plock - Locks a process' text and/or data segments in memory
int opr) ;
The plock() function locks or unlocks a process' text segments, data segments, or both in physical memory. When locked, the physical pages containing the text or data segment will not be paged out. It is an error to lock a segment that is already locked.
The caller must have superuser privilege to use the plock() function.
Note that memory acquired subsequent to a plock() function may or may not be locked in memory, depending on the specific acquisition method. Memory acquired using the brk() function (or the sbrk() function) is locked if the data segment was locked. Memory acquired via the mmap() or vm_allocate() functions will not be locked.
Upon successful completion, a value of 0 (zero) is returned to the calling process. Otherwise, a value of -1 is returned and errno is set to indicate the error.
If the plock() function fails, errno may be set to one of the following values: The caller does not have appropriate privilege. There are insufficient resources to perform the operation. The opr parameter is PROCLOCK, but the text segment or the data segment is already locked. The opr parameter is TXTLOCK, but the text segment is already locked. The opr parameter is DATLOCK, but the data segment is already locked. The opr parameter is UNLOCK, but neither the text segment nor the data segment is locked.
Functions: brk(2), mmap(2) delim off