/*                  pong.c Generic Benchmark code
 *               Dave Turner - Ames Lab - July of 1994+++
 *
 *  Most Unix timers can't be trusted for very short times, so take this
 *  into account when looking at the results.  This code also only times
 *  a single message passing event for each size, so the results may vary
 *  between runs.  For more accurate measurements, grab NetPIPE from
 *  http://www.scl.ameslab.gov/ .
 */
#include "rompi.h"

typedef uvlong ticks;
struct AmRing * amringsetup(int logN, int core);
void amrstartup(struct AmRing *amr);
int amrsend(struct AmRing *amr, void *data, int size, int rank);
unsigned char *amrrecvbuf(struct AmRing *amr, unsigned char *p, int *rank);
double MPI_Wtime(void);
int MPI_Init(int *argc,char ***argv);
extern int myproc, nproc;

int debug = 0;

static __inline__ ticks getticks(void)
{
     unsigned int tbl, tbu0, tbu1;

     do {
	  __asm__ __volatile__ ("mftbu %0" : "=r"(tbu0));
	  __asm__ __volatile__ ("mftb %0" : "=r"(tbl));
	  __asm__ __volatile__ ("mftbu %0" : "=r"(tbu1));
     } while (tbu0 != tbu1);

     return (((unsigned long long)tbu0) << 32) | tbl;
}

uvlong
mynsec(void)
{
	uvlong t;
	static int fd = -1;
	extern int pread(int, void *, int, unsigned long long);

	if (fd < 0) {
		fd = open("/dev/bintime", 0);
		if (fd < 0)
			panic("Can't open /dev/bintime");
	}

	pread(fd, &t, sizeof(t), 0ULL);
	return t;
}

ticks ring(struct AmRing *amring, int iter)
{
	ticks start = 0ULL;
	/* send the message around the ring */
	Tpkt *p = (void *)mallocz(1024, 1);
	int rx, ry, rz;
	int rrank;
	unsigned char data[240];

	/* the usual 'kick it off cause we're special */
	/* and we send a different message type for the initial case */
	if (! myproc) {
		start = getticks();
		data[0] = 'p';
		amrsend(amring, data, 240, 1);
	} 
	int i;
	for(i = 0; i < iter; i++) {
		waitamrpacket(amring, 'p', p, &rx, &ry, &rz, 0);
		if (! start)
			start = getticks();
		if (debug) {
		    rrank = xyztorank(rx, ry, rz);
		    print("Got 'p' from %d(%d,%d,%d)\n", rrank, rx, ry, rz);
		}
		data[0] = 'p';
		amrsend(amring, data, 240, (myproc+1)%nproc);
		if (debug)
			print("Done %d/%d iterations\n", i, iter);
	}
	if (! myproc) {
		waitamrpacket(amring, 'p', p, &rx, &ry, &rz, 0);
		rrank = xyztorank(rx, ry, rz);
		if (debug) print("Got 'p' from %d(%d,%d,%d)\n", rrank, rx, ry, rz);
	}
	
	return start;
}
int
main (int argc, char **argv)
{
	MPI_Init(&argc, &argv);
	
	struct AmRing *amring;
	extern int amrdebug;
	amrdebug = 0;
	int iter = 1;
	if (argc > 1)
		iter = strtol(argv[1], 0, 0);

	print("Call amrstartup, myproc %d nproc %d\n", myproc, nproc);
	if (myproc < nproc){
		amring = amringsetup(20, 0);
		if (0 && myproc)
			torusctl("debug 64", 1);
		amrstartup(amring);	
	} else
		while(1);
	print("amrstartup returns\n");
	ticks start, end;
	start = ring(amring, iter);
	end  = getticks();
	print("%lld %lld - %d / p\n", end, start, iter);
	return 0;
}