U_NAMESPACE_BEGIN
U_COMMON_API UBool U_EXPORT2 umtx_initImplPreInit(UInitOnce &uio) {
for (;;) {
int32_t previousState = InterlockedCompareExchange(
(LONG volatile *) // this is the type given in the API doc for this function.
&uio.fState, // Destination
1, // Exchange Value
0); // Compare value
if (previousState == 0) {
return true; // Caller will next call the init function.
// Current state == 1.
} else if (previousState == 2) {
// Another thread already completed the initialization.
// We can simply return FALSE, indicating no
// further action is needed by the caller.
return FALSE;
} else {
// Another thread is currently running the initialization.
// Wait until it completes.
do {
Sleep(1);
previousState = umtx_loadAcquire(uio.fState);
} while (previousState == 1);
}
}
}
int32_t
SharedObject::getRefCount() const {
return umtx_loadAcquire(refCount);
}