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5eb91c98 DG |
1 | /* |
2 | * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca> | |
3 | * | |
d14d33bf AM |
4 | * This program is free software; you can redistribute it and/or modify |
5 | * it under the terms of the GNU General Public License, version 2 only, | |
6 | * as published by the Free Software Foundation. | |
5eb91c98 DG |
7 | * |
8 | * This program is distributed in the hope that it will be useful, but WITHOUT | |
9 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
10 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
11 | * more details. | |
12 | * | |
d14d33bf AM |
13 | * You should have received a copy of the GNU General Public License along |
14 | * with this program; if not, write to the Free Software Foundation, Inc., | |
15 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. | |
5eb91c98 DG |
16 | */ |
17 | ||
18 | #ifndef _LTT_POLL_H | |
19 | #define _LTT_POLL_H | |
20 | ||
beaad64c | 21 | #include <assert.h> |
5eb91c98 DG |
22 | #include <string.h> |
23 | #include <unistd.h> | |
24 | ||
990570ed | 25 | #include <common/common.h> |
5eb91c98 DG |
26 | |
27 | /* | |
28 | * Maximum number of fd we can monitor. | |
29 | * | |
30 | * For epoll(7), /proc/sys/fs/epoll/max_user_watches (since Linux 2.6.28) will | |
31 | * be used for the maximum size of the poll set. If this interface is not | |
32 | * available, according to the manpage, the max_user_watches value is 1/25 (4%) | |
33 | * of the available low memory divided by the registration cost in bytes which | |
34 | * is 90 bytes on a 32-bit kernel and 160 bytes on a 64-bit kernel. | |
35 | * | |
36 | * For poll(2), the max fds must not exceed RLIMIT_NOFILE given by | |
37 | * getrlimit(2). | |
38 | */ | |
39 | extern unsigned int poll_max_size; | |
40 | ||
41 | /* | |
42 | * Used by lttng_poll_clean to free the events structure in a lttng_poll_event. | |
43 | */ | |
44 | static inline void __lttng_poll_free(void *events) | |
45 | { | |
b3066218 DG |
46 | if (events) { |
47 | free(events); | |
48 | } | |
5eb91c98 DG |
49 | } |
50 | ||
51 | /* | |
52 | * epoll(7) implementation. | |
53 | */ | |
54 | #ifdef HAVE_EPOLL | |
55 | #include <sys/epoll.h> | |
76d7553f | 56 | #include <stdio.h> |
5eb91c98 DG |
57 | |
58 | /* See man epoll(7) for this define path */ | |
990570ed | 59 | #define COMPAT_EPOLL_PROC_PATH "/proc/sys/fs/epoll/max_user_watches" |
5eb91c98 DG |
60 | |
61 | enum { | |
62 | /* Polling variables compatibility for epoll */ | |
63 | LPOLLIN = EPOLLIN, | |
64 | LPOLLPRI = EPOLLPRI, | |
65 | LPOLLOUT = EPOLLOUT, | |
66 | LPOLLRDNORM = EPOLLRDNORM, | |
67 | LPOLLRDBAND = EPOLLRDBAND, | |
68 | LPOLLWRNORM = EPOLLWRNORM, | |
69 | LPOLLWRBAND = EPOLLWRBAND, | |
70 | LPOLLMSG = EPOLLMSG, | |
71 | LPOLLERR = EPOLLERR, | |
72 | LPOLLHUP = EPOLLHUP, | |
73 | LPOLLNVAL = EPOLLHUP, | |
74 | LPOLLRDHUP = EPOLLRDHUP, | |
75 | /* Close on exec feature of epoll */ | |
76 | LTTNG_CLOEXEC = EPOLL_CLOEXEC, | |
77 | }; | |
78 | ||
79 | struct compat_epoll_event { | |
80 | int epfd; | |
81 | uint32_t nb_fd; /* Current number of fd in events */ | |
d21b0d71 DG |
82 | uint32_t alloc_size; /* Size of events array */ |
83 | uint32_t init_size; /* Initial size of events array */ | |
5eb91c98 DG |
84 | struct epoll_event *events; |
85 | }; | |
86 | #define lttng_poll_event compat_epoll_event | |
87 | ||
beaad64c DG |
88 | static inline int __lttng_epoll_get_prev_fd(struct lttng_poll_event *events, |
89 | int index, uint32_t nb_fd) | |
90 | { | |
91 | assert(events); | |
92 | assert(index != nb_fd); | |
93 | ||
94 | if (index == 0 || nb_fd == 0) { | |
95 | return -1; | |
96 | } else { | |
97 | return events->events[index - 1].data.fd; | |
98 | } | |
99 | } | |
100 | ||
5eb91c98 DG |
101 | /* |
102 | * For the following calls, consider 'e' to be a lttng_poll_event pointer and i | |
103 | * being the index of the events array. | |
104 | */ | |
105 | #define LTTNG_POLL_GETFD(e, i) LTTNG_REF(e)->events[i].data.fd | |
106 | #define LTTNG_POLL_GETEV(e, i) LTTNG_REF(e)->events[i].events | |
107 | #define LTTNG_POLL_GETNB(e) LTTNG_REF(e)->nb_fd | |
108 | #define LTTNG