rb_w32_time_subtract  737 include/ruby/win32.h int  rb_w32_time_subtract(struct timeval *rest, const struct timeval *wait);
rb_w32_time_subtract  484 thread_win32.c     if (!rb_w32_time_subtract(&tv, &now))
rb_w32_time_subtract 3073 win32/win32.c  		    if (!rb_w32_time_subtract(&rest, &now)) break;