'\"macro stdmacro
.\"
.\" Copyright (c) 2022 Ken McDonell.  All Rights Reserved.
.\"
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.TH PMLOGWRITEMARK 3 "PCP" "Performance Co-Pilot"
.SH NAME
\f3__pmLogWriteMark\f1 \- append a <mark> record to a PCP archive
.SH "C SYNOPSIS"
.ft 3
#include <pcp/pmapi.h>
.br
#include <pcp/libpcp.h>
.sp
int __pmLogWriteMark(__pmArchCtl *\fIacp\fP, const __pmTimestamp *\fIlast_stamp\fP, const __pmTimestamp *\fIinc\fP);
.sp
cc ... \-lpcp
.ft 1
.SH CAVEAT
This documentation is intended for internal Performance Co-Pilot
(PCP) developer use.
.PP
These interfaces are not part of the PCP APIs that are guaranteed to
remain fixed across releases, and at some point in the future
they may not work or may provide different semantics.
.SH DESCRIPTION
.de CR
.ie t \f(CR\\$1\fR\\$2
.el \fI\\$1\fR\\$2
..
.B __pmLogWriteMark
appends a <mark> record to the current data file of a PCP archive.
A <mark> record indicates a discontinuity in the time series of
logged data in the archive, see
.BR PCPIntro (1)
for more information.
.PP
The timestamp of the <mark> record is given by
.I last_stamp
optionally incremented by
.I inc
unless
.I inc
is NULL (in which case no increment is done).
.PP
The current data volume's I/O stream and the archive version
(determines the format of the <mark> record)
are determined from
.BR acp .
.SH DIAGNOSTICS AND RETURN VALUES
The return value is 0 if all is well, else
some error code less than zero that can be turned into an error
message by calling
.BR pmErrStr (3).
.SH SEE ALSO
.BR PCPIntro (1),
.BR PMAPI (3)
and
.BR __pmLogWrite (3).