#ifndef _THREADH_#define _THREADH_ 1 /* avoid conflicts with socket library */#undef send#define send _threadsend#undef recv#define recv _threadrecv typedef struct Alt	Alt;typedef struct Channel	Channel;typedef struct Ref	Ref; /* Channel structure.  S is the size of the buffer.  For unbuffered channels * s is zero.  v is an array of s values.  If s is zero, v is unused. * f and n represent the state of the queue pointed to by v. */ enum {	Nqwds = 2,	Nqshift = 5,	// 2log #of bits in long	Nqmask =  - 1,	Nqbits = (1 << Nqshift) * 2,}; struct Channel {	int			s;		// Size of the channel (may be zero)	unsigned int	f;		// Extraction point (insertion pt: (f + n) % s)	unsigned int	n;		// Number of values in the channel	int			e;		// Element size	int			freed;	// Set when channel is being deleted	volatile Alt	**qentry;	// Receivers/senders waiting (malloc)	volatile int	nentry;	// # of entries malloc-ed	unsigned char		v[1];		// Array of s values in the channel};  /* Channel operations for alt: */typedef enum {	CHANEND,	CHANSND,	CHANRCV,	CHANNOP,	CHANNOBLK,} ChanOp; struct Alt {	Channel	*c;		/* channel */	void		*v;		/* pointer to value */	ChanOp	op;		/* operation */ 	/* the next variables are used internally to alt	 * they need not be initialized	 */	Channel	**tag;	/* pointer to rendez-vous tag */	int		entryno;	/* entry number */}; struct Ref {	long ref;}; int		alt(Alt alts[]);Channel*	chancreate(int elemsize, int bufsize);int		chaninit(Channel *c, int elemsize, int elemcnt);void		chanfree(Channel *c);int		chanprint(Channel *, char *, ...);long		decref(Ref *r);		/* returns 0 iff value is now zero */void		incref(Ref *r);int		nbrecv(Channel *c, void *v);void*		nbrecvp(Channel *c);unsigned long		nbrecvul(Channel *c);int		nbsend(Channel *c, void *v);int		nbsendp(Channel *c, void *v);int		nbsendul(Channel *c, unsigned long v);int		proccreate(void (*f)(void *arg), void *arg, unsigned int stacksize);int		procrfork(void (*f)(void *arg), void *arg, unsigned int stacksize, int flag);void**		procdata(void);void		procexec(Channel *, char *, char *[]);void		procexecl(Channel *, char *, ...);int		recv(Channel *c, void *v);void*		recvp(Channel *c);unsigned long		recvul(Channel *c);int		send(Channel *c, void *v);int		sendp(Channel *c, void *v);int		sendul(Channel *c, unsigned long v);int		threadcreate(void (*f)(void *arg), void *arg, unsigned int stacksize);void**		threaddata(void);void		threadexits(char *);void		threadexitsall(char *);int		threadgetgrp(void);	/* return thread group of current thread */char*		threadgetname(void);void		threadint(int);	/* interrupt thread */void		threadintgrp(int);	/* interrupt threads in grp */void		threadkill(int);	/* kill thread */void		threadkillgrp(int);	/* kill threads in group */void		threadmain(int argc, char *argv[]);void		threadnonotes(void);int		threadnotify(int (*f)(void*, char*), int in);int		threadid(void);int		threadpid(int);int		threadsetgrp(int);	/* set thread group, return old */void		threadsetname(char *name);Channel*	threadwaitchan(void);int	tprivalloc(void);void	tprivfree(int);void	**tprivaddr(int);void		yield(void); long		threadstack(void); extern	int		mainstacksize; /* slave I/O processes */typedef struct Ioproc Ioproc; Ioproc*	ioproc(void);void		closeioproc(Ioproc*);void		iointerrupt(Ioproc*); int		ioclose(Ioproc*, int);int		iodial(Ioproc*, char*, char*, char*, int*);int		ioopen(Ioproc*, char*, int);long		ioread(Ioproc*, int, void*, long);long		ioreadn(Ioproc*, int, void*, long);long		iowrite(Ioproc*, int, void*, long);int		iosleep(Ioproc*, long); long		iocall(Ioproc*, long (*)(va_list*), ...);void		ioret(Ioproc*, int); #endif	/* _THREADH_ */