Multithreaded Management of Sockets

/*
**	(c) COPYRIGHT CERN 1994.
**	Please first read the full copyright statement in the file COPYRIGH.
*/
This module contains the routines for handling the set of active sockets currently in use by the multithreaded clients. It is an internal module to the Library, the application interface is implemented in the Event Module. Look for more information in the Multithread Specifications.

This module is implemented by HTThread.c, and it is a part of the Library of Common Code. 

#ifndef HTTHREAD_H
#define HTTHREAD_H

Initiation

 This function initiates the arrays of socket descriptors used in the Library. It is currently done in the private HTAccessInit function. 

extern BOOL HTThreadInit	NOPARAMS;
NOTE It is VERY important that this one is called before the first request, as otherwise the socket bit arrays are uninitialized.

Registration of a Thread

These two functions put a HTNetInfo object into the list of threads and takes it out again respectively. A normal place to call these functions would be on creation and deletion of the HTNetInfo data structure. 
extern void HTThread_new	PARAMS((HTNetInfo * new_net));
extern int  HTThread_clear	PARAMS((HTNetInfo * old_net));

Get Bit-arrays for Select()

This function returns a copy of the current bit-arrays contaning the active sockets registered for READ and WRITE. 
extern int HTThreadGetFDInfo 	PARAMS((fd_set * read, fd_set * write));

Registration of the State of a Socket

When a new request is initiated from the client and a socket has been created, is gets registered in a linked list of HTNetInfo objects. The object stays in this list until the request has ended (either having an error or success as result). Every time the program execution gets to a point where a socket operation would normally block the program, this function is called in order to register the socket as waiting for the actual operation. 
typedef enum _HTThreadAction {
    THD_SET_WRITE=0,
    THD_CLR_WRITE,
    THD_SET_READ,
    THD_CLR_READ,
    THD_SET_INTR,
    THD_CLR_INTR,
    THD_CLOSE
} HTThreadAction;

extern void HTThreadState PARAMS((int sockfd, HTThreadAction action));
This function makes life easier if you want to mark all sockets as interrupted. 
extern void HTThreadMarkIntrAll	PARAMS((CONST fd_set * fd_user));

Is a Thread Interrupted?

This function returns YES if the socket is registered as interrupted 
extern BOOL HTThreadIntr	PARAMS((int sockfd));

Any Threads Registered?

This function returns YES if any HTTP sockets are still registered in the set of active sockets. Otherwise it returns NO. 
extern BOOL HTThreadActive	NOPARAMS;

Select an Active Thread

When the select function has returned a set of pending sockets this functions selects one of them and finds the correseponding request structure. 
extern HTRequest *HTThread_getRequest	PARAMS((CONST fd_set * fd_read,
						CONST fd_set * fd_write));

#endif
End of HTThread module