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NAME | C++ SYNOPSIS | DESCRIPTION | CONSTRUCTORS | DESCRIPTOR LOOKUP | SEE ALSO | DIAGNOSTICS | COLOPHON |
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QMC_CONTEXT(3) Library Functions Manual QMC_CONTEXT(3)
QmcContext - container for a PMAPI context and its metrics
#include <QmcContext.h>
CC ... -lqmc -lpcp
A QmcContext object is a container for a single PMAPI(3) context.
The object maintains a list of all the metric descriptors (QmcDesc),
instance domains (QmcIndom) and metrics (QmcMetric) using the context
to minimize the duplication of these objects.
A QmcContext object should be constructed through the QmcGroup::use
interface.
The metric and instance domain descriptors are cached by the
QmcContext object to reduce duplicate QmcDesc(3) and QmcIndom(3)
objects and PMAPI(3) calls required to create them. Also the mapping
from metrics names to pmIDs is also maintained to avoid
pmLookupName(3) calls.
int lookupDesc(const char *name, pmID& id);
Search for the metric name in the name list and set id to the
known pmID. If not found, use pmLookupName(3) to get the
mapping. If this call fails, the PMAPI(3) error code will be
returned.
int lookupDesc(const char *name, uint_t& desc, uint_t& indom);
Find the index desc and indom to the QmcDesc object and the
QmcIndom object for the metric name. The indexes can then be
used with QmcContext::desc and QmcContext::indom to obtain
references to the real objects. The methods will return a
PMAPI(3) error code if the metric descriptor or instance domain
could not be obtained.
int lookupDesc(pmID pmid, uint_t& desc, uint_t& indom);
Find the index desc and indom to the QmcDesc object and the
QmcIndom object for the metric pmid. The indexes can then be
used with QmcContext::desc and QmcContext::indom to obtain
references to the real objects. The methods will return a
PMAPI(3) error code if the metric descriptor or instance domain
could not be obtained.
PMAPI(3), QMC(3), QmcDesc(3), QmcGroup(3), QmcIndom(3), QmcMetric(3),
pmflush(3), pmLookupName(3) and pmprintf(3).
Error messages are generated using pmprintf(3) but are not flushed.
It is the responsibility of the user to call pmflush(3) to output any
messages.
Additional diagnostics may be activated by adding the options pmc
and/or optfetch to the global debugging specification, as described
in pmSetDebug(3).
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
pcp@groups.io. This page was obtained from the project's upstream
Git repository ⟨https://github.com/performancecopilot/pcp.git⟩ on
2018-02-02. (At that time, the date of the most recent commit that
was found in the repository was 2018-02-02.) If you discover any
rendering problems in this HTML version of the page, or you believe
there is a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
man-pages@man7.org
Performance Co-Pilot SGI QMC_CONTEXT(3)
Pages that refer to this page: QMC(3), QmcGroup(3), QmcIndom(3), QmcSource(3)
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