[jcifs] Threads locked while calling SmbFile.getSecurity
Michael B Allen
ioplex at gmail.com
Wed Jun 4 16:58:15 GMT 2008
I think you're hitting jcifs.smb.maxBuffers which defaults to 16.
But I have to wonder how you're getting into that scenario and if
increasing that value is the right thing to do.
Mike
On 6/4/08, Marc Brette <marc.brette at gmail.com> wrote:
> I have an issue where 16 threads calling SmbFile.getSecurity are blocked.
> When I have only 15 threads, it works fine (note that each thread accesses a
> different document, but on the same server).
> I use JCIFS 1.2.21. And tested on different shared drives (with and without
> credentials). I initially tested with 1.2.18 with a more complex example so
> I guess it s not specific to the JCIFS version.
> Is it something known ? I saw some thread talking about deadlock in jcifs
> but it seemed to be in situation unlikely to occur in reality.
>
> Here is my code:
> import java.util.List;
> import java.util.Arrays;
>
> import jcifs.smb.SmbFile;
> import jcifs.smb.NtlmPasswordAuthentication;
>
> public class TestDeadlock
> {
> static
> {
> System.setProperty("java.protocol.handler.pkgs",
> "jcifs");
> }
>
> public static void main(String[] args) throws InterruptedException
> {
> final List<String> dataset = Arrays.asList(
>
> "smb://frgr1dev1/Y_Drive/Documentation/javadocs/ant/ant
> 1.6.2 api/org/apache/tools/zip/package-frame.html"
> ,
> "smb://frgr1dev1/Y_Drive/Documentation/javadocs/ant/ant
> 1.6.2
> api/org/apache/tools/ant/taskdefs/optional/ejb/BorlandDeploymentTool.html"
> ,
> "smb://frgr1dev1/Y_Drive/Documentation/javadocs/ant/ant
> 1.6.2 api/org/apache/tools/ant/types/Reference.html"
> ,
> "smb://frgr1dev1/Y_Drive/Documentation/javadocs/jdk/jdk1.3.1/javax/rmi/package-use.html"
> ,
> "smb://frgr1dev1/Y_Drive/Documentation/javadocs/jdk/jdk1.3.1/java/io/FilterOutputStream.html"
> ,
> "smb://frgr1dev1/Y_Drive/Documentation/javadocs/jdk/jdk1.3.1/javax/accessibility/AccessibleTableModelChange.html"
> ,
> "smb://frgr1dev1/Y_Drive/Documentation/javadocs/jdk/jdk1.4.2/org/omg/stub/java/"
> ,
> "smb://frgr1dev1/Y_Drive/Documentation/javadocs/jdk/jdk1.3.1/javax/transaction/InvalidTransactionException.html"
> ,
> "smb://frgr1dev1/Y_Drive/Documentation/javadocs/ant/ant
> 1.6.2
> api/org/apache/tools/ant/taskdefs/optional/junit/DOMUtil.NodeListImpl.html"
> ,
> "smb://frgr1dev1/Y_Drive/Documentation/javadocs/jdk/jdk1.4.2/java/awt/geom/AffineTransform.html"
> ,
> "smb://frgr1dev1/Y_Drive/Documentation/javadocs/jdk/jdk1.3.1/javax/naming/ldap/package-frame.html"
> ,
> "smb://frgr1dev1/Y_Drive/Documentation/javadocs/jdk/jdk1.3.1/java/awt/Shape.html"
> ,
> "smb://frgr1dev1/Y_Drive/Documentation/javadocs/jdk/jdk1.4.2/javax/transaction/xa/package-summary.html"
> ,
> "smb://frgr1dev1/Y_Drive/Documentation/javadocs/ant/ant
> 1.6.2
> api/org/apache/tools/ant/taskdefs/optional/script/package-summary.html"
> ,
> "smb://frgr1dev1/Y_Drive/Documentation/javadocs/jdk/jdk1.4.2/javax/net/ServerSocketFactory.html");
