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24.4.3 Pre-processor for T1, T2, T3, T4 and T9:
The only job of the preprocessors T1_pre to T4_pre, and T9_pre is to grab an available so that
they can start. However, the preprocessors for T5-T8 have one more job to do, that is to make
sure that they fire only once (or consume only one token after T4 has fired).
Pre-processor for T1, T2, T3, T4 and T9 are similar:
function [fire, new_color,override,selected_tokens,global_info] = ...
T1_pre(PN, new_color,override,selected_tokens,global_info)
% T1_pre
task_nr = 1;
% TASK-1
occu_semafor = global_info.semafor;
semafor = ~occu_semafor;
[row, cols] = find(semafor);
% find any available semafor (value ~= 0)
if ~isempty(cols),
sema = cols(1); % which is the first avialble semafor
global_info.my_semafor(task_nr) = sema; % that will be mine
global_info.semafor(sema) = task_nr; % then reserve it
% pack results
global_info.timing(task_nr, 1) = sema;
% task handler
global_info.timing(task_nr, 2) = PN.current_time; % task starting time
fire = 1;
else
fire = 0;
end;
Pre-processor for T5, T6, T7, and T8 are similar; they first check whether the transition is
already fired once. If yes, then no more firing. Other wise, they try to grab a semafor.
function [fire, new_color,override,selected_tokens,global_info] = ...
T5_pre(PN, new_color,override,selected_tokens,global_info)
% T5_pre
task_nr = 5;
% TASK-5
occu_semafor = global_info.semafor;
semafor = ~occu_semafor;
[row, cols] = find(semafor);
% find any available semafor (value ~= 0)
tx = get_trans(PN, 'T5');
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