Experimental Physics and
Industrial Control System

Kay-Uwe Kasemir <[email protected]> · Tue, 04 Dec 2007 14:56:39 -0500

Hi:
The code below uses JCA to do a simple
context setup, PV connection, cleanup.
Then the same again.
On Linux, that second time around results in
"pthread_create error Invalid argument"
errors in the createChannel() call.
On OS X it works OK.
The same code also works OK when using CAJ
instead of the JNI version of the ChannelAccess
client lib.
Haven't tried Windows.
Any ideas?
Thanks,
-Kay


import gov.aps.jca.Channel;
import gov.aps.jca.Context;
import gov.aps.jca.JCALibrary;
/** Test JCA context setup and cleanup. */
public class JCAContextTest
{	
	/** Test run: Setup, connect, cleanup */
	private void run(final String pv_name) throws Exception
	{
		final JCALibrary jca = JCALibrary.getInstance();
		// Select JCA
		final Context context = jca.createContext(JCALibrary.JNI_THREAD_SAFE);
		final Channel pv = context.createChannel(pv_name);
		context.pendIO(5.0);
		pv.dispose();
		context.dispose();
	}
	
	public static void main(final String[] args) throws Exception
	{
		// First test runs OK
		final JCAContextTest test = new JCAContextTest();
		test.run("ramp1");
		
		// Second time, different PV or not, results in
		// ""
		//   pthread_create error Invalid argument
		//   CAC: Unexpected exception during virtual circuit creation
		// ""
		// on Linux.
		// On OS X, it's fine.
		System.out.println("Trying again:");
		test.run("ramp2");
	}
}

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System