2 Unix SMB/CIFS implementation.
3 main select loop and event handling
4 Copyright (C) Andrew Tridgell 2003
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 PLEASE READ THIS BEFORE MODIFYING!
24 This module is a general abstraction for the main select loop and
25 event handling. Do not ever put any localised hacks in here, instead
26 register one of the possible event types and implement that event
29 There are 2 types of event handling that are handled in this module:
31 1) a file descriptor becoming readable or writeable. This is mostly
32 used for network sockets, but can be used for any type of file
33 descriptor. You may only register one handler for each file
34 descriptor/io combination or you will get unpredictable results
35 (this means that you can have a handler for read events, and a
36 separate handler for write events, but not two handlers that are
37 both handling read events)
39 2) a timed event. You can register an event that happens at a
40 specific time. You can register as many of these as you
41 like. They are single shot - add a new timed event in the event
42 handler to get another event.
44 To setup a set of events you first need to create a event_context
45 structure using the function event_context_init(); This returns a
46 'struct event_context' that you use in all subsequent calls.
48 After that you can add/remove events that you are interested in
49 using event_add_*() and talloc_free()
51 Finally, you call event_loop_wait_once() to block waiting for one of the
52 events to occor or event_loop_wait() which will loop
58 #include "lib/events/events.h"
59 #include "lib/events/events_internal.h"
62 create a event_context structure for a specific implemementation.
63 This must be the first events call, and all subsequent calls pass
64 this event_context as the first element. Event handlers also
65 receive this as their first argument.
67 This function is for allowing third-party-applications to hook in gluecode
68 to their own event loop code, so that they can make async usage of our client libs
70 NOTE: use event_context_init() inside of samba!
72 struct event_context *event_context_init_ops(TALLOC_CTX *mem_ctx, const struct event_ops *ops, void *private_data)
74 struct event_context *ev;
77 ev = talloc_zero(mem_ctx, struct event_context);
82 ret = ev->ops->context_init(ev, private_data);
92 create a event_context structure. This must be the first events
93 call, and all subsequent calls pass this event_context as the first
94 element. Event handlers also receive this as their first argument.
96 struct event_context *event_context_init(TALLOC_CTX *mem_ctx)
98 const struct event_ops *ops = event_standard_get_ops();
99 return event_context_init_ops(mem_ctx, ops, NULL);
104 return NULL on failure (memory allocation error)
106 struct fd_event *event_add_fd(struct event_context *ev, TALLOC_CTX *mem_ctx,
107 int fd, uint16_t flags, event_fd_handler_t handler,
110 return ev->ops->add_fd(ev, mem_ctx, fd, flags, handler, private_data);
114 return the fd event flags
116 uint16_t event_get_fd_flags(struct fd_event *fde)
119 return fde->event_ctx->ops->get_fd_flags(fde);
123 set the fd event flags
125 void event_set_fd_flags(struct fd_event *fde, uint16_t flags)
128 fde->event_ctx->ops->set_fd_flags(fde, flags);
133 return NULL on failure
135 struct timed_event *event_add_timed(struct event_context *ev, TALLOC_CTX *mem_ctx,
136 struct timeval next_event,
137 event_timed_handler_t handler,
140 return ev->ops->add_timed(ev, mem_ctx, next_event, handler, private_data);
144 do a single event loop using the events defined in ev
146 _PUBLIC_ int event_loop_once(struct event_context *ev)
148 return ev->ops->loop_once(ev);
152 return on failure or (with 0) if all fd events are removed
154 int event_loop_wait(struct event_context *ev)
156 return ev->ops->loop_wait(ev);
160 find an event context that is a parent of the given memory context,
161 or create a new event context as a child of the given context if
164 This should be used in preference to event_context_init() in places
165 where you would prefer to use the existing event context if possible
166 (which is most situations)
168 struct event_context *event_context_find(TALLOC_CTX *mem_ctx)
170 struct event_context *ev = talloc_find_parent_bytype(mem_ctx, struct event_context);
172 ev = event_context_init(mem_ctx);