/*++ /* NAME /* master_proto 3h /* SUMMARY /* master process protocol /* SYNOPSIS /* #include <master_proto.h> /* DESCRIPTION /* .nf /* * Transport names. The master passes the transport name on the command * line, and thus the name is part of the master to child protocol. */ #define MASTER_XPORT_NAME_UNIX "unix" /* local IPC */ #define MASTER_XPORT_NAME_FIFO "fifo" /* local IPC */ #define MASTER_XPORT_NAME_INET "inet" /* non-local IPC */ #define MASTER_XPORT_NAME_PASS "pass" /* local IPC */ /* * Format of a status message sent by a child process to the process * manager. Since this is between processes on the same machine we need not * worry about byte order and word length. */ typedef struct MASTER_STATUS { int pid; /* process ID */ unsigned gen; /* child generation number */ int avail; /* availability */ } MASTER_STATUS; #define MASTER_GEN_NAME "GENERATION" /* passed via environment */ #define MASTER_STAT_TAKEN 0 /* this one is occupied */ #define MASTER_STAT_AVAIL 1 /* this process is idle */ extern int master_notify(int, unsigned, int); /* encapsulate status msg */ /* * File descriptors inherited from the master process. The flow control pipe * is read by receive processes and is written to by send processes. If * receive processes get too far ahead they will pause for a brief moment. */ #define MASTER_FLOW_READ 3 #define MASTER_FLOW_WRITE 4 /* * File descriptors inherited from the master process. All processes that * provide a given service share the same status file descriptor, and listen * on the same service socket(s). The kernel decides what process gets the * next connection. Usually the number of listening processes is small, so * one connection will not cause a "thundering herd" effect. When no process * listens on a given socket, the master process will. MASTER_LISTEN_FD is * actually the lowest-numbered descriptor of a sequence of descriptors to * listen on. */ #define MASTER_STATUS_FD 5 /* shared channel to parent */ #define MASTER_LISTEN_FD 6 /* accept connections here */ /* 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 /*--*/