Annotation of libwww/Library/src/HTEvtLst.html, revision 1.1.2.2
1.1.2.1 eric 1: <HTML>
2: <HEAD>
3: <!-- Changed by: Henrik Frystyk Nielsen, 16-May-1996 -->
4: <TITLE>W3C Reference Library libwww Default Event Manager</TITLE>
5: </HEAD>
6: <BODY>
7: <H1>
8: Default Event Manager
9: </H1>
10: <PRE>
11: /*
12: ** (c) COPYRIGHT MIT 1995.
13: ** Please first read the full copyright statement in the file COPYRIGH.
14: */
15: </PRE>
16: <P>
17: This module provides an event registry and a multi-threaded event
18: loop. An application may use this module for:
19: <UL>
20: <LI>event loop and registry - Application registers <A
21: HREF="#registry">HTEvntrg_register and HTEvntrg_unregister</A> and
22: calls <A HREF="#eventLoop">HTEventList_loop</A> to dispatch events as
23: they occur.<P>
24:
25: <LI>event registry - Application just registers its own <A
26: HREF="HTEvent.html#eventHandlers">event handlers</A> and chains them
27: to <A HREF="#registry">HTEvntrg_register and
28: HTEvntrg_unregister</A>. When the application's event loop gets
29: activity on a socket, it calls <A
30: HREF="#dispatch">HTEvent_dispatch</A> to handle it.<P>
31:
32: <LI>nothing - Application registers its own <A
33: HREF="HTEvent.html#eventHandlers">event handler</A> uses its own event
34: loop to dispatch those events.<P>
35: </UL>
36:
37: This module is implemented by <A HREF="HTEvntrg.c">HTEvntrg.c</A>, and it
38: is a part of the <A HREF="http://www.w3.org/pub/WWW/Library/">W3C Reference
39: Library</A>.
40: <PRE>
41: #ifndef HTEVNTLST_H
42: #define HTEVNTLST_H
43:
44: #include "sysdep.h"
45: #include "HTEvent.h"
46: #include "HTReq.h"
47: </PRE>
48: <H3>
49: Windows Specific Handles
50: </H3>
51: <PRE>
52: #if defined(WWW_WIN_ASYNC) || defined(WWW_WIN_DLL)
53: extern BOOL HTEventList_winHandle (HTRequest * request);
54: extern BOOL HTEventList_setWinHandle (HWND window, unsigned long message);
55: extern HWND HTEventList_getWinHandle (unsigned long * pMessage);
56: extern LRESULT CALLBACK AsyncWindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam);
57: #endif
58: </PRE>
59: <H2>
60: <A NAME="registry">Event Reagistry</A>
61: </H2>
62: The libwww's event registry binds a socket and operation (FD_READ,
63: FD_WRITE...) to a callback function. Event are registered,
64: unregistered, and dispatched.
65: <H3>
66: Register an Event Handler
67: </H3>
68: <P>
69: For a given socket, reqister a request structure, a set of operations, a
70: HTEventCallback function, and a priority. For this implementation, we allow
71: only a single HTEventCallback function for all operations. and the priority
72: field is ignored.
73: <PRE>
1.1.2.2 ! eric 74: extern int HTEventList_register (SOCKET, HTEventType, HTEvent *);
1.1.2.1 eric 75: </PRE>
76: <H3>
77: Unregister an Event Handler
78: </H3>
79: <P>
80: Remove the registered information for the specified socket for the actions
81: specified in ops. if no actions remain after the unregister, the registered
82: info is deleted, and, if the socket has been registered for notification,
83: the HTEventCallback will be invoked.
84: <PRE>
1.1.2.2 ! eric 85: extern int HTEventList_unregister (SOCKET, HTEventType);
1.1.2.1 eric 86: </PRE>
87: <H3>
88: Unregister ALL Event Handlers
89: </H3>
90: <P>
91: Unregister all sockets. N.B. we just remove them for our internal data
92: structures: it is up to the application to actually close the socket.
93: <PRE>
94: extern int HTEventList_unregisterAll (void);
95: </PRE>
96: <H3>
97: <A NAME="dispatch">HTEventList_dispatch</A>
98: </H3>
99: <P>
100: Dispatches a callback based on the socket and operation (read/write/oob)
101: <PRE>
1.1.2.2 ! eric 102: extern int HTEventList_dispatch( SOCKET, HTEventType);
1.1.2.1 eric 103: </PRE>
104: <H2>
105: Handler for Timeout on Sockets
106: </H2>
107: <P>
108: This function sets the timeout for sockets in the <CODE>select()</CODE> call
109: and registers a timeout function that is called if select times out. This
110: does only works on NON windows platforms as we need to poll for the console
111: on windows If <CODE>tv = NULL</CODE> then timeout is disabled. Default is
112: no timeout. If <EM>always=YES</EM> then the callback is called at all times,
113: if NO then only when Library sockets are active. Returns YES if OK else NO.
114: <PRE>
115: typedef int HTEventTimeout (HTRequest *);
116:
117: extern BOOL HTEventList_registerTimeout (struct timeval *tp, HTRequest * request,
118: HTEventTimeout *tcbf, BOOL always);
119: </PRE>
120: <H2>
121: <A NAME="eventLoop">Event Loop</A>
122: </H2>
123: The libwww's default event loop dispatches events to the <A
124: HREF="#registry">event registry</A>.
125: <H3>
126: Start and Stop the Event Manager
127: </H3>
128: <PRE>
129: extern BOOL HTEventInit (void);
130: extern BOOL HTEventTerminate (void);
131: </PRE>
132: <H3>
133: Start the Event Loop
134: </H3>
135: <P>
136: That is, we wait for activity from one of our registered channels, and dispatch
137: on that. Under Windows/NT, we must treat the console and sockets as distinct.
138: That means we can't avoid a busy wait, but we do our best.
139: <PRE>
140: extern int HTEventList_loop (HTRequest * request);
141: </PRE>
142: <H3>
143: Stop the Event Loop
144: </H3>
145: <P>
146: Stops the (select based) event loop. The function does not guarantee that
147: all requests have terminated. This is for the app to do
148: <PRE>
149: extern void HTEventList_stopLoop (void);
150: </PRE>
151: <PRE>
152: #endif /* HTEVTLST_H */
153: </PRE>
154: <P>
155: <HR>
156: <ADDRESS>
1.1.2.2 ! eric 157: @(#) $Id: HTEvtLst.html,v 1.1.2.1 1996/10/29 21:27:36 eric Exp $
1.1.2.1 eric 158: </ADDRESS>
159: </BODY></HTML>
Webmaster
![[BACK]](/cvsweb/icons/back.gif){kind=icon}
Return to HTEvtLst.html CVS log ![[TXT]](/cvsweb/icons/text.gif){kind=icon}
![[DIR]](/cvsweb/icons/dir.gif){kind=icon}
Up to [Public] / libwww / Library / src