According to the OP these are Java threads, so it is whatever the JVM is using to multiplex threads. Possibly Unix threads, possibly something else? It depends on the JVM implementation, right?
But I'm just fishing here, since I am anything but a JVM expert. Peter -----Original Message----- From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf Of Kirk Wolf Sent: Wednesday, June 29, 2016 5:07 PM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: Multithreaded output to stderr and stdout When using two Unix threads in the same z/OS Unix process, operations to sdout/stderr are serialized. Are you certain that these are two threads in the same process rather than threads in different processes (which would be at least separate LE enclaves, and perhaps different address spaces) ? -- This message and any attachments are intended only for the use of the addressee and may contain information that is privileged and confidential. If the reader of the message is not the intended recipient or an authorized representative of the intended recipient, you are hereby notified that any dissemination of this communication is strictly prohibited. If you have received this communication in error, please notify us immediately by e-mail and delete the message and any attachments from your system. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN