[uml-user] xterm got kill when i run application in uml, how come ?

[ning ji <ni...@ho...>]

it's a little bit complicated,1. i have a script starts 20 xterms like this,   xterm -e "uml ..."   so basically i run 20 umls in my pc, each in a xterm so i can check the progress.2. each of uml will automatically start my application,   which is multithreaded, has pipes, sockets etc.when i do this, every once a while some xterms disappear.if the UMLs don't run my app, i know it's fine.but if my app has bug, how can it kills the xterm ?During this procedure, i keep on checking pc memory by "free -m",and seems it has plenty of free memory.Total is ~3GB, but i never see the used memory exceed 2GB.
Shared memory usage is only ~20%.thanks !