/sys$common/syshlp/helplib.hlb System Services, $LCKPAG *Conan The Librarian (sorry for the slow response - running on an old VAX) |
Locks a page or range of pages in memory. The specified virtual pages are forced into the working set and then locked in memory. A locked page is not swapped out of memory if the working set of the process is swapped out. These pages are not candidates for page replacement and in this sense are locked in the working set as well. Format SYS$LCKPAG inadr ,[retadr] ,[acmode] C Prototype int sys$lckpag (struct _va_range *inadr, struct _va_range *retadr, unsigned int acmode); Arguments inadr OpenVMS usage:address_range type: longword (unsigned) access: read only mechanism: by reference Starting and ending virtual addresses of the range of pages to be locked. The inadr argument is the address of a 2-longword array containing, in order, the starting and ending process virtual addresses. Only the virtual page number portion of each virtual address is used; the low-order byte-within-page bits are ignored. On VAX systems, if the starting and ending virtual addresses are the same, a single page is locked. retadr OpenVMS usage:address_range type: longword (unsigned) access: write only mechanism: by reference Starting and ending process virtual addresses of the pages that $LCKPAG actually locked. The retadr argument is the address of a 2-longword array containing, in order, the starting and ending process virtual addresses. acmode OpenVMS usage:access_mode type: longword (unsigned) access: read only mechanism: by value Access mode to be associated with the pages to be locked. The acmode argument is a longword containing the access mode. The $PSLDEF macro defines the four access modes. The most privileged access mode used is the access mode of the caller. For the $LCKPAG service to complete successfully, the resultant access mode must be equal to or more privileged than the access mode already associated with the pages to be locked.
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