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Message-ID: <c3755b3a0607210227w6957e6d1g20ae280f443e1b0f@mail.gmail.com>
Date: Fri, 21 Jul 2006 13:27:41 +0400
From: "Alexey Petrenko" <alexey.a.petrenko@gmail.com>
To: harmony-dev@incubator.apache.org
Subject: Re: Suggestion (was: Re: [jira] Closed: (HARMONY-932)
 [classlib][nio]java.nio.?hannel.DatagramChannel.read(ByteBuffer[] , int,
 Integer.MAX_VALUE) throws NotYetConnectedException while RI throws
 IndexOutOfBoundsException)
In-Reply-To: <4d0b24970607202000u6608fad6i7292b4b336031505@mail.gmail.com>
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References: <4d0b24970607202000u6608fad6i7292b4b336031505@mail.gmail.com>

My two cents... :)

Put all the array size checking code in one place is a good idea. Code
reuse is always good idea.

But do not forget that Java has 2 problems here:
1. It can not inline methods or include code in java file
2. Method call is a long operation.

So huge number of additional method calls can significantly downgrade
the performance...

Probably VM JIT guys will correct me.

Anyway... I think that the best plays for such tool methods is a misc
module, not util.

SY, Alexey

2006/7/21, Andrew Zhang <zhanghuangzhu@gmail.com>:
> Hi Vladimir,
>
> I noticed the same problem is existing in many places of NIO module.
>
> How about writing a utility function for array index exception check? like:
>
> void assertArrayIndex(Object[] array, int offset, int length){
>  if(offset < 0 || length < 0 || (long)offset + (long)length >  array.length
> ){
>     throw new IndexOutOfBoundsException();
>  }
> }
>
> How do you think about it? Any suggestions?
>
> Thanks!
> Best regards,
>
>
> On 7/21/06, Paulex Yang (JIRA) <jira@apache.org> wrote:
> >
> >     [ http://issues.apache.org/jira/browse/HARMONY-932?page=all ]
> >
> > Paulex Yang closed HARMONY-932.
> > -------------------------------
> >
> >    Estimated Complexity: Novice
> >
> > Verified by Vladimir.
> >
> > > [classlib][nio]java.nio.?hannel.DatagramChannel.read(ByteBuffer[] , int,
> > Integer.MAX_VALUE) throws NotYetConnectedException while RI throws
> > IndexOutOfBoundsException
> > >
> > ---------------------------------------------------------------------------------------------------------------------------------------------------------------------
> > >
> > >                 Key: HARMONY-932
> > >                 URL: http://issues.apache.org/jira/browse/HARMONY-932
> > >             Project: Harmony
> > >          Issue Type: Bug
> > >          Components: Classlib
> > >            Reporter: Vladimir Ivanov
> > >         Assigned To: Paulex Yang
> > >         Attachments: DatagramChannelImpl.patch
> > >
> > >
> > > The Harmony methods java.nio.?hannel.DatagramChannel.read/write(ByteBuffer[]
> > , int, Integer.MAX_VALUE) throws NotYetConnectedException while RI throws
> > IndexOutOfBoundsException.
> > > ==================== test.java ======================
> > > import java.nio.channels.*;
> > > import java.nio.*;
> > > public class test  {
> > >     public static void main (String[] args) {
> > >         try {
> > >             DatagramChannel.open().read(new ByteBuffer[] {}, 2,
> > Integer.MAX_VALUE);
> > >         } catch (Exception e) {
> > >             e.printStackTrace();
> > >         }
> > >         try {
> > >             DatagramChannel.open().write(new ByteBuffer[] {}, 2,
> > Integer.MAX_VALUE);
> > >         } catch (Exception e) {
> > >             e.printStackTrace();
> > >         }
> > >     }
> > > }
> > > =================================================
> > > Output:
> > > C:\tmp\tmp17>C:\jdk1.5.0_06\bin\java.exe -cp . -showversion test
> > > java version "1.5.0_06"
> > > Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_06-b05)
> > > Java HotSpot(TM) Client VM (build 1.5.0_06-b05, mixed mode)
> > > java.lang.IndexOutOfBoundsException
> > >         at sun.nio.ch.DatagramChannelImpl.read(DatagramChannelImpl.java
> > :366)
> > >         at test.main(test.java:8)
> > > java.lang.IndexOutOfBoundsException
> > >         at sun.nio.ch.DatagramChannelImpl.write(DatagramChannelImpl.java
> > :429)
> > >         at test.main(test.java:13)
> > > C:\tmp\tmp17>C:\jrockit-jdk1.5.0-windows-ia32\bin\java.exe -cp .
> > -showversion test
> > > java version "1.5.0"
> > > Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0-b64)
> > > BEA WebLogic JRockit(R) (build dra-38972-20041208-2001-win-ia32,
> > R25.0.0-75, GC: System optimized over throughput (initial strategy
> > singleparpar))
> > > OutOfMemoryError
> > > -------end of stacktrace
> > > C:\tmp\tmp17>C:\harmony\trunk_0427\deploy\jdk\jre\bin\java.exe -cp .
> > -showversion test
> > > java version 1.5 (subset)
> > > (c) Copyright 1991, 2006 The Apache Software Foundation or its
> > licensors, as applicable.
> > > java.nio.channels.NotYetConnectedException
> > >         at
> > org.apache.harmony.nio.internal.DatagramChannelImpl.checkOpenConnected(
> > DatagramChannelImpl.java:567)
> > >         at org.apache.harmony.nio.internal.DatagramChannelImpl.read(
> > DatagramChannelImpl.java:387)
> > >         at test.main(test.java:8)
> > > java.nio.channels.NotYetConnectedException
> > >         at
> > org.apache.harmony.nio.internal.DatagramChannelImpl.checkOpenConnected(
> > DatagramChannelImpl.java:567)
> > >         at org.apache.harmony.nio.internal.DatagramChannelImpl.write(
> > DatagramChannelImpl.java:477)
> > >         at test.main(test.java:13)
> > >
> > C:\tmp\tmp17>C:\harmony\drlvm\trunk\build\win_ia32_msvc_debug\deploy\jre\bin\ij
> > -Dvm.assert_dialog=false -cp . -showversion test
> > > Apache Harmony DRLVM HEAD-4807 (2006-05-02), Windows/ia32/msvc 1310,
> > debug
> > > java.nio.channels.NotYetConnectedException
> > >         at
> > org.apache.harmony.nio.internal.DatagramChannelImpl.checkOpenConnected(
> > DatagramChannelImpl.java:567)
> > >         at org.apache.harmony.nio.internal.DatagramChannelImpl.read(
> > DatagramChannelImpl.java:387)
> > >         at test.main(test.java:8)
> > > java.nio.channels.NotYetConnectedException
> > >         at
> > org.apache.harmony.nio.internal.DatagramChannelImpl.checkOpenConnected(
> > DatagramChannelImpl.java:567)
> > >         at org.apache.harmony.nio.internal.DatagramChannelImpl.write(
> > DatagramChannelImpl.java:477)
> > >         at test.main(test.java:13)
> >
> > --
> > This message is automatically generated by JIRA.
> > -
> > If you think it was sent incorrectly contact one of the administrators:
> > http://issues.apache.org/jira/secure/Administrators.jspa
> > -
> > For more information on JIRA, see: http://www.atlassian.com/software/jira
> >
> >
> >
>
>
> --
> Andrew Zhang
> China Software Development Lab, IBM
>
>


-- 
Alexey A. Petrenko
Intel Middleware Products Division

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