[jcifs] bugs in JCIFS 1.2.9
Tim Struyf
tim.struyf at roots.be
Wed Nov 8 19:20:22 GMT 2006
indeed
but its required that you also interrupt the writerthread (w)!
w.interrupt();
2026 } catch( Exception ex ) {
w.interrupt(); //Stop the writer thread!
2027 if( log.level > 1 )
2028 ex.printStackTrace( log );
2029 } finally { <<---- important to always close!
so you should add this in the catch block started at line 2026
otherwise these writer threads remain in their locked state (caused by the wait() )... and will eventually cause an OutOfMemoryExeception / unable to start new native thread, as we have experienced in our production environment,
The first bug in my mail is a new one i guess...
The code that throws the exception for the first bug i reported isn't inside the try catch block you proposed to change (invoking the 'close()')
You should really give the test case a try for the first one... you'll see a lot of writer threads that are locked!
I think the best solution is to put a try catch block inside the copyTo() method catching any exception thrown after w.start();
just put up a share, and try to copy a file that doesnt exist ... do like 1000 times... and put a breakpoint outside the loop!
You see 1000 writerthreads all locked up.
best regards,
Tim
________________________________
Van: Michael B Allen [mailto:mba2000 at ioplex.com]
Verzonden: wo 8/11/2006 19:03
Aan: Tim Struyf
CC: jcifs at lists.samba.org; contact! Support
Onderwerp: Re: [jcifs] bugs in JCIFS 1.2.9
Yes, I believe this is all the same bug someone reported before. The
bug is because of a big try catch added to SmbFile.copyTo0 during some
debugging. Try to remove/move the try catch to look like the below:
And please let me know if it works. I'm going to do an update soon.
1972 }
1973 } else {
1974 int off;
1975
1976 try {
1977 open( SmbFile.O_RDONLY, 0, ATTR_NORMAL, 0 );
1978 try {
....
2022 dest.send( new Trans2SetFileInformation(
2023 dest.fid, attributes, createTime, lastModified ),
2024 new Trans2SetFileInformationResponse() );
2025 dest.close( 0L );
2026 } catch( Exception ex ) {
2027 if( log.level > 1 )
2028 ex.printStackTrace( log );
2029 } finally { <<---- important to always close!
2030 close();
2031 }
2032 }
2033 }
2034 /**
On Wed, 8 Nov 2006 17:00:18 +0100
"Tim Struyf" <tim.struyf at roots.be> wrote:
> Dear,
>
>
>
> I found a bug in JCIFS 1.2.9
>
>
>
> Apparently when trying to copy a file that does not exist the
> writerthread isn't closed.
>
> Thus causing problems with a lot of writerthreads that are and remain in
> the "wait" state
>
>
>
> For example if you execute this testcase with version 1.2.9 you will get
> 1000 writer threads in the "wait" state
>
> Important is that you have a share and try to open a file that does not
> exist, you will get a stacktrace printed in your console ... but the
> writer thread stays open...
>
>
>
> public class JCifsTest extends TestCase {
>
> public void testCopy() {
>
> for(int i = 0; i < 1000; i++) {
>
> try {
>
> SmbFile file
> = JCifsUtil.getSmbFileFor( "myComputer/someShare/fileDoesNotExist.txt"
> );
>
> SmbFile to
> = JCifsUtil.getSmbFileFor( "myComputer/someShare/fileDoesNotExist.txt");
>
> file.copyTo(to);
>
> } catch (Exception e) {
>
> e.printStackTrace();
>
> }
>
> }
>
> //put a breakpoint up here and see... 1000
> writer threads waiting...
>
> System.out.println("boom!");
>
> }
>
> }
>
>
>
> I fixed this by adding a try catch clause in the copyTo method in
> SmbFile.java
>
>
>
> /** copy to method.... **/
>
>
>
> w = new WriterThread();
>
> w.setDaemon( true );
>
> w.start();
>
> //added a try catch block
>
> try {
>
> /* Downgrade one transport to the lower of the
> negotiated buffer sizes
>
> * so we can just send whatever is received.
>
> */
>
>
>
> SmbTransport t1 = tree.session.transport;
>
> SmbTransport t2 = dest.tree.session.transport;
>
>
>
> if( t1.snd_buf_size < t2.snd_buf_size ) {
>
> t2.snd_buf_size = t1.snd_buf_size;
>
> } else {
>
> t1.snd_buf_size = t2.snd_buf_size;
>
> }
>
>
>
> bsize = Math.min( t1.rcv_buf_size - 70,
> t1.snd_buf_size - 70 );
>
> b = new byte[2][bsize];
>
>
>
> copyTo0( dest, b, bsize, w, req, resp );
>
> w.write( null, -1, null, 0 );
>
> } catch (Exception e ){
>
> //stop the writer thread! If we get an exception
>
> e.printStackTrace();
>
> w.interrupt();
>
> }
>
>
>
>
>
> Another bug was already posted here.
>
> If you try to copy a file to a share on which you don't have access
> rights, this fails but the writer threads don't close... also the source
> file you are copying from cant be deleted... because its in use... (by
> the writerthread that's locked...)
>
>
>
> public void testCopyAndDelete() throws SmbException {
>
> for(int i = 0; i < 1000; i++) {
>
> try {
>
> SmbFile file =
> JCifsUtil.getSmbFileFor( "myComputer/myShare/someFile.txt" );
>
>
> System.out.println(file.getUncPath() + " exists: " + file.exists());
>
> SmbFile to
> = JCifsUtil.getSmbFileFor(
> "myComputer/ShareOnWhichIDontHaveAccessRights/someFile.txt");
>
>
> System.out.println(to.getUncPath() + " exists: " + to.exists());
>
> file.copyTo( to );
>
> file.delete();
>
> } catch (Exception e) {
>
> e.printStackTrace();
>
> }
>
> }
>
> }
>
>
>
> In version 1.2.9 of JCIFS this code will cause the errors described
> above, a lot of writer threads that are locked + files that are in use,
> and cant be deleted...
>
> I fixed this by changing the copyTo0 method in SmbFile.java
>
>
>
>
>
> dest.send( new
> Trans2SetFileInformation(dest.fid, attributes, createTime, lastModified
> ), new Trans2SetFileInformationResponse() );
>
> dest.close( 0L );
>
> } catch( Exception ex ) {
>
> //stop the writerthreads
>
> w.interrupt();
>
> if( log.level > 1 )
>
>
> ex.printStackTrace( log );
>
> } finally {
>
> //added a finally clause
>
> close();
>
> }
>
> Best regards,
>
> Tim
>
> groetjes,
>
> Tim Struyf
> Consultant,
>
> Roots Software
> Oudestraat 113 * 2630 Aartselaar * Belgium
> Phone + 32 3 870 71 11 * Fax + 32 3 870 71 19
> Email: tim.struyf at roots.be <mailto:tim.struyf at roots.be>
> http://www.roots.be
>
>
>
>
--
Michael B Allen
PHP Active Directory SSO
http://www.ioplex.com/
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