[ Previous |
Next |
Contents |
Glossary |
Home |
Search ]
AIX Version 4.3 Base Operating System and Extensions Technical Reference, Volume 1
munmap Subroutine
Purpose
Unmaps a mapped region.
Library
Standard C Library (libc.a)
Syntax
#include <sys/types.h>
#include <sys/mman.h>
int munmap (addr, len)
void *addr;
size_t len;
Description
The munmap subroutine unmaps a mapped file region or anonymous memory region. The munmap subroutine unmaps regions created from calls to the mmap subroutine only.
If an address lies in a region that is unmapped by the munmap subroutine and that region is not subsequently mapped again, any reference to that address will result in the delivery of a SIGSEGV signal to the process.
Parameters
addr |
Specifies the address of the region to be unmapped. Must be a multiple of the page size returned by the sysconf subroutine using the _SC_PAGE_SIZE value for the Name parameter. |
len |
Specifies the length, in bytes, of the region to be unmapped. If the len parameter is not a multiple of the page size returned by the sysconf subroutine using the _SC_PAGE_SIZE value for the Name parameter, the length of the region is rounded up to the next multiple of the page size. |
Return Values
When successful, the munmap subroutine returns 0. Otherwise, it returns -1 and sets the errno global variable to indicate the error.
Error Codes
If the munmap subroutine is unsuccessful, the errno global variable is set to the following value:
EINVAL |
The addr parameter is not a multiple of the page size as returned by the sysconf subroutine using the _SC_PAGE_SIZE value for the Name parameter. |
EINVAL |
The application has requested X/Open UNIX95 Specification compliant behavior and the len arguement is 0. |
[ Previous |
Next |
Contents |
Glossary |
Home |
Search ]