock();

    93     }

    93     }

    94 

    94 

    95     /**

    95     /**

    96      * Read the values from the port file in the file system.

    96      * Read the values from the port file in the file system.

   113                     containsPortInfo = true;

   113                     containsPortInfo = true;

   114                 } else {

   114                 } else {

   115                     containsPortInfo = false;

   115                     containsPortInfo = false;

   116                 }

   116                 }

   117             }

   117             }

   119             containsPortInfo = false;

   119             containsPortInfo = false;

   120         }

   120         }

   121     }

   121     }

   122 

   122 

   123     /**

   123     /**

   129 

   129 

   130     /**

   130     /**

   131      * If so, then we can acquire the tcp/ip port on localhost.

   131      * If so, then we can acquire the tcp/ip port on localhost.

   132      */

   132      */

   133     public int getPort() {

   133     public int getPort() {

   135         return serverPort;

   135         return serverPort;

   136     }

   136     }

   137 

   137 

   138     /**

   138     /**

   139      * If so, then we can acquire the server cookie.

   139      * If so, then we can acquire the server cookie.

   140      */

   140      */

   141     public long getCookie() {

   141     public long getCookie() {

   143         return serverCookie;

   143         return serverCookie;

   144     }

   144     }

   145 

   145 

   146     /**

   146     /**

   147      * Store the values into the locked port file.

   147      * Store the values into the locked port file.

   148      */

   148      */

   149     public void setValues(int port, long cookie) throws IOException {

   149     public void setValues(int port, long cookie) throws IOException {

   151         rwfile.seek(0);

   151         rwfile.seek(0);

   152         // Write the magic nr that identifes a port file.

   152         // Write the magic nr that identifes a port file.

   153         rwfile.writeInt(magicNr);

   153         rwfile.writeInt(magicNr);

   154         rwfile.writeInt(port);

   154         rwfile.writeInt(port);

   155         rwfile.writeLong(cookie);

   155         rwfile.writeLong(cookie);

   190 

   190 

   191     /**

   191     /**

   192      * Unlock the port file.

   192      * Unlock the port file.

   193      */

   193      */

   194     public void unlock() throws IOException {

   194     public void unlock() throws IOException {

   196         lock.release();

   196         lock.release();

   197         lock = null;

   197         lock = null;

   198     }

   198     }

   199 

   199 

   200     /**

   200     /**