diff options
| -rw-r--r-- | src/corelib/thread/qfutureinterface.cpp | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/src/corelib/thread/qfutureinterface.cpp b/src/corelib/thread/qfutureinterface.cpp index 71d6670538..a54caa878b 100644 --- a/src/corelib/thread/qfutureinterface.cpp +++ b/src/corelib/thread/qfutureinterface.cpp @@ -45,6 +45,10 @@ #include <QtCore/qthread.h> #include <private/qthreadpool_p.h> +#ifdef Q_PROCESSOR_X86 +# include <immintrin.h> // for _mm_pause() +#endif + #ifdef interface # undef interface #endif @@ -106,9 +110,14 @@ static inline int switch_from_to(QAtomicInt &a, int from, int to) { int newValue; int expected = a.loadRelaxed(); - do { + for (;;) { newValue = (expected & ~from) | to; - } while (!a.testAndSetRelaxed(expected, newValue, expected)); + if (a.testAndSetRelaxed(expected, newValue, expected)) + break; +#ifdef Q_PROCESSOR_X86 + _mm_pause(); +#endif + } return newValue; } |