Experimental Physics and
Industrial Control System

"Kasemir, Kay" <[email protected]> · Fri, 03 Apr 2009 11:52:00 -0400

Hi:

Matej might have already explained this elsewhere, but
I didn't "get it" from the JCA notes.

JCA 2.3.1 as well as the latest 2.3.2 have a memory
leak when used with EPICS base _older_than_ R3.14.9
because JCA must call the JNI AttachCurrentThreadAsDaemon()
in CA callbacks but EPICS base _before_ R3.14.9 didn't allow
JCA to detach later.

With R3.14.9/10, epicsAtThreadExit() allows JCA to detach,
but it added a small mem leak in src/libCom/misc/epicsExit.c
that's now fixed in R3.14.11:
static void destroyExitPvt ( exitPvt * pep )
{
     ellFree ( &pep->list );
     // Fix:
     free (pep);
}

To my astonishment, test code that connects, subscribes, then unsubscribes
and disconnects PVs in a loop still showed memory leaks under "valgrind"
on Linux, pointing to memory allocated by the JVM's
AttachCurrentThreadAsDaemon which supposedly should be free'd by
JCA now calling DetachCurrentThread via epicsAtThreadExit.

Turns out that problem is fixed by changing from JSK 1.5.0_09 to
a newer one (tried 1.5.0_17 and 1.6.0_13).

Isn't it great that it's Friday?
-Kay

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System