2 Unix SMB/CIFS implementation.
4 generalised event loop handling
6 Copyright (C) Andrew Tridgell 2005
7 Copyright (C) Stefan Metzmacher 2005-2009
8 Copyright (C) Volker Lendecke 2008
10 ** NOTE! The following LGPL license applies to the tevent
11 ** library. This does NOT imply that all of Samba is released
14 This library is free software; you can redistribute it and/or
15 modify it under the terms of the GNU Lesser General Public
16 License as published by the Free Software Foundation; either
17 version 3 of the License, or (at your option) any later version.
19 This library is distributed in the hope that it will be useful,
20 but WITHOUT ANY WARRANTY; without even the implied warranty of
21 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
22 Lesser General Public License for more details.
24 You should have received a copy of the GNU Lesser General Public
25 License along with this library; if not, see <http://www.gnu.org/licenses/>.
36 struct tevent_context;
40 struct tevent_immediate;
42 struct tevent_thread_proxy;
43 struct tevent_threaded_context;
46 * @defgroup tevent The tevent API
48 * The tevent low-level API
50 * This API provides the public interface to manage events in the tevent
51 * mainloop. Functions are provided for managing low-level events such
52 * as timer events, fd events and signal handling.
57 /* event handler types */
59 * Called when a file descriptor monitored by tevent has
60 * data to be read or written on it.
62 typedef void (*tevent_fd_handler_t)(struct tevent_context *ev,
63 struct tevent_fd *fde,
68 * Called when tevent is ceasing the monitoring of a file descriptor.
70 typedef void (*tevent_fd_close_fn_t)(struct tevent_context *ev,
71 struct tevent_fd *fde,
76 * Called when a tevent timer has fired.
78 typedef void (*tevent_timer_handler_t)(struct tevent_context *ev,
79 struct tevent_timer *te,
80 struct timeval current_time,
84 * Called when a tevent immediate event is invoked.
86 typedef void (*tevent_immediate_handler_t)(struct tevent_context *ctx,
87 struct tevent_immediate *im,
91 * Called after tevent detects the specified signal.
93 typedef void (*tevent_signal_handler_t)(struct tevent_context *ev,
94 struct tevent_signal *se,
101 * @brief Create a event_context structure.
103 * This must be the first events call, and all subsequent calls pass this
104 * event_context as the first element. Event handlers also receive this as
105 * their first argument.
107 * @param[in] mem_ctx The memory context to use.
109 * @return An allocated tevent context, NULL on error.
111 * @see tevent_context_init()
113 struct tevent_context *tevent_context_init(TALLOC_CTX *mem_ctx);
116 * @brief Create a event_context structure and select a specific backend.
118 * This must be the first events call, and all subsequent calls pass this
119 * event_context as the first element. Event handlers also receive this as
120 * their first argument.
122 * @param[in] mem_ctx The memory context to use.
124 * @param[in] name The name of the backend to use.
126 * @return An allocated tevent context, NULL on error.
128 struct tevent_context *tevent_context_init_byname(TALLOC_CTX *mem_ctx, const char *name);
131 * @brief Create a custom event context
133 * @param[in] mem_ctx The memory context to use.
134 * @param[in] ops The function pointer table of the backend.
135 * @param[in] additional_data The additional/private data to this instance
137 * @return An allocated tevent context, NULL on error.
140 struct tevent_context *tevent_context_init_ops(TALLOC_CTX *mem_ctx,
141 const struct tevent_ops *ops,
142 void *additional_data);
145 * @brief List available backends.
147 * @param[in] mem_ctx The memory context to use.
149 * @return A string vector with a terminating NULL element, NULL
152 const char **tevent_backend_list(TALLOC_CTX *mem_ctx);
155 * @brief Set the default tevent backend.
157 * @param[in] backend The name of the backend to set.
159 void tevent_set_default_backend(const char *backend);
163 * @brief Add a file descriptor based event.
165 * @param[in] ev The event context to work on.
167 * @param[in] mem_ctx The talloc memory context to use.
169 * @param[in] fd The file descriptor to base the event on.
171 * @param[in] flags #TEVENT_FD_READ or #TEVENT_FD_WRITE
173 * @param[in] handler The callback handler for the event.
175 * @param[in] private_data The private data passed to the callback handler.
177 * @return The file descriptor based event, NULL on error.
179 * @note To cancel the monitoring of a file descriptor, call talloc_free()
180 * on the object returned by this function.
182 * @note The caller should avoid closing the file descriptor before
183 * calling talloc_free()! Otherwise the behaviour is undefined which
184 * might result in crashes. See https://bugzilla.samba.org/show_bug.cgi?id=11141
187 struct tevent_fd *tevent_add_fd(struct tevent_context *ev,
191 tevent_fd_handler_t handler,
194 struct tevent_fd *_tevent_add_fd(struct tevent_context *ev,
198 tevent_fd_handler_t handler,
200 const char *handler_name,
201 const char *location);
202 #define tevent_add_fd(ev, mem_ctx, fd, flags, handler, private_data) \
203 _tevent_add_fd(ev, mem_ctx, fd, flags, handler, private_data, \
204 #handler, __location__)
209 * @brief Add a timed event
211 * @param[in] ev The event context to work on.
213 * @param[in] mem_ctx The talloc memory context to use.
215 * @param[in] next_event Timeval specifying the absolute time to fire this
216 * event. This is not an offset.
218 * @param[in] handler The callback handler for the event.
220 * @param[in] private_data The private data passed to the callback handler.
222 * @return The newly-created timer event, or NULL on error.
224 * @note To cancel a timer event before it fires, call talloc_free() on the
225 * event returned from this function. This event is automatically
226 * talloc_free()-ed after its event handler files, if it hasn't been freed yet.
228 * @note Unlike some mainloops, tevent timers are one-time events. To set up
229 * a recurring event, it is necessary to call tevent_add_timer() again during
230 * the handler processing.
232 * @note Due to the internal mainloop processing, a timer set to run
233 * immediately will do so after any other pending timers fire, but before
234 * any further file descriptor or signal handling events fire. Callers should
235 * not rely on this behavior!
237 struct tevent_timer *tevent_add_timer(struct tevent_context *ev,
239 struct timeval next_event,
240 tevent_timer_handler_t handler,
243 struct tevent_timer *_tevent_add_timer(struct tevent_context *ev,
245 struct timeval next_event,
246 tevent_timer_handler_t handler,
248 const char *handler_name,
249 const char *location);
250 #define tevent_add_timer(ev, mem_ctx, next_event, handler, private_data) \
251 _tevent_add_timer(ev, mem_ctx, next_event, handler, private_data, \
252 #handler, __location__)
256 * @brief Set the time a tevent_timer fires
258 * @param[in] te The timer event to reset
260 * @param[in] next_event Timeval specifying the absolute time to fire this
261 * event. This is not an offset.
263 void tevent_update_timer(struct tevent_timer *te, struct timeval next_event);
267 * Initialize an immediate event object
269 * This object can be used to trigger an event to occur immediately after
270 * returning from the current event (before any other event occurs)
272 * @param[in] mem_ctx The talloc memory context to use as the parent
274 * @return An empty tevent_immediate object. Use tevent_schedule_immediate
275 * to populate and use it.
277 * @note Available as of tevent 0.9.8
279 struct tevent_immediate *tevent_create_immediate(TALLOC_CTX *mem_ctx);
281 struct tevent_immediate *_tevent_create_immediate(TALLOC_CTX *mem_ctx,
282 const char *location);
283 #define tevent_create_immediate(mem_ctx) \
284 _tevent_create_immediate(mem_ctx, __location__)
290 * Schedule an event for immediate execution. This event will occur
291 * immediately after returning from the current event (before any other
294 * @param[in] im The tevent_immediate object to populate and use
295 * @param[in] ctx The tevent_context to run this event
296 * @param[in] handler The event handler to run when this event fires
297 * @param[in] private_data Data to pass to the event handler
299 void tevent_schedule_immediate(struct tevent_immediate *im,
300 struct tevent_context *ctx,
301 tevent_immediate_handler_t handler,
304 void _tevent_schedule_immediate(struct tevent_immediate *im,
305 struct tevent_context *ctx,
306 tevent_immediate_handler_t handler,
308 const char *handler_name,
309 const char *location);
310 #define tevent_schedule_immediate(im, ctx, handler, private_data) \
311 _tevent_schedule_immediate(im, ctx, handler, private_data, \
312 #handler, __location__);
317 * @brief Add a tevent signal handler
319 * tevent_add_signal() creates a new event for handling a signal the next
320 * time through the mainloop. It implements a very simple traditional signal
321 * handler whose only purpose is to add the handler event into the mainloop.
323 * @param[in] ev The event context to work on.
325 * @param[in] mem_ctx The talloc memory context to use.
327 * @param[in] signum The signal to trap
329 * @param[in] handler The callback handler for the signal.
331 * @param[in] sa_flags sigaction flags for this signal handler.
333 * @param[in] private_data The private data passed to the callback handler.
335 * @return The newly-created signal handler event, or NULL on error.
337 * @note To cancel a signal handler, call talloc_free() on the event returned
338 * from this function.
340 * @see tevent_num_signals, tevent_sa_info_queue_count
342 struct tevent_signal *tevent_add_signal(struct tevent_context *ev,
346 tevent_signal_handler_t handler,
349 struct tevent_signal *_tevent_add_signal(struct tevent_context *ev,
353 tevent_signal_handler_t handler,
355 const char *handler_name,
356 const char *location);
357 #define tevent_add_signal(ev, mem_ctx, signum, sa_flags, handler, private_data) \
358 _tevent_add_signal(ev, mem_ctx, signum, sa_flags, handler, private_data, \
359 #handler, __location__)
363 * @brief the number of supported signals
365 * This returns value of the configure time TEVENT_NUM_SIGNALS constant.
367 * The 'signum' argument of tevent_add_signal() must be less than
368 * TEVENT_NUM_SIGNALS.
370 * @see tevent_add_signal
372 size_t tevent_num_signals(void);
375 * @brief the number of pending realtime signals
377 * This returns value of TEVENT_SA_INFO_QUEUE_COUNT.
379 * The tevent internals remember the last TEVENT_SA_INFO_QUEUE_COUNT
380 * siginfo_t structures for SA_SIGINFO signals. If the system generates
381 * more some signals get lost.
383 * @see tevent_add_signal
385 size_t tevent_sa_info_queue_count(void);
389 * @brief Pass a single time through the mainloop
391 * This will process any appropriate signal, immediate, fd and timer events
393 * @param[in] ev The event context to process
395 * @return Zero on success, nonzero if an internal error occurred
397 int tevent_loop_once(struct tevent_context *ev);
399 int _tevent_loop_once(struct tevent_context *ev, const char *location);
400 #define tevent_loop_once(ev) \
401 _tevent_loop_once(ev, __location__)
406 * @brief Run the mainloop
408 * The mainloop will run until there are no events remaining to be processed
410 * @param[in] ev The event context to process
412 * @return Zero if all events have been processed. Nonzero if an internal
415 int tevent_loop_wait(struct tevent_context *ev);
417 int _tevent_loop_wait(struct tevent_context *ev, const char *location);
418 #define tevent_loop_wait(ev) \
419 _tevent_loop_wait(ev, __location__)
424 * Assign a function to run when a tevent_fd is freed
426 * This function is a destructor for the tevent_fd. It does not automatically
427 * close the file descriptor. If this is the desired behavior, then it must be
428 * performed by the close_fn.
430 * @param[in] fde File descriptor event on which to set the destructor
431 * @param[in] close_fn Destructor to execute when fde is freed
433 void tevent_fd_set_close_fn(struct tevent_fd *fde,
434 tevent_fd_close_fn_t close_fn);
437 * Automatically close the file descriptor when the tevent_fd is freed
439 * This function calls close(fd) internally.
441 * @param[in] fde File descriptor event to auto-close
443 void tevent_fd_set_auto_close(struct tevent_fd *fde);
446 * Return the flags set on this file descriptor event
448 * @param[in] fde File descriptor event to query
450 * @return The flags set on the event. See #TEVENT_FD_READ and
453 uint16_t tevent_fd_get_flags(struct tevent_fd *fde);
456 * Set flags on a file descriptor event
458 * @param[in] fde File descriptor event to set
459 * @param[in] flags Flags to set on the event. See #TEVENT_FD_READ and
462 void tevent_fd_set_flags(struct tevent_fd *fde, uint16_t flags);
465 * Query whether tevent supports signal handling
467 * @param[in] ev An initialized tevent context
469 * @return True if this platform and tevent context support signal handling
471 bool tevent_signal_support(struct tevent_context *ev);
473 void tevent_set_abort_fn(void (*abort_fn)(const char *reason));
475 /* bits for file descriptor event flags */
478 * Monitor a file descriptor for data to be read
480 #define TEVENT_FD_READ 1
482 * Monitor a file descriptor for writeability
484 #define TEVENT_FD_WRITE 2
487 * Convenience function for declaring a tevent_fd writable
489 #define TEVENT_FD_WRITEABLE(fde) \
490 tevent_fd_set_flags(fde, tevent_fd_get_flags(fde) | TEVENT_FD_WRITE)
493 * Convenience function for declaring a tevent_fd readable
495 #define TEVENT_FD_READABLE(fde) \
496 tevent_fd_set_flags(fde, tevent_fd_get_flags(fde) | TEVENT_FD_READ)
499 * Convenience function for declaring a tevent_fd non-writable
501 #define TEVENT_FD_NOT_WRITEABLE(fde) \
502 tevent_fd_set_flags(fde, tevent_fd_get_flags(fde) & ~TEVENT_FD_WRITE)
505 * Convenience function for declaring a tevent_fd non-readable
507 #define TEVENT_FD_NOT_READABLE(fde) \
508 tevent_fd_set_flags(fde, tevent_fd_get_flags(fde) & ~TEVENT_FD_READ)
511 * Debug level of tevent
513 enum tevent_debug_level {
516 TEVENT_DEBUG_WARNING,
521 * @brief The tevent debug callbac.
523 * @param[in] context The memory context to use.
525 * @param[in] level The debug level.
527 * @param[in] fmt The format string.
529 * @param[in] ap The arguments for the format string.
531 typedef void (*tevent_debug_fn)(void *context,
532 enum tevent_debug_level level,
534 va_list ap) PRINTF_ATTRIBUTE(3,0);
537 * Set destination for tevent debug messages
539 * @param[in] ev Event context to debug
540 * @param[in] debug Function to handle output printing
541 * @param[in] context The context to pass to the debug function.
543 * @return Always returns 0 as of version 0.9.8
545 * @note Default is to emit no debug messages
547 int tevent_set_debug(struct tevent_context *ev,
548 tevent_debug_fn debug,
552 * Designate stderr for debug message output
554 * @param[in] ev Event context to debug
556 * @note This function will only output TEVENT_DEBUG_FATAL, TEVENT_DEBUG_ERROR
557 * and TEVENT_DEBUG_WARNING messages. For TEVENT_DEBUG_TRACE, please define a
558 * function for tevent_set_debug()
560 int tevent_set_debug_stderr(struct tevent_context *ev);
562 enum tevent_trace_point {
564 * Corresponds to a trace point just before waiting
566 TEVENT_TRACE_BEFORE_WAIT,
568 * Corresponds to a trace point just after waiting
570 TEVENT_TRACE_AFTER_WAIT,
571 #define TEVENT_HAS_LOOP_ONCE_TRACE_POINTS 1
573 * Corresponds to a trace point just before calling
574 * the loop_once() backend function.
576 TEVENT_TRACE_BEFORE_LOOP_ONCE,
578 * Corresponds to a trace point right after the
579 * loop_once() backend function has returned.
581 TEVENT_TRACE_AFTER_LOOP_ONCE,
584 typedef void (*tevent_trace_callback_t)(enum tevent_trace_point,
588 * Register a callback to be called at certain trace points
590 * @param[in] ev Event context
591 * @param[in] cb Trace callback
592 * @param[in] private_data Data to be passed to callback
594 * @note The callback will be called at trace points defined by
595 * tevent_trace_point. Call with NULL to reset.
597 void tevent_set_trace_callback(struct tevent_context *ev,
598 tevent_trace_callback_t cb,
602 * Retrieve the current trace callback
604 * @param[in] ev Event context
605 * @param[out] cb Registered trace callback
606 * @param[out] private_data Registered data to be passed to callback
608 * @note This can be used to allow one component that wants to
609 * register a callback to respect the callback that another component
610 * has already registered.
612 void tevent_get_trace_callback(struct tevent_context *ev,
613 tevent_trace_callback_t *cb,
621 * @defgroup tevent_request The tevent request functions.
624 * A tevent_req represents an asynchronous computation.
626 * The tevent_req group of API calls is the recommended way of
627 * programming async computations within tevent. In particular the
628 * file descriptor (tevent_add_fd) and timer (tevent_add_timed) events
629 * are considered too low-level to be used in larger computations. To
630 * read and write from and to sockets, Samba provides two calls on top
631 * of tevent_add_fd: tstream_read_packet_send/recv and tstream_writev_send/recv.
632 * These requests are much easier to compose than the low-level event
633 * handlers called from tevent_add_fd.
635 * A lot of the simplicity tevent_req has brought to the notoriously
636 * hairy async programming came via a set of conventions that every
637 * async computation programmed should follow. One central piece of
638 * these conventions is the naming of routines and variables.
640 * Every async computation needs a name (sensibly called "computation"
641 * down from here). From this name quite a few naming conventions are
644 * Every computation that requires local state needs a
646 * struct computation_state {
650 * Even if no local variables are required, such a state struct should
651 * be created containing a dummy variable. Quite a few helper
652 * functions and macros (for example tevent_req_create()) assume such
655 * An async computation is started by a computation_send
656 * function. When it is finished, its result can be received by a
657 * computation_recv function. For an example how to set up an async
658 * computation, see the code example in the documentation for
659 * tevent_req_create() and tevent_req_post(). The prototypes for _send
660 * and _recv functions should follow some conventions:
663 * struct tevent_req *computation_send(TALLOC_CTX *mem_ctx,
664 * struct tevent_req *ev,
666 * int computation_recv(struct tevent_req *req, ... further output args);
669 * The "int" result of computation_recv() depends on the result the
670 * sync version of the function would have, "int" is just an example
673 * Another important piece of the conventions is that the program flow
674 * is interrupted as little as possible. Because a blocking
675 * sub-computation requires that the flow needs to continue in a
676 * separate function that is the logical sequel of some computation,
677 * it should lexically follow sending off the blocking
678 * sub-computation. Setting the callback function via
679 * tevent_req_set_callback() requires referencing a function lexically
680 * below the call to tevent_req_set_callback(), forward declarations
681 * are required. A lot of the async computations thus begin with a
682 * sequence of declarations such as
685 * static void computation_step1_done(struct tevent_req *subreq);
686 * static void computation_step2_done(struct tevent_req *subreq);
687 * static void computation_step3_done(struct tevent_req *subreq);
690 * It really helps readability a lot to do these forward declarations,
691 * because the lexically sequential program flow makes the async
692 * computations almost as clear to read as a normal, sync program
695 * It is up to the user of the async computation to talloc_free it
696 * after it has finished. If an async computation should be aborted,
697 * the tevent_req structure can be talloc_free'ed. After it has
698 * finished, it should talloc_free'ed by the API user.
700 * tevent_req variable naming conventions:
702 * The name of the variable pointing to the tevent_req structure
703 * returned by a _send() function SHOULD be named differently between
704 * implementation and caller.
706 * From the point of view of the implementation (of the _send() and
707 * _recv() functions) the variable returned by tevent_req_create() is
708 * always called @em req.
710 * While the caller of the _send() function should use @em subreq to
713 * @see tevent_req_create()
714 * @see tevent_req_fn()
720 * An async request moves from TEVENT_REQ_INIT to
721 * TEVENT_REQ_IN_PROGRESS. All other states are valid after a request
724 enum tevent_req_state {
726 * We are creating the request
730 * We are waiting the request to complete
732 TEVENT_REQ_IN_PROGRESS,
734 * The request is finished successfully
738 * A user error has occurred. The user error has been
739 * indicated by tevent_req_error(), it can be retrieved via
740 * tevent_req_is_error().
742 TEVENT_REQ_USER_ERROR,
744 * Request timed out after the timeout set by tevent_req_set_endtime.
746 TEVENT_REQ_TIMED_OUT,
748 * An internal allocation has failed, or tevent_req_nomem has
749 * been given a NULL pointer as the first argument.
751 TEVENT_REQ_NO_MEMORY,
753 * The request has been received by the caller. No further
760 * @brief An async request
765 * @brief A tevent request callback function.
767 * @param[in] subreq The tevent async request which executed this callback.
769 typedef void (*tevent_req_fn)(struct tevent_req *subreq);
772 * @brief Set an async request callback.
774 * See the documentation of tevent_req_post() for an example how this
775 * is supposed to be used.
777 * @param[in] req The async request to set the callback.
779 * @param[in] fn The callback function to set.
781 * @param[in] pvt A pointer to private data to pass to the async request
784 void tevent_req_set_callback(struct tevent_req *req, tevent_req_fn fn, void *pvt);
788 * @brief Get the private data cast to the given type for a callback from
789 * a tevent request structure.
792 * static void computation_done(struct tevent_req *subreq) {
793 * struct tevent_req *req = tevent_req_callback_data(subreq, struct tevent_req);
794 * struct computation_state *state = tevent_req_data(req, struct computation_state);
795 * .... more things, eventually maybe call tevent_req_done(req);
799 * @param[in] req The structure to get the callback data from.
801 * @param[in] type The type of the private callback data to get.
803 * @return The type casted private data set NULL if not set.
805 void *tevent_req_callback_data(struct tevent_req *req, #type);
807 void *_tevent_req_callback_data(struct tevent_req *req);
808 #define tevent_req_callback_data(_req, _type) \
809 talloc_get_type_abort(_tevent_req_callback_data(_req), _type)
814 * @brief Get the private data for a callback from a tevent request structure.
816 * @param[in] req The structure to get the callback data from.
818 * @return The private data or NULL if not set.
820 void *tevent_req_callback_data_void(struct tevent_req *req);
822 #define tevent_req_callback_data_void(_req) \
823 _tevent_req_callback_data(_req)
828 * @brief Get the private data from a tevent request structure.
830 * When the tevent_req has been created by tevent_req_create, the
831 * result of tevent_req_data() is the state variable created by
832 * tevent_req_create() as a child of the req.
834 * @param[in] req The structure to get the private data from.
836 * @param[in] type The type of the private data
838 * @return The private data or NULL if not set.
840 void *tevent_req_data(struct tevent_req *req, #type);
842 void *_tevent_req_data(struct tevent_req *req);
843 #define tevent_req_data(_req, _type) \
844 talloc_get_type_abort(_tevent_req_data(_req), _type)
848 * @brief The print function which can be set for a tevent async request.
850 * @param[in] req The tevent async request.
852 * @param[in] ctx A talloc memory context which can be uses to allocate
855 * @return An allocated string buffer to print.
859 * static char *my_print(struct tevent_req *req, TALLOC_CTX *mem_ctx)
861 * struct my_data *data = tevent_req_data(req, struct my_data);
864 * result = tevent_req_default_print(mem_ctx, req);
865 * if (result == NULL) {
869 * return talloc_asprintf_append_buffer(result, "foo=%d, bar=%d",
870 * data->foo, data->bar);
874 typedef char *(*tevent_req_print_fn)(struct tevent_req *req, TALLOC_CTX *ctx);
877 * @brief This function sets a print function for the given request.
879 * This function can be used to setup a print function for the given request.
880 * This will be triggered if the tevent_req_print() function was
881 * called on the given request.
883 * @param[in] req The request to use.
885 * @param[in] fn A pointer to the print function
887 * @note This function should only be used for debugging.
889 void tevent_req_set_print_fn(struct tevent_req *req, tevent_req_print_fn fn);
892 * @brief The default print function for creating debug messages.
894 * The function should not be used by users of the async API,
895 * but custom print function can use it and append custom text
898 * @param[in] req The request to be printed.
900 * @param[in] mem_ctx The memory context for the result.
902 * @return Text representation of request.
905 char *tevent_req_default_print(struct tevent_req *req, TALLOC_CTX *mem_ctx);
908 * @brief Print an tevent_req structure in debug messages.
910 * This function should be used by callers of the async API.
912 * @param[in] mem_ctx The memory context for the result.
914 * @param[in] req The request to be printed.
916 * @return Text representation of request.
918 char *tevent_req_print(TALLOC_CTX *mem_ctx, struct tevent_req *req);
921 * @brief A typedef for a cancel function for a tevent request.
923 * @param[in] req The tevent request calling this function.
925 * @return True if the request could be canceled, false if not.
927 typedef bool (*tevent_req_cancel_fn)(struct tevent_req *req);
930 * @brief This function sets a cancel function for the given tevent request.
932 * This function can be used to setup a cancel function for the given request.
933 * This will be triggered if the tevent_req_cancel() function was
934 * called on the given request.
936 * @param[in] req The request to use.
938 * @param[in] fn A pointer to the cancel function.
940 void tevent_req_set_cancel_fn(struct tevent_req *req, tevent_req_cancel_fn fn);
944 * @brief Try to cancel the given tevent request.
946 * This function can be used to cancel the given request.
948 * It is only possible to cancel a request when the implementation
949 * has registered a cancel function via the tevent_req_set_cancel_fn().
951 * @param[in] req The request to use.
953 * @return This function returns true if the request is
954 * cancelable, otherwise false is returned.
956 * @note Even if the function returns true, the caller need to wait
957 * for the function to complete normally.
958 * Only the _recv() function of the given request indicates
959 * if the request was really canceled.
961 bool tevent_req_cancel(struct tevent_req *req);
963 bool _tevent_req_cancel(struct tevent_req *req, const char *location);
964 #define tevent_req_cancel(req) \
965 _tevent_req_cancel(req, __location__)
969 * @brief A typedef for a cleanup function for a tevent request.
971 * @param[in] req The tevent request calling this function.
973 * @param[in] req_state The current tevent_req_state.
976 typedef void (*tevent_req_cleanup_fn)(struct tevent_req *req,
977 enum tevent_req_state req_state);
980 * @brief This function sets a cleanup function for the given tevent request.
982 * This function can be used to setup a cleanup function for the given request.
983 * This will be triggered when the tevent_req_done() or tevent_req_error()
984 * function was called, before notifying the callers callback function,
985 * and also before scheduling the deferred trigger.
987 * This might be useful if more than one tevent_req belong together
988 * and need to finish both requests at the same time.
990 * The cleanup function is able to call tevent_req_done() or tevent_req_error()
991 * recursively, the cleanup function is only triggered the first time.
993 * The cleanup function is also called by tevent_req_received()
994 * (possibly triggered from tevent_req_destructor()) before destroying
995 * the private data of the tevent_req.
997 * @param[in] req The request to use.
999 * @param[in] fn A pointer to the cancel function.
1001 void tevent_req_set_cleanup_fn(struct tevent_req *req, tevent_req_cleanup_fn fn);
1005 * @brief Create an async tevent request.
1007 * The new async request will be initialized in state TEVENT_REQ_IN_PROGRESS.
1010 * struct tevent_req *req;
1011 * struct computation_state *state;
1012 * req = tevent_req_create(mem_ctx, &state, struct computation_state);
1015 * Tevent_req_create() allocates and zeros the state variable as a talloc
1016 * child of its result. The state variable should be used as the talloc
1017 * parent for all temporary variables that are allocated during the async
1018 * computation. This way, when the user of the async computation frees
1019 * the request, the state as a talloc child will be free'd along with
1020 * all the temporary variables hanging off the state.
1022 * @param[in] mem_ctx The memory context for the result.
1023 * @param[in] pstate Pointer to the private request state.
1024 * @param[in] type The name of the request.
1026 * @return A new async request. NULL on error.
1028 struct tevent_req *tevent_req_create(TALLOC_CTX *mem_ctx,
1029 void **pstate, #type);
1031 struct tevent_req *_tevent_req_create(TALLOC_CTX *mem_ctx,
1035 const char *location);
1037 #define tevent_req_create(_mem_ctx, _pstate, _type) \
1038 _tevent_req_create((_mem_ctx), (_pstate), sizeof(_type), \
1039 #_type, __location__)
1043 * @brief Set a timeout for an async request. On failure, "req" is already
1044 * set to state TEVENT_REQ_NO_MEMORY.
1046 * @param[in] req The request to set the timeout for.
1048 * @param[in] ev The event context to use for the timer.
1050 * @param[in] endtime The endtime of the request.
1052 * @return True if succeeded, false if not.
1054 bool tevent_req_set_endtime(struct tevent_req *req,
1055 struct tevent_context *ev,
1056 struct timeval endtime);
1059 * @brief Reset the timer set by tevent_req_set_endtime.
1061 * @param[in] req The request to reset the timeout for
1063 void tevent_req_reset_endtime(struct tevent_req *req);
1067 * @brief Call the notify callback of the given tevent request manually.
1069 * @param[in] req The tevent request to call the notify function from.
1071 * @see tevent_req_set_callback()
1073 void tevent_req_notify_callback(struct tevent_req *req);
1075 void _tevent_req_notify_callback(struct tevent_req *req, const char *location);
1076 #define tevent_req_notify_callback(req) \
1077 _tevent_req_notify_callback(req, __location__)
1082 * @brief An async request has successfully finished.
1084 * This function is to be used by implementors of async requests. When a
1085 * request is successfully finished, this function calls the user's completion
1088 * @param[in] req The finished request.
1090 void tevent_req_done(struct tevent_req *req);
1092 void _tevent_req_done(struct tevent_req *req,
1093 const char *location);
1094 #define tevent_req_done(req) \
1095 _tevent_req_done(req, __location__)
1100 * @brief An async request has seen an error.
1102 * This function is to be used by implementors of async requests. When a
1103 * request can not successfully completed, the implementation should call this
1104 * function with the appropriate status code.
1106 * If error is 0 the function returns false and does nothing more.
1108 * @param[in] req The request with an error.
1110 * @param[in] error The error code.
1112 * @return On success true is returned, false if error is 0.
1115 * int error = first_function();
1116 * if (tevent_req_error(req, error)) {
1120 * error = second_function();
1121 * if (tevent_req_error(req, error)) {
1125 * tevent_req_done(req);
1129 bool tevent_req_error(struct tevent_req *req,
1132 bool _tevent_req_error(struct tevent_req *req,
1134 const char *location);
1135 #define tevent_req_error(req, error) \
1136 _tevent_req_error(req, error, __location__)
1141 * @brief Helper function for nomem check.
1143 * Convenience helper to easily check alloc failure within a callback
1144 * implementing the next step of an async request.
1146 * @param[in] p The pointer to be checked.
1148 * @param[in] req The request being processed.
1151 * p = talloc(mem_ctx, bla);
1152 * if (tevent_req_nomem(p, req)) {
1157 bool tevent_req_nomem(const void *p,
1158 struct tevent_req *req);
1160 bool _tevent_req_nomem(const void *p,
1161 struct tevent_req *req,
1162 const char *location);
1163 #define tevent_req_nomem(p, req) \
1164 _tevent_req_nomem(p, req, __location__)
1169 * @brief Indicate out of memory to a request
1171 * @param[in] req The request being processed.
1173 void tevent_req_oom(struct tevent_req *req);
1175 void _tevent_req_oom(struct tevent_req *req,
1176 const char *location);
1177 #define tevent_req_oom(req) \
1178 _tevent_req_oom(req, __location__)
1182 * @brief Finish a request before the caller had the change to set the callback.
1184 * An implementation of an async request might find that it can either finish
1185 * the request without waiting for an external event, or it can not even start
1186 * the engine. To present the illusion of a callback to the user of the API,
1187 * the implementation can call this helper function which triggers an
1188 * immediate event. This way the caller can use the same calling
1189 * conventions, independent of whether the request was actually deferred.
1192 * struct tevent_req *computation_send(TALLOC_CTX *mem_ctx,
1193 * struct tevent_context *ev)
1195 * struct tevent_req *req, *subreq;
1196 * struct computation_state *state;
1197 * req = tevent_req_create(mem_ctx, &state, struct computation_state);
1198 * if (req == NULL) {
1201 * subreq = subcomputation_send(state, ev);
1202 * if (tevent_req_nomem(subreq, req)) {
1203 * return tevent_req_post(req, ev);
1205 * tevent_req_set_callback(subreq, computation_done, req);
1210 * @param[in] req The finished request.
1212 * @param[in] ev The tevent_context for the immediate event.
1214 * @return The given request will be returned.
1216 struct tevent_req *tevent_req_post(struct tevent_req *req,
1217 struct tevent_context *ev);
1220 * @brief Finish multiple requests within one function
1222 * Normally tevent_req_notify_callback() and all wrappers
1223 * (e.g. tevent_req_done() and tevent_req_error())
1224 * need to be the last thing an event handler should call.
1225 * This is because the callback is likely to destroy the
1226 * context of the current function.
1228 * If a function wants to notify more than one caller,
1229 * it is dangerous if it just triggers multiple callbacks
1230 * in a row. With tevent_req_defer_callback() it is possible
1231 * to set an event context that will be used to defer the callback
1232 * via an immediate event (similar to tevent_req_post()).
1235 * struct complete_state {
1236 * struct tevent_context *ev;
1238 * struct tevent_req **reqs;
1241 * void complete(struct complete_state *state)
1243 * size_t i, c = talloc_array_length(state->reqs);
1245 * for (i=0; i < c; i++) {
1246 * tevent_req_defer_callback(state->reqs[i], state->ev);
1247 * tevent_req_done(state->reqs[i]);
1252 * @param[in] req The finished request.
1254 * @param[in] ev The tevent_context for the immediate event.
1256 * @return The given request will be returned.
1258 void tevent_req_defer_callback(struct tevent_req *req,
1259 struct tevent_context *ev);
1262 * @brief Check if the given request is still in progress.
1264 * It is typically used by sync wrapper functions.
1266 * @param[in] req The request to poll.
1268 * @return The boolean form of "is in progress".
1270 bool tevent_req_is_in_progress(struct tevent_req *req);
1273 * @brief Actively poll for the given request to finish.
1275 * This function is typically used by sync wrapper functions.
1277 * @param[in] req The request to poll.
1279 * @param[in] ev The tevent_context to be used.
1281 * @return On success true is returned. If a critical error has
1282 * happened in the tevent loop layer false is returned.
1283 * This is not the return value of the given request!
1285 * @note This should only be used if the given tevent context was created by the
1286 * caller, to avoid event loop nesting.
1289 * req = tstream_writev_queue_send(mem_ctx,
1294 * ok = tevent_req_poll(req, tctx->ev);
1295 * rc = tstream_writev_queue_recv(req, &sys_errno);
1299 bool tevent_req_poll(struct tevent_req *req,
1300 struct tevent_context *ev);
1303 * @brief Get the tevent request state and the actual error set by
1307 * int computation_recv(struct tevent_req *req, uint64_t *perr)
1309 * enum tevent_req_state state;
1311 * if (tevent_req_is_error(req, &state, &err)) {
1319 * @param[in] req The tevent request to get the error from.
1321 * @param[out] state A pointer to store the tevent request error state.
1323 * @param[out] error A pointer to store the error set by tevent_req_error().
1325 * @return True if the function could set error and state, false
1328 * @see tevent_req_error()
1330 bool tevent_req_is_error(struct tevent_req *req,
1331 enum tevent_req_state *state,
1335 * @brief Use as the last action of a _recv() function.
1337 * This function destroys the attached private data.
1339 * @param[in] req The finished request.
1341 void tevent_req_received(struct tevent_req *req);
1344 * @brief Create a tevent subrequest at a given time.
1346 * The idea is that always the same syntax for tevent requests.
1348 * @param[in] mem_ctx The talloc memory context to use.
1350 * @param[in] ev The event handle to setup the request.
1352 * @param[in] wakeup_time The time to wakeup and execute the request.
1354 * @return The new subrequest, NULL on error.
1358 * static void my_callback_wakeup_done(tevent_req *subreq)
1360 * struct tevent_req *req = tevent_req_callback_data(subreq,
1361 * struct tevent_req);
1364 * ok = tevent_wakeup_recv(subreq);
1365 * TALLOC_FREE(subreq);
1367 * tevent_req_error(req, -1);
1375 * subreq = tevent_wakeup_send(mem_ctx, ev, wakeup_time);
1376 * if (tevent_req_nomem(subreq, req)) {
1379 * tevent_set_callback(subreq, my_callback_wakeup_done, req);
1382 * @see tevent_wakeup_recv()
1384 struct tevent_req *tevent_wakeup_send(TALLOC_CTX *mem_ctx,
1385 struct tevent_context *ev,
1386 struct timeval wakeup_time);
1389 * @brief Check if the wakeup has been correctly executed.
1391 * This function needs to be called in the callback function set after calling
1392 * tevent_wakeup_send().
1394 * @param[in] req The tevent request to check.
1396 * @return True on success, false otherwise.
1398 * @see tevent_wakeup_recv()
1400 bool tevent_wakeup_recv(struct tevent_req *req);
1405 * @defgroup tevent_helpers The tevent helper functions
1414 * @brief Compare two timeval values.
1416 * @param[in] tv1 The first timeval value to compare.
1418 * @param[in] tv2 The second timeval value to compare.
1420 * @return 0 if they are equal.
1421 * 1 if the first time is greater than the second.
1422 * -1 if the first time is smaller than the second.
1424 int tevent_timeval_compare(const struct timeval *tv1,
1425 const struct timeval *tv2);
1428 * @brief Get a zero timeval value.
1430 * @return A zero timeval value.
1432 struct timeval tevent_timeval_zero(void);
1435 * @brief Get a timeval value for the current time.
1437 * @return A timeval value with the current time.
1439 struct timeval tevent_timeval_current(void);
1442 * @brief Get a timeval structure with the given values.
1444 * @param[in] secs The seconds to set.
1446 * @param[in] usecs The microseconds to set.
1448 * @return A timeval structure with the given values.
1450 struct timeval tevent_timeval_set(uint32_t secs, uint32_t usecs);
1453 * @brief Get the difference between two timeval values.
1455 * @param[in] tv1 The first timeval.
1457 * @param[in] tv2 The second timeval.
1459 * @return A timeval structure with the difference between the
1460 * first and the second value.
1462 struct timeval tevent_timeval_until(const struct timeval *tv1,
1463 const struct timeval *tv2);
1466 * @brief Check if a given timeval structure is zero.
1468 * @param[in] tv The timeval to check if it is zero.
1470 * @return True if it is zero, false otherwise.
1472 bool tevent_timeval_is_zero(const struct timeval *tv);
1475 * @brief Add the given amount of time to a timeval structure.
1477 * @param[in] tv The timeval structure to add the time.
1479 * @param[in] secs The seconds to add to the timeval.
1481 * @param[in] usecs The microseconds to add to the timeval.
1483 * @return The timeval structure with the new time.
1485 struct timeval tevent_timeval_add(const struct timeval *tv, uint32_t secs,
1489 * @brief Get a timeval in the future with a specified offset from now.
1491 * @param[in] secs The seconds of the offset from now.
1493 * @param[in] usecs The microseconds of the offset from now.
1495 * @return A timval with the given offset in the future.
1497 struct timeval tevent_timeval_current_ofs(uint32_t secs, uint32_t usecs);
1503 * @defgroup tevent_queue The tevent queue functions
1506 * A tevent_queue is used to queue up async requests that must be
1507 * serialized. For example writing buffers into a socket must be
1508 * serialized. Writing a large lump of data into a socket can require
1509 * multiple write(2) or send(2) system calls. If more than one async
1510 * request is outstanding to write large buffers into a socket, every
1511 * request must individually be completed before the next one begins,
1512 * even if multiple syscalls are required.
1514 * Take a look at @ref tevent_queue_tutorial for more details.
1518 struct tevent_queue;
1519 struct tevent_queue_entry;
1523 * @brief Create and start a tevent queue.
1525 * @param[in] mem_ctx The talloc memory context to allocate the queue.
1527 * @param[in] name The name to use to identify the queue.
1529 * @return An allocated tevent queue on success, NULL on error.
1531 * @see tevent_queue_start()
1532 * @see tevent_queue_stop()
1534 struct tevent_queue *tevent_queue_create(TALLOC_CTX *mem_ctx,
1537 struct tevent_queue *_tevent_queue_create(TALLOC_CTX *mem_ctx,
1539 const char *location);
1541 #define tevent_queue_create(_mem_ctx, _name) \
1542 _tevent_queue_create((_mem_ctx), (_name), __location__)
1546 * @brief A callback trigger function run by the queue.
1548 * @param[in] req The tevent request the trigger function is executed on.
1550 * @param[in] private_data The private data pointer specified by
1551 * tevent_queue_add().
1553 * @see tevent_queue_add()
1554 * @see tevent_queue_add_entry()
1555 * @see tevent_queue_add_optimize_empty()
1557 typedef void (*tevent_queue_trigger_fn_t)(struct tevent_req *req,
1558 void *private_data);
1561 * @brief Add a tevent request to the queue.
1563 * @param[in] queue The queue to add the request.
1565 * @param[in] ev The event handle to use for the request.
1567 * @param[in] req The tevent request to add to the queue.
1569 * @param[in] trigger The function triggered by the queue when the request
1570 * is called. Since tevent 0.9.14 it's possible to
1571 * pass NULL, in order to just add a "blocker" to the
1574 * @param[in] private_data The private data passed to the trigger function.
1576 * @return True if the request has been successfully added, false
1579 bool tevent_queue_add(struct tevent_queue *queue,
1580 struct tevent_context *ev,
1581 struct tevent_req *req,
1582 tevent_queue_trigger_fn_t trigger,
1583 void *private_data);
1586 * @brief Add a tevent request to the queue.
1588 * The request can be removed from the queue by calling talloc_free()
1589 * (or a similar function) on the returned queue entry. This
1590 * is the only difference to tevent_queue_add().
1592 * @param[in] queue The queue to add the request.
1594 * @param[in] ev The event handle to use for the request.
1596 * @param[in] req The tevent request to add to the queue.
1598 * @param[in] trigger The function triggered by the queue when the request
1599 * is called. Since tevent 0.9.14 it's possible to
1600 * pass NULL, in order to just add a "blocker" to the
1603 * @param[in] private_data The private data passed to the trigger function.
1605 * @return a pointer to the tevent_queue_entry if the request
1606 * has been successfully added, NULL otherwise.
1608 * @see tevent_queue_add()
1609 * @see tevent_queue_add_optimize_empty()
1611 struct tevent_queue_entry *tevent_queue_add_entry(
1612 struct tevent_queue *queue,
1613 struct tevent_context *ev,
1614 struct tevent_req *req,
1615 tevent_queue_trigger_fn_t trigger,
1616 void *private_data);
1619 * @brief Add a tevent request to the queue using a possible optimization.
1621 * This tries to optimize for the empty queue case and may calls
1622 * the trigger function directly. This is the only difference compared
1623 * to tevent_queue_add_entry().
1625 * The caller needs to be prepared that the trigger function has
1626 * already called tevent_req_notify_callback(), tevent_req_error(),
1627 * tevent_req_done() or a similar function.
1629 * The trigger function has no chance to see the returned
1630 * queue_entry in the optimized case.
1632 * The request can be removed from the queue by calling talloc_free()
1633 * (or a similar function) on the returned queue entry.
1635 * @param[in] queue The queue to add the request.
1637 * @param[in] ev The event handle to use for the request.
1639 * @param[in] req The tevent request to add to the queue.
1641 * @param[in] trigger The function triggered by the queue when the request
1642 * is called. Since tevent 0.9.14 it's possible to
1643 * pass NULL, in order to just add a "blocker" to the
1646 * @param[in] private_data The private data passed to the trigger function.
1648 * @return a pointer to the tevent_queue_entry if the request
1649 * has been successfully added, NULL otherwise.
1651 * @see tevent_queue_add()
1652 * @see tevent_queue_add_entry()
1654 struct tevent_queue_entry *tevent_queue_add_optimize_empty(
1655 struct tevent_queue *queue,
1656 struct tevent_context *ev,
1657 struct tevent_req *req,
1658 tevent_queue_trigger_fn_t trigger,
1659 void *private_data);
1662 * @brief Untrigger an already triggered queue entry.
1664 * If a trigger function detects that it needs to remain
1665 * in the queue, it needs to call tevent_queue_stop()
1666 * followed by tevent_queue_entry_untrigger().
1668 * @note In order to call tevent_queue_entry_untrigger()
1669 * the queue must be already stopped and the given queue_entry
1670 * must be the first one in the queue! Otherwise it calls abort().
1672 * @note You can't use this together with tevent_queue_add_optimize_empty()
1673 * because the trigger function don't have access to the quene entry
1674 * in the case of an empty queue.
1676 * @param[in] queue_entry The queue entry to rearm.
1678 * @see tevent_queue_add_entry()
1679 * @see tevent_queue_stop()
1681 void tevent_queue_entry_untrigger(struct tevent_queue_entry *entry);
1684 * @brief Start a tevent queue.
1686 * The queue is started by default.
1688 * @param[in] queue The queue to start.
1690 void tevent_queue_start(struct tevent_queue *queue);
1693 * @brief Stop a tevent queue.
1695 * The queue is started by default.
1697 * @param[in] queue The queue to stop.
1699 void tevent_queue_stop(struct tevent_queue *queue);
1702 * @brief Get the length of the queue.
1704 * @param[in] queue The queue to get the length from.
1706 * @return The number of elements.
1708 size_t tevent_queue_length(struct tevent_queue *queue);
1711 * @brief Is the tevent queue running.
1713 * The queue is started by default.
1715 * @param[in] queue The queue.
1717 * @return Wether the queue is running or not..
1719 bool tevent_queue_running(struct tevent_queue *queue);
1722 * @brief Create a tevent subrequest that waits in a tevent_queue
1724 * The idea is that always the same syntax for tevent requests.
1726 * @param[in] mem_ctx The talloc memory context to use.
1728 * @param[in] ev The event handle to setup the request.
1730 * @param[in] queue The queue to wait in.
1732 * @return The new subrequest, NULL on error.
1734 * @see tevent_queue_wait_recv()
1736 struct tevent_req *tevent_queue_wait_send(TALLOC_CTX *mem_ctx,
1737 struct tevent_context *ev,
1738 struct tevent_queue *queue);
1741 * @brief Check if we no longer need to wait in the queue.
1743 * This function needs to be called in the callback function set after calling
1744 * tevent_queue_wait_send().
1746 * @param[in] req The tevent request to check.
1748 * @return True on success, false otherwise.
1750 * @see tevent_queue_wait_send()
1752 bool tevent_queue_wait_recv(struct tevent_req *req);
1754 typedef int (*tevent_nesting_hook)(struct tevent_context *ev,
1759 const char *location);
1762 * @brief Create a tevent_thread_proxy for message passing between threads.
1764 * The tevent_context must have been allocated on the NULL
1765 * talloc context, and talloc_disable_null_tracking() must
1768 * @param[in] dest_ev_ctx The tevent_context to receive events.
1770 * @return An allocated tevent_thread_proxy, NULL on error.
1771 * If tevent was compiled without PTHREAD support
1772 * NULL is always returned and errno set to ENOSYS.
1774 * @see tevent_thread_proxy_schedule()
1776 struct tevent_thread_proxy *tevent_thread_proxy_create(
1777 struct tevent_context *dest_ev_ctx);
1780 * @brief Schedule an immediate event on an event context from another thread.
1782 * Causes dest_ev_ctx, being run by another thread, to receive an
1783 * immediate event calling the handler with the *pp_private parameter.
1785 * *pp_im must be a pointer to an immediate event talloced on a context owned
1786 * by the calling thread, or the NULL context. Ownership will
1787 * be transferred to the tevent_thread_proxy and *pp_im will be returned as NULL.
1789 * *pp_private_data must be a talloced area of memory with no destructors.
1790 * Ownership of this memory will be transferred to the tevent library and
1791 * *pp_private_data will be set to NULL on successful completion of
1792 * the call. Set pp_private to NULL if no parameter transfer
1793 * needed (a pure callback). This is an asynchronous request, caller
1794 * does not wait for callback to be completed before returning.
1796 * @param[in] tp The tevent_thread_proxy to use.
1798 * @param[in] pp_im Pointer to immediate event pointer.
1800 * @param[in] handler The function that will be called.
1802 * @param[in] pp_private_data The talloced memory to transfer.
1804 * @see tevent_thread_proxy_create()
1806 void tevent_thread_proxy_schedule(struct tevent_thread_proxy *tp,
1807 struct tevent_immediate **pp_im,
1808 tevent_immediate_handler_t handler,
1809 void *pp_private_data);
1812 * @brief Create a context for threaded activation of immediates
1814 * A tevent_treaded_context provides a link into an event
1815 * context. Using tevent_threaded_schedule_immediate, it is possible
1816 * to activate an immediate event from within a thread.
1818 * It is the duty of the caller of tevent_threaded_context_create() to
1819 * keep the event context around longer than any
1820 * tevent_threaded_context. tevent will abort if ev is talloc_free'ed
1821 * with an active tevent_threaded_context.
1823 * If tevent is build without pthread support, this always returns
1824 * NULL with errno=ENOSYS.
1826 * @param[in] mem_ctx The talloc memory context to use.
1827 * @param[in] ev The event context to link this to.
1828 * @return The threaded context, or NULL with errno set.
1830 * @see tevent_threaded_schedule_immediate()
1832 * @note Available as of tevent 0.9.30
1834 struct tevent_threaded_context *tevent_threaded_context_create(
1835 TALLOC_CTX *mem_ctx, struct tevent_context *ev);
1839 * @brief Activate an immediate from a thread
1841 * Activate an immediate from within a thread.
1843 * This routine does not watch out for talloc hierarchies. This means
1844 * that it is highly recommended to create the tevent_immediate in the
1845 * thread owning tctx, allocate a threaded job description for the
1846 * thread, hand over both pointers to a helper thread and not touch it
1847 * in the main thread at all anymore.
1849 * tevent_threaded_schedule_immediate is intended as a job completion
1850 * indicator for simple threaded helpers.
1852 * Please be aware that tevent_threaded_schedule_immediate is very
1853 * picky about its arguments: An immediate may not already be
1854 * activated and the handler must exist. With
1855 * tevent_threaded_schedule_immediate memory ownership is transferred
1856 * to the main thread holding the tevent context behind tctx, the
1857 * helper thread can't access it anymore.
1859 * @param[in] tctx The threaded context to go through
1860 * @param[in] im The immediate event to activate
1861 * @param[in] handler The immediate handler to call in the main thread
1862 * @param[in] private_data Pointer for the immediate handler
1864 * @see tevent_threaded_context_create()
1866 * @note Available as of tevent 0.9.30
1868 void tevent_threaded_schedule_immediate(struct tevent_threaded_context *tctx,
1869 struct tevent_immediate *im,
1870 tevent_immediate_handler_t handler,
1871 void *private_data);
1873 void _tevent_threaded_schedule_immediate(struct tevent_threaded_context *tctx,
1874 struct tevent_immediate *im,
1875 tevent_immediate_handler_t handler,
1877 const char *handler_name,
1878 const char *location);
1879 #define tevent_threaded_schedule_immediate(tctx, im, handler, private_data) \
1880 _tevent_threaded_schedule_immediate(tctx, im, handler, private_data, \
1881 #handler, __location__);
1884 #ifdef TEVENT_DEPRECATED
1885 #ifndef _DEPRECATED_
1886 #ifdef HAVE___ATTRIBUTE__
1887 #define _DEPRECATED_ __attribute__ ((deprecated))
1889 #define _DEPRECATED_
1892 void tevent_loop_allow_nesting(struct tevent_context *ev) _DEPRECATED_;
1893 void tevent_loop_set_nesting_hook(struct tevent_context *ev,
1894 tevent_nesting_hook hook,
1895 void *private_data) _DEPRECATED_;
1896 int _tevent_loop_until(struct tevent_context *ev,
1897 bool (*finished)(void *private_data),
1899 const char *location) _DEPRECATED_;
1900 #define tevent_loop_until(ev, finished, private_data) \
1901 _tevent_loop_until(ev, finished, private_data, __location__)
1904 int tevent_re_initialise(struct tevent_context *ev);
1909 * @defgroup tevent_ops The tevent operation functions
1912 * The following structure and registration functions are exclusively
1913 * needed for people writing and pluggin a different event engine.
1914 * There is nothing useful for normal tevent user in here.
1920 int (*context_init)(struct tevent_context *ev);
1922 /* fd_event functions */
1923 struct tevent_fd *(*add_fd)(struct tevent_context *ev,
1924 TALLOC_CTX *mem_ctx,
1925 int fd, uint16_t flags,
1926 tevent_fd_handler_t handler,
1928 const char *handler_name,
1929 const char *location);
1930 void (*set_fd_close_fn)(struct tevent_fd *fde,
1931 tevent_fd_close_fn_t close_fn);
1932 uint16_t (*get_fd_flags)(struct tevent_fd *fde);
1933 void (*set_fd_flags)(struct tevent_fd *fde, uint16_t flags);
1935 /* timed_event functions */
1936 struct tevent_timer *(*add_timer)(struct tevent_context *ev,
1937 TALLOC_CTX *mem_ctx,
1938 struct timeval next_event,
1939 tevent_timer_handler_t handler,
1941 const char *handler_name,
1942 const char *location);
1944 /* immediate event functions */
1945 void (*schedule_immediate)(struct tevent_immediate *im,
1946 struct tevent_context *ev,
1947 tevent_immediate_handler_t handler,
1949 const char *handler_name,
1950 const char *location);
1952 /* signal functions */
1953 struct tevent_signal *(*add_signal)(struct tevent_context *ev,
1954 TALLOC_CTX *mem_ctx,
1955 int signum, int sa_flags,
1956 tevent_signal_handler_t handler,
1958 const char *handler_name,
1959 const char *location);
1961 /* loop functions */
1962 int (*loop_once)(struct tevent_context *ev, const char *location);
1963 int (*loop_wait)(struct tevent_context *ev, const char *location);
1966 bool tevent_register_backend(const char *name, const struct tevent_ops *ops);
1970 struct tevent_threadpool;
1973 * @defgroup tevent_threadpool The tevent_threadpool API
1975 * This API provides a way to run threadsafe functions via tevent
1976 * requests in a helper threadpool.
1981 * @brief Create a tevent_threadpool
1983 * A struct tevent_threadpool is the basis for for running tevent
1984 * requests in parralel in a threadpool.
1986 * @param[in] max_threads Maximum parallelism in this pool
1987 * @param[in] ev tevent_context the pool lives in
1988 * @param[out] presult Pointer to the threadpool returned
1989 * @return success: 0, failure: errno
1991 * max_threads=0 means unlimited parallelism. The caller has to take
1992 * care to not overload the system.
1994 struct tevent_threadpool *tevent_threadpool_create(TALLOC_CTX *mem_ctx,
1995 struct tevent_context *ev,
1998 struct tevent_threadpool *_tevent_threadpool_create(TALLOC_CTX *mem_ctx,
1999 struct tevent_context *ev,
2001 const char *location);
2002 #define tevent_threadpool_create(mem_ctx, ev, max_threads) \
2003 _tevent_threadpool_create((mem_ctx), (ev), (max_threads), \
2009 * @brief Destroy a tevent_threadpool
2011 * Destroy a tevent_threadpool. If jobs are still active, those are
2012 * cancelled and waited upon.
2014 * @param[in] pool The pool to destroy
2015 * @return success: 0, failure: errno
2017 int tevent_threadpool_destroy(struct tevent_threadpool *pool);
2021 * @brief Create a job to run in a threadpool
2023 * Only one instance of the job can run at a time,
2024 * but the job can be reused multiple times.
2026 If you want to run multiple instances of similar jobs
2027 * at the same time, you need to create a tevent_threadpool_job
2028 * for each instance.
2030 * @param[in] mem_ctx The memory context for the result.
2031 * @param[in] fn The function to execute the job (must be thread safe!)
2032 * @param[in] pstate Pointer to the request state.
2033 * @param[in] type The name of the job.
2035 struct tevent_threadpool_job *tevent_threadpool_job_create(TALLOC_CTX *mem_ctx,
2039 struct tevent_threadpool_job_description {
2040 int (*fn)(void *args);
2041 const char *args_type;
2045 #define TEVENT_THREADPOOL_JOB_DESCRIPTION_DECL(__fn) \
2046 static const struct tevent_threadpool_job_description *__fn##_description(void) \
2048 static const union { \
2049 struct tevent_threadpool_job_description generic; \
2051 int (*fn)(struct __fn##_args *args); \
2052 const char *args_type; \
2058 .args_type = "struct " #__fn "_args", \
2059 .args_size = sizeof(struct __fn##_args), \
2063 return &description.generic; \
2066 struct tevent_threadpool_job *_tevent_threadpool_job_create(TALLOC_CTX *mem_ct,
2067 const struct tevent_threadpool_job_description *desc,
2069 const char *location);
2071 #define tevent_threadpool_job_create(mem_ctx, __fn, pargs) \
2072 _tevent_threadpool_job_create((mem_ctx), __fn##_description(), \
2073 (pargs), __location__)
2078 * @brief Schedule a computation to run in a threadpool
2080 * @param[in] mem_ctx The talloc memory context to use.
2081 * @param[in] ev The event handle to setup the request.
2082 * @param[in] pool The threadpool to use
2083 * @param[in] job The job to run
2084 * @return tevent request on sucess, NULL on failure
2086 struct tevent_req *tevent_threadpool_job_send(TALLOC_CTX *mem_ctx,
2087 struct tevent_context *ev,
2088 struct tevent_threadpool *pool,
2089 struct tevent_threadpool_job *job);
2092 * @brief Get the result of a computation
2094 * @param[in] req the computation request
2095 * @param[out] perror errno in case of failure
2096 * @return 0 on sucess or -1 if an error occured
2098 int tevent_threadpool_job_recv(struct tevent_req *req, int *perror);
2101 * @defgroup tevent_wrapper_ops The tevent wrapper operation functions
2104 * The following structure and registration functions are exclusively
2105 * needed for people writing wrapper functions for event handlers
2106 * e.g. wrappers can be used for debugging/profiling or impersonation.
2108 * There is nothing useful for normal tevent user in here.
2112 struct tevent_wrapper_ops {
2115 bool (*before_use)(struct tevent_context *wrap_ev,
2116 void *private_state,
2117 struct tevent_context *main_ev,
2118 const char *location);
2119 void (*after_use)(struct tevent_context *wrap_ev,
2120 void *private_state,
2121 struct tevent_context *main_ev,
2122 const char *location);
2124 void (*before_fd_handler)(struct tevent_context *wrap_ev,
2125 void *private_state,
2126 struct tevent_context *main_ev,
2127 struct tevent_fd *fde,
2129 const char *handler_name,
2130 const char *location);
2131 void (*after_fd_handler)(struct tevent_context *wrap_ev,
2132 void *private_state,
2133 struct tevent_context *main_ev,
2134 struct tevent_fd *fde,
2136 const char *handler_name,
2137 const char *location);
2139 void (*before_timer_handler)(struct tevent_context *wrap_ev,
2140 void *private_state,
2141 struct tevent_context *main_ev,
2142 struct tevent_timer *te,
2143 struct timeval requested_time,
2144 struct timeval trigger_time,
2145 const char *handler_name,
2146 const char *location);
2147 void (*after_timer_handler)(struct tevent_context *wrap_ev,
2148 void *private_state,
2149 struct tevent_context *main_ev,
2150 struct tevent_timer *te,
2151 struct timeval requested_time,
2152 struct timeval trigger_time,
2153 const char *handler_name,
2154 const char *location);
2156 void (*before_immediate_handler)(struct tevent_context *wrap_ev,
2157 void *private_state,
2158 struct tevent_context *main_ev,
2159 struct tevent_immediate *im,
2160 const char *handler_name,
2161 const char *location);
2162 void (*after_immediate_handler)(struct tevent_context *wrap_ev,
2163 void *private_state,
2164 struct tevent_context *main_ev,
2165 struct tevent_immediate *im,
2166 const char *handler_name,
2167 const char *location);
2169 void (*before_signal_handler)(struct tevent_context *wrap_ev,
2170 void *private_state,
2171 struct tevent_context *main_ev,
2172 struct tevent_signal *se,
2176 const char *handler_name,
2177 const char *location);
2178 void (*after_signal_handler)(struct tevent_context *wrap_ev,
2179 void *private_state,
2180 struct tevent_context *main_ev,
2181 struct tevent_signal *se,
2185 const char *handler_name,
2186 const char *location);
2191 * @brief Create a wrapper tevent_context.
2193 * @param[in] main_ev The main event context to work on.
2195 * @param[in] mem_ctx The talloc memory context to use.
2197 * @param[in] ops The tevent_wrapper_ops function table.
2199 * @param[out] private_state The private state use by the wrapper functions.
2201 * @param[in] private_type The talloc type of the private_state.
2203 * @return The wrapper event context, NULL on error.
2206 struct tevent_context *tevent_context_wrapper_create(struct tevent_context *main_ev,
2207 TALLOC_CTX *mem_ctx,
2208 const struct tevent_wrapper_ops *ops,
2209 void **private_state,
2210 const char *private_type);
2212 struct tevent_context *_tevent_context_wrapper_create(struct tevent_context *main_ev,
2213 TALLOC_CTX *mem_ctx,
2214 const struct tevent_wrapper_ops *ops,
2218 const char *location);
2219 #define tevent_context_wrapper_create(main_ev, mem_ctx, ops, state, type) \
2220 _tevent_context_wrapper_create(main_ev, mem_ctx, ops, \
2221 state, sizeof(type), #type, __location__)
2226 * @brief Prepare the environment of a (wrapper) event context.
2228 * A caller might call this before passing a wrapper event context
2229 * to a tevent_req based *_send() function.
2231 * The wrapper event context might do something like impersonation.
2233 * @param[in] ev The event context to work on.
2235 * @return Success (true) or failure (false).
2237 * @note This is only needed if wrapper event contexts are in use.
2239 * @see tevent_context_after_use
2241 bool tevent_context_before_use(struct tevent_context *ev);
2243 bool _tevent_context_before_use(struct tevent_context *ev,
2244 const char *location);
2245 #define tevent_context_before_use(ev) \
2246 _tevent_context_before_use(ev, __location__)
2251 * @brief Release the environment of a (wrapper) event context.
2253 * A caller might call this after receiving the result from
2254 * a *_recv function of a tevent_req based function pair.
2256 * The wrapper event context might undo something like impersonation.
2258 * @param[in] ev The event context to work on.
2260 * @note This is only needed if wrapper event contexts are in use.
2262 * @see tevent_context_before_use
2264 void tevent_context_after_use(struct tevent_context *ev);
2266 void _tevent_context_after_use(struct tevent_context *ev,
2267 const char *location);
2268 #define tevent_context_after_use(ev) \
2269 _tevent_context_after_use(ev, __location__)
2273 * @brief Check is the two context pointers belong to the same low level loop
2275 * With the introduction of wrapper contexts it's not trivial
2276 * to check if two context pointers belong to the same low level
2277 * event loop. Some code may need to know this in order
2278 * to make some caching decisions.
2280 * @param[in] ev1 The first event context.
2281 * @param[in] ev2 The second event context.
2283 * @return true if both contexts belong to the same (still existing) context
2284 * loop, false otherwise.
2286 * @see tevent_context_wrapper_create
2288 bool tevent_context_same_loop(struct tevent_context *ev1,
2289 struct tevent_context *ev2);
2294 * @defgroup tevent_compat The tevent compatibility functions
2297 * The following definitions are usueful only for compatibility with the
2298 * implementation originally developed within the samba4 code and will be
2299 * soon removed. Please NEVER use in new code.
2306 #ifdef TEVENT_COMPAT_DEFINES
2308 #define event_context tevent_context
2309 #define event_ops tevent_ops
2310 #define fd_event tevent_fd
2311 #define timed_event tevent_timer
2312 #define signal_event tevent_signal
2314 #define event_fd_handler_t tevent_fd_handler_t
2315 #define event_timed_handler_t tevent_timer_handler_t
2316 #define event_signal_handler_t tevent_signal_handler_t
2318 #define event_context_init(mem_ctx) \
2319 tevent_context_init(mem_ctx)
2321 #define event_context_init_byname(mem_ctx, name) \
2322 tevent_context_init_byname(mem_ctx, name)
2324 #define event_backend_list(mem_ctx) \
2325 tevent_backend_list(mem_ctx)
2327 #define event_set_default_backend(backend) \
2328 tevent_set_default_backend(backend)
2330 #define event_add_fd(ev, mem_ctx, fd, flags, handler, private_data) \
2331 tevent_add_fd(ev, mem_ctx, fd, flags, handler, private_data)
2333 #define event_add_timed(ev, mem_ctx, next_event, handler, private_data) \
2334 tevent_add_timer(ev, mem_ctx, next_event, handler, private_data)
2336 #define event_add_signal(ev, mem_ctx, signum, sa_flags, handler, private_data) \
2337 tevent_add_signal(ev, mem_ctx, signum, sa_flags, handler, private_data)
2339 #define event_loop_once(ev) \
2340 tevent_loop_once(ev)
2342 #define event_loop_wait(ev) \
2343 tevent_loop_wait(ev)
2345 #define event_get_fd_flags(fde) \
2346 tevent_fd_get_flags(fde)
2348 #define event_set_fd_flags(fde, flags) \
2349 tevent_fd_set_flags(fde, flags)
2351 #define EVENT_FD_READ TEVENT_FD_READ
2352 #define EVENT_FD_WRITE TEVENT_FD_WRITE
2354 #define EVENT_FD_WRITEABLE(fde) \
2355 TEVENT_FD_WRITEABLE(fde)
2357 #define EVENT_FD_READABLE(fde) \
2358 TEVENT_FD_READABLE(fde)
2360 #define EVENT_FD_NOT_WRITEABLE(fde) \
2361 TEVENT_FD_NOT_WRITEABLE(fde)
2363 #define EVENT_FD_NOT_READABLE(fde) \
2364 TEVENT_FD_NOT_READABLE(fde)
2366 #define ev_debug_level tevent_debug_level
2368 #define EV_DEBUG_FATAL TEVENT_DEBUG_FATAL
2369 #define EV_DEBUG_ERROR TEVENT_DEBUG_ERROR
2370 #define EV_DEBUG_WARNING TEVENT_DEBUG_WARNING
2371 #define EV_DEBUG_TRACE TEVENT_DEBUG_TRACE
2373 #define ev_set_debug(ev, debug, context) \
2374 tevent_set_debug(ev, debug, context)
2376 #define ev_set_debug_stderr(_ev) tevent_set_debug_stderr(ev)
2378 #endif /* TEVENT_COMPAT_DEFINES */
2382 #endif /* __TEVENT_H__ */