PMGENMAP(1)						      General Commands Manual						       PMGENMAP(1)

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  out-
       put 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	configura-
       tion 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).

Performance Co-Pilot							PCP							       PMGENMAP(1)