1QMC_CONTEXT(3) Library Functions Manual QMC_CONTEXT(3)
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6 QmcContext - container for a PMAPI context and its metrics
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9 #include <QmcContext.h>
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11 CC ... -lqmc -lpcp
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14 A QmcContext object is a container for a single PMAPI(3) context. The
15 object maintains a list of all the metric descriptors (QmcDesc),
16 instance domains (QmcIndom) and metrics (QmcMetric) using the context
17 to minimize the duplication of these objects.
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20 A QmcContext object should be constructed through the QmcGroup::use
21 interface.
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24 The metric and instance domain descriptors are cached by the QmcContext
25 object to reduce duplicate QmcDesc(3) and QmcIndom(3) objects and
26 PMAPI(3) calls required to create them. Also the mapping from metrics
27 names to pmIDs is also maintained to avoid pmLookupName(3) calls.
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29 int lookupDesc(const char *name, pmID& id);
30 Search for the metric name in the name list and set id to the known
31 pmID. If not found, use pmLookupName(3) to get the mapping. If
32 this call fails, the PMAPI(3) error code will be returned.
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34 int lookupDesc(const char *name, uint_t& desc, uint_t& indom);
35 Find the index desc and indom to the QmcDesc object and the QmcIn‐
36 dom object for the metric name. The indexes can then be used with
37 QmcContext::desc and QmcContext::indom to obtain references to the
38 real objects. The methods will return a PMAPI(3) error code if the
39 metric descriptor or instance domain could not be obtained.
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41 int lookupDesc(pmID pmid, uint_t& desc, uint_t& indom);
42 Find the index desc and indom to the QmcDesc object and the QmcIn‐
43 dom object for the metric pmid. The indexes can then be used with
44 QmcContext::desc and QmcContext::indom to obtain references to the
45 real objects. The methods will return a PMAPI(3) error code if the
46 metric descriptor or instance domain could not be obtained.
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49 PMAPI(3), QMC(3), QmcDesc(3), QmcGroup(3), QmcIndom(3), QmcMetric(3),
50 pmflush(3), pmLookupName(3) and pmprintf(3).
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53 Error messages are generated using pmprintf(3) but are not flushed. It
54 is the responsibility of the user to call pmflush(3) to output any mes‐
55 sages.
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57 Additional diagnostics may be activated by adding DBG_TRACE_PMC and
58 DBG_TRACE_OPTFETCH to the global pmDebug.
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62Performance Co-Pilot SGI QMC_CONTEXT(3)