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Posted to issues@commons.apache.org by "Sebb (JIRA)" <ji...@apache.org> on 2013/04/18 00:25:17 UTC
[jira] [Updated] (NET-501) Race Condition on
TelnetClient.disconnect() and TelnetInputStream.run() .
java.lang.IllegalStateException: Queue is full! Cannot process another
character.
[ https://issues.apache.org/jira/browse/NET-501?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Sebb updated NET-501:
---------------------
Description:
I'm getting the following exception while disconnecting a threaded (readerThread=true) TelnetClient connection.
{code}
Exception in thread "Thread-160" java.lang.IllegalStateException: Queue is full! Cannot process another character.
at org.apache.commons.net.telnet.TelnetInputStream.__processChar(TelnetInputStream.java:339)
at org.apache.commons.net.telnet.TelnetInputStream.run(TelnetInputStream.java:647)
at java.lang.Thread.run(Thread.java:722)
{code}
I noticed that when TelnetClient.disconnect() is called the attribute __threaded is set to false while the thread in the TelnetInputStream.run() method could call TelnetInputStream().__processChar(...) throwing IllegalStateException
This is a test program to reproduce the issue
{code}
public class TestTelnetClient implements Runnable {
/**
* @param args
*/
public static void main(String[] args) {
ArrayList<Thread> workers = new ArrayList<Thread>();
for( int i=0; i<1000; ++i){
Thread t = new Thread ( new TestTelnetClient() );
t.start();
workers.add(t);
}
for (Thread t : workers ) {
try {
t.join();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
@Override
public void run() {
System.out.println("Starting thread...");
TelnetClient tc = new TelnetClient();
// tc.setReaderThread(false);
try {
tc.connect("localhost", 23);
tc.setSoTimeout(1000);
InputStream in = tc.getInputStream();
int ch;
in.read();
} catch (SocketException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
System.out.println("Disconnecting...");
try {
tc.disconnect();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
{code}
A telnet server (telnetd) is required. I also modified the initial banner ( /etc/issue.net ) with a lot of characters to get a better chance to receive information while calling disconnect.
was:
I'm getting the following exception while disconnecting a threaded (readerThread=true) TelnetClient connection.
Exception in thread "Thread-160" java.lang.IllegalStateException: Queue is full! Cannot process another character.
at org.apache.commons.net.telnet.TelnetInputStream.__processChar(TelnetInputStream.java:339)
at org.apache.commons.net.telnet.TelnetInputStream.run(TelnetInputStream.java:647)
at java.lang.Thread.run(Thread.java:722)
I noticed that when TelnetClient.disconnect() is called the attribute __threaded is set to false while the thread in the TelnetInputStream.run() method could call TelnetInputStream().__processChar(...) throwing IllegalStateException
This is a test program to reproduce the issue
public class TestTelnetClient implements Runnable {
/**
* @param args
*/
public static void main(String[] args) {
ArrayList<Thread> workers = new ArrayList<Thread>();
for( int i=0; i<1000; ++i){
Thread t = new Thread ( new TestTelnetClient() );
t.start();
workers.add(t);
}
for (Thread t : workers ) {
try {
t.join();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
@Override
public void run() {
System.out.println("Starting thread...");
TelnetClient tc = new TelnetClient();
// tc.setReaderThread(false);
try {
tc.connect("localhost", 23);
tc.setSoTimeout(1000);
InputStream in = tc.getInputStream();
int ch;
in.read();
} catch (SocketException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
System.out.println("Disconnecting...");
try {
tc.disconnect();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
A telnet server (telnetd) is required. I also modified the initial banner ( /etc/issue.net ) with a lot of characters to get a better chance to receive information while calling disconnect.
> Race Condition on TelnetClient.disconnect() and TelnetInputStream.run() . java.lang.IllegalStateException: Queue is full! Cannot process another character.
> -----------------------------------------------------------------------------------------------------------------------------------------------------------
>
> Key: NET-501
> URL: https://issues.apache.org/jira/browse/NET-501
> Project: Commons Net
> Issue Type: Bug
> Components: Telnet
> Affects Versions: 3.2
> Environment: Ubuntu 12.04 64 bits x86
> Reporter: Julián Lastiri
> Priority: Minor
>
> I'm getting the following exception while disconnecting a threaded (readerThread=true) TelnetClient connection.
> {code}
> Exception in thread "Thread-160" java.lang.IllegalStateException: Queue is full! Cannot process another character.
> at org.apache.commons.net.telnet.TelnetInputStream.__processChar(TelnetInputStream.java:339)
> at org.apache.commons.net.telnet.TelnetInputStream.run(TelnetInputStream.java:647)
> at java.lang.Thread.run(Thread.java:722)
> {code}
> I noticed that when TelnetClient.disconnect() is called the attribute __threaded is set to false while the thread in the TelnetInputStream.run() method could call TelnetInputStream().__processChar(...) throwing IllegalStateException
> This is a test program to reproduce the issue
> {code}
> public class TestTelnetClient implements Runnable {
> /**
> * @param args
> */
> public static void main(String[] args) {
> ArrayList<Thread> workers = new ArrayList<Thread>();
> for( int i=0; i<1000; ++i){
> Thread t = new Thread ( new TestTelnetClient() );
> t.start();
> workers.add(t);
> }
> for (Thread t : workers ) {
> try {
> t.join();
> } catch (InterruptedException e) {
> e.printStackTrace();
> }
> }
> }
> @Override
> public void run() {
> System.out.println("Starting thread...");
> TelnetClient tc = new TelnetClient();
> // tc.setReaderThread(false);
> try {
> tc.connect("localhost", 23);
> tc.setSoTimeout(1000);
> InputStream in = tc.getInputStream();
> int ch;
> in.read();
> } catch (SocketException e) {
> e.printStackTrace();
> } catch (IOException e) {
> e.printStackTrace();
> } finally {
> System.out.println("Disconnecting...");
> try {
> tc.disconnect();
> } catch (IOException e) {
> // TODO Auto-generated catch block
> e.printStackTrace();
> }
> }
>
> }
> }
> {code}
> A telnet server (telnetd) is required. I also modified the initial banner ( /etc/issue.net ) with a lot of characters to get a better chance to receive information while calling disconnect.
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