mmv_lookup_value_desc (3) - Linux Manuals

mmv_lookup_value_desc: find a value in the Memory Mapped Value file

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.