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123 lines
4.2 KiB
Plaintext
123 lines
4.2 KiB
Plaintext
.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved
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.TH "MLOCK" P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual"
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.\" mlock
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.SH NAME
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mlock, munlock \- lock or unlock a range of process address space (\fBREALTIME\fP)
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.SH SYNOPSIS
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.LP
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\fB#include <sys/mman.h>
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.br
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.sp
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int mlock(const void *\fP\fIaddr\fP\fB, size_t\fP \fIlen\fP\fB);
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.br
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int munlock(const void *\fP\fIaddr\fP\fB, size_t\fP \fIlen\fP\fB);
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\fP
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\fB
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.br
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\fP
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.SH DESCRIPTION
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.LP
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The \fImlock\fP() function shall cause those whole pages containing
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any part of the address space of the process starting at
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address \fIaddr\fP and continuing for \fIlen\fP bytes to be memory-resident
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until unlocked or until the process exits or \fIexec\fPs another process
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image. The implementation may require that \fIaddr\fP be a multiple
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of
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{PAGESIZE}.
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.LP
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The \fImunlock\fP() function shall unlock those whole pages containing
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any part of the address space of the process starting at
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address \fIaddr\fP and continuing for \fIlen\fP bytes, regardless
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of how many times \fImlock\fP() has been called by the process
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for any of the pages in the specified range. The implementation may
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require that \fIaddr\fP be a multiple of {PAGESIZE}.
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.LP
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If any of the pages in the range specified to a call to \fImunlock\fP()
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are also mapped into the address spaces of other
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processes, any locks established on those pages by another process
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are unaffected by the call of this process to \fImunlock\fP().
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If any of the pages in the range specified by a call to \fImunlock\fP()
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are also mapped into other portions of the address space
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of the calling process outside the range specified, any locks established
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on those pages via the other mappings are also unaffected
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by this call.
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.LP
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Upon successful return from \fImlock\fP(), pages in the specified
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range shall be locked and memory-resident. Upon successful
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return from \fImunlock\fP(), pages in the specified range shall be
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unlocked with respect to the address space of the process.
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Memory residency of unlocked pages is unspecified.
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.LP
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The appropriate privilege is required to lock process memory with
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\fImlock\fP().
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.SH RETURN VALUE
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.LP
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Upon successful completion, the \fImlock\fP() and \fImunlock\fP()
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functions shall return a value of zero. Otherwise, no change
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is made to any locks in the address space of the process, and the
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function shall return a value of -1 and set \fIerrno\fP to
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indicate the error.
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.SH ERRORS
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.LP
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The \fImlock\fP() and \fImunlock\fP() functions shall fail if:
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.TP 7
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.B ENOMEM
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Some or all of the address range specified by the \fIaddr\fP and \fIlen\fP
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arguments does not correspond to valid mapped
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pages in the address space of the process.
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.sp
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.LP
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The \fImlock\fP() function shall fail if:
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.TP 7
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.B EAGAIN
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Some or all of the memory identified by the operation could not be
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locked when the call was made.
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.sp
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.LP
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The \fImlock\fP() and \fImunlock\fP() functions may fail if:
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.TP 7
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.B EINVAL
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The \fIaddr\fP argument is not a multiple of {PAGESIZE}.
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.sp
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.LP
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The \fImlock\fP() function may fail if:
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.TP 7
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.B ENOMEM
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Locking the pages mapped by the specified range would exceed an implementation-defined
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limit on the amount of memory that the
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process may lock.
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.TP 7
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.B EPERM
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The calling process does not have the appropriate privilege to perform
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the requested operation.
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.sp
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.LP
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\fIThe following sections are informative.\fP
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.SH EXAMPLES
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.LP
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None.
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.SH APPLICATION USAGE
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.LP
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None.
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.SH RATIONALE
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.LP
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None.
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.SH FUTURE DIRECTIONS
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.LP
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None.
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.SH SEE ALSO
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.LP
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\fIexec\fP() , \fIexit\fP() , \fIfork\fP() , \fImlockall\fP() , \fImunmap\fP()
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, the
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Base Definitions volume of IEEE\ Std\ 1003.1-2001, \fI<sys/mman.h>\fP
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.SH COPYRIGHT
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Portions of this text are reprinted and reproduced in electronic form
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from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
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-- Portable Operating System Interface (POSIX), The Open Group Base
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Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
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Electrical and Electronics Engineers, Inc and The Open Group. In the
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event of any discrepancy between this version and the original IEEE and
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The Open Group Standard, the original IEEE and The Open Group Standard
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is the referee document. The original Standard can be obtained online at
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http://www.opengroup.org/unix/online.html .
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