pmParseTimeWindow is designed to encapsulate the interpretation of
the -S, -T, -A and -O command line options used by Performance Co-
Pilot (PCP) applications to define a time window of interest. The
time window is defined by a start time and an end time that
constrains the time interval during which the PCP application will
retrieve and display performance metrics. In the absence of the -O
and -A options to specify an initial sample time origin and time
alignment (see below), the PCP application will retrieve the first
sample at the start of the time window.
The syntax and meaning of the various argument formats for these
options is described in PCPIntro(1).
pmParseTimeWindow expects to be called with the argument of the -S
option as swStart, the argument of the -T option as swEnd, the
argument of the -A option as swAlign, and the argument of the -O
option as swOffset. Any or all of these parameters may be NULL to
indicate that the corresponding command line option was not present.
If the application is using a set of PCP archive logs as the source
of performance metrics, you also need to supply the time of the first
archive log entry as logStart, and the time of the last archive log
entry as logEnd. See pmGetArchiveLabel(3) and pmGetArchiveEnd(3) for
how to obtain values for these times.
If the application is manipulating multiple concurrent archive logs,
then the caller must resolve how the default time window is to be
defined (the union of the time intervals in all archive logs is a
If the application is using a live feed of performance data, logStart
should be the current time (but could be aligned on the next second
for example), while logEnd should have its tv_sec component set to
The rsltStart, rsltEnd and rsltOffset structures must be allocated
before calling pmParseTimeWindow.
You also need to set the current PCP reporting time zone to correctly
reflect the -z and -Z command line parameters before calling
pmParseTimeWindow. See pmUseZone(3) and friends for information on
how this is done.
If the conversion is successful, pmParseTimeWindow returns 1 and
fills in rsltStart, rsltEnd and rsltOffset with the start, end, and
offset times for the time window defined by the input parameters.
The errMsg parameter is not changed when pmParseTimeWindow returns 1.
If the conversion is successful, but the requested alignment could
not be performed (e.g. the set of PCP archive logs is too short) the
alignment is ignored, rsltStart, rsltEnd and rsltOffset are filled in
and pmParseTimeWindow returns 0. In this case, errMsg will point to
a warning message in an internal static buffer. This buffer should
not be freed.
If the argument strings could not be parsed, pmParseTimeWindow
returns -1. In this case, errMsg will point to an error message in a
static internal buffer.
This page is part of the PCP (Performance Co-Pilot) project.
Information about the project can be found at ⟨http://www.pcp.io/⟩.
If you have a bug report for this manual page, send it to
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you have corrections or improvements to the information in this
COLOPHON (which is not part of the original manual page), send a mail
Performance Co-Pilot PCP PMPARSETIMEWINDOW(3)