контейнер для контекста PMAPI и его метрик (container for a PMAPI context and its metrics)
Имя (Name)
QmcContext
- container for a PMAPI context and its metrics
Синопсис C ++ (C++ synopsis)
#include <QmcContext.h>
CC ... -lqmc -lpcp
Описание (Description)
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.
Конструкторы (Constructors)
A QmcContext
object should be constructed through the
QmcGroup::use
interface.
DESCRIPTOR LOOKUP
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 pmID
s 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.
Диагностика (Diagnostic)
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).
Смотри также (See also)
PMAPI(3), QMC(3), QmcDesc(3), QmcGroup(3), QmcIndom(3),
QmcMetric(3), pmflush(3), pmLookupName(3) and pmprintf(3).