#include <Sync.h>

Collaboration diagram for Semaphore:

Public Member Functions
	Semaphore (int initialcount=0, int maxcount=0)

	~Semaphore ()

bool	IsOk () const

bool	Wait ()

bool	TryWait ()

bool	Post ()

Private Attributes
Mutex	m_mutex

Condition	m_cond

int	m_count

int	m_maxcount

bool	m_isOk

Detailed Description

Definition at line 65 of file Sync.h.

Constructor & Destructor Documentation

Semaphore	(	int	initialcount = `0`,
		int	maxcount = `0`
	)

Definition at line 170 of file Sync.C.

References Mutex::IsOk(), Condition::IsOk(), m_cond, m_count, m_isOk, m_maxcount, and m_mutex.

 : m_cond(m_mutex)
 {
   if ((initialcount < 0 || maxcount < 0)
       || ((maxcount > 0) && (initialcount > maxcount))) {
     std::cerr << "Semaphore::Semaphore(): invalid initial or maximal count."
               << std::endl;
 
     m_isOk = false;
   } else {
     m_maxcount = maxcount;
     m_count = initialcount;
   }
 
   m_isOk = m_mutex.IsOk() && m_cond.IsOk();
 }

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~Semaphore ( )

Definition at line 187 of file Sync.C.

188 {

189 }

Member Function Documentation

bool IsOk ( ) const

inline

Definition at line 71 of file Sync.h.

References m_isOk.

71 { return m_isOk; }

Semaphore::m_isOk

bool m_isOk

Definition: Sync.h:82

bool Post ( )

Definition at line 223 of file Sync.C.

References Mutex::Lock(), m_cond, m_count, m_maxcount, m_mutex, Condition::Signal(), and Mutex::Unlock().

 {
   m_mutex.Lock();
 
   if (m_maxcount > 0 && m_count == m_maxcount) {
     m_mutex.Unlock();
     return false;
   }
 
   ++m_count;
 
   int result = m_cond.Signal();
   m_mutex.Unlock();
 
   return (result == 0);
 }

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bool TryWait ( )

Definition at line 208 of file Sync.C.

References Mutex::Lock(), m_count, m_mutex, and Mutex::Unlock().

 {
   m_mutex.Lock();
 
   if (m_count == 0) {
     m_mutex.Unlock();
     return false;
   }
 
   --m_count;
   m_mutex.Unlock();
 
   return true;
 }

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bool Wait ( )

Definition at line 191 of file Sync.C.

References Mutex::Lock(), m_cond, m_count, m_mutex, Mutex::Unlock(), and Condition::Wait().

 {
   m_mutex.Lock();
 
   while (m_count == 0) {
     if (m_cond.Wait() != 0) {
       m_mutex.Unlock();
       return false;
     }
   }
 
   --m_count;
   m_mutex.Unlock();
 
   return true;
 }