class GangSched

a gang scheduler

Inheritance:

Public Methods

GangSched()

Default constructor

virtual ~GangSched()

Destructor

virtual void setComputers(map<ID, Computer>* computers)

Gives the scheduler access to the system's computers

virtual bool submitProcess(const Token& token)

Informs the scheduler a process has been submitted

virtual bool startProcess(const Token& token)

Informs the scheduler a process has started.

virtual bool terminateProcess(const Token& token)

Informs the scheduler a process has terminated

virtual bool timeQuantumExpired()

Informs the scheduler that the time quantum for this time slice has expired.

virtual bool schedule(bool start = true)

Implements the gang scheduling algorithm

virtual Policy getPolicy() const

SIZE getCurrMPL(void) const

SIZE getHighestMPL(void) const

double getAverageMPL(void) const

unsigned long getTotalPCS(void) const

void setQuantumLength(const TIME time)

Sets the length of each time quantum

void setMaxMPL(const SIZE newMPL)

Sets the largest number of time slices that may be used

void setPCSTime(const TIME newTime)

list<ID> getCurrentlyRunning()

bool isCurrentlyRunning(Process* process)

virtual void setMemoryAware(const bool value)

Sets whether the scheduler will concern itself with memory constraints or not.

Public Members

End Scheduling Interface ///////////////////////////

Inherited from Scheduler:

Public Methods

void setNetwork(Network* newNetwork)

void setQueuedEvents(QueuedEvents* newEvents)

void setProcessList(map <ID, Process*>* newList)

void setPacking(const Packing newPacking)

void setPriority(const Priority newPriority)

void setSchedulingOverhead(const TIME overhead)

bool getMemoryAware() const

static Policy stringToPolicy(string str)

static Priority stringToPriority(string str)

static Packing stringToPacking(string str)

static string policyToString(Policy pol)

static string priorityToString(Priority pri)

static string packingToString(Packing pack)

virtual string toString() const

Documentation

This object implements a gang scheduler. The scheduler is responsible for keeping track of what processes are running in which time quantums and ensures that they are properly started and stopped at the beginning and end of each quantum. The gang scheduler can be configured in many ways. For instance, it can take memory considerations into account, or not. The MPL can be set to any number and to infinity, etc. Also available are slot unification and alternative scheduling

GangSched()

virtual ~GangSched()

virtual void setComputers(map<ID, Computer>* computers)

virtual bool submitProcess(const Token& token)

The gang scheduler attempts to find a time slice the process can fit into. If none is found, then it attempts to create a new one - subject to MPL and (if desired) memory considerations.

virtual bool startProcess(const Token& token)

The gang scheduler has nothing special to do a process start time

virtual bool terminateProcess(const Token& token)

If jobs are waiting, and can fit in the empty space in the time slice, they are scheduled to run. Also, slot unification is attempted at job termination.

virtual bool timeQuantumExpired()

At this event, the scheduler do a parallel context switch. This entails suspending all running processes in the current time slice and resuming all processes that are scheduled to run in the next time slice. At this point alternative scheduling is attempted.

virtual bool schedule(bool start = true)

virtual Policy getPolicy() const

Returns:

gang.

End Scheduling Interface ///////////////////////////

End Scheduling Interface /

SIZE getCurrMPL(void) const

Returns:

the current number of time slices used.

SIZE getHighestMPL(void) const

double getAverageMPL(void) const

unsigned long getTotalPCS(void) const

void setQuantumLength(const TIME time)

void setMaxMPL(const SIZE newMPL)

void setPCSTime(const TIME newTime)

list<ID> getCurrentlyRunning()

Returns:

a list of processes running in the current time slice

bool isCurrentlyRunning(Process* process)

virtual void setMemoryAware(const bool value)

This class has no child classes.

Author:

John Oleszkiewicz

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