msync(2) [opendarwin man page]

MSYNC(2)						      BSD System Calls Manual							  MSYNC(2)

NAME

     msync -- synchronize a mapped region

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <sys/types.h>
     #include <sys/mman.h>

     int
     msync(void *addr, size_t len, int flags);

DESCRIPTION

     The msync() system call writes modified whole pages back to the filesystem and updates the file modification time.  Only those pages contain-
     ing addr and len-1 succeeding locations will be examined.	The flags argument may be specified as follows:

     MS_ASYNC	     Return immediately
     MS_SYNC	     Perform synchronous writes
     MS_INVALIDATE   Invalidate all cached data

     The MS_ASYNC flag is not permitted to be combined with other flags.

RETURN VALUES

     If any errors occur, -1 is returned and errno is set to indicate the error.  Otherwise, a 0 value is returned.

ERRORS

     msync() will fail if:

     [EINVAL]		addr is not a multiple of the hardware page size.

     [EINVAL]		len is too large, or less than 1.

     [EINVAL]		flags combined MS_ASYNC with another flag, which is not permitted.

     [EIO]		An I/O error occurred while writing to the file system.

SEE ALSO

     madvise(2), mincore(2), mprotect(2), munmap(2)

HISTORY

     The msync() function first appeared in 4.4BSD.

BSD
								   June 21, 1994							       BSD

MSYNC(2)						      BSD System Calls Manual							  MSYNC(2)

NAME

     msync -- synchronize a mapped region

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <sys/mman.h>

     int
     msync(void *addr, size_t len, int flags);

DESCRIPTION

     The msync() system call writes modified whole pages back to the filesystem and updates the file modification time.  Only those pages contain-
     ing addr and len-1 succeeding locations will be examined.

     The flags argument may be specified as follows:

     MS_ASYNC	     Return immediately
     MS_SYNC	     Perform synchronous writes
     MS_INVALIDATE   Invalidate all cached data

     The MS_ASYNC flag is not permitted to be combined with other flags.

RETURN VALUES

     If any errors occur, -1 is returned and errno is set to indicate the error.  Otherwise, a 0 value is returned.

ERRORS

     msync() will fail if:

     [EBUSY]		Some of the specified addresses are locked and MS_INVALIDATE is specified.

     [EINVAL]		addr is not a multiple of the hardware page size.

     [EINVAL]		len is too large, or less than 1.

     [EINVAL]		flags is invalid (e.g., it combines MS_ASYNC with another flag, which is not permitted).

     [EIO]		An I/O error occurs while writing to the file system.

     [ENOMEM]		The specified address range is outside of the address range of the process or includes an unmapped page.

LEGACY SYNOPSIS

     #include <sys/types.h>
     #include <sys/mman.h>

     The include file <sys/types.h> is necessary.

SEE ALSO

     madvise(2), mincore(2), mprotect(2), munmap(2), compat(5)

HISTORY

     The msync() function first appeared in 4.4BSD.

BSD
								   June 21, 1994							       BSD