Programming Assignment #2
CSci 430 Spring 2019
Dates:
Assigned: Monday February 4, 2019
Due: Wednesday February 20, 2019 (before Midnight)
Objectives:
ˆ Explore the Process state models from an implementation point of
view.
ˆ Practice using basic queue data types and implementing in C.
ˆ Use C/C++ data structures to implement a process control block and
round robin scheduling queues.
ˆ Learn about Process switching and multiprogramming concepts.
Description:
In this assignment you will simulate a Three-State process model (ready,
running and blocked) and a simple process control block structure as dis-
cussed in Chapter 3. Your program will read input and directives from a
�le. The input describes a time sequence of events that occur. These are the
full set of events you will simulate:
1
Event Description
cpu The processor executes for 1 time step the currently running process
new A new process is created and put at tail of the ready queue
done The currently running process has �nished
wait X The currently running process has done an I/O operation and
is waiting on event X
event X Event X has occurred, the process waiting on that event should
be made ready.
The input �le will simply be a list of events that occur in the system, in
the order they are to occur. For example:
----- simulation-01.sim --------
new
cpu
cpu
cpu
new
cpu
cpu
cpu
cpu
wait 1
cpu
cpu
event 1
cpu
cpu
done
cpu
cpu
cpu
cpu
exit
----------------------------------
Your task is to read in the events, and simulate the creation and execution
of processes in the system as they move through the various three-states of
their process life cycle. You need to:
2
ˆ De�ne a simple process control block (PCB) to hold information about
all processes currently running in your system. The PCB can be a
simple C struct or a C++ class. At a minimum you need to have a
�eld for the process identi�er and the process state (Ready, Running or
Blocked). You need to also keep track of the time step that the process
entered the system, and the number of steps the process has been
running. Minimal credit will be given to programs that at least handle
new events and create a process in a simulated PCB. You probably
need a list or an array to hold the current processes that have been
created and are being managed by your simulated system.
ˆ You will need a ready queue of some kind. You should use a C++
Standard Template Library (STL) container to manage your ready
queue.
ˆ You will need to implement a simple dispatcher function. Whenever
a cpu event occurs, and no process is currently running, you should
select the next Ready process from the head of your ready queue and
start it running on the processor.
ˆ You need to also implement a simple time slicing mechanism. The
time slice value to use will be passed into your program when it is
started. At the end of a cpu cycle, you should check if the currently
running process has executed for its full time quant ...
Programming Assignment #2CSci 430 Spring 2019Dates.docx
1. Programming Assignment #2
CSci 430 Spring 2019
Dates:
Assigned: Monday February 4, 2019
Due: Wednesday February 20, 2019 (before Midnight)
Objectives:
ˆ Explore the Process state models from an implementation
point of
view.
ˆ Practice using basic queue data types and implementing in C.
ˆ Use C/C++ data structures to implement a process control
block and
round robin scheduling queues.
ˆ Learn about Process switching and multiprogramming
concepts.
Description:
In this assignment you will simulate a Three-State process
model (ready,
running and blocked) and a simple process control block
structure as dis-
cussed in Chapter 3. Your program will read input and
directives from a
2. �le. The input describes a time sequence of events that occur.
These are the
full set of events you will simulate:
1
Event Description
cpu The processor executes for 1 time step the currently running
process
new A new process is created and put at tail of the ready queue
done The currently running process has �nished
wait X The currently running process has done an I/O operation
and
is waiting on event X
event X Event X has occurred, the process waiting on that event
should
be made ready.
The input �le will simply be a list of events that occur in the
system, in
the order they are to occur. For example:
----- simulation-01.sim --------
new
cpu
cpu
cpu
4. Your task is to read in the events, and simulate the creation and
execution
of processes in the system as they move through the various
three-states of
their process life cycle. You need to:
2
ˆ De�ne a simple process control block (PCB) to hold
information about
all processes currently running in your system. The PCB can be
a
simple C struct or a C++ class. At a minimum you need to have
a
�eld for the process identi�er and the process state (Ready,
Running or
Blocked). You need to also keep track of the time step that the
process
entered the system, and the number of steps the process has
been
running. Minimal credit will be given to programs that at least
handle
new events and create a process in a simulated PCB. You
probably
need a list or an array to hold the current processes that have
been
created and are being managed by your simulated system.
ˆ You will need a ready queue of some kind. You should use a
C++
Standard Template Library (STL) container to manage your
ready
queue.
5. ˆ You will need to implement a simple dispatcher function.
Whenever
a cpu event occurs, and no process is currently running, you
should
select the next Ready process from the head of your ready queue
and
start it running on the processor.
ˆ You need to also implement a simple time slicing mechanism.
The
time slice value to use will be passed into your program when it
is
started. At the end of a cpu cycle, you should check if the
currently
running process has executed for its full time quantum. In that
case,
the currently running process should timeout, and be returned to
the
end of the Ready queue.
ˆ new events should cause a new process to be created
(including creating
its PCB and �lling it in). New processes should be placed on
the tail
of the ready queue after being created. You should assign each
new
process a process identi�er. The process identi�er should be a
simple
integer value, and you should start numbering processes from 1.
ˆ For a done event, if a process is currently running it should
then be
released. It should be removed from the CPU, and not placed
back on
the ready or blocked queue. If a done occurs when the CPU is
6. idle,
then nothing will happen as a result of this event.
ˆ A wait event simulates the currently running process
performing some
I/O operation. If a wait occurs, the currently running process
should
become blocked and put on the blocked queue. You also need an
entry
in the PCB so you know what event the process is waiting for.
The
3
wait event is followed by an integer number, which is an
indication of
the type of event the process has requested.
ˆ Likewise the event directive simulates the �nishing of some
I/O oper-
ation. When an event occurs, you should scan your blocked
processes
and make any process ready that was waiting on that event. The
in-
teger value following an event indicates the type of event that
just
occurred.
You have been given some example event sequences
(simulation-01.sim,
simulation-02.sim, etc.) along with the expected output for
those sequence
of events (simulation-01.res, simulation-02.res, etc.). The
output of your
7. program should be sent to standard output. The correct output
for the
simulation-01.sim simulation is:
Time: 1
CPU (currently running):
pid=1, state=RUNNING, start=1, slice=1,
Ready Queue:
EMPTY
Blocked Queue:
EMPTY
Time: 2
CPU (currently running):
pid=1, state=RUNNING, start=1, slice=2,
Ready Queue:
EMPTY
Blocked Queue:
EMPTY
Time: 3
CPU (currently running):
13. pid=2, state=RUNNING, start=4, slice=4,
Ready Queue:
EMPTY
Blocked Queue:
EMPTY
Your output to standard out should look exactly the same as this
output
(i.e. if I do a di� and your program is generating the correct
output, then
there will be no di�erence between the output your program
generates and
the above output format). The output is generated by displaying
the system
state after each cpu cycle executes. Basically we print out the
system time.
Then we show which process (if any) is currently running on the
CPU (or
say it is IDLE if no process is running). Then we display the
queue of
processes currently on the Ready and Blocked queues. Note that
the queues
are displayed in order. The top of the output corresponds to the
head of the
queue. Thus when a new process is dispatched, the next one
selected should
be the �rst process listed from the ready queue in the previous
system cycle.
I have given you some template code (p2-start.cpp) to get you
started
The code is meant to be run from the command line, thus from a
14. shell or
dos prompt you would do something like:
$ p2-start simulation-01.sim 5
i.e. the program expects two parameters on the command line,
which
should be the name of a �le that holds the events to be
simulated, and the
value to be used for the time slice quantum. If you need to test
your program
and can't �gure out how to invoke running it from the command
line, you
can change the line in 'p2-start.cpp' to explicitly run a particular
simulation
�le, like this:
runSimulation("simulation-01.sim", time_slice_quantum)
7
However, you need to make sure that your program correctly
works using
the command line invocation, as shown in `p2-start.cpp`.
