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).