Public Types | Public Member Functions | List of all members
CriticalSection Class Reference

A re-entrant mutex. More...

Inheritance diagram for CriticalSection:

Public Types

typedef GenericScopedLock< CriticalSectionScopedLockType
 Provides the type of scoped lock to use with a CriticalSection. More...
 
typedef GenericScopedUnlock< CriticalSectionScopedUnlockType
 Provides the type of scoped unlocker to use with a CriticalSection. More...
 
typedef GenericScopedTryLock< CriticalSectionScopedTryLockType
 Provides the type of scoped try-locker to use with a CriticalSection. More...
 

Public Member Functions

 CriticalSection () noexcept
 Creates a CriticalSection object. More...
 
 ~CriticalSection () noexcept
 Destructor. More...
 
void enter () const noexcept
 Acquires the lock. More...
 
bool tryEnter () const noexcept
 Attempts to lock this critical section without blocking. More...
 
void exit () const noexcept
 Releases the lock. More...
 

Detailed Description

A re-entrant mutex.

A CriticalSection acts as a re-entrant mutex object. The best way to lock and unlock one of these is by using RAII in the form of a local ScopedLock object - have a look through the codebase for many examples of how to do this.

In almost all cases you'll want to declare your CriticalSection as a member variable. Occasionally you may want to declare one as a static variable, but in that case the usual C++ static object order-of-construction warnings should be heeded.

See also
ScopedLock, ScopedTryLock, ScopedUnlock, SpinLock, ReadWriteLock, Thread, InterProcessLock

Member Typedef Documentation

◆ ScopedLockType

Provides the type of scoped lock to use with a CriticalSection.

◆ ScopedUnlockType

Provides the type of scoped unlocker to use with a CriticalSection.

◆ ScopedTryLockType

Provides the type of scoped try-locker to use with a CriticalSection.

Constructor & Destructor Documentation

◆ CriticalSection()

CriticalSection::CriticalSection ( )
noexcept

Creates a CriticalSection object.

◆ ~CriticalSection()

CriticalSection::~CriticalSection ( )
noexcept

Destructor.

If the critical section is deleted whilst locked, any subsequent behaviour is unpredictable.

Member Function Documentation

◆ enter()

void CriticalSection::enter ( ) const
noexcept

Acquires the lock.

If the lock is already held by the caller thread, the method returns immediately. If the lock is currently held by another thread, this will wait until it becomes free.

It's strongly recommended that you never call this method directly - instead use the ScopedLock class to manage the locking using an RAII pattern instead.

See also
exit, tryEnter, ScopedLock

◆ tryEnter()

bool CriticalSection::tryEnter ( ) const
noexcept

Attempts to lock this critical section without blocking.

This method behaves identically to CriticalSection::enter, except that the caller thread does not wait if the lock is currently held by another thread but returns false immediately.

Returns
false if the lock is currently held by another thread, true otherwise.
See also
enter

◆ exit()

void CriticalSection::exit ( ) const
noexcept

Releases the lock.

If the caller thread hasn't got the lock, this can have unpredictable results.

If the enter() method has been called multiple times by the thread, each call must be matched by a call to exit() before other threads will be allowed to take over the lock.

See also
enter, ScopedLock

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