> -----Original Message----- > From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On > Behalf Of Paul Schuster > Sent: Tuesday, July 24, 2007 12:33 AM > To: IBM-MAIN@BAMA.UA.EDU > Subject: Is a page protected?--how to determine > > Hello: I have a need to determine if an address in storage is page > protected > in order to determine if a PGSER UNPROTECT needs to be done. > > The best I have tried and seen in earlier posts is to look for a CC=1 on a > TPROT backed up with an ESTAE. > > Are there any other methods to do this? > > Thank you. > > Paul Schuster
In addition to what else has been posted, be very careful about unprotecting a page that your application did not explicitly protect. An application that uses IARVSERV to share pages with COPY_ON_WRITE will implicitly page-protect the shared pages. When a unit of work attempts to store into the protected page, the system catches the PIC 0004 and copies the contents to another real frame. Then the page table entry is modified to point to the new real frame and the unit of work is redispatched to try the update again; this time succeeding. The unit of work never sees the PIC 0004. If you explicitly unprotect such a shared page, then you will screw up shared pages scheme. Jeffrey D. Smith Principal Product Architect Farsight Systems Corporation 700 KEN PRATT BLVD. #204-159 LONGMONT, CO 80501-6452 303-774-9381 direct 303-484-6170 FAX http://www.farsight-systems.com/ ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
