InterlockedExchange 305 gc/include/private/gc_locks.h # define GC_test_and_set(addr) InterlockedExchange((LPLONG)addr,1) InterlockedExchange 97 gc/win32_threads.c for (i = 0; InterlockedExchange((IE_t)&thread_table[i].in_use,1) != 0; i++) {