Read hardware counters from an event set. More...

Detailed Description

C Interface:: #include <papi.h>
int PAPI_read(int EventSet, long_long * values );

PAPI_read() copies the counters of the indicated event set into the provided array.

The counters continue counting after the read.

Note the differences between PAPI_read() and PAPI_accum(), specifically that PAPI_accum() resets the values array to zero.

PAPI_read() assumes an initialized PAPI library and a properly added event set.

Parameters:

[in]	EventSet	-- an integer handle for a PAPI Event Set as created by PAPI_create_eventset()
[out]	*values	-- an array to hold the counter values of the counting events

Return values:

PAPI_EINVAL	One or more of the arguments is invalid.
PAPI_ESYS	A system or C library call failed inside PAPI, see the errno variable.
PAPI_ENOEVST	The event set specified does not exist.

Examples

 do_100events();
 if (PAPI_read(EventSet, values) != PAPI_OK)
    handle_error(1);
 // values[0] now equals 100
 do_100events();
 if (PAPI_accum(EventSet, values) != PAPI_OK)
    handle_error(1);
 // values[0] now equals 200
 values[0] = -100;
 do_100events();
 if (PAPI_accum(EventSet, values) != PAPI_OK)
     handle_error(1);
 // values[0] now equals 0

Bug:: These functions have no known bugs.

See also:: PAPI_accum; PAPI_start; PAPI_stop; PAPI_reset

The documentation for this class was generated from the following file:

papi.c