/* From Dave McNamara at PSRV. Thanks! */

/* If an event is countable but you've exhausted the counter resources

and you try to add an event, it seems subsequent PAPI_start and/or

PAPI_stop will causes a Seg. Violation.

   I got around this by calling PAPI to get the # of countable events,

then making sure that I didn't try to add more than these number of

events. I still have a problem if someone adds Level 2 cache misses

and then adds FLOPS 'cause I didn't count FLOPS as actually requiring

2 counters. */

#include "papi_test.h"

#include <mpi.h>

#include <stdio.h>

#include <math.h>

extern int TESTS_QUIET;				   /* Declared in test_utils.c */

char *netevents[] =

	{ "LO_RX_PACKETS", "LO_TX_PACKETS", "ETH0_RX_PACKETS", "ETH0_TX_PACKETS" };

double

f( double a )

{

	return ( 4.0 / ( 1.0 + a * a ) );

}

int

main( int argc, char **argv )

{

	int EventSet = PAPI_NULL, EventSet1 = PAPI_NULL;

	int evtcode;

	int retval, i, ins = 0;

	long long g1[2], g2[2];

	int done = 0, n, myid, numprocs;

	double PI25DT = 3.141592653589793238462643;

	double mypi, pi, h, sum, x;

	double startwtime = 0.0, endwtime;

	int namelen;

	char processor_name[MPI_MAX_PROCESSOR_NAME];

	tests_quiet( argc, argv );	/* Set TESTS_QUIET variable */

	if ( ( retval =

		   PAPI_library_init( PAPI_VER_CURRENT ) ) != PAPI_VER_CURRENT )

		test_fail( __FILE__, __LINE__, "PAPI_library_init", retval );

	if ( ( retval = PAPI_create_eventset( &EventSet ) ) != PAPI_OK )

		test_fail( __FILE__, __LINE__, "PAPI_create_eventset", retval );

	if ( ( retval = PAPI_create_eventset( &EventSet1 ) ) != PAPI_OK )

		test_fail( __FILE__, __LINE__, "PAPI_create_eventset", retval );

	PAPI_event_name_to_code( netevents[2], &evtcode );

	if ( ( retval = PAPI_query_event( evtcode ) ) != PAPI_OK ) {

		if ( retval != PAPI_ECNFLCT )

			test_fail( __FILE__, __LINE__, "PAPI_aquery_event", retval );

	}

	if ( ( retval = PAPI_add_event( EventSet, evtcode ) ) != PAPI_OK ) {

		if ( retval != PAPI_ECNFLCT )

			test_fail( __FILE__, __LINE__, "PAPI_add_event", retval );

	}

	PAPI_event_name_to_code( netevents[3], &evtcode );

	if ( ( retval = PAPI_query_event( evtcode ) ) != PAPI_OK ) {

		if ( retval != PAPI_ECNFLCT )

			test_fail( __FILE__, __LINE__, "PAPI_aquery_event", retval );

	}

	if ( ( retval = PAPI_add_event( EventSet, evtcode ) ) != PAPI_OK ) {

		if ( retval != PAPI_ECNFLCT )

			test_fail( __FILE__, __LINE__, "PAPI_add_event", retval );

	}

	if ( ( retval = PAPI_query_event( PAPI_FP_INS ) ) != PAPI_OK ) {

		if ( ( retval = PAPI_query_event( PAPI_FP_OPS ) ) == PAPI_OK ) {

			ins = 2;

			if ( ( retval =

				   PAPI_add_event( EventSet1, PAPI_FP_OPS ) ) != PAPI_OK ) {

				if ( retval != PAPI_ECNFLCT )

					test_fail( __FILE__, __LINE__, "PAPI_add_event", retval );

			}

		}

	} else {

		ins = 1;

		if ( ( retval = PAPI_add_event( EventSet1, PAPI_FP_INS ) ) != PAPI_OK ) {

			if ( retval != PAPI_ECNFLCT )

				test_fail( __FILE__, __LINE__, "PAPI_add_event", retval );

		}

	}

	if ( ( retval = PAPI_add_event( EventSet1, PAPI_TOT_CYC ) ) != PAPI_OK ) {

		if ( retval != PAPI_ECNFLCT )

			test_fail( __FILE__, __LINE__, "PAPI_add_event", retval );

	}

	MPI_Init( &argc, &argv );

	MPI_Comm_size( MPI_COMM_WORLD, &numprocs );

	MPI_Comm_rank( MPI_COMM_WORLD, &myid );

	MPI_Get_processor_name( processor_name, &namelen );

	fprintf( stdout, "Process %d of %d on %s\n",

			 myid, numprocs, processor_name );

	fflush( stdout );

	if ( ( retval = PAPI_start( EventSet ) ) != PAPI_OK )

		test_fail( __FILE__, __LINE__, "PAPI_start", retval );

	if ( ( retval = PAPI_start( EventSet1 ) ) != PAPI_OK )

		test_fail( __FILE__, __LINE__, "PAPI_start", retval );

	n = 0;

	while ( !done ) {

		if ( myid == 0 ) {

			if ( n == 0 )

				n = 1000000;

			else

				n = 0;

			startwtime = MPI_Wtime(  );

		}

		MPI_Bcast( &n, 1, MPI_INT, 0, MPI_COMM_WORLD );

		if ( n == 0 )

			done = 1;

		else {

			h = 1.0 / ( double ) n;

			sum = 0.0;

			/* A slightly better approach starts from large i and works back */

			for ( i = myid + 1; i <= n; i += numprocs ) {

				x = h * ( ( double ) i - 0.5 );

				sum += f( x );

			}

			mypi = h * sum;

			MPI_Reduce( &mypi, &pi, 1, MPI_DOUBLE, MPI_SUM, 0, MPI_COMM_WORLD );

			if ( myid == 0 ) {

				printf( "pi is approximately %.16f, Error is %.16f\n",

						pi, fabs( pi - PI25DT ) );

				endwtime = MPI_Wtime(  );

				printf( "wall clock time = %f\n", endwtime - startwtime );

				fflush( stdout );

			}

		}

	}

	if ( ( retval = PAPI_stop( EventSet1, g1 ) ) != PAPI_OK )

		test_fail( __FILE__, __LINE__, "PAPI_stop", retval );

	if ( ( retval = PAPI_stop( EventSet, g2 ) ) != PAPI_OK )

		test_fail( __FILE__, __LINE__, "PAPI_stop", retval );

	MPI_Finalize(  );

	printf( "ETH0_RX_BYTES: %lld   ETH0_TX_BYTES: %lld\n", g2[0], g2[1] );

	if ( ins == 0 ) {

		printf( "PAPI_TOT_CYC : %lld\n", g1[0] );

	} else if ( ins == 1 ) {

		printf( "PAPI_FP_INS  : %lld   PAPI_TOT_CYC : %lld\n", g1[0], g1[1] );

	} else if ( ins == 2 ) {

		printf( "PAPI_FP_OPS  : %lld   PAPI_TOT_CYC : %lld\n", g1[0], g1[1] );

	}

	test_pass( __FILE__, NULL, 0 );

	return 0;

}