source: lib/events_libevent.c @ ddca104

Last change on this file since ddca104 was c5c18c1, checked in by Wilmer van der Gaast <wilmer@…>, at 2009-10-10T23:57:26Z

Hacked up a B_EV_FLAG_FORCE_REPEAT event handler flag to make libpurple
happy.

  • Property mode set to 100644
File size: 7.8 KB
Line 
1  /********************************************************************\
2  * BitlBee -- An IRC to other IM-networks gateway                     *
3  *                                                                    *
4  * Copyright 2002-2006 Wilmer van der Gaast and others                *
5  \********************************************************************/
6
7/*
8 * Event handling (using libevent)
9 */
10
11/*
12  This program is free software; you can redistribute it and/or modify
13  it under the terms of the GNU General Public License as published by
14  the Free Software Foundation; either version 2 of the License, or
15  (at your option) any later version.
16
17  This program is distributed in the hope that it will be useful,
18  but WITHOUT ANY WARRANTY; without even the implied warranty of
19  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  GNU General Public License for more details.
21
22  You should have received a copy of the GNU General Public License with
23  the Debian GNU/Linux distribution in /usr/share/common-licenses/GPL;
24  if not, write to the Free Software Foundation, Inc., 59 Temple Place,
25  Suite 330, Boston, MA  02111-1307  USA
26*/
27
28#define BITLBEE_CORE
29#include <stdio.h>
30#include <stdlib.h>
31#include <string.h>
32#include <unistd.h>
33#include <sys/types.h>
34#include <sys/time.h>
35#include <event.h>
36#include "proxy.h"
37
38static void b_main_restart();
39static guint id_next = 1; /* Next ID to be allocated to an event handler. */
40static guint id_cur = 0; /* Event ID that we're currently handling. */
41static guint id_dead; /* Set to 1 if b_event_remove removes id_cur. */
42static GHashTable *id_hash;
43static int quitting = 0; /* Prepare to quit, stop handling events. */
44
45/* Since libevent doesn't handle two event handlers for one fd-condition
46   very well (which happens sometimes when BitlBee changes event handlers
47   for a combination), let's buid some indexes so we can delete them here
48   already, just in time. */
49static GHashTable *read_hash;
50static GHashTable *write_hash;
51
52struct event_base *leh;
53struct event_base *old_leh;
54
55struct b_event_data
56{
57        guint id;
58        struct event evinfo;
59        gint timeout;
60        b_event_handler function;
61        void *data;
62        guint flags;
63};
64
65void b_main_init()
66{
67        if( leh != NULL )
68        {
69                /* Clean up the hash tables? */
70               
71                b_main_restart();
72                old_leh = leh;
73        }
74       
75        leh = event_init();
76       
77        id_hash = g_hash_table_new( g_int_hash, g_int_equal );
78        read_hash = g_hash_table_new( g_int_hash, g_int_equal );
79        write_hash = g_hash_table_new( g_int_hash, g_int_equal );
80}
81
82void b_main_run()
83{
84        /* This while loop is necessary to exit the event loop and start a
85           different one (necessary for ForkDaemon mode). */
86        while( event_base_dispatch( leh ) == 0 && !quitting )
87        {
88                if( old_leh != NULL )
89                {
90                        /* For some reason this just isn't allowed...
91                           Possibly a bug in older versions, will see later.
92                        event_base_free( old_leh ); */
93                        old_leh = NULL;
94                }
95               
96                event_debug( "New event loop.\n" );
97        }
98}
99
100static void b_main_restart()
101{
102        struct timeval tv;
103       
104        memset( &tv, 0, sizeof( struct timeval ) );
105        event_base_loopexit( leh, &tv );
106       
107        event_debug( "b_main_restart()\n" );
108}
109
110void b_main_quit()
111{
112        /* Tell b_main_run() that it shouldn't restart the loop. Also,
113           libevent sometimes generates events before really quitting,
114           we want to stop them. */
115        quitting = 1;
116       
117        b_main_restart();
118}
119
120static void b_event_passthrough( int fd, short event, void *data )
121{
122        struct b_event_data *b_ev = data;
123        b_input_condition cond = 0;
124        gboolean st;
125       
126        if( fd >= 0 )
127        {
128                if( event & EV_READ )
129                        cond |= B_EV_IO_READ;
130                if( event & EV_WRITE )
131                        cond |= B_EV_IO_WRITE;
132        }
133       
134        event_debug( "b_event_passthrough( %d, %d, 0x%x ) (%d)\n", fd, event, (int) data, b_ev->id );
135       
136        /* Since the called function might cancel this handler already
137           (which free()s b_ev), we have to remember the ID here. */
138        id_cur = b_ev->id;
139        id_dead = 0;
140       
141        if( quitting )
142        {
143                b_event_remove( id_cur );
144                return;
145        }
146       
147        st = b_ev->function( b_ev->data, fd, cond );
148        if( id_dead )
149        {
150                /* This event was killed already, don't touch it! */
151                return;
152        }
153        else if( !st && !( b_ev->flags & B_EV_FLAG_FORCE_REPEAT ) )
154        {
155                event_debug( "Handler returned FALSE: " );
156                b_event_remove( id_cur );
157        }
158        else if( fd == -1 )
159        {
160                /* fd == -1 means it was a timer. These can't be auto-repeated
161                   so it has to be recreated every time. */
162                struct timeval tv;
163               
164                tv.tv_sec = b_ev->timeout / 1000;
165                tv.tv_usec = ( b_ev->timeout % 1000 ) * 1000;
166               
167                evtimer_add( &b_ev->evinfo, &tv );
168        }
169}
170
171gint b_input_add( gint fd, b_input_condition condition, b_event_handler function, gpointer data )
172{
173        struct b_event_data *b_ev;
174       
175        event_debug( "b_input_add( %d, %d, 0x%x, 0x%x ) ", fd, condition, function, data );
176       
177        if( ( condition & B_EV_IO_READ  && ( b_ev = g_hash_table_lookup( read_hash,  &fd ) ) ) ||
178            ( condition & B_EV_IO_WRITE && ( b_ev = g_hash_table_lookup( write_hash, &fd ) ) ) )
179        {
180                /* We'll stick with this libevent entry, but give it a new BitlBee id. */
181                g_hash_table_remove( id_hash, &b_ev->id );
182               
183                event_debug( "(replacing old handler (id = %d)) = %d\n", b_ev->id, id_next );
184               
185                b_ev->id = id_next++;
186                b_ev->function = function;
187                b_ev->data = data;
188        }
189        else
190        {
191                GIOCondition out_cond;
192               
193                event_debug( "(new) = %d\n", id_next );
194               
195                b_ev = g_new0( struct b_event_data, 1 );
196                b_ev->id = id_next++;
197                b_ev->function = function;
198                b_ev->data = data;
199               
200                out_cond = EV_PERSIST;
201                if( condition & B_EV_IO_READ )
202                        out_cond |= EV_READ;
203                if( condition & B_EV_IO_WRITE )
204                        out_cond |= EV_WRITE;
205               
206                event_set( &b_ev->evinfo, fd, out_cond, b_event_passthrough, b_ev );
207                event_add( &b_ev->evinfo, NULL );
208               
209                if( out_cond & EV_READ )
210                        g_hash_table_insert( read_hash, &b_ev->evinfo.ev_fd, b_ev );
211                if( out_cond & EV_WRITE )
212                        g_hash_table_insert( write_hash, &b_ev->evinfo.ev_fd, b_ev );
213        }
214       
215        b_ev->flags = condition;
216        g_hash_table_insert( id_hash, &b_ev->id, b_ev );
217        return b_ev->id;
218}
219
220/* TODO: Persistence for timers! */
221gint b_timeout_add( gint timeout, b_event_handler function, gpointer data )
222{
223        struct b_event_data *b_ev = g_new0( struct b_event_data, 1 );
224        struct timeval tv;
225       
226        b_ev->id = id_next++;
227        b_ev->timeout = timeout;
228        b_ev->function = function;
229        b_ev->data = data;
230       
231        tv.tv_sec = timeout / 1000;
232        tv.tv_usec = ( timeout % 1000 ) * 1000;
233       
234        evtimer_set( &b_ev->evinfo, b_event_passthrough, b_ev );
235        evtimer_add( &b_ev->evinfo, &tv );
236       
237        event_debug( "b_timeout_add( %d, 0x%x, 0x%x ) = %d\n", timeout, function, data, b_ev->id );
238       
239        g_hash_table_insert( id_hash, &b_ev->id, b_ev );
240       
241        return b_ev->id;
242}
243
244void b_event_remove( gint id )
245{
246        struct b_event_data *b_ev = g_hash_table_lookup( id_hash, &id );
247       
248        event_debug( "b_event_remove( %d )\n", id );
249        if( b_ev )
250        {
251                if( id == id_cur )
252                        id_dead = TRUE;
253               
254                g_hash_table_remove( id_hash, &b_ev->id );
255                if( b_ev->evinfo.ev_fd >= 0 )
256                {
257                        if( b_ev->evinfo.ev_events & EV_READ )
258                                g_hash_table_remove( read_hash, &b_ev->evinfo.ev_fd );
259                        if( b_ev->evinfo.ev_events & EV_WRITE )
260                                g_hash_table_remove( write_hash, &b_ev->evinfo.ev_fd );
261                }
262               
263                event_del( &b_ev->evinfo );
264                g_free( b_ev );
265        }
266        else
267        {
268                event_debug( "Already removed?\n" );
269        }
270}
271
272void closesocket( int fd )
273{
274        struct b_event_data *b_ev;
275       
276        /* Since epoll() (the main reason we use libevent) automatically removes sockets from
277           the epoll() list when a socket gets closed and some modules have a habit of
278           closing sockets before removing event handlers, our and libevent's administration
279           get a little bit messed up. So this little function will remove the handlers
280           properly before closing a socket. */
281       
282        if( ( b_ev = g_hash_table_lookup( read_hash, &fd ) ) )
283        {
284                event_debug( "Warning: fd %d still had a read event handler when shutting down.\n", fd );
285                b_event_remove( b_ev->id );
286        }
287        if( ( b_ev = g_hash_table_lookup( write_hash, &fd ) ) )
288        {
289                event_debug( "Warning: fd %d still had a write event handler when shutting down.\n", fd );
290                b_event_remove( b_ev->id );
291        }
292       
293        close( fd );
294}
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