HP-UX Reference (11i v3 07/02) - 3 Library Functions A-M (vol 6)
d
datalock(3C) datalock(3C)
NAME
datalock( ) - lock process into memory after allocating data and stack space
SYNOPSIS
#include <sys/lock.h>
int datalock(size_t datsiz, size_t stsiz);
DESCRIPTION
datalock() allocates at least datsiz bytes of data space and stsiz bytes of stack space, then locks the
program in memory. The data space is allocated by
malloc() (see malloc(3C)). After the program is
locked, this space is released by
free() (see malloc(3C)), making it available for use. This allows the cal-
ling program to use that much space dynamically without receiving the
SIGSEGV signal.
The effective user
ID of the calling process must be super-user or be a member of or have an effective group
ID of a group having PRIV_MLOCK access to use this call (see setprivgrp(2) in getprivgrp(2)).
EXAMPLES
The following call to
datalock() allocates 4096 bytes of data space and 2048 bytes of stack space, then
locks the process in memory:
datalock (4096, 2048);
RETURN VALUE
datalock() returns -1 if malloc() cannot allocate enough memory or if plock() returned an error
(see plock(2)).
WARNINGS
Multiple datalocks cannot be the same as one big one.
Methods for calculating the required size are not yet well developed.
AUTHOR
datalock() was developed by HP.
SEE ALSO
getprivgrp(2), plock(2), thread_safety(5).
HP-UX 11i Version 3: February 2007 − 1 − Hewlett-Packard Company 261