Re: PVM

[Marek Habersack <grendel@vip.net.pl>]

* Blazej Sawionek said:
> I found myself too stupid to execute Python examples, so I decided to turn to PVM (I was told it could also do the task I need), but during installation of pvm and pvm-dev
> I got the following warnings:
> 
> ldconfig: warning: /usr/lib/libtcpwrapGK.so.1 is not a symlink
> ldconfig: warning: /usr/lib/libomnithread.so.2 is not a symlink
> ldconfig: warning: /usr/lib/libomniORB2.so.6 is not a symlink
> ldconfig: warning: /usr/lib/libomniLC.so.2 is not a symlink
> 
> Now I can't compile nor run PVM examples. Does it mean I have to gove up?
Funny you asked about PVM :)). I don't know the answer for your problem, but
I have one myself - pvm installs, pvmd runs just fine, but spawning a new
process is a disaster... A stupid program which does NOTHING at all
(attached) allocates as much memory as it can. I even ran it as root - just
to test how it will behave. Within 1min from the startup it allocated 570MB
of memory (on a 512MB RAM machine :) and kept doing it happily :). The
loadavg jumped to 10 and was increasing. I killed pvmd and the process and
everything came back to normal. Launching the program as a regular user
allocated mere 140MB memory (which was the limit for that user). What gives?
Can anybody explain to me what's wrong? I'm completely new to PVM.

thanks,
marek

#include <stdio.h>
#include <stdlib.h>
#include <pvm3.h>

#define GROUPNAME "ouzo"
#define OUZO_TAG 10
#define VERBOSE 1
#define MSG_NEW 1

void msg(char * text)
{
	if (VERBOSE) fprintf(stdout, text);
}


int main(int argc, char **argv)
{
	int mytid; 
	int myinstance;
	int message[2];
	int send_to;
	int grpsize;
	int max_instance;
	int found=0;
	int tid;
	int i;
	
	char text_message[100];

	mytid=pvm_mytid();
	
	msg("Joining to goup ouzo.\n");
	pvm_joingroup(GROUPNAME);
	
	msg("Checking if I am first.\n");
	grpsize=pvm_gsize(GROUPNAME);
	
	myinstance=pvm_getinst(GROUPNAME, mytid);
	
	switch (grpsize)
	{
		case 1: msg("I am first so I initiate the ring.\n");
			max_instance=myinstance;
	 		send_to=myinstance;		
			break;

		default: 
			msg("Ring is already set.\n");
			msg("Trying to join the ring.\n");
			msg("Searching for the process to connect to.\n");
			for (i=0; (i==myinstance) || ((tid=pvm_gettid(GROUPNAME, i))<=0); i++);
			//przygotuj wiadomosc
			pvm_initsend( PvmDataDefault );
			message[0]=MSG_NEW;
			message[1]=myinstance;
			pvm_pkint(message, 2, 1);
			pvm_send(tid, OUZO_TAG);		
			break;
	}
	
	do
	{
		msg("Listening..\n");
		pvm_recv(-1, OUZO_TAG);
		//obsluga przychodzacych wiadomosci
		//rodzaje przychodzacych wiadomosci
		//MSG_STD - normalny broadcast - do wyswietlenia i do wyslania dalej
		//MSG_NEW - poszukiwanie miejsca w ringu dla nowego procesu
		//MSG_LAST_UPDATE - update numeru ostatniej instancji w ringu
		//	zakeszowac i przeslac dalej
		//MSG_TERMINATE -- przeslac dalej i zakonczyc program.
		
	} while (1);
	
	
	
/*
	if (instance && argc==2 && !strcmp(argv[1], "terminate"))

	{
		printf("terminating ring\n");
		pvm_initsend(PvmDataDefault);
		message=-1;
		pvm_pkint(&message, 1, 1);
		pvm_send(0, MESSAGE_TAG);
		pvm_exit();
	}
	
	if  (!instance)
	{

		//i am the first one ... who the fuck is alice ? 
		//czekam na komunikat o nastepnym przylaczonym procesie 
		pvm_recv(-1,MESSAGE_TAG);
		pvm_upkint(message,1 , 1);
		switch (message)
		{
			case 1: //niech to bedzie przylaczenie nowego procesu
			case -1: //to bedzie ring terminate
				printf("terminating ring - instance %d", instance);
				pvm_exit();
				
			case 2: //to bedzie normalna wiadomosc;
				pvm_upkstr(text_message);
				break;
		}
		
	}*/
	msg("Leaving the Group ouzo.\n");
	pvm_lvgroup(GROUPNAME);	
	pvm_exit();
	return 0;
}

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