NAME

mlock, munlock − lock (or unlock) pages in memory

SYNOPSIS

#include <sys/types.h>
int mlock(caddr_t addr, size_t len);
int munlock(caddr_t addr, size_t len);

DESCRIPTION

The function mlock uses the mappings established for the address range [addr, addr + len) to identify pages to be locked in memory. The effect of mlock(addr, len) is equivalent to memcntl(addr, len, MC_LOCK, 0, 0, 0). 

munlock removes locks established with mlock.  The effect of munlock(addr, len) is equivalent to memcntl(addr, len, MC_UNLOCK, 0, 0, 0). 

Locks established with mlock are not inherited by a child process after a fork and are not nested. 

SEE ALSO

fork(2), memcntl(2), mmap(2), mlockall(3C), plock(2), sysconf(3C)

DIAGNOSTICS

Upon successful completion, the functions mlock and munlock return 0; otherwise, they return −1 and set errno to indicate the error. 

NOTES

Use of mlock and munlock requires that the user have appropriate privileges.