Fix microsoft#370

stl/src/atomic.cpp

@@ -4,33 +4,21 @@
 // implement shared_ptr spin lock
 
 #include <yvals.h>
+#include <synchapi.h>
 
-#include <intrin.h>
-#pragma warning(disable : 4793)
+namespace {
+    // MUTEX FOR shared_ptr ATOMIC OPERATIONS
+    SRWLOCK _Shared_ptr_lock = SRWLOCK_INIT;
+} // unnamed namespace
 
 _EXTERN_C
 
-// SPIN LOCK FOR shared_ptr ATOMIC OPERATIONS
-volatile long _Shared_ptr_flag;
-
 _CRTIMP2_PURE void __cdecl _Lock_shared_ptr_spin_lock() { // spin until _Shared_ptr_flag successfully set
-#ifdef _M_ARM
-    while (_InterlockedExchange_acq(&_Shared_ptr_flag, 1)) {
-        __yield();
-    }
-#else // _M_ARM
-    while (_interlockedbittestandset(&_Shared_ptr_flag, 0)) { // set bit 0
-    }
-#endif // _M_ARM
+    AcquireSRWLockExclusive(&_Shared_ptr_lock);
 }
 
 _CRTIMP2_PURE void __cdecl _Unlock_shared_ptr_spin_lock() { // release previously obtained lock
-#ifdef _M_ARM
-    __dmb(_ARM_BARRIER_ISH);
-    __iso_volatile_store32(reinterpret_cast<volatile int*>(&_Shared_ptr_flag), 0);
-#else // _M_ARM
-    _interlockedbittestandreset(&_Shared_ptr_flag, 0); // reset bit 0
-#endif // _M_ARM
+    ReleaseSRWLockExclusive(&_Shared_ptr_lock);
 }
 
 _END_EXTERN_C