Semaphore used for synchronization of threads. More...

#include <sync/semaphore.h>

Inheritance diagram for Semaphore:

Collaboration diagram for Semaphore:

Public Member Functions
	Semaphore (unsigned c=0)
	Constructor; initialized the counter with provided value `c` More...

void	p ()
	Wait for access to the critical area. More...

void	v ()
	Leave the critical area. More...

Public Member Functions inherited from Waitingroom
	Waitingroom ()
	Constructor. More...

virtual	~Waitingroom ()
	Destructor. More...

virtual void	remove (Thread *customer)
	Remove a given thread prematurely from the Waitingroom.

Public Member Functions inherited from Queue< Thread >
	Queue ()
	Default constructor; initialized the queue as empty.

void	enqueue (Thread *item)
	Enqueues the provided item at the end of the queue. More...

Thread *	dequeue ()
	Removes the first element in the queue and returns it. More...

Iterator	begin ()

Iterator	end ()

Thread *	remove (Thread item, bool(cmp)(Thread , Thread )=[](Thread a, Thread b) {return a==b;})
	Removes and returns a single element from the queue. More...

void	insertFirst (Thread *item)
	Adds `item` to the beginning of the queue. More...

void	insertAfter (Thread old_item, Thread new_item)
	Inserts the element `new_item` directly after `old_item`. More...

Thread *	first ()
	Returns the first element in the queue without removing it. More...

Thread *	next (Thread *o)
	Returns the next element in the queue for a given element.

Detailed Description

Semaphore used for synchronization of threads.

The class Semaphore implements the concept of counting semaphores. The waiting list is provided by the base class Waitingroom.

Constructor & Destructor Documentation

Semaphore::Semaphore ( unsigned c = 0 )

inlineexplicit

Constructor; initialized the counter with provided value c

Parameters

c	Initial counter value

Member Function Documentation

void Semaphore::p ( )

Wait for access to the critical area.

Enter/Wait operation: If the counter is greater than 0, then it is decremented by one. Otherwise the calling thread will be enqueued into the Waitingroom and marked as blocked.

void Semaphore::v ( )

Leave the critical area.

Leave operation: If there are threads in the Waitingroom, wake the first one; otherwise increment the counter by one.

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

sync/semaphore.h
sync/semaphore.cc

Aufgabe 7: Anwendung

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation