The user can ask, from the Run Interactive Menu, for an execution of the events one by one and a display of some of the effects of the executions. This is useful for a detailed understanding of the process and for debugging purposes.
A partial trace of the simulation of this program is shown below. To follow the trace the following remarks must be regarded:
******************>>>>>>>>>>>>>> indicates the beginning
of an event. Its number (order of the node in the NETWORK) and the
index IEV is indicated. Then the name of the node firstly activated
is shown.In the example the trace displays the content of the FEL. It only has the event scheduled by the ACT instruction in the INIT section. This event is an activation of the node Entry at TIME = 0. The index of the event is 1 and the event parameter is 0.
The EVENT 1, that activates the node Entry at time 0, starts adding other event number 1 (next activation) to the FEL for the future time 0.353 (this number comes from the EXPO function).
A message numbered # 1 that was generated at Entry is added to the EL of the node Window, that previously had length LL equal to 0. Notice that the messages generated in a node contains a sequential number and the name of that node.
Following the scanning of the network the node Window is activated.
The message 1 (generated at Entry) is examined, then extracted from the EL.
An event of type 2 (activation of node Window) is put into the FEL to schedule the end of service at time 4.409.
The extracted message is added to the IL of the node Window.
Three events of type 1 (arrivals) happen at times 0.353, 0.888 and 4.108. These are intercalated in the FEL before the end of service event, scheduled for TIME 4.409.
The generated messages are added to EL_Window and remain there because the IL is occupied.
The next event is of type 2 (activation of Window) at TIME 4.409 scheduled at TIME 0. This event examines the IL of Window seeking for a message with EXIT TIME 4.409. The message is extracted and added to the EL of the Exit node.
Then the EL of Window is examined. The next message (number 2) in the queue (EL_Window) is extracted, its exit time is scheduled at time 7.784 and the message is added to the IL of Window. The following message (number 3) is also examined but as the IL is occupied, the message remains in the EL.
In the same event the node Exit is activated, the message number 2 extracted from its EL and deleted.
The network (excluded the Entry node that is of I type) is scanned again and, as no messages are moved, the next event in the FEL is processed.
The reader can continue the examination of this simulation. In this simple example only two events are at most in the FEL (next arrival and next end of service). In more complex models the FEL can be longer.
The examination of traces is very useful to understand the GLIDER system works. It is also very important for debugging.
Future Event List at Time 0.000 NODE ENTRY T 0.000 IND 1 EVP 0 EVENT 1 IEV 1 ******************>>>>>>>>>>>>>> TIME 0.000 NODE ENTRY[1] ADD TO FEL EV 1 IEV 1 TIME 0.353 ADD MESS.# 1 GEN ENTRY TO EL_WINDOW 1 LL 0 TIME 0.000 NODE WINDOW[1] EXA.MESS.# 1 GEN ENTRY EXT.MESS.# 1 GEN ENTRY FROM EL_WINDOW 1 LL 1 TIME 0.000 ADD TO FEL EV 2 IEV 1 TIME 4.409 ADD MESS.# 1 GEN ENTRY TO IL_WINDOW 1 LL 0 TIME 0.000 Future Event List at Time 0.000 NODE ENTRY T 0.353 IND 1 EVP 0 NODE WINDOW T 4.409 IND 1 EVP 0 EVENT 1 IEV 1 ******************>>>>>>>>>>>>>> TIME 0.353 NODE ENTRY[1] ADD TO FEL EV 1 IEV 1 TIME 0.888 ADD MESS.# 2 GEN ENTRY TO EL_WINDOW 1 LL 0 TIME 0.353 NODE WINDOW[1] EXA.MESS.# 2 GEN ENTRY NODE WINDOW[1] EXA.MESS.# 2 GEN ENTRY Future Event List at Time 0.353 NODE ENTRY T 0.888 IND 1 EVP 0 NODE WINDOW T 4.409 IND 1 EVP 0 EVENT 1 IEV 1 ******************>>>>>>>>>>>>>> TIME 0.888 NODE ENTRY[1] ADD TO FEL EV 1 IEV 1 TIME 4.108 ADD MESS.# 3 GEN ENTRY TO EL_WINDOW 1 LL 1 TIME 0.888 NODE WINDOW[1] EXA.MESS.# 2 GEN ENTRY NODE WINDOW[1] EXA.MESS.# 2 GEN ENTRY Future Event List at Time 0.888 NODE ENTRY T 4.108 IND 1 EVP 0 NODE WINDOW T 4.409 IND 1 EVP 0 EVENT 1 IEV 1 ******************>>>>>>>>>>>>>> TIME 4.108 NODE ENTRY[1] ADD TO FEL EV 1 IEV 1 TIME 7.614 ADD MESS.# 4 GEN ENTRY TO EL_WINDOW 1 LL 2 TIME 4.108 NODE WINDOW[1] EXA.MESS.# 2 GEN ENTRY NODE WINDOW[1] EXA.MESS.# 2 GEN ENTRY Future Event List at Time 4.108 NODE WINDOW T 4.409 IND 1 EVP 0 NODE ENTRY T 7.614 IND 1 EVP 0 EVENT 2 IEV 1 ******************>>>>>>>>>>>>>> TIME 4.409 NODE WINDOW[1] EXAM.LIST IL_WINDOW 1 SEEK EXIT TIME 4.409 EXT.MESS.# 1 GEN ENTRY FROM IL_WINDOW 1 LL 1 TIME 4.409 ADD MESS.# 1 GEN ENTRY TO EL_EXIT 1 LL 0 TIME 4.409 EXA.MESS.# 2 GEN ENTRY EXT.MESS.# 2 GEN ENTRY FROM EL_WINDOW 1 LL 3 TIME 4.409 ADD TO FEL EV 2 IEV 1 TIME 7.784 ADD MESS.# 2 GEN ENTRY TO IL_WINDOW 1 LL 0 TIME 4.409 EXA.MESS.# 3 GEN ENTRY NODE EXIT[1] EXT.MESS.# 1 GEN ENTRY FROM EL_EXIT 1 LL 1 TIME 4.409 DELETED MESS# 1 GENERATED IN ENTRY AT 0.000 NODE WINDOW[1] EXA.MESS.# 3 GEN ENTRY Future Event List at Time 4.409 NODE ENTRY T 7.614 IND 1 EVP 0 NODE WINDOW T 7.784 IND 1 EVP 0 EVENT 1 IEV 1 ******************>>>>>>>>>>>>>> TIME 7.614 NODE ENTRY[1] ADD TO FEL EV 1 IEV 1 TIME 7.917 ADD MESS.# 5 GEN ENTRY TO EL_WINDOW 1 LL 2 TIME 7.614 NODE WINDOW[1] EXA.MESS.# 3 GEN ENTRY NODE WINDOW[1] EXA.MESS.# 3 GEN ENTRY Future Event List at Time 7.614 NODE WINDOW T 7.784 IND 1 EVP 0 NODE ENTRY T 7.917 IND 1 EVP 0 EVENT 2 IEV 1 ******************>>>>>>>>>>>>>> TIME 7.784 NODE WINDOW[1] EXAM.LIST IL_WINDOW 1 SEEK EXIT TIME 7.784 EXT.MESS.# 2 GEN ENTRY FROM IL_WINDOW 1 LL 1 TIME 7.784 ADD MESS.# 2 GEN ENTRY TO EL_EXIT 1 LL 0 TIME 7.784 EXA.MESS.# 3 GEN ENTRY EXT.MESS.# 3 GEN ENTRY FROM EL_WINDOW 1 LL 3 TIME 7.784 ADD TO FEL EV 2 IEV 1 TIME 11.858 ADD MESS.# 3 GEN ENTRY TO IL_WINDOW 1 LL 0 TIME 7.784 EXA.MESS.# 4 GEN ENTRY NODE EXIT[1] EXT.MESS.# 2 GEN ENTRY FROM EL_EXIT 1 LL 1 TIME 7.784 DELETED MESS# 2 GENERATED IN ENTRY AT 0.353 NODE WINDOW[1] EXA.MESS.# 4 GEN ENTRY Future Event List at Time 7.784 NODE ENTRY T 7.917 IND 1 EVP 0 NODE WINDOW T 11.858 IND 1 EVP 0 EVENT 1 IEV 1 ******************>>>>>>>>>>>>>> TIME 7.917 NODE ENTRY[1] ADD TO FEL EV 1 IEV 1 TIME 11.890 ADD MESS.# 6 GEN ENTRY TO EL_WINDOW 1 LL 2 TIME 7.917 NODE WINDOW[1] EXA.MESS.# 4 GEN ENTRY NODE WINDOW[1] EXA.MESS.# 4 GEN ENTRY Future Event List at Time 7.917 NODE WINDOW T 11.858 IND 1 EVP 0 NODE ENTRY T 11.890 IND 1 EVP 0 EVENT 2 IEV 1 ******************>>>>>>>>>>>>>> TIME 11.858 NODE WINDOW[1] EXAM.LIST IL_WINDOW 1 SEEK EXIT TIME 11.858 EXT.MESS.# 3 GEN ENTRY FROM IL_WINDOW 1 LL 1 TIME 11.858 ADD MESS.# 3 GEN ENTRY TO EL_EXIT 1 LL 0 TIME 11.858 EXA.MESS.# 4 GEN ENTRY EXT.MESS.# 4 GEN ENTRY FROM EL_WINDOW 1 LL 3 TIME 11.858 ADD TO FEL EV 2 IEV 1 TIME 16.019 ADD MESS.# 4 GEN ENTRY TO IL_WINDOW 1 LL 0 TIME 11.858 EXA.MESS.# 5 GEN ENTRY NODE EXIT[1] EXT.MESS.# 3 GEN ENTRY FROM EL_EXIT 1 LL 1 TIME 11.858 DELETED MESS# 3 GENERATED IN ENTRY AT 0.888 NODE WINDOW[1] EXA.MESS.# 5 GEN ENTRY Future Event List at Time 11.858 NODE ENTRY T 11.890 IND 1 EVP 0 NODE WINDOW T 16.019 IND 1 EVP 0 EVENT 1 IEV 1 ******************>>>>>>>>>>>>>> TIME 11.890 NODE ENTRY[1]