/*++
/* NAME
/*	master 3h
/* SUMMARY
/*	Postfix master - data structures and prototypes
/* SYNOPSIS
/*	#include "master.h"
/* DESCRIPTION
/* .nf

 /*
  * Server processes that provide the same service share a common "listen"
  * socket to accept connection requests, and share a common pipe to the
  * master process to send status reports. Server processes die voluntarily
  * when idle for a configurable amount of time, or after servicing a
  * configurable number of requests; the master process spawns new processes
  * on demand up to a configurable concurrency limit and/or periodically.
  */
typedef struct MASTER_SERV {
    int     flags;			/* status, features, etc. */
    char   *name;			/* service endpoint name */
    int     type;			/* UNIX-domain, INET, etc. */
    int     wakeup_time;		/* wakeup interval */
    int    *listen_fd;			/* incoming requests */
    int     listen_fd_count;		/* nr of descriptors */
#ifdef MASTER_SERV_TYPE_PASS
    struct PASS_INFO *pass_info;	/* descriptor passing state */
#endif
    union {
	struct {
	    char   *port;		/* inet listen port */
	    struct INET_ADDR_LIST *addr;/* inet listen address */
	}       inet_ep;
#define MASTER_INET_ADDRLIST(s)	((s)->endpoint.inet_ep.addr)
#define MASTER_INET_PORT(s)	((s)->endpoint.inet_ep.port)
    }       endpoint;
    int     max_proc;			/* upper bound on # processes */
    char   *path;			/* command pathname */
    struct ARGV *args;			/* argument vector */
    int     avail_proc;			/* idle processes */
    int     total_proc;			/* number of processes */
    int     throttle_delay;		/* failure recovery parameter */
    int     status_fd[2];		/* child status reports */
    struct BINHASH *children;		/* linkage */
    struct MASTER_SERV *next;		/* linkage */
} MASTER_SERV;

 /*
  * Per-service flag bits. We assume trouble when a child process terminates
  * before completing its first request: either the program is defective,
  * some configuration is wrong, or the system is out of resources.
  */
#define MASTER_FLAG_THROTTLE	(1<<0)	/* we're having trouble */
#define MASTER_FLAG_MARK	(1<<1)	/* garbage collection support */
#define MASTER_FLAG_CONDWAKE	(1<<2)	/* wake up if actually used */
#define MASTER_FLAG_INETHOST	(1<<3)	/* endpoint name specifies host */

#define MASTER_THROTTLED(f)	((f)->flags & MASTER_FLAG_THROTTLE)

#define MASTER_LIMIT_OK(limit, count) ((limit) == 0 || ((count) < (limit)))

 /*
  * Service types.
  */
#define MASTER_SERV_TYPE_UNIX	1	/* AF_UNIX domain socket */
#define MASTER_SERV_TYPE_INET	2	/* AF_INET domain socket */
#define MASTER_SERV_TYPE_FIFO	3	/* fifo (named pipe) */
/*#define MASTER_SERV_TYPE_PASS	4	/* AF_UNIX domain socket */

 /*
  * Default process management policy values. This is only the bare minimum.
  * Most policy management is delegated to child processes. The process
  * manager runs at high privilege level and has to be kept simple.
  */
#define MASTER_DEF_MIN_IDLE	1	/* preferred # of idle processes */

 /*
  * Structure of child process.
  */
typedef int MASTER_PID;			/* pid is key into binhash table */

typedef struct MASTER_PROC {
    MASTER_PID pid;			/* child process id */
    unsigned gen;			/* child generation number */
    int     avail;			/* availability */
    MASTER_SERV *serv;			/* parent linkage */
    int     use_count;			/* number of service requests */
} MASTER_PROC;

 /*
  * Other manifest constants.
  */
#define MASTER_BUF_LEN	2048		/* logical config line length */

 /*
  * master_ent.c
  */
extern void fset_master_ent(char *);
extern void set_master_ent(void);
extern void end_master_ent(void);
extern void print_master_ent(MASTER_SERV *);
extern MASTER_SERV *get_master_ent(void);
extern void free_master_ent(MASTER_SERV *);

 /*
  * master_conf.c
  */
extern void master_config(void);
extern void master_refresh(void);

 /*
  * master_vars.c
  */
extern void master_vars_init(void);

 /*
  * master_tab.c
  */
extern MASTER_SERV *master_head;
extern void master_start_service(MASTER_SERV *);
extern void master_stop_service(MASTER_SERV *);
extern void master_restart_service(MASTER_SERV *);

 /*
  * master_events.c
  */
extern int master_gotsighup;
extern int master_gotsigchld;
extern void master_sigsetup(void);

 /*
  * master_status.c
  */
extern void master_status_init(MASTER_SERV *);
extern void master_status_cleanup(MASTER_SERV *);

 /*
  * master_wakeup.c
  */
extern void master_wakeup_init(MASTER_SERV *);
extern void master_wakeup_cleanup(MASTER_SERV *);


 /*
  * master_listen.c
  */
extern void master_listen_init(MASTER_SERV *);
extern void master_listen_cleanup(MASTER_SERV *);

 /*
  * master_avail.c
  */
extern void master_avail_listen(MASTER_SERV *);
extern void master_avail_cleanup(MASTER_SERV *);
extern void master_avail_more(MASTER_SERV *, MASTER_PROC *);
extern void master_avail_less(MASTER_SERV *, MASTER_PROC *);

 /*
  * master_spawn.c
  */
extern struct BINHASH *master_child_table;
extern void master_spawn(MASTER_SERV *);
extern void master_reap_child(void);
extern void master_delete_children(MASTER_SERV *);

 /*
  * master_flow.c
  */
extern void master_flow_init(void);
extern int master_flow_pipe[2];

/* DIAGNOSTICS
/* BUGS
/* SEE ALSO
/* LICENSE
/* .ad
/* .fi
/*	The Secure Mailer license must be distributed with this software.
/* AUTHOR(S)
/*	Wietse Venema
/*	IBM T.J. Watson Research
/*	P.O. Box 704
/*	Yorktown Heights, NY 10598, USA
/*--*/