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PAPI_read(3) PAPI PAPI_read(3)

NAME

PAPI_read - Read hardware counters from an event set.

SYNOPSIS

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, PAPI_accum() adds the values of the counters to the values stored in the array (the second parameter in PAPI_accum()) and then resets the counters to zero.

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

Parameters

EventSet -- an integer handle for a PAPI Event Set as created by PAPI_create_eventset()
*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 300
values[0] = -100;
do_100events();
if (PAPI_accum(EventSet, values) != PAPI_OK)


    handle_error(1);
// values[0] now equals 0

See also

PAPI_accum

PAPI_start

PAPI_stop

PAPI_reset

Author

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Mon Feb 24 2025 21:11:21 Version 7.2.0.0b2