mas_get_metadata(3mas)

mas_get_metadata -- get information about a metric for consumer use

Synopsis

   cc [options] file -lmas
   
   #include <mas.h>
   name_t      mas_get_met_name(int md, metid_t id);
   units_t    *mas_get_met_units(int md, metid_t id);
   name_t      mas_get_met_unitsnm(int md, metid_t id);
   uint32     *mas_get_met_status(int md, metid_t id);
   uint32     *mas_get_met_objsz(int md, metid_t id);
   uint32     *mas_get_met_nobj(int md, metid_t id);
   uint32     *mas_get_met_nlocs(int md, metid_t id);
   resource_t *mas_get_met_resources(int md, metid_t id);

Description

The mas_get_metadata functions return information about individual metrics that have been registered. There is one function call for each field in the metric's metric registration table entry. For a complete description of each field, see the mas_register_met manual page.

In the following functions, the md argument is a metric descriptor returned from mas_open, and the id argument is the metric ID number of the metric whose information is to be returned.

The function mas_get_met_name returns a pointer to the metric name string.

The function mas_get_met_units returns a pointer to the units field for the metric.

The function mas_get_met_unitsnm returns a pointer to a string describing the units of the metric.

The function mas_get_met_status returns a pointer to the metric status word. The metric status can be either MAS_AVAILABLE, indicating the metric is fully registered and in use, or MAS_UPDATE, indicating the metric is in the process of being registered.

The function mas_get_met_objsz returns a pointer to the elementary object size of the metric.

The function mas_get_met_nobj returns a pointer to the number of objects, the array size, of the metric.

The function mas_get_met_nlocs returns a pointer to the total number of possible instances of the metric. This number is the (multiplicative) product of all of the metric's resource's values.

The function mas_get_met_resources returns a pointer to a null terminated list of resource ID numbers.

Return values

On success, these functions return a pointer to the data field in the caller's address space.

On failure, these functions return NULL and set mas_errno to identify the error.

Errors

MAS_NOMETRIC - id not in mas: The requested metric ID id is not registered in the metric registration file referred to by md.
MAS_INVALID_ARG - invalid metric descriptor: The metric descriptor, md does not correspond to a metric registration file previously opened by mas_open.

References

Intro(3mas)