>
> int start = 0;
> int end = 15;
> Thread[] workers = new Thread[end - start];
> for (int i = start; i < end; i++)
> {
> final String url = dataset.get(i);
> workers[i - start] = new Thread(new Runnable()
> {
> public void run()
> {
> try
> {
> SmbFile f = new SmbFile(url);
> System.out.println(url + " security = " +
> f.getSecurity(true)); //This trace never shows up
>
> } catch (Throwable e)
> {
> e.printStackTrace();
> }
> }
> });
> }
>
> for (Thread worker : workers)
> {
> worker.start();
> }
>
> for (Thread worker : workers)
> {
> worker.join();
> }
> }
> }
>
> Here is an extract of the threads stacktrace dump:
>
> "Thread-4" prio=6 tid=0x0033dde8 nid=0x64d4 in Object.wait()
> [0x031bf000..0x031bf9e8]
> at java.lang.Object.wait(Native Method)
> - waiting on <0x2465e260> (a [Ljava.lang.Object;)
> at java.lang.Object.wait(Object.java:474)
> at
> jcifs.smb.BufferCache.getBuffers(BufferCache.java:55)
> - locked <0x2465e260> (a [Ljava.lang.Object;)
> at jcifs.smb.SmbTransport.send(SmbTransport.java:547)
> at jcifs.smb.SmbSession.send(SmbSession.java:239)
> - locked <0x2467f780> (a java.lang.Object)
> at jcifs.smb.SmbTree.send(SmbTree.java:109)
> at jcifs.smb.SmbFile.send(SmbFile.java:695)
> at
> jcifs.smb.TransactNamedPipeOutputStream.write(TransactNamedPipeOutputStream.java:65)
> at
> jcifs.dcerpc.DcerpcPipeHandle.doSendFragment(DcerpcPipeHandle.java:59)
> at
> jcifs.dcerpc.DcerpcHandle.sendrecv(DcerpcHandle.java:164)
> at
> jcifs.dcerpc.msrpc.LsaPolicyHandle.<init>(LsaPolicyHandle.java:34)
> at jcifs.smb.SID.resolveSids0(SID.java:136)
> at jcifs.smb.SID.resolveSids(SID.java:179)
> at jcifs.smb.SmbFile.processAces(SmbFile.java:2774)
> at jcifs.smb.SmbFile.getSecurity(SmbFile.java:2808)
> at TestDeadlock$1.run(TestDeadlock.java:84)
> at java.lang.Thread.run(Thread.java:595)
>
> "Thread-3" prio=6 tid=0x0033dc60 nid=0x4494 waiting for monitor entry
> [0x0317f000..0x0317fce8]
> at jcifs.smb.SmbTree.treeConnect(SmbTree.java:128)
> - waiting to lock <0x2467f780> (a java.lang.Object)
> at jcifs.smb.SmbTree.send(SmbTree.java:64)
> at jcifs.smb.SmbFile.send(SmbFile.java:695)
> at
> jcifs.smb.TransactNamedPipeOutputStream.write(TransactNamedPipeOutputStream.java:65)
> at
> jcifs.dcerpc.DcerpcPipeHandle.doSendFragment(DcerpcPipeHandle.java:59)
> at
> jcifs.dcerpc.DcerpcHandle.sendrecv(DcerpcHandle.java:164)
> at
> jcifs.dcerpc.msrpc.LsaPolicyHandle.<init>(LsaPolicyHandle.java:34)
> at jcifs.smb.SID.resolveSids0(SID.java:136)
> at jcifs.smb.SID.resolveSids(SID.java:179)
> at jcifs.smb.SmbFile.processAces(SmbFile.java:2774)
> at jcifs.smb.SmbFile.getSecurity(SmbFile.java:2808)
> at TestDeadlock$1.run(TestDeadlock.java:84)
> at java.lang.Thread.run(Thread.java:595)
>
> ... other threads stack traces are similar to "Thread-3" above.
>
> Regards
> -- Marc
>
>
>
>
--
Michael B Allen
PHP Active Directory SPNEGO SSO
http://www.ioplex.com/
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