I have given some template code to get you started in the �le
called
p2-start.cpp. I have already provided you with the code needed
in order to
correctly parse the command line parameters for the program,
and to open
and read in the simulation �le events. Your job is to implement
the necessary
actions and data structures to handle the simulated events
15. described. The
runSimulation() in 'p2-start.cpp holds example code and
indicates locations
where you need to write your own functions to implement the
simulation.
You can use this as a starting point to implement your solution.
Assignment Submission and Requirements
All source �les you create for you solution (.c or .cpp/.c++ and
.h header
�les) should be uploaded to the MyLeo Online submission
folder created for
this assignment by the deadline. You should not attach any �les
besides the
source �les containing your C/C++ code. But you should make
sure you
attach all needed �les you create to your submission, so that I
can compile
and run your solution.
You are required to write the program in standard C/C++
programming
language. You should use a relatively recent version of the
C/C++ compiler
(C90 C++98 is �ne, or the more recent C99 C++11 will also be
acceptable),
and/or recent IDE that has an up to date compiler. You should
only use
standard C/C++ libraries, do not use Microsoft speci�c or other
third-party
developed external libraries. This page
http://en.cppreference.com/w/
provides a good up to date reference of the libraries in the
standard C++ and
C languages. You may use the C++ standard template library
16. containers
(like the list and queue items) to implement the ready queue you
need. We
will go over a simple implementation of a queue using pointers
and/or arrays
in class, if you would like an example implementation in plain
C that might
be simpler to use than learning the STL.
8
http://en.cppreference.com/w/
p2-start.cppp2-start.cpp/**
* @author Your Name Here
* @cwid 123 45 678
* @class CSci 430, Summer 2017
* @ide Visual Studio Express 2017
* @date June 11, 2017
* @assg Programming Assignment #2
*
* @description Implement a simulation of a basic 3 process sta
te system
* Ready, Running, Blocked. Simulation includes a round-
robin scheduler
* with time slice scheduling. Need to implement a basic Proc
ess
* Control Block (PCB) in order to implement the round robin
scheduler.
* Program will also have ready queues, and possible queues o
r other
* structures to keep track of blocked processes and the events
they
* are waiting on.
*
17. */
#include<stdlib.h>
#include<iostream>
#include<fstream>
#include<string>
usingnamespace std;
/** The process simulator.
* The main loop for running a simulation. We read simulation
* events from a file
*
* @param simfilename The name of the file (e.g. simulaiton-
01.sim) to open
* and read simulated event sequence from.
* @param timeSliceQuantum The value to be used for system ti
me slicing preemption
* for this simulation.
*/
void runSimulation(char* simfilename,int timeSliceQuantum)
{
ifstream simeventsfile(simfilename);
string command;
int eventnum;
if(!simeventsfile.is_open())
{
cout <<"Error: could not open simulator events file: "<< simf
ilename << endl;
exit(1);
}
while(!simeventsfile.eof())
{
simeventsfile >> command;
18. // Handle the next simulated event we just read from the
// simulation event file
if(command =="cpu")
{
cout <<" cpu: simulate a cpu cycle here"<< endl;
}
elseif(command =="new")
{
cout <<" new: simulate creation of new process here"<< e
ndl;
}
elseif(command =="done")
{
cout <<" done: simulate termination of currently running p
rocess here"<< endl;
}
elseif(command =="wait")
{
simeventsfile >> eventnum;
cout <<" wait: eventnum: "<< eventnum <<
" simulate event blocked and waiting"<< endl;
}
elseif(command =="event")
{
simeventsfile >> eventnum;
cout <<" event: eventnum: "<< eventnum <<
" simulate event occurring possibly making some processes read
y"<< endl;
}
elseif(command =="exit")
{
// we use an explicit indicator to ensure simulation exits correctl
y
break;
}
19. else
{
cout <<" ERROR: unknown command: "<< command << e
ndl;
exit(0);
}
}
simeventsfile.close();
}
/** Main entry point of simulator
* The main entry point of the process simulator. We simply se
t up
* and initialize the environment, then call the appropriate func
tion
* to begin the simulation. We expect a single command line ar
gument
* which is the name of the simulation event file to process.
