PLOCK(S)                 XENIX System V                  PLOCK(S)



     Name
          plock - Lock process, text, or data in memory.

     Syntax
          #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 root user to use this call.
          op specifies the following:

          PROCLOCK
               Lock text and data segments into memory.

          TXTLOCK
               Lock text segment into memory.

          DATLOCK
               Lock data segment into memory.

          UNLOCK
               Remove all process locks.

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

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

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

          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.  [EINVAL]

     Return Value
          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.



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     PLOCK(S)                 XENIX System V                  PLOCK(S)



     See Also
          exec(S), exit(S), fork(S)





















































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