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(5) 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 */

EXAMPLES

       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(5).

SEE ALSO

       cpp(1), PMAPI(3), pmFetch(3), pmLookupName(3), pmNewContext(3), pcp.conf(5), pcp.env(5) and PMNS(5).