plock(2)                                                 plock(2)



NAME
     plock - enables a lock process for text or data in memory

SYNOPSIS
     #include <sys/lock.h>

     int plock(op)
     int op;

DESCRIPTION
     plock 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 superuser 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

STATUS MESSAGES AND VALUES
     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.

     The plock command will fail and not perform the requested
     operation if one or more of the following is true:

     EPERM
          The effective user ID of the calling process is not
          superuser.

     EAGAIN
          The system has temporarily exhausted its available
          memory or swap space.

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

     EINVAL



January 1992                                                    1

plock(2)                                                 plock(2)



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

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

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

SEE ALSO
     exec(2), exit(2), fork(2)










































2                                                    January 1992