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  1. JDK
  2. JDK-6416884

(fc) FileChannel.map throws IOExceptions with non-intuitive messages in some error situations

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    • Subcomponent:
    • Resolved In Build:
      b07
    • CPU:
      generic
    • OS:
      generic
    • Verification:
      Not verified

      Description

      Crated a File of size 100 bytes less Integer.MAX_VALUE.

      1)When tried to map this file region from postion 0. it throws "IOException:The parameter is incorrect" on windows but it doesnt throw any exception on solaris

      Parameters passed to FileChannel.map method are as per spec
       mode - MapMode.READ_ONLY
       position - 0
       size = 2147483549 ( less than Integer.MAX_VALUE )
       
      2)if the following Parameters passed to FileChannel.map then the Exception message is "Access is denied" on windows ,"bad file number" on solaris , if region to be mapped is
      decreased to 10000, it doesnt throw any exception as in case 3.
       
       mode - MapMode.READ_ONLY
       position - 1
       size = 2147483549 ( less than Integer.MAX_VALUE )

      3) doesnt throw any Exception for the following parameters
       mode - MapMode.READ_ONLY
       position - 0/1
       size = 10000

      Please See the following Code and Result
      <version>
      java version "1.6.0-beta2"
      Java(TM) SE Runtime Environment (build 1.6.0-beta2-b80)
      Java HotSpot(TM) Client VM (build 1.6.0-beta2-b80, mixed mode)
      </version>
      1)
      <Code>
      import java.io.*;
      import java.nio.channels.*;
      import java.nio.*;

      public class TestFile {
         public static void main(String... args) {

              try {
                  File fn = new File("gbfile");
                  //Creating a file 100 byts less 2GB file.
                  RandomAccessFile raf = new RandomAccessFile(fn,"rw");
                  long size = (1024L * 1024L * 1024L) * 2L;
                  raf.seek ( size - 101 );
                  raf.write( 1 );
                  raf.close();

                  //Mapping the created File
                  FileInputStream fis = new FileInputStream(fn);
                  FileChannel fc = fis.getChannel();
                  System.out.println("File size : "+ fc.size() +" << "+ " Integer.MAX_VALUE = "+Integer.MAX_VALUE + ((fc.size() < Integer.MAX_VALUE)?" yes":" no"));
                  MappedByteBuffer mbb = fc.map(FileChannel.MapMode.READ_ONLY, 0,fc.size());
      }catch( IOException e) {
      e.printStackTrace ();
      }
            }

      }

      </Code>
      <Result on windows>
      File size : 2147483549 << Integer.MAX_VALUE = 2147483647 yes
      java.io.IOException: The parameter is incorrect
              at sun.nio.ch.FileChannelImpl.map0(Native Method)
              at sun.nio.ch.FileChannelImpl.map(FileChannelImpl.java:742)
              at TestFile.main(TestFile.java:21)
      </Result on windows>
      <Result on Solaris>
      # /net/sqindia.india/export/disk09/jdk/1.6.0/latest/binaries/solsparc/bin/java TestFile
      File size : 2147483548 << Integer.MAX_VALUE = 2147483647 yes
      <Result on Solaris>

      2)
      <Code>
      //Same as Above Program except the position within the file at which the mapped region is to start 1
      import java.io.*;
      import java.nio.channels.*;
      import java.nio.*;

      public class TestFile {
          public static void main(String... args) {

              try {
                  File fn = new File("gbfile");
                  //Creating a file 100 byts less 2GB file.
                  RandomAccessFile raf = new RandomAccessFile(fn,"rw");
                  long size = (1024L * 1024L * 1024L) * 2L;
                  raf.seek ( size - 101 );
                  raf.write( 1 );
                  raf.close();

                  //Mapping the created File
                  FileInputStream fis = new FileInputStream(fn);
                  System.out.println("Can Read " + fn.canRead());
                  FileChannel fc = fis.getChannel();
                  System.out.println("File size : "+ fc.size() +" << "+ " Integer.MAX_VALUE = "+Integer.MAX_VALUE + ((fc.size() < Integer.MAX_VALUE)?" yes":" no"));
                  MappedByteBuffer mbb = fc.map(FileChannel.MapMode.READ_ONLY, 1,fc.size());
      }catch( IOException e) {
      e.printStackTrace ();
      }
          }
      }

      </Code>
      <Result on windows>
      Can Read true
      File size : 2147483549 << Integer.MAX_VALUE = 2147483647 yes
      java.io.IOException: Access is denied
              at sun.nio.ch.FileChannelImpl.truncate0(Native Method)
              at sun.nio.ch.FileChannelImpl.map(FileChannelImpl.java:731)
              at TestFile.main(TestFile.java:22)
      </Result on windows>
      <Result on Solaris>
      Can Read true
      File size : 2147483548 << Integer.MAX_VALUE = 2147483647 yes
      java.io.IOException: Bad file number
              at sun.nio.ch.FileChannelImpl.truncate0(Native Method)
              at sun.nio.ch.FileChannelImpl.map(FileChannelImpl.java:731)
              at TestFile.main(TestFile.java:43)
      </Result on Solaris>

      3)
      <Code>
      import java.io.*;
      import java.nio.channels.*;
      import java.nio.*;

      public class TestFile {
          public static void main(String... args) {

              try {
                  File fn = new File("gbfile");
                  //Creating a file 100 byts less 2GB file.
                  RandomAccessFile raf = new RandomAccessFile(fn,"rw");
                  long size = (1024L * 1024L * 1024L) * 2L;
                  raf.seek ( size - 101 );
                  raf.write( 1 );
                  raf.close();

                  //Mapping the created File
                  FileInputStream fis = new FileInputStream(fn);
                  System.out.println("Can Read " + fn.canRead());
                  FileChannel fc = fis.getChannel();
                  System.out.println("File size : "+ fc.size() +" << "+ " Integer.MAX_VALUE = "+Integer.MAX_VALUE + ((fc.size() < Integer.MAX_VALUE)?" yes":" no"));
                  MappedByteBuffer mbb = fc.map(FileChannel.MapMode.READ_ONLY, 1,10000);
      }catch( IOException e) {
      e.printStackTrace ();
      }
          }
      }
      </Code>
      <Result on windows>
      C:\home\rg157576\tmpjava>java TestFile
      Can Read true
      File size : 2147483548 << Integer.MAX_VALUE = 2147483647 yes
      <Result on windows>
      <Result on Solaris>
      # /net/sqindia.india/export/disk09/jdk/1.6.0/latest/binaries/solsparc/bin/java TestFile
      Can Read true
      File size : 2147483548 << Integer.MAX_VALUE = 2147483647 yes
      </Result on Solaris >

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              Assignee:
              alanb Alan Bateman
              Reporter:
              rgutupalsunw Rajendra Gutupalli (Inactive)
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