extern StgWord RTS_VAR(blocked_queue_hd), RTS_VAR(blocked_queue_tl);
extern StgWord RTS_VAR(sleeping_queue);
extern StgWord RTS_VAR(blackhole_queue);
extern StgWord RTS_VAR(blocked_queue_hd), RTS_VAR(blocked_queue_tl);
extern StgWord RTS_VAR(sleeping_queue);
extern StgWord RTS_VAR(blackhole_queue);