typedef struct mthread {
	PerlInterpreter* interp;
	perl_mutex lock;
	message_queue* queue;
	UV id;
	bool alive;
#ifndef WIN32
	sigset_t initial_sigmask;   /* Thread wakes up with signals blocked */
#endif
	AV* cache;
	struct {
		IV* list;
		UV head;
		UV alloc;
	} listeners;
} mthread;

extern void S_create_push_threads(PerlInterpreter*, HV* options, SV* startup);
#define create_push_threads(options, startup) S_create_push_threads(aTHX, options, startup)
void store_self(pTHX, mthread*);
mthread* S_get_self(pTHX);
#define get_self() S_get_self(aTHX)
perl_mutex* get_shutdown_mutex();