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plock(S)


plock -- lock process, text, or data in memory

Syntax

cc . . . -lc

#include  <sys/lock.h>

int plock (op) int op;

Description

The plock system call allows the calling process to lock its text segment (text lock), its data segment (data lock), or both its text and data segments (process lock) into memory. Locked segments are immune to all routine swapping. plock also allows these segments to be unlocked. The effective user ID of the calling process must be super user to use this call. op specifies the following:


PROCLOCK-
lock text and data segments into memory (process lock)

TXTLOCK-
lock text segment into memory (text lock)

DATLOCK-
lock data segment into memory (data lock)

UNLOCK-
remove locks

The plock system call fails and does not perform the requested operation if one or more of the following is true:


[EAGAIN]
Not enough memory.

[EINVAL]

  1. op is equal to PROCLOCK and a process lock, a text lock, or a data lock already exists on the calling process.

  2. op is equal to TXTLOCK and a text lock or a process lock already exists on the calling process.

  3. op is equal to DATLOCK and a data lock or a process lock already exists on the calling process.

  4. op is equal to UNLOCK and no type of lock exists on the calling process.

[EPERM]
The effective user ID of the calling process is not super user.

Diagnostics

Upon successful completion, a value of 0 is returned to the calling process. Otherwise, a value of -1 is returned, and errno is set to indicate the error.

See also

exec(S), exit(S), fork(S)

Standards conformance

plock is not part of any currently supported standard; it was developed by UNIX System Laboratories, Inc. and maintained by The SCO Group.
© 2003 Caldera International, Inc. All rights reserved.
SCO OpenServer Release 5.0.7 -- 11 February 2003