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NAME

       pmgenmap - generate C code to simplify handling of performance 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  Metrics  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 naming 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:

            # leading block of multi-line comments
            # 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
             * 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

            /*
             * Performance Metrics Name Space Map
             * 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  Collection  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 particular, 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 pmgenmap which may
       be used as a basis for program development  are  included  in  the  PCP
       demos, e.g.  $PCP_DEMOS_DIR/pmclient.

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),   pmNewContext(3),
       pcp.conf(4), pcp.env(4) and pmns(4).