NAME
pmgenmap - generate C code to simplify handling of perfor
mance metrics
SYNOPSIS
pmgenmap [infile]
DESCRIPTION
Given one or more lists of metric names in infile or on
standard input, pmgenmap generates C declarations and
cpp(1) macros suitable for use across the Performance Met
rics Programming Interface (PMAPI) on standard output.
The declarations produced by pmgenmap simplify the coding
for client applications using the PMAPI.
The input should consist of one or more lists of metric
names of the form
listname {
metricname1 symbolname1
metricname2 symbolname2
...
}
which will generate C and cpp(1) declarations of the form
char *listname[] = {
#define symbolname1 0
"metricname1",
#define symbolname2 1
"metricname2",
...
};
The array declarations produced are suitable as parameters
to pmLookupName(3) and the #defined constants may be used
to index the vsets in the pmResult structure returned by a
pmFetch(3) call.
Obviously, listname must conform to the C identifier nam
ing rules, each symbolname must conform to the cpp(1)
macro naming rules, and each metricname is expected to be
a valid performance metrics name (see pmns(4) for more
details).
The input may include sh-style comment lines, i.e. with a
`#' as the first non-blank character of a line, and these
are translated on output to either single line or multi-
line C comments in the K&R style. For example, the input:
# RCS: $Revision: 2.9 $
# initialization group
foo {
a.b.c ONE
d.e.f.g TWO
# embedded block of multi-lines
# comments and boring pad text
xx.yy.zz THREE
}
# trailing single line comment
Produces the output:
/*
* leading block of multi-line comments
* RCS: $Revision: 2.9 $
* initialization group
*/
char *foo[] = {
#define ONE 0
"a.b.c",
#define TWO 1
"d.e.f.g",
/*
* embedded block of multi-lines
* comments and boring pad text
*/
#define THREE 2
"xx.yy.zz",
};
/* trailing single line comment */
EXAMPLE
For brevity we have removed the error handling code, and
assumed the chosen metrics do not have multiple values.
The input file
mystats {
kernel.percpu.cpu.idle IDLE
kernel.percpu.cpu.sys SYS
kernel.percpu.cpu.user USER
hinv.ncpu NCPU
}
produces the following C code, suitable for #include-ing
/*
* Built by pmgenmap from the file
* mystats.metrics
* on Wed Dec 28 19:44:17 EST 1994
*
* Do not edit this file!
*/
char *mystats[] = {
#define IDLE 0
"kernel.percpu.cpu.idle",
#define SYS 1
"kernel.percpu.cpu.sys",
#define USER 2
"kernel.percpu.cpu.user",
#define NCPU 3
"hinv.ncpu",
};
Using the code generated by pmgenmap, we are now able to
easily obtain metrics from the Performance Metrics Collec
tion Subsystem (PMCS) as follows:
#define MAX_PMID 4
int trip = 0;
int numpmid = sizeof(mystats)/sizeof(mystats[0]);
double duration;
pmResult *resp;
pmResult *prev;
pmID pmidlist[MAX_PMID];
pmNewContext(PM_CONTEXT_HOST, "localhost");
pmLookupName(numpmid, mystats, pmidlist);
pmFetch(numpmid, pmidlist, &resp);
printf("%d CPUs: %d usr %d sys %d idle0,
resp->vset[NCPU]->vlist[0].value.lval,
resp->vset[USER]->vlist[0].value.lval,
resp->vset[SYS]->vlist[0].value.lval,
resp->vset[IDLE]->vlist[0].value.lval);
Some calls to ensure portability have been removed from
the code above for the sake of clarity - the example above
should not be used as a template for programming. In par
ticular, the raw values of the metrics were used when
pmLookupDesc(3) should have been called to determine the
semantics of each metric.
More complete examples that demonstrate the use of pmgen
map which may be used as a basis for program development
are included in the PCP demos, e.g.
FILES
$PCP_VAR_DIR/pmns/*
default PMNS specification files
PCP ENVIRONMENT
Environment variables with the prefix PCP_ are used to
parameterize the file and directory names used by PCP. On
each installation, the file /etc/pcp.conf contains the
local values for these variables. The $PCP_CONF variable
may be used to specify an alternative configuration file,
as described in pcp.conf(4).
SEE ALSO
cpp(1), PMAPI(3), pmFetch(3), pmLookupName(3), pmNewCon
text(3), pcp.conf(4), pcp.env(4) and pmns(4).
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