C++ Crashkurs
Semaphore Class Reference
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. More... | |
| 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
|
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