- manages contexts created by all groups
CC ... -lqmc -lpcp
class maintains a unique list of all metric sources in use
to minimize the creation of new contexts (see pmNewContext
(3)) when the
context could have been duplicated (see pmDupContext
(3)). This also
reduces the duplication of descriptions of each source.
In general, QMC
users should only need to access QmcSource
to obtain source descriptions for a QmcContext
(3) object. All context
creation by the user should be handled through QmcGroup
- static QmcSource* getSource(int type, const char*
- bool matchHosts)
This method will return a QmcSource object that represents a context
of type to source. The QmcSource object may be a new
object if the source has not been previously requested. Memory
management of the QmcSource objects is handled by QmcSource.
If all QmcContext(3)s to the QmcSource have been deleted,
the QmcSource object will also be deleted.
The matchHosts flag controls the algorithm that is used to match
hosts to archives. If matchHosts is equal to false then no
attempt will be made by this method to match a host context to an existing
source context. A QmcSource object will always be returned in this
case, although the QmcSource::status method may indicate that a
context to source failed.
If matchHosts is equal to true, host contexts will be matched
to a pre-defined archive source collected from that source. If no
archive sources for the source have been previous specified,
getSource will return a NULL pointer.
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
Additional diagnostics may be activated by adding DBG_TRACE_PMC