1 /*
2    Unix SMB/CIFS implementation.
3 
4    generalised event loop handling
5 
6    INTERNAL STRUCTS. THERE ARE NO API GUARANTEES.
7    External users should only ever have to include this header when
8    implementing new tevent backends.
9 
10    Copyright (C) Stefan Metzmacher 2005-2009
11 
12      ** NOTE! The following LGPL license applies to the tevent
13      ** library. This does NOT imply that all of Samba is released
14      ** under the LGPL
15 
16    This library is free software; you can redistribute it and/or
17    modify it under the terms of the GNU Lesser General Public
18    License as published by the Free Software Foundation; either
19    version 3 of the License, or (at your option) any later version.
20 
21    This library is distributed in the hope that it will be useful,
22    but WITHOUT ANY WARRANTY; without even the implied warranty of
23    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
24    Lesser General Public License for more details.
25 
26    You should have received a copy of the GNU Lesser General Public
27    License along with this library; if not, see <http://www.gnu.org/licenses/>.
28 */
29 
30 struct tevent_req {
31 	/**
32 	 * @brief What to do on completion
33 	 *
34 	 * This is used for the user of an async request, fn is called when
35 	 * the request completes, either successfully or with an error.
36 	 */
37 	struct {
38 		/**
39 		 * @brief Completion function
40 		 * Completion function, to be filled by the API user
41 		 */
42 		tevent_req_fn fn;
43 		/**
44 		 * @brief Private data for the completion function
45 		 */
46 		void *private_data;
47 	} async;
48 
49 	/**
50 	 * @brief Private state pointer for the actual implementation
51 	 *
52 	 * The implementation doing the work for the async request needs to
53 	 * keep around current data like for example a fd event. The user of
54 	 * an async request should not touch this.
55 	 */
56 	void *data;
57 
58 	/**
59 	 * @brief A function to overwrite the default print function
60 	 *
61 	 * The implementation doing the work may want to implement a
62 	 * custom function to print the text representation of the async
63 	 * request.
64 	 */
65 	tevent_req_print_fn private_print;
66 
67 	/**
68 	 * @brief A function to cancel the request
69 	 *
70 	 * The implementation might want to set a function
71 	 * that is called when the tevent_req_cancel() function
72 	 * was called.
73 	 */
74 	tevent_req_cancel_fn private_cancel;
75 
76 	/**
77 	 * @brief A function to cleanup the request
78 	 *
79 	 * The implementation might want to set a function
80 	 * that is called before the tevent_req_done() and tevent_req_error()
81 	 * trigger the callers callback function.
82 	 */
83 	struct {
84 		tevent_req_cleanup_fn fn;
85 		enum tevent_req_state state;
86 	} private_cleanup;
87 
88 	/**
89 	 * @brief Internal state of the request
90 	 *
91 	 * Callers should only access this via functions and never directly.
92 	 */
93 	struct {
94 		/**
95 		 * @brief The talloc type of the data pointer
96 		 *
97 		 * This is filled by the tevent_req_create() macro.
98 		 *
99 		 * This for debugging only.
100 		 */
101 		const char *private_type;
102 
103 		/**
104 		 * @brief The location where the request was created
105 		 *
106 		 * This uses the __location__ macro via the tevent_req_create()
107 		 * macro.
108 		 *
109 		 * This for debugging only.
110 		 */
111 		const char *create_location;
112 
113 		/**
114 		 * @brief The location where the request was finished
115 		 *
116 		 * This uses the __location__ macro via the tevent_req_done(),
117 		 * tevent_req_error() or tevent_req_nomem() macro.
118 		 *
119 		 * This for debugging only.
120 		 */
121 		const char *finish_location;
122 
123 		/**
124 		 * @brief The location where the request was canceled
125 		 *
126 		 * This uses the __location__ macro via the
127 		 * tevent_req_cancel() macro.
128 		 *
129 		 * This for debugging only.
130 		 */
131 		const char *cancel_location;
132 
133 		/**
134 		 * @brief The external state - will be queried by the caller
135 		 *
136 		 * While the async request is being processed, state will remain in
137 		 * TEVENT_REQ_IN_PROGRESS. A request is finished if
138 		 * req->state>=TEVENT_REQ_DONE.
139 		 */
140 		enum tevent_req_state state;
141 
142 		/**
143 		 * @brief status code when finished
144 		 *
145 		 * This status can be queried in the async completion function. It
146 		 * will be set to 0 when everything went fine.
147 		 */
148 		uint64_t error;
149 
150 		/**
151 		 * @brief the immediate event used by tevent_req_post
152 		 *
153 		 */
154 		struct tevent_immediate *trigger;
155 
156 		/**
157 		 * @brief An event context which will be used to
158 		 *        defer the _tevent_req_notify_callback().
159 		 */
160 		struct tevent_context *defer_callback_ev;
161 
162 		/**
163 		 * @brief the timer event if tevent_req_set_endtime was used
164 		 *
165 		 */
166 		struct tevent_timer *timer;
167 
168 		/**
169 		 * @brief The place where profiling data is kept
170 		 */
171 		struct tevent_req_profile *profile;
172 	} internal;
173 };
174 
175 struct tevent_req_profile {
176 	struct tevent_req_profile *prev, *next;
177 	struct tevent_req_profile *parent;
178 	const char *req_name;
179 	pid_t pid;
180 	const char *start_location;
181 	struct timeval start_time;
182 	const char *stop_location;
183 	struct timeval stop_time;
184 	enum tevent_req_state state;
185 	uint64_t user_error;
186 	struct tevent_req_profile *subprofiles;
187 };
188 
189 struct tevent_fd {
190 	struct tevent_fd *prev, *next;
191 	struct tevent_context *event_ctx;
192 	struct tevent_wrapper_glue *wrapper;
193 	bool busy;
194 	bool destroyed;
195 	int fd;
196 	uint16_t flags; /* see TEVENT_FD_* flags */
197 	tevent_fd_handler_t handler;
198 	tevent_fd_close_fn_t close_fn;
199 	/* this is private for the specific handler */
200 	void *private_data;
201 	/* this is for debugging only! */
202 	const char *handler_name;
203 	const char *location;
204 	/* this is private for the events_ops implementation */
205 	uint64_t additional_flags;
206 	void *additional_data;
207 };
208 
209 struct tevent_timer {
210 	struct tevent_timer *prev, *next;
211 	struct tevent_context *event_ctx;
212 	struct tevent_wrapper_glue *wrapper;
213 	bool busy;
214 	bool destroyed;
215 	struct timeval next_event;
216 	tevent_timer_handler_t handler;
217 	/* this is private for the specific handler */
218 	void *private_data;
219 	/* this is for debugging only! */
220 	const char *handler_name;
221 	const char *location;
222 	/* this is private for the events_ops implementation */
223 	void *additional_data;
224 };
225 
226 struct tevent_immediate {
227 	struct tevent_immediate *prev, *next;
228 	struct tevent_context *event_ctx;
229 	struct tevent_wrapper_glue *wrapper;
230 	bool busy;
231 	bool destroyed;
232 	tevent_immediate_handler_t handler;
233 	/* this is private for the specific handler */
234 	void *private_data;
235 	/* this is for debugging only! */
236 	const char *handler_name;
237 	const char *create_location;
238 	const char *schedule_location;
239 	/* this is private for the events_ops implementation */
240 	void (*cancel_fn)(struct tevent_immediate *im);
241 	void *additional_data;
242 };
243 
244 struct tevent_signal {
245 	struct tevent_signal *prev, *next;
246 	struct tevent_context *event_ctx;
247 	struct tevent_wrapper_glue *wrapper;
248 	bool busy;
249 	bool destroyed;
250 	int signum;
251 	int sa_flags;
252 	tevent_signal_handler_t handler;
253 	/* this is private for the specific handler */
254 	void *private_data;
255 	/* this is for debugging only! */
256 	const char *handler_name;
257 	const char *location;
258 	/* this is private for the events_ops implementation */
259 	void *additional_data;
260 };
261 
262 struct tevent_threaded_context {
263 	struct tevent_threaded_context *next, *prev;
264 
265 #ifdef HAVE_PTHREAD
266 	pthread_mutex_t event_ctx_mutex;
267 #endif
268 	struct tevent_context *event_ctx;
269 };
270 
271 struct tevent_debug_ops {
272 	void (*debug)(void *context, enum tevent_debug_level level,
273 		      const char *fmt, va_list ap) PRINTF_ATTRIBUTE(3,0);
274 	void *context;
275 };
276 
277 void tevent_debug(struct tevent_context *ev, enum tevent_debug_level level,
278 		  const char *fmt, ...) PRINTF_ATTRIBUTE(3,4);
279 
280 void tevent_abort(struct tevent_context *ev, const char *reason);
281 
282 void tevent_common_check_double_free(TALLOC_CTX *ptr, const char *reason);
283 
284 struct tevent_context {
285 	/* the specific events implementation */
286 	const struct tevent_ops *ops;
287 
288 	/*
289 	 * The following three pointers are queried on every loop_once
290 	 * in the order in which they appear here. Not measured, but
291 	 * hopefully putting them at the top together with "ops"
292 	 * should make tevent a *bit* more cache-friendly than before.
293 	 */
294 
295 	/* list of signal events - used by common code */
296 	struct tevent_signal *signal_events;
297 
298 	/* List of threaded job indicators */
299 	struct tevent_threaded_context *threaded_contexts;
300 
301 	/* list of immediate events - used by common code */
302 	struct tevent_immediate *immediate_events;
303 
304 	/* list of fd events - used by common code */
305 	struct tevent_fd *fd_events;
306 
307 	/* list of timed events - used by common code */
308 	struct tevent_timer *timer_events;
309 
310 	/* List of scheduled immediates */
311 	pthread_mutex_t scheduled_mutex;
312 	struct tevent_immediate *scheduled_immediates;
313 
314 	/* this is private for the events_ops implementation */
315 	void *additional_data;
316 
317 	/* pipe hack used with signal handlers */
318 	struct tevent_fd *wakeup_fde;
319 	int wakeup_fd;		/* fd to write into */
320 #ifndef HAVE_EVENT_FD
321 	int wakeup_read_fd;
322 #endif
323 
324 	/* debugging operations */
325 	struct tevent_debug_ops debug_ops;
326 
327 	/* info about the nesting status */
328 	struct {
329 		bool allowed;
330 		uint32_t level;
331 		tevent_nesting_hook hook_fn;
332 		void *hook_private;
333 	} nesting;
334 
335 	struct {
336 		tevent_trace_callback_t callback;
337 		void *private_data;
338 	} tracing;
339 
340 	struct {
341 		/*
342 		 * This is used on the main event context
343 		 */
344 		struct tevent_wrapper_glue *list;
345 
346 		/*
347 		 * This is used on the wrapper event context
348 		 */
349 		struct tevent_wrapper_glue *glue;
350 	} wrapper;
351 
352 	/*
353 	 * an optimization pointer into timer_events
354 	 * used by used by common code via
355 	 * tevent_common_add_timer_v2()
356 	 */
357 	struct tevent_timer *last_zero_timer;
358 
359 #ifdef HAVE_PTHREAD
360 	struct tevent_context *prev, *next;
361 #endif
362 };
363 
364 const struct tevent_ops *tevent_find_ops_byname(const char *name);
365 
366 int tevent_common_context_destructor(struct tevent_context *ev);
367 int tevent_common_loop_wait(struct tevent_context *ev,
368 			    const char *location);
369 
370 int tevent_common_fd_destructor(struct tevent_fd *fde);
371 struct tevent_fd *tevent_common_add_fd(struct tevent_context *ev,
372 				       TALLOC_CTX *mem_ctx,
373 				       int fd,
374 				       uint16_t flags,
375 				       tevent_fd_handler_t handler,
376 				       void *private_data,
377 				       const char *handler_name,
378 				       const char *location);
379 void tevent_common_fd_set_close_fn(struct tevent_fd *fde,
380 				   tevent_fd_close_fn_t close_fn);
381 uint16_t tevent_common_fd_get_flags(struct tevent_fd *fde);
382 void tevent_common_fd_set_flags(struct tevent_fd *fde, uint16_t flags);
383 int tevent_common_invoke_fd_handler(struct tevent_fd *fde, uint16_t flags,
384 				    bool *removed);
385 
386 struct tevent_timer *tevent_common_add_timer(struct tevent_context *ev,
387 					     TALLOC_CTX *mem_ctx,
388 					     struct timeval next_event,
389 					     tevent_timer_handler_t handler,
390 					     void *private_data,
391 					     const char *handler_name,
392 					     const char *location);
393 struct tevent_timer *tevent_common_add_timer_v2(struct tevent_context *ev,
394 						TALLOC_CTX *mem_ctx,
395 					        struct timeval next_event,
396 					        tevent_timer_handler_t handler,
397 					        void *private_data,
398 					        const char *handler_name,
399 					        const char *location);
400 struct timeval tevent_common_loop_timer_delay(struct tevent_context *);
401 int tevent_common_invoke_timer_handler(struct tevent_timer *te,
402 				       struct timeval current_time,
403 				       bool *removed);
404 
405 void tevent_common_schedule_immediate(struct tevent_immediate *im,
406 				      struct tevent_context *ev,
407 				      tevent_immediate_handler_t handler,
408 				      void *private_data,
409 				      const char *handler_name,
410 				      const char *location);
411 int tevent_common_invoke_immediate_handler(struct tevent_immediate *im,
412 					   bool *removed);
413 bool tevent_common_loop_immediate(struct tevent_context *ev);
414 void tevent_common_threaded_activate_immediate(struct tevent_context *ev);
415 
416 bool tevent_common_have_events(struct tevent_context *ev);
417 int tevent_common_wakeup_init(struct tevent_context *ev);
418 int tevent_common_wakeup_fd(int fd);
419 int tevent_common_wakeup(struct tevent_context *ev);
420 
421 struct tevent_signal *tevent_common_add_signal(struct tevent_context *ev,
422 					       TALLOC_CTX *mem_ctx,
423 					       int signum,
424 					       int sa_flags,
425 					       tevent_signal_handler_t handler,
426 					       void *private_data,
427 					       const char *handler_name,
428 					       const char *location);
429 int tevent_common_check_signal(struct tevent_context *ev);
430 void tevent_cleanup_pending_signal_handlers(struct tevent_signal *se);
431 int tevent_common_invoke_signal_handler(struct tevent_signal *se,
432 					int signum, int count, void *siginfo,
433 					bool *removed);
434 
435 struct tevent_context *tevent_wrapper_main_ev(struct tevent_context *ev);
436 
437 struct tevent_wrapper_ops;
438 
439 struct tevent_wrapper_glue {
440 	struct tevent_wrapper_glue *prev, *next;
441 	struct tevent_context *wrap_ev;
442 	struct tevent_context *main_ev;
443 	bool busy;
444 	bool destroyed;
445 	const struct tevent_wrapper_ops *ops;
446 	void *private_state;
447 };
448 
449 void tevent_wrapper_push_use_internal(struct tevent_context *ev,
450 				      struct tevent_wrapper_glue *wrapper);
451 void tevent_wrapper_pop_use_internal(const struct tevent_context *__ev_ptr,
452 				     struct tevent_wrapper_glue *wrapper);
453 
454 bool tevent_standard_init(void);
455 bool tevent_poll_init(void);
456 bool tevent_poll_event_add_fd_internal(struct tevent_context *ev,
457 				       struct tevent_fd *fde);
458 bool tevent_poll_mt_init(void);
459 #ifdef HAVE_EPOLL
460 bool tevent_epoll_init(void);
461 void tevent_epoll_set_panic_fallback(struct tevent_context *ev,
462 			bool (*panic_fallback)(struct tevent_context *ev,
463 					       bool replay));
464 #endif
465 #ifdef HAVE_SOLARIS_PORTS
466 bool tevent_port_init(void);
467 #endif
468 
469 
470 void tevent_trace_point_callback(struct tevent_context *ev,
471 				 enum tevent_trace_point);
472