*
* @param argc The argument count
* @param argv The command line argument values. We expect
argv[1] to be the
* name of a file in the current directory holding proces
s events
* to simulate.
*/
int main(int argc,char** argv)
{
int timeSliceQuantum =0;
// validate command line arguments
if(argc !=3)
{
cout <<"Error: expecting event file as first command line par
20. ameter and time slice quantum as second"<< endl;
cout <<"Usage: "<< argv[0]<<" simeventfile.sim time_slice"
<< endl;
exit(1);
}
// Assume second command line argument is the time slice quan
tum and parse it
timeSliceQuantum = atoi(argv[2]);
if(timeSliceQuantum <=0)
{
cout <<"Error: invalid time slice quantum received: "<< time
SliceQuantum << endl;
exit(1);
}
// Invoke the function to actually run the simulation
runSimulation(argv[1], timeSliceQuantum);
// if don't want to use command line do following.
// need to recompile by hand since file
// name to get simulated events from is hard coded
//runSimulation("simulation-01.sim", 5);
return0;
}
p2-start.c
/**
* @author Your Name Here
* @cwid 123 45 678
* @class CSci 430, Summer 2017
* @ide Visual Studio Express 2017
* @date June 11, 2017
* @assg Programming Assignment #2
21. *
* @description Implement a simulation of a basic 3 process
state system
* Ready, Running, Blocked. Simulation includes a round-
robin scheduler
* with time slice scheduling. Need to implement a basic
Process
* Control Block (PCB) in order to implement the round robin
scheduler.
* Program will also have ready queues, and possible queues
or other
* structures to keep track of blocked processes and the events
they
* are waiting on.
*
*/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
/** The process simulator.
* The main loop for running a simulation. We read simulation
* events from a file
*
* @param simfilename The name of the file (e.g. simulaiton-
01.sim) to open
* and read simulated event sequence from.
* @param timeSliceQuantum The value to be used for system
time slicing preemption
* for this simulation.
*/
void runSimulation(char* simfilename, int timeSliceQuantum)
{
FILE* simeventsfile;
char line[256]; // temporary buffer to hold the whole line we
22. read in
char* command;
char* eventnumstr;
int eventnum;
// open the simulation file, and make sure we were successful
// before continuing
simeventsfile = fopen(simfilename, "r");
if (!simeventsfile)
{
fprintf(stderr, "Error: could not open simulator events file:
%sn", simfilename);
exit(1);
}
while (fgets(line, sizeof(line), simeventsfile))
{
// get first token from line, up to first whitespace character,
put into command
command = strtok(line, " tn"); // splits line on space, tab or
newline
// Handle the next simulated event we just read from the
// simulation event file
if (strcmp(command, "cpu") == 0)
{
printf(" cpu: simulate a cpu cycle heren");
}
else if (strcmp(command, "new") == 0)
{
printf(" new: simulate creation of a new process heren");
}
else if (strcmp(command, "done") == 0)
{
printf(" done: simulate termination of currently running
process heren");
23. }
else if (strcmp(command, "wait") == 0)
{
eventnumstr = strtok(NULL, " tn"); // get pointer to event
number string
sscanf(eventnumstr, "%d", &eventnum);
printf(" wait: eventnum: %d simulate event blocked and
waitingn", eventnum);
}
else if (strcmp(command, "event") == 0)
{
eventnumstr = strtok(NULL, " tn"); // get pointer to event
number string
sscanf(eventnumstr, "%d", &eventnum);
printf(" event: eventnum: %d simulate event occurring
possibly making some processes readyn", eventnum);
}
else if (strcmp(command, "exit") == 0)
{
// we use an explicit indicator to ensure simulation exits
correctly
break;
}
else
{
fprintf(stderr, "Error: unknown command: %sn",
command);
exit(0);
}
}
fclose(simeventsfile);
}
/** Main entry point of simulator
24. * The main entry point of the process simulator. We simply
set up
* and initialize the environment, then call the appropriate
function
* to begin the simulation. We expect a single command line
argument
* which is the name of the simulation event file to process.
*
* @param argc The argument count
* @param argv The command line argument values. We expect
argv[1] to be the
* name of a file in the current directory holding
process events
* to simulate.
*/
int main(int argc, char** argv)
{
int timeSliceQuantum = 0;
// validate command line arguments
if (argc != 3)
{
printf("Error: expecting event file as first command line
parameter and time slice quantum as secondn");
printf("Usage: %s simeventfile.sim time_slicen", argv[0]);
exit(1);
}
// Assume second command line argument is the time slice
quantum and parse it
timeSliceQuantum = atoi(argv[2]);
if (timeSliceQuantum <= 0)
{
printf("Error: invalid time slice quantum received: %dn",
timeSliceQuantum);
exit(1);
25. }
// Invoke the function to actually run the simulation
runSimulation(argv[1], timeSliceQuantum);
// if don't want to use command line do following.
// need to recompile by hand since file
// name to get simulated events from is hard coded
//runSimulation("simulation-01.sim", 5);
return 0;
}
prog-02.pdf
Programming Assignment #2
CSci 430 Spring 2019
Dates:
Assigned: Monday February 4, 2019
Due: Wednesday February 20, 2019 (before Midnight)
Objectives:
� Explore the Process state models from an implementation
point of
view.
� Practice using basic queue data types and implementing in C.
� Use C/C++ data structures to implement a process control
block and
26. round robin scheduling queues.
� Learn about Process switching and multiprogramming
concepts.
Description:
In this assignment you will simulate a Three-State process
model (ready,
running and blocked) and a simple process control block
structure as dis-
cussed in Chapter 3. Your program will read input and
directives from a
�le. The input describes a time sequence of events that occur.
These are the
full set of events you will simulate:
1
Event Description
cpu The processor executes for 1 time step the currently running
process
new A new process is created and put at tail of the ready queue
done The currently running process has �nished
wait X The currently running process has done an I/O operation
and
is waiting on event X
event X Event X has occurred, the process waiting on that event
should
be made ready.
27. The input �le will simply be a list of events that occur in the
system, in
the order they are to occur. For example:
----- simulation-01.sim --------
new
cpu
cpu
cpu
new
cpu
cpu
cpu
cpu
wait 1
cpu
cpu
event 1
cpu
cpu
28. done
cpu
cpu
cpu
cpu
exit
----------------------------------
Your task is to read in the events, and simulate the creation and
execution
of processes in the system as they move through the various
three-states of
their process life cycle. You need to:
2
� De�ne a simple process control block (PCB) to hold
information about
all processes currently running in your system. The PCB can be
a
simple C struct or a C++ class. At a minimum you need to have
a
�eld for the process identi�er and the process state (Ready,
Running or
Blocked). You need to also keep track of the time step that the
process
entered the system, and the number of steps the process has
been
29. running. Minimal credit will be given to programs that at least
handle
new events and create a process in a simulated PCB. You
probably
need a list or an array to hold the current processes that have
been
created and are being managed by your simulated system.
� You will need a ready queue of some kind. You should use a
C++
Standard Template Library (STL) container to manage your
ready
queue.
� You will need to implement a simple dispatcher function.
Whenever
a cpu event occurs, and no process is currently running, you
should
select the next Ready process from the head of your ready queue
and
start it running on the processor.
� You need to also implement a simple time slicing mechanism.
The
time slice value to use will be passed into your program when it
is
started. At the end of a cpu cycle, you should check if the
currently
running process has executed for its full time quantum. In that
case,
the currently running process should timeout, and be returned to
the
end of the Ready queue.
� new events should cause a new process to be created
(including creating
30. its PCB and �lling it in). New processes should be placed on
the tail
of the ready queue after being created. You should assign each
new
process a process identi�er. The process identi�er should be a
simple
integer value, and you should start numbering processes from 1.
� For a done event, if a process is currently running it should
then be
released. It should be removed from the CPU, and not placed
back on
the ready or blocked queue. If a done occurs when the CPU is
idle,
then nothing will happen as a result of this event.
� A wait event simulates the currently running process
performing some
I/O operation. If a wait occurs, the currently running process
should
become blocked and put on the blocked queue. You also need an
entry
in the PCB so you know what event the process is waiting for.
The
3
wait event is followed by an integer number, which is an
indication of
the type of event the process has requested.
� Likewise the event directive simulates the �nishing of some
I/O oper-
ation. When an event occurs, you should scan your blocked
31. processes
and make any process ready that was waiting on that event. The
in-
teger value following an event indicates the type of event that
just
occurred.
You have been given some example event sequences
(simulation-01.sim,
simulation-02.sim, etc.) along with the expected output for
those sequence
of events (simulation-01.res, simulation-02.res, etc.). The
output of your
program should be sent to standard output. The correct output
for the
simulation-01.sim simulation is:
Time: 1
CPU (currently running):
pid=1, state=RUNNING, start=1, slice=1,
Ready Queue:
EMPTY
Blocked Queue:
EMPTY
Time: 2
CPU (currently running):
pid=1, state=RUNNING, start=1, slice=2,
37. Ready Queue:
EMPTY
Blocked Queue:
EMPTY
Time: 15
CPU (currently running):
pid=2, state=RUNNING, start=4, slice=4,
Ready Queue:
EMPTY
Blocked Queue:
EMPTY
Your output to standard out should look exactly the same as this
output
(i.e. if I do a di� and your program is generating the correct
output, then
there will be no di�erence between the output your program
generates and
the above output format). The output is generated by displaying
the system
state after each cpu cycle executes. Basically we print out the
system time.
Then we show which process (if any) is currently running on the
CPU (or
say it is IDLE if no process is running). Then we display the
38. queue of
processes currently on the Ready and Blocked queues. Note that
the queues
are displayed in order. The top of the output corresponds to the
head of the
queue. Thus when a new process is dispatched, the next one
selected should
be the �rst process listed from the ready queue in the previous
system cycle.
I have given you some template code (p2-start.cpp) to get you
started
The code is meant to be run from the command line, thus from a
shell or
dos prompt you would do something like:
$ p2-start simulation-01.sim 5
i.e. the program expects two parameters on the command line,
which
should be the name of a �le that holds the events to be
simulated, and the
value to be used for the time slice quantum. If you need to test
your program
and can't �gure out how to invoke running it from the command
line, you
can change the line in 'p2-start.cpp' to explicitly run a particular
simulation
�le, like this:
runSimulation("simulation-01.sim", time_slice_quantum)
7
39. However, you need to make sure that your program correctly
works using
the command line invocation, as shown in `p2-start.cpp`.
I have given some template code to get you started in the �le
called
p2-start.cpp. I have already provided you with the code needed
in order to
correctly parse the command line parameters for the program,
and to open
and read in the simulation �le events. Your job is to implement
the necessary
actions and data structures to handle the simulated events
described. The
runSimulation() in 'p2-start.cpp holds example code and
indicates locations
where you need to write your own functions to implement the
simulation.
You can use this as a starting point to implement your solution.
Assignment Submission and Requirements
All source �les you create for you solution (.c or .cpp/.c++ and
.h header
�les) should be uploaded to the MyLeo Online submission
folder created for
this assignment by the deadline. You should not attach any �les
besides the
source �les containing your C/C++ code. But you should make
sure you
attach all needed �les you create to your submission, so that I
can compile
and run your solution.
You are required to write the program in standard C/C++
programming
40. language. You should use a relatively recent version of the
C/C++ compiler
(C90 C++98 is �ne, or the more recent C99 C++11 will also be
acceptable),
and/or recent IDE that has an up to date compiler. You should
only use
standard C/C++ libraries, do not use Microsoft speci�c or other
third-party
developed external libraries. This page
http://en.cppreference.com/w/
provides a good up to date reference of the libraries in the
standard C++ and
C languages. You may use the C++ standard template library
containers
(like the list and queue items) to implement the ready queue you
need. We
will go over a simple implementation of a queue using pointers
and/or arrays
in class, if you would like an example implementation in plain
C that might
be simpler to use than learning the STL.
8
http://en.cppreference.com/w/
simulation-01.sim
new
cpu
cpu
cpu
new
cpu
cpu
cpu
cpu