1 /* Licensed to the Apache Software Foundation (ASF) under one or more
2 * contributor license agreements. See the NOTICE file distributed with
3 * this work for additional information regarding copyright ownership.
4 * The ASF licenses this file to You under the Apache License, Version 2.0
5 * (the "License"); you may not use this file except in compliance with
6 * the License. You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
21 * @brief APR Poll interface
24 #include "apr_pools.h"
25 #include "apr_errno.h"
26 #include "apr_inherit.h"
27 #include "apr_file_io.h"
28 #include "apr_network_io.h"
30 #if APR_HAVE_NETINET_IN_H
31 #include <netinet/in.h>
36 #endif /* __cplusplus */
39 * @defgroup apr_poll Poll Routines
47 #define APR_POLLIN 0x001 /**< Can read without blocking */
48 #define APR_POLLPRI 0x002 /**< Priority data available */
49 #define APR_POLLOUT 0x004 /**< Can write without blocking */
50 #define APR_POLLERR 0x010 /**< Pending error */
51 #define APR_POLLHUP 0x020 /**< Hangup occurred */
52 #define APR_POLLNVAL 0x040 /**< Descriptor invalid */
57 #define APR_POLLSET_THREADSAFE 0x001 /**< Adding or removing a descriptor is
60 #define APR_POLLSET_NOCOPY 0x002 /**< Descriptors passed to apr_pollset_add()
63 #define APR_POLLSET_WAKEABLE 0x004 /**< Poll operations are interruptable by
64 * apr_pollset_wakeup()
66 #define APR_POLLSET_NODEFAULT 0x010 /**< Do not try to use the default method if
67 * the specified non-default method cannot be
75 APR_POLLSET_DEFAULT, /**< Platform default poll method */
76 APR_POLLSET_SELECT, /**< Poll uses select method */
77 APR_POLLSET_KQUEUE, /**< Poll uses kqueue method */
78 APR_POLLSET_PORT, /**< Poll uses Solaris event port method */
79 APR_POLLSET_EPOLL, /**< Poll uses epoll method */
80 APR_POLLSET_POLL /**< Poll uses poll method */
81 } apr_pollset_method_e;
83 /** Used in apr_pollfd_t to determine what the apr_descriptor is */
85 APR_NO_DESC, /**< nothing here */
86 APR_POLL_SOCKET, /**< descriptor refers to a socket */
87 APR_POLL_FILE, /**< descriptor refers to a file */
88 APR_POLL_LASTDESC /**< @deprecated descriptor is the last one in the list */
91 /** Union of either an APR file or socket. */
93 apr_file_t *f; /**< file */
94 apr_socket_t *s; /**< socket */
97 /** @see apr_pollfd_t */
98 typedef struct apr_pollfd_t apr_pollfd_t;
100 /** Poll descriptor set. */
101 struct apr_pollfd_t {
102 apr_pool_t *p; /**< associated pool */
103 apr_datatype_e desc_type; /**< descriptor type */
104 apr_int16_t reqevents; /**< requested events */
105 apr_int16_t rtnevents; /**< returned events */
106 apr_descriptor desc; /**< @see apr_descriptor */
107 void *client_data; /**< allows app to associate context */
111 /* General-purpose poll API for arbitrarily large numbers of
115 /** Opaque structure used for pollset API */
116 typedef struct apr_pollset_t apr_pollset_t;
119 * Set up a pollset object
120 * @param pollset The pointer in which to return the newly created object
121 * @param size The maximum number of descriptors that this pollset can hold
122 * @param p The pool from which to allocate the pollset
123 * @param flags Optional flags to modify the operation of the pollset.
125 * @remark If flags contains APR_POLLSET_THREADSAFE, then a pollset is
126 * created on which it is safe to make concurrent calls to
127 * apr_pollset_add(), apr_pollset_remove() and apr_pollset_poll()
128 * from separate threads. This feature is only supported on some
129 * platforms; the apr_pollset_create() call will fail with
130 * APR_ENOTIMPL on platforms where it is not supported.
131 * @remark If flags contains APR_POLLSET_WAKEABLE, then a pollset is
132 * created with an additional internal pipe object used for the
133 * apr_pollset_wakeup() call. The actual size of pollset is
134 * in that case size + 1. This feature is only supported on some
135 * platforms; the apr_pollset_create() call will fail with
136 * APR_ENOTIMPL on platforms where it is not supported.
137 * @remark If flags contains APR_POLLSET_NOCOPY, then the apr_pollfd_t
138 * structures passed to apr_pollset_add() are not copied and
139 * must have a lifetime at least as long as the pollset.
140 * @remark Some poll methods (including APR_POLLSET_KQUEUE,
141 * APR_POLLSET_PORT, and APR_POLLSET_EPOLL) do not have a
142 * fixed limit on the size of the pollset. For these methods,
143 * the size parameter controls the maximum number of
144 * descriptors that will be returned by a single call to
145 * apr_pollset_poll().
147 APR_DECLARE(apr_status_t) apr_pollset_create(apr_pollset_t **pollset,
153 * Set up a pollset object
154 * @param pollset The pointer in which to return the newly created object
155 * @param size The maximum number of descriptors that this pollset can hold
156 * @param p The pool from which to allocate the pollset
157 * @param flags Optional flags to modify the operation of the pollset.
158 * @param method Poll method to use. See #apr_pollset_method_e. If this
159 * method cannot be used, the default method will be used unless the
160 * APR_POLLSET_NODEFAULT flag has been specified.
162 * @remark If flags contains APR_POLLSET_THREADSAFE, then a pollset is
163 * created on which it is safe to make concurrent calls to
164 * apr_pollset_add(), apr_pollset_remove() and apr_pollset_poll()
165 * from separate threads. This feature is only supported on some
166 * platforms; the apr_pollset_create_ex() call will fail with
167 * APR_ENOTIMPL on platforms where it is not supported.
168 * @remark If flags contains APR_POLLSET_WAKEABLE, then a pollset is
169 * created with additional internal pipe object used for the
170 * apr_pollset_wakeup() call. The actual size of pollset is
171 * in that case size + 1. This feature is only supported on some
172 * platforms; the apr_pollset_create_ex() call will fail with
173 * APR_ENOTIMPL on platforms where it is not supported.
174 * @remark If flags contains APR_POLLSET_NOCOPY, then the apr_pollfd_t
175 * structures passed to apr_pollset_add() are not copied and
176 * must have a lifetime at least as long as the pollset.
177 * @remark Some poll methods (including APR_POLLSET_KQUEUE,
178 * APR_POLLSET_PORT, and APR_POLLSET_EPOLL) do not have a
179 * fixed limit on the size of the pollset. For these methods,
180 * the size parameter controls the maximum number of
181 * descriptors that will be returned by a single call to
182 * apr_pollset_poll().
184 APR_DECLARE(apr_status_t) apr_pollset_create_ex(apr_pollset_t **pollset,
188 apr_pollset_method_e method);
191 * Destroy a pollset object
192 * @param pollset The pollset to destroy
194 APR_DECLARE(apr_status_t) apr_pollset_destroy(apr_pollset_t *pollset);
197 * Add a socket or file descriptor to a pollset
198 * @param pollset The pollset to which to add the descriptor
199 * @param descriptor The descriptor to add
200 * @remark If you set client_data in the descriptor, that value
201 * will be returned in the client_data field whenever this
202 * descriptor is signalled in apr_pollset_poll().
203 * @remark If the pollset has been created with APR_POLLSET_THREADSAFE
204 * and thread T1 is blocked in a call to apr_pollset_poll() for
205 * this same pollset that is being modified via apr_pollset_add()
206 * in thread T2, the currently executing apr_pollset_poll() call in
207 * T1 will either: (1) automatically include the newly added descriptor
208 * in the set of descriptors it is watching or (2) return immediately
209 * with APR_EINTR. Option (1) is recommended, but option (2) is
210 * allowed for implementations where option (1) is impossible
212 * @remark If the pollset has been created with APR_POLLSET_NOCOPY, the
213 * apr_pollfd_t structure referenced by descriptor will not be copied
214 * and must have a lifetime at least as long as the pollset.
215 * @remark Do not add the same socket or file descriptor to the same pollset
216 * multiple times, even if the requested events differ for the
217 * different calls to apr_pollset_add(). If the events of interest
218 * for a descriptor change, you must first remove the descriptor
219 * from the pollset with apr_pollset_remove(), then add it again
220 * specifying all requested events.
222 APR_DECLARE(apr_status_t) apr_pollset_add(apr_pollset_t *pollset,
223 const apr_pollfd_t *descriptor);
226 * Remove a descriptor from a pollset
227 * @param pollset The pollset from which to remove the descriptor
228 * @param descriptor The descriptor to remove
229 * @remark If the pollset has been created with APR_POLLSET_THREADSAFE
230 * and thread T1 is blocked in a call to apr_pollset_poll() for
231 * this same pollset that is being modified via apr_pollset_remove()
232 * in thread T2, the currently executing apr_pollset_poll() call in
233 * T1 will either: (1) automatically exclude the newly added descriptor
234 * in the set of descriptors it is watching or (2) return immediately
235 * with APR_EINTR. Option (1) is recommended, but option (2) is
236 * allowed for implementations where option (1) is impossible
238 * @remark apr_pollset_remove() cannot be used to remove a subset of requested
239 * events for a descriptor. The reqevents field in the apr_pollfd_t
240 * parameter must contain the same value when removing as when adding.
242 APR_DECLARE(apr_status_t) apr_pollset_remove(apr_pollset_t *pollset,
243 const apr_pollfd_t *descriptor);
246 * Block for activity on the descriptor(s) in a pollset
247 * @param pollset The pollset to use
248 * @param timeout The amount of time in microseconds to wait. This is a
249 * maximum, not a minimum. If a descriptor is signalled, the
250 * function will return before this time. If timeout is
251 * negative, the function will block until a descriptor is
252 * signalled or until apr_pollset_wakeup() has been called.
253 * @param num Number of signalled descriptors (output parameter)
254 * @param descriptors Array of signalled descriptors (output parameter)
255 * @remark APR_EINTR will be returned if the pollset has been created with
256 * APR_POLLSET_WAKEABLE, apr_pollset_wakeup() has been called while
257 * waiting for activity, and there were no signalled descriptors at the
258 * time of the wakeup call.
259 * @remark Multiple signalled conditions for the same descriptor may be reported
260 * in one or more returned apr_pollfd_t structures, depending on the
262 * @bug With versions 1.4.2 and prior on Windows, a call with no descriptors
263 * and timeout will return immediately with the wrong error code.
265 APR_DECLARE(apr_status_t) apr_pollset_poll(apr_pollset_t *pollset,
266 apr_interval_time_t timeout,
268 const apr_pollfd_t **descriptors);
271 * Interrupt the blocked apr_pollset_poll() call.
272 * @param pollset The pollset to use
273 * @remark If the pollset was not created with APR_POLLSET_WAKEABLE the
274 * return value is APR_EINIT.
276 APR_DECLARE(apr_status_t) apr_pollset_wakeup(apr_pollset_t *pollset);
279 * Poll the descriptors in the poll structure
280 * @param aprset The poll structure we will be using.
281 * @param numsock The number of descriptors we are polling
282 * @param nsds The number of descriptors signalled (output parameter)
283 * @param timeout The amount of time in microseconds to wait. This is a
284 * maximum, not a minimum. If a descriptor is signalled, the
285 * function will return before this time. If timeout is
286 * negative, the function will block until a descriptor is
287 * signalled or until apr_pollset_wakeup() has been called.
288 * @remark The number of descriptors signalled is returned in the third argument.
289 * This is a blocking call, and it will not return until either a
290 * descriptor has been signalled or the timeout has expired.
291 * @remark The rtnevents field in the apr_pollfd_t array will only be filled-
292 * in if the return value is APR_SUCCESS.
293 * @bug With versions 1.4.2 and prior on Windows, a call with no descriptors
294 * and timeout will return immediately with the wrong error code.
296 APR_DECLARE(apr_status_t) apr_poll(apr_pollfd_t *aprset, apr_int32_t numsock,
298 apr_interval_time_t timeout);
301 * Return a printable representation of the pollset method.
302 * @param pollset The pollset to use
304 APR_DECLARE(const char *) apr_pollset_method_name(apr_pollset_t *pollset);
307 * Return a printable representation of the default pollset method
308 * (APR_POLLSET_DEFAULT).
310 APR_DECLARE(const char *) apr_poll_method_defname(void);
312 /** Opaque structure used for pollset API */
313 typedef struct apr_pollcb_t apr_pollcb_t;
316 * Set up a pollcb object
317 * @param pollcb The pointer in which to return the newly created object
318 * @param size The maximum number of descriptors that a single _poll can return.
319 * @param p The pool from which to allocate the pollcb
320 * @param flags Optional flags to modify the operation of the pollcb.
322 * @remark Pollcb is only supported on some platforms; the apr_pollcb_create()
323 * call will fail with APR_ENOTIMPL on platforms where it is not supported.
325 APR_DECLARE(apr_status_t) apr_pollcb_create(apr_pollcb_t **pollcb,
331 * Set up a pollcb object
332 * @param pollcb The pointer in which to return the newly created object
333 * @param size The maximum number of descriptors that a single _poll can return.
334 * @param p The pool from which to allocate the pollcb
335 * @param flags Optional flags to modify the operation of the pollcb.
336 * @param method Poll method to use. See #apr_pollset_method_e. If this
337 * method cannot be used, the default method will be used unless the
338 * APR_POLLSET_NODEFAULT flag has been specified.
340 * @remark Pollcb is only supported on some platforms; the apr_pollcb_create_ex()
341 * call will fail with APR_ENOTIMPL on platforms where it is not supported.
343 APR_DECLARE(apr_status_t) apr_pollcb_create_ex(apr_pollcb_t **pollcb,
347 apr_pollset_method_e method);
350 * Add a socket or file descriptor to a pollcb
351 * @param pollcb The pollcb to which to add the descriptor
352 * @param descriptor The descriptor to add
353 * @remark If you set client_data in the descriptor, that value will be
354 * returned in the client_data field whenever this descriptor is
355 * signalled in apr_pollcb_poll().
356 * @remark Unlike the apr_pollset API, the descriptor is not copied, and users
357 * must retain the memory used by descriptor, as the same pointer will
358 * be returned to them from apr_pollcb_poll.
359 * @remark Do not add the same socket or file descriptor to the same pollcb
360 * multiple times, even if the requested events differ for the
361 * different calls to apr_pollcb_add(). If the events of interest
362 * for a descriptor change, you must first remove the descriptor
363 * from the pollcb with apr_pollcb_remove(), then add it again
364 * specifying all requested events.
366 APR_DECLARE(apr_status_t) apr_pollcb_add(apr_pollcb_t *pollcb,
367 apr_pollfd_t *descriptor);
369 * Remove a descriptor from a pollcb
370 * @param pollcb The pollcb from which to remove the descriptor
371 * @param descriptor The descriptor to remove
372 * @remark apr_pollcb_remove() cannot be used to remove a subset of requested
373 * events for a descriptor. The reqevents field in the apr_pollfd_t
374 * parameter must contain the same value when removing as when adding.
376 APR_DECLARE(apr_status_t) apr_pollcb_remove(apr_pollcb_t *pollcb,
377 apr_pollfd_t *descriptor);
379 /** Function prototype for pollcb handlers
380 * @param baton Opaque baton passed into apr_pollcb_poll()
381 * @param descriptor Contains the notification for an active descriptor,
382 * the rtnevents member contains what events were triggered
383 * for this descriptor.
385 typedef apr_status_t (*apr_pollcb_cb_t)(void *baton, apr_pollfd_t *descriptor);
388 * Block for activity on the descriptor(s) in a pollcb
389 * @param pollcb The pollcb to use
390 * @param timeout The amount of time in microseconds to wait. This is a
391 * maximum, not a minimum. If a descriptor is signalled, the
392 * function will return before this time. If timeout is
393 * negative, the function will block until a descriptor is
395 * @param func Callback function to call for each active descriptor.
396 * @param baton Opaque baton passed to the callback function.
397 * @remark Multiple signalled conditions for the same descriptor may be reported
398 * in one or more calls to the callback function, depending on the
400 * @bug With versions 1.4.2 and prior on Windows, a call with no descriptors
401 * and timeout will return immediately with the wrong error code.
403 APR_DECLARE(apr_status_t) apr_pollcb_poll(apr_pollcb_t *pollcb,
404 apr_interval_time_t timeout,
405 apr_pollcb_cb_t func,
414 #endif /* ! APR_POLL_H */