/*
 * Copyright (c) 2011 Ken McDonell.  All Rights Reserved.
 *
 * exercise multi-threaded support for traverse and load/unload
 * PMNS operations
 */

#include <stdio.h>
#include <stdlib.h>
#include <pcp/pmapi.h>
#include <pcp/impl.h>
#include <pthread.h>

#ifndef HAVE_PTHREAD_BARRIER_T
#include "pthread_barrier.h"
#endif

#define ITER 10

static int nmetric;

void
dometric(const char *name)
{
    nmetric++;
}

static void *
func1(void *arg)
{
    int		sts;
    int		i;
    char	msgbuf[PM_MAXERRMSGLEN];

    for (i = 0; i < ITER; i++) {
	nmetric = 0;
	sts = pmTraversePMNS("", dometric);
	if (sts >= 0)
	    printf("traverse: found %d metrics, sts %d\n", nmetric, sts);
	else {
	    /*
	     * expect 0 metrics and PM_ERR_NOPMNS if the pmTraversePMNS
	     * gets in between the pmUnloadPMNS and the pmLoadPMNS in the
	     * other thread
	     */
	    if (nmetric > 0 || sts != PM_ERR_NOPMNS)
		printf("traverse: found %d metrics, sts %s\n", nmetric, pmErrStr_r(sts, msgbuf, PM_MAXERRMSGLEN));
	    else {
		/* 
		 * nmetric == 0 && sts == PM_ERR_NOPMNS, so try again ...
		 * won't loop forever because eventually func2() will
		 * finish
		 */
		i--;
	    }
	}
    }

    pthread_exit(NULL);
}

static void *
func2(void *arg)
{
    int		sts;
    char	*fn = "func2";
    int		i;
    char	msgbuf[PM_MAXERRMSGLEN];

    for (i = 0; i < ITER; i++) {
	pmUnloadNameSpace();
	if ((sts = pmLoadNameSpace(PM_NS_DEFAULT)) < 0) {
	    printf("%s: pmLoadNameSpace[%d]: %s\n", fn, i, pmErrStr_r(sts, msgbuf, PM_MAXERRMSGLEN));
	    exit(1);
	}
    }

    pthread_exit(NULL);
}

int
main(int argc, char **argv)
{
    pthread_t		tid1;
    pthread_t		tid2;
    int			sts;
    char		*msg;
    unsigned int	in[PDU_MAX+1];
    unsigned int	out[PDU_MAX+1];
    int			i;
    char		msgbuf[PM_MAXERRMSGLEN];

    setvbuf(stdout, NULL, _IONBF, 0);

    if (argc != 1) {
	printf("Usage: multithread4\n");
	exit(1);
    }

    for (i = 0; i <= PDU_MAX; i++) {
	in[i] = out[i] = 0;
    }
    __pmSetPDUCntBuf(in, out);

    if ((sts = pmLoadNameSpace(PM_NS_DEFAULT)) < 0) {
	printf("%s: pmLoadNameSpace: %s\n", argv[0], pmErrStr_r(sts, msgbuf, PM_MAXERRMSGLEN));
	exit(1);
    }

    sts = pthread_create(&tid1, NULL, func1, NULL);
    if (sts != 0) {
	printf("thread_create: tid1: sts=%d\n", sts);
	exit(1);
    }
    sts = pthread_create(&tid2, NULL, func2, NULL);
    if (sts != 0) {
	printf("thread_create: tid2: sts=%d\n", sts);
	exit(1);
    }

    pthread_join(tid1, (void *)&msg);
    if (msg != NULL) printf("tid1: %s\n", msg);
    pthread_join(tid2, (void *)&msg); 
    if (msg != NULL) printf("tid2: %s\n", msg);

    printf("Total PDU counts\n");
    printf("in:");
    for (i = 0; i <= PDU_MAX; i++)
	printf(" %d", in[i]);
    putchar('\n');
    printf("out:");
    for (i = 0; i <= PDU_MAX; i++)
	printf(" %d", out[i]);
    putchar('\n');

    exit(0);
}