GuardedScheduler Class Reference

Guarded interface to the Scheduler used by user applications. More...

#include <syscall/guarded_scheduler.h>

Inheritance diagram for GuardedScheduler:

Collaboration diagram for GuardedScheduler:

Static Public Member Functions
static void	ready (Thread *that)
	Include a thread in scheduling decisions. More...
static void	exit ()
	(Self-)termination of the calling thread. More...
static void	kill (Thread *that)
	Kills the passed thread. More...
static void	resume ()
	Issue a thread change. More...
Static Public Member Functions inherited from Scheduler
static void	schedule ()
	Start scheduling. More...
static void	ready (Thread *that)
	Include a thread in scheduling decisions. More...
static void	exit ()
	(Self-)termination of the calling thread. More...
static void	kill (Thread *that)
	Kills the passed thread. More...
static void	resume ()
	Issue a thread change. More...
Static Public Member Functions inherited from Dispatcher
static Thread *	active ()
	Returns the thread currently running on the CPU core calling this method.
static bool	isActive (const Thread *thread, unsigned *cpu=nullptr)
	Check if thread is currently active. More...
static void	go (Thread *first)
	This method stores first as life pointer for this CPU core and triggers the execution of first thread. More...
static void	dispatch (Thread *next)
	Updates the life pointer to next and issues a thread change from the old to the new life pointer. More...

Detailed Description

Guarded interface to the Scheduler used by user applications.

Implements the system call interface for class Scheduler. All methods provided by this class are wrappers for the respective method from the base class, which provide additional synchronization by using the class Guarded.

Member Function Documentation

ready()

static void GuardedScheduler::ready ( Thread *  that )

inlinestatic

Include a thread in scheduling decisions.

This method will register a thread for scheduling. It will be appended to the ready queue and dispatched once its time has come.

Parameters

that	Thread to be scheduled

Note

This method is equal to the correspondent method in base class Scheduler, with the only difference that the call will be protected by a Guarded object.

exit()

static void GuardedScheduler::exit ( )

inlinestatic

(Self-)termination of the calling thread.

This method can be used by a thread to exit itself. The calling thread will not be appended to the ready queue; a reschedule will be issued.

Note

This method is equal to the correspondent method in base class Scheduler, with the only difference that the call will be protected by a Guarded object.

kill()

static void GuardedScheduler::kill ( Thread *  that )

inlinestatic

Kills the passed thread.

This method is used to kill the Thread that. For OOStuBS, it is sufficient to remove that from the ready queue and, thereby, exclude the thread from scheduling. For MPStuBS, a simple removal is not sufficient, as the thread might currently be running on another CPU core. In this case, the thread needs to be marked as dying (a flag checked by resume prior to enqueuing into the ready queue) and the executing CPU core needs to be notified.

Note

The thread should be able to kill itself.

See also

Dispatcher::isActive

Todo:

Adapt method (for MPStuBS)

Note

This method is equal to the correspondent method in base class Scheduler, with the only difference that the call will be protected by a Guarded object.

resume()

static void GuardedScheduler::resume ( )

inlinestatic

Issue a thread change.

This method issues the change of the currently active thread without requiring the calling thread to be aware of the other threads. Scheduling decisions, i.e. which thread will be run next, are made by the scheduler itself with the knowledge of the currently ready threads. The currently active thread is appended to the end of the queue; the first thread in the queue will be activated (to implement the FIFO policy).

Note

This method is equal to the correspondent method in base class Scheduler, with the only difference that the call will be protected by a Guarded object.

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The documentation for this class was generated from the following file:

• syscall/guarded_scheduler.h