[Development] QThreadStorage and C++11

[Olivier Goffart]

Am Mittwoch, 30. März 2016, 22:23:35 CEST schrieb Konstantin Tokarev:
> Hello,
> 
> Are there any plans to reimplement QThreadStorage via thread_local for
> compilers which support it?

QThreadStorage is already implemented with __thread which is a bit like 
thread_local before it existed.
https://code.woboq.org/qt5/qtbase/src/corelib/thread/qthread_unix.cpp.html#_ZL17currentThreadData

But it's not possible to make each instance of QThreadStorage a thread_local,
because QThreadStorage is creating an instance and you can't have thread_local
per instance of QThreadStorage.

The best we could do is a macro: something like this

// if the compiler don't have thread_local
#define Q_THREAD_LOCAL(TYPE, XX)   QThreadStorage<TYPE> XX

// else
#define Q_THREAD_LOCAL(TYPE, XX)   thread_local QFakeThreadStorage<TYPE> XX

(where QFakeThreadStorage is just a class that contains an instance with
the same API as QThreadStorage)


-- 
Olivier 

Woboq - Qt services and support - https://woboq.com - https://code.woboq.org