Mutex Locker utility class to lock/unlock mbed RTOS mutexes. Create and pass a mutex, it locks the mutex then unlocks it when destroyed.
Dependents: SmartLight HelloThreadsYo
Mutex Locker
This utility class is most useful when you have an activity that needs to be protected by a mutex that has multiple return points.
You would normally do this:
Using standard mutex access
Mutex myMutex; void do_some_stuff() { myMutex.lock(); /* Do Stuff */ if (condition) { myMutex.unlock(); return 0; } /* Call other method */ int temp = other_method(); // Temp so can unlock after function returns myMutex.unlock(); return temp; }
However, it's very easy to miss one of the unlock points which would later freeze the application.
Debugging this kind of error can be very hard.
The same example using MutexLocker:
Using a MutexLocker
Mutex myMutex; int do_some_stuff() { MutexLocker locker(myMutex); /* Do Stuff */ if (condition) { return 0; } /* Call other method */ return other_method(); /* Mutex unlocks itself here */ }
No matter where or how your method returns, the mutex will always be unlocked as the MutexLocker goes out of scope.
mutexlocker.h
- Committer:
- Tomo2k
- Date:
- 2014-04-10
- Revision:
- 2:8bf85ca6ccee
- Parent:
- 1:1a8b1de53954
- Child:
- 3:aab6944f2ed3
File content as of revision 2:8bf85ca6ccee:
/* (C) 2014 Richard Thompson (Tomo2k) This software is Apache 2.0 licenced for this to be reused. That said, it's trivial and rather obvious! */ #pragma once #include "rtos.h" //! Lock/Unlock Mutex using variable scope. //! Ensures always unlocked regardless of method exit class MutexLocker { public: //! Lock the mutex MutexLocker(Mutex &mutex) : m_mutex(mutex) { m_mutex.lock(); } //! Unlocks on destruction ~MutexLocker() { m_mutex.unlock(); } private: Mutex &m_mutex; };