mm1smpl.c

a simple M/M/1 queue simulation with poession process

//========================================================== file = mm1.c =====
//=  A simple M/M/1 queue simulation using SMPL                               =
//=============================================================================
//=  Notes: This program is adapted from "Figure 1.7" in Simulating Computer  =
//=         Systems, Techniques and Tools by M. H. MacDougall (1987)          =
//=---------------------------------------------------------------------------=
//=  Build: bcc32 mm1.c smpl.c bmeans.c rand.c                                =
//=         gcc mm1.c smpl.c bmeans.c rand.c -lm                              =
//=---------------------------------------------------------------------------=
//=  History: KJC (10/04/98) - Genesis                                        =
//=           KJC (02/18/05) - Cleaned-up for better understanding            =
//=============================================================================
//----- Include files ---------------------------------------------------------
#include <stdio.h>      // Needed for printf()
#include "smpl.h"       // Needed for SMPL

//===== Main program ==========================================================
void main(void)
{
  real Ta = 200;        // Mean interarrival time (seconds)
  real Ts = 100;        // Mean service time
  real te = 1.0e6;      // Total simulation time
  int customer = 1;     // Customer id (always '1' for this simulation)
  int event;            // Event (1 = arrival, 2 = request, 3 = completion)
  int server;           // Handle for server facility

  // Initialize SMPL subsystem
  smpl(0, "M/M/1 Queue");

  // Initialize server facility (single server)
  server=facility("server", 1);

  // Schedule arrival event at time 0 to kick-off simulation
  schedule(1, 0.0, customer);

  // Loop while simulation time is less than te
  while (time() < te)
  {
    // "Cause" the next event on the event list
    cause(&event,&customer);

    // Process the event
    switch(event)
    {
      case 1:  // *** Arrival
        schedule(2, 0.0, customer);
        schedule(1, expntl(Ta), customer);
        break;

      case 2:  // *** Request Server
        if (request(server, customer, 0) == 0)
          schedule(3, expntl(Ts), customer);
        break;

      case 3:  // *** Release server
        release(server, customer);
        break;
    }
  }

  // Output standard SMPL report
  report();
}