WinAPI callbacks and GC

[Jack Applegame]

I'm writing Ctrl-C handler for console application for Windows:

extern(Windows) {
   int CtrlHandler(uint flag) nothrow {
     auto tmp = new SomeClass; // is it safe?
     ...
     return true;
   }
}

...

SetConsoleCtrlHandler(&CtrlHandler, true);

...

According WinAPI documentation, CtrlHandler will be called in new 
additional thread. Is it safe to allocate GC memory in NOT Phobos 
threads?
If not, how to make it safe? I'm trying call thread_attachThis() 
at the beginning of CtrlHandler fucntion, but it doesn't compile 
because thread_attachThis() is not nothrow.