mmv_lookup_value_desc(3) [centos man page]

MMV_LOOKUP_VALUE_DESC(3)				     Library Functions Manual					  MMV_LOOKUP_VALUE_DESC(3)

NAME

       mmv_lookup_value_desc - find a value in the Memory Mapped Value file

C SYNOPSIS

       #include <pcp/pmapi.h>
       #include <pcp/mmv_stats.h>

       pmAtomValue *mmv_lookup_value_desc(void *addr, const char *metric, const char *inst);

       cc ... -lpcp_mmv -lpcp

DESCRIPTION

       mmv_lookup_value_desc  searches	for  the  value  of the instance identified by the external instance name inst of the metric metric in the
       MMV(5) file.  addr is the address returned from mmv_stats_init().

       The pointer returned points to a pmAtomValue union, which is defined as follows:

	   typedef union {
	       __int32_t   l;	   /* 32-bit signed */
	       __uint32_t  ul;	   /* 32-bit unsigned */
	       __int64_t   ll;	   /* 64-bit signed */
	       __uint64_t  ull;    /* 64-bit unsigned */
	       float	   f;	   /* 32-bit floating point */
	       double	   d;	   /* 64-bit floating point */
	       char	    *cp;   /* char ptr */
	    pmValueBlock *vbp;	/* pmValueBlock ptr */
	   } pmAtomValue;

       MMV string values should be set using either of the mmv_set_string or mmv_set_strlen routines.

RETURNS

       The function returns the address inside of the memory mapped region on success or NULL on failure.

SEE ALSO

       mmv_stats_init(3), mmv_inc_value(3) and mmv(5).

Performance Co-Pilot													  MMV_LOOKUP_VALUE_DESC(3)

PMATOMSTR(3)						     Library Functions Manual						      PMATOMSTR(3)

NAME

       pmAtomStr, pmAtomStr_r - convert a performance metric value into a string

C SYNOPSIS

       #include <pcp/pmapi.h>

       const char *pmAtomStr(const pmAtomValue *avp, int type);
       char *pmAtomStr_r(const pmAtomValue *avp, int type, char *buf, int buflen);

       cc ... -lpcp

DESCRIPTION

       All performance metric values may be encoded in a pmAtomValue union, defined as follows;

	    typedef union {
		__int32_t    l;     /* 32-bit signed */
		__uint32_t   ul;    /* 32-bit unsigned */
		__int64_t    ll;    /* 64-bit signed */
		__uint64_t   ull;   /* 64-bit unsigned */
		float	     f;     /* 32-bit floating point */
		double	     d;     /* 64-bit floating point */
		char	     *cp;   /* char ptr */
		pmValueBlock *vbp;  /* pmValueBlock ptr */
	    } pmAtomValue;

       Given  the  performance	metric	value pointed to by avp, and a performance metric type defined by type, pmAtomStr will generate the corre-
       sponding metric value as a string, suitable for diagnostic or report output.  The pmAtomStr_r function does the same, but stores the result
       in a user-supplied buffer buf of length buflen, which should have room for at least 80 bytes.

       The value for type is typically extracted from a pmDesc structure, following a call to pmLookupDesc(3) for a particular performance metric.

       If  the	type  is PM_TYPE_STRING values longer than 38 characters will be truncated after 34 characters, and truncation shown with ellipsis
       ``...'' at the end of the value.

       If the type is PM_TYPE_AGGREGATE then up to the first three 32-bit words are displayed as hexadecimal values.

       If the type is PM_TYPE_EVENT then a summary of the number of event records found in the value is generated.

       The return value from pmAtomStr is held in a single static buffer, so the returned value is only valid until the next call to pmAtomStr.

NOTES

       pmAtomStr returns a pointer to a static buffer and hence is not thread-safe.  Multi-threaded applications should use pmAtomStr_r instead.

SEE ALSO

       PMAPI(3), pmConvScale(3), pmExtractValue(3), pmLookupDesc(3), pmPrintValue(3), pmTypeStr(3) and pmUnitsStr(3).

Performance Co-Pilot							PCP							      PMATOMSTR(3)