% 00example.gpss
% A synthetic example of a gpss model.
% Usage:
% >> clear all; prepare('00example.gpss')
% >> ta_mean= 5; tfinal= 300;
% >> [QAbuffer1,FRserver1]= schedule(1,0, ta_mean,tfinal)
% >> printstat

% declaration part
inparms     ta_mean tfinal  % declaration of input variables
outparms    QA(buffer1) FR(server1)  % declaration of output variables
facilities  server1         % declaration of facility names
queues      buffer1 system  % declaration of queue names

% initialisation part (processing at T=0)
init  
      count_Xacts= 0;          % initialize statistical variable
      allXactVec = [];         % initialize a vector

% model part (processing at simulation time)
model
      % 1st Process (buffer and server system in a loop)
      generate(expod(1,ta_mean),0,0,0,1); 
        P(1,0);                % Xact Parameter P(1)=0          
        P(2,duniformd(2,1,3)); % number of loops of Xact is 1 to 3

        queue(system,1);       % register that Xact in system (statistic)
loop    queue(buffer1,1);      % loop is a statemant label
        seize(server1);      
	depart(buffer1,1);
        advance(cuniformd(3,3,7),0);    % ts=continuous_uniform[3,7]
        release(server1);
        P(1, P(1)+1);                   % increment Xact Parameter P(1)
          % regular Matlab expressions must be specified in one row
        if P(1) < P(2), transfer(loop); end 
         
        allXactVec = [allXactVec, P(2)]; % save Xact's number of loops
	count_Xacts= count_Xacts + 1;    % count finished Xacts
        depart(system,1);       % register that Xact leaves system (statistic)
        terminate(0);
         
      % 2nd Process (time based simulation stop)   
      generate(tfinal,0,tfinal,0,0)
        terminate(1)

% final part (processing at the end of simulation)
final	   
      stem(allXactVec); grid 
      title('Number of loops for each Xact')
      disp(['mean number of loops of a Xact= ', num2str(mean(allXactVec))])
      disp(['number of finished Xacts......= ', num2str(count_Xacts)])
      disp(['Xact''s mean time in system....= ', num2str(QT(2))])
      disp(['mean length buffer1...........= ', num2str(QA(1))])
      disp(['utilization of server1........= ', num2str(FR(1))])

%################################################################################
% model execution at Matlab prompt and simulation results
% (without the plot figure)
%################################################################################
% >> prepare('00example.gpss'), ta_mean= 5; tfinal= 300;...
%    [QAbuffer1,FRserver1]= schedule(1,0, ta_mean,tfinal)
% >> printstat
% ...
% T = 300.00             
%mean number of loops of a Xact= 1.7941
%number of finished Xacts......= 34
%Xact's mean time in system....= 71.8312
%mean length buffer1...........= 13.3826
%utilization of server1........= 0.98365
%Simulation beendet
%
%QAbuffer1 = 13.3826
%FRserver1 = 0.9837
%
%>> printstat
%--------------------------------------------------------------------------------
%QUEUE-STATISTIK, T = 300.00 
%Nr.  max.  mittl. Eintritte zeitlose    mittl.   Verweilzeit aktuelle Name
%    Laenge Laenge  insges.  Eintritte Verweilzeit    WZ~=0    Laenge  ####
% 1   26    13.38     88        30       45.62      69.22        25    buffer1
% 2   27    14.37     60         0       71.83      71.83        26    system 
%--------------------------------------------------------------------------------
%FACILITY-STATISTIK, T = 300.00 
%Nr.  belegende    mittl.     Anzahl      mittl.     Name
%     Transakt.  Auslastung  Eintritte  Verweilzeit  ####
% 1      29         0.98           63        4.68    server1
%--------------------------------------------------------------------------------
%kein STORAGE betreten
%--------------------------------------------------------------------------------
%keine USER-CHAIN betreten
%--------------------------------------------------------------------------------
%BLOCK-STATISTIK, T = 300.00 
%    60     generate(expod(1,ta_mean),0,0,0,1);
%    60     P(1,0);                            
%    60     P(2,duniformd(2,1,3));             
%    60     queue(system,1);                   
%    88     queue(buffer1,1);                  
%    63     seize(server1);                    
%    63     depart(buffer1,1);                 
%    63     advance(cuniformd(3,3,7),0);       
%    62     release(server1);                  
%    62     P(1, P(1)+1);                      
%    62     if P(1) < P(2), transfer(loop); end
%    34     allXactVec = [allXactVec, P(2)];   
%    34     count_Xacts= count_Xacts + 1;      
%    34     depart(system,1);                  
%    34     terminate(0);                      
%     1     generate(tfinal,0,tfinal,0,0)      
%     1     terminate(1)                       
%--------------------------------------------------------------------------------
%>>