QRecursiveMutex Class Reference

\inmodule QtCore More...

#include <qmutex.h>

Inheritance diagram for QRecursiveMutex:

Collaboration diagram for QRecursiveMutex:

Additional Inherited Members
Public Member Functions inherited from QMutex
constexpr	QMutex () noexcept
	Constructs a new mutex.
void	lock () noexcept
	Locks the mutex.
bool	tryLock (int timeout=0) noexcept
	Attempts to lock the mutex.
bool	try_lock () noexcept
void	unlock () noexcept
	Unlocks the mutex.
template<class Rep , class Period >
bool	try_lock_for (std::chrono::duration< Rep, Period > duration) noexcept
template<class Clock , class Duration >
bool	try_lock_until (std::chrono::time_point< Clock, Duration > timePoint) noexcept

Detailed Description

\inmodule QtCore

Since

5.14

The QRecursiveMutex class provides access serialization between threads.

\threadsafe

The QRecursiveMutex class is a mutex, like QMutex, with which it is API-compatible. It differs from QMutex by accepting lock() calls from the same thread any number of times. QMutex would deadlock in this situation.

QRecursiveMutex is much more expensive to construct and operate on, so use a plain QMutex whenever you can. Sometimes, one public function, however, calls another public function, and they both need to lock the same mutex. In this case, you have two options:

\list

• Factor the code that needs mutex protection into private functions, which assume that the mutex is held when they are called, and lock a plain QMutex in the public functions before you call the private implementation ones.
• Or use a recursive mutex, so it doesn't matter that the first public function has already locked the mutex when the second one wishes to do so. \endlist

See also

QMutex, QMutexLocker, QReadWriteLock, QSemaphore, QWaitCondition

Definition at line 313 of file qmutex.h.

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

• qtbase/src/corelib/thread/qmutex.h