disclaim

Purpose

     Disclaims content of a memory address range.

Syntax

     #include <sys/shm.h>

     int disclaim (addr, length, flag)
     char *addr;
     unsigned int length, flag;

Description

     The disclaim system call marks an area of memory that has
     content that is no longer needed.  This allows the system
     to discontinue paging the  memory area.  This system call
     cannot be used on memory that  is mapped to a file by the
     shmat system call.

     The addr parameter points to  the beginning of the memory
     area, and  the length  parameter specifies its  length in
     bytes.  The  flag parameter  must be the  value ZERO_MEM,
     which indicates that each  memory location in the address
     range is to be set to 0.

Return Value

     Upon  successful  completion,  the disclaim  system  call
     returns a value of 0.  If it fails, it returns a value of
     -1 and sets errno to indicate the error.

Diagnostics

     The disclaim system call fails if one or more of the fol-
     lowing is true:

     EFAULT     The calling process does not have write access
                to the  area of memory that  begins at address
                and extends for length bytes.

     EINVAL     The value of the flag parameter is not valid.

     EINVAL     The memory area is mapped to a file.

Related Information

     In this book:  "shmat" and "shmctl."