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Do not use Q_GLOBAL_STATIC in the implementation of QMutex

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Since Q_GLOBAL_STATIC might use QMutex and cause a stack overflow.

Task-number: QTBUG-47554
Change-Id: I4853c5e9b9168d4a417200e2a45a1bf9cb103a30
Reviewed-by: David Faure <david.faure@kdab.com>
Reviewed-by: Pierre Rossi <pierre.rossi@theqtcompany.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
This commit is contained in:
Olivier Goffart 2015-07-31 22:55:55 +02:00 committed by Olivier Goffart (Woboq GmbH)
parent e3d7cf7c96
commit 314c83c0c2
1 changed files with 22 additions and 1 deletions
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23
src/corelib/thread/qmutex.cpp
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@ -563,7 +563,28 @@ const int FreeListConstants::Sizes[FreeListConstants::BlockCount] = {
}; };
typedef QFreeList<QMutexPrivate, FreeListConstants> FreeList; typedef QFreeList<QMutexPrivate, FreeListConstants> FreeList;
Q_GLOBAL_STATIC(FreeList, freelist); // We cannot use Q_GLOBAL_STATIC because it uses QMutex
#if defined(Q_COMPILER_THREADSAFE_STATICS)
FreeList *freelist()
{
static FreeList list;
return &list;
}
#else
FreeList *freelist()
{
static QAtomicPointer<FreeList> list;
FreeList *local = list.loadAcquire();
if (!local) {
local = new FreeList;
if (!list.testAndSetRelease(0, local)) {
delete local;
local = list.loadAcquire();
}
}
return local;
}
#endif
} }
QMutexPrivate *QMutexPrivate::allocate() QMutexPrivate *QMutexPrivate::allocate()