1PMUNPACKEVENTRECORDS(3) Library Functions Manual PMUNPACKEVENTRECORDS(3)
2
6 pmUnpackEventRecords, pmUnpackHighResEventRecords - unpack event
7 records
8
10 #include <pcp/pmapi.h>
11 int pmUnpackEventRecords(pmValueSet *vsp, int idx, pmResult ***rap);
13 int pmUnpackHighResEventRecords(pmValueSet *vsp, int idx, pmHighResRe‐
15 sult ***hrap);
16 cc ... -lpcp
18
20 Event records are encoded as a packed array of records within a pmRe‐
21 sult using a container metric with a value of type PM_TYPE_EVENT , and
22 a pmHighResResult when using a metric of type PM_TYPE_HIGHRES_EVENT.
23 pmUnpackEventRecords and pmUnpackHighResEventRecords may be used to un‐
25 pack event records from a metric value identified by vsp and idx. If
26 the metric has a singular value, idx should be 0, else the ordinal in‐
27 stance value identified by idx will be unpacked, i.e. vsp->vlist[idx].
28 The unpacked records are turned into either pmResult or pmHighResResult
29 structures, one per event record and one metric per event parameter,
30 and rap is returned as a pointer to an array (NULL pointer terminated)
31 of pointers to the result structures.
32 The only difference between the two result types is the timestamp
34 scale; the pmHighResResult allows for nanosecond precision, whereas pm‐
35 Result allows for microsecond resolution.
36 Some control information from the packed event records is unpacked into
38 additional ``anonymous'' metrics as follows:
39 1. If the event record has a non-zero flags value, then the corre‐
41 sponding pmResult/pmHighResResult will have the flags value encoded
42 with the additional metric event.flags that is inserted ahead of
43 all other event parameters.
44 2. If the event record flag is set to PM_EVENT_FLAG_MISSED, then the
46 corresponding pmResult/pmHighResResult will have one metric
47 event.missed with a value that equals the number of event records
48 ``missed'' because either the PMDA could not keep up, or the PMAPI
49 client did not collect the event records fast enough.
50 pmUnpackEventRecords returns the number of pmResult structures as the
52 return value, which is >= 0 for success. Similarly, pmUnpackHighResEv‐
53 entRecords returns the number of pmHighResResult structures as the re‐
54 turn value, which is >= 0 for success.
55 rap and the associated pmResult structures may be freed using the con‐
57 venience function pmFreeEventResult(3).
58 Similarly, the hrap and the associated pmHighResResult structures may
60 be freed using the convenience function pmFreeHighResEventResult.
61
63 The following errors are possible:
64 PM_ERR_CONV
66 The values associated with vsp are not encoded using the for‐
67 mat PM_VAL_DPTR or PM_VAL_SPTR, or the flags at the head of
68 the event record has an unexpected value.
69 PM_ERR_INST
71 The value associated with vsp is not singular as expected.
72 PM_ERR_TYPE
74 vsp is not a value of type PM_TYPE_EVENT.
75 PM_ERR_TOOSMALL
77 The value identified by vbp is not legal because the value
78 length is less than the minimum size, or the number of event
79 records encoded in the (value header) pmEventArray/pmEven‐
80 tHighResArray structure is negative, or the number of missed
81 event records in the array is negative.
82 PM_ERR_TOOBIG
84 Either vsp indicates more than one value is present (all the
85 event records are expected to be packed in a single metric
86 value), or when unpacking the event records, the processing
87 continues past the end of the enclosing value. Indicates
88 corruption of the packed event record.
89 PM_ERR_TYPE
91 Event parameters must have one of the arithmetic types, else
92 PM_TYPE_AGGREGATE, PM_TYPE_STRING or PM_TYPE_AGGRE‐
93 GATE_STATIC.
94 other values < 0
96 refer to pmErrStr(3).
97
99 PMAPI(3) and pmFreeEventResult(3).
100Performance Co-Pilot PCP PMUNPACKEVENTRECORDS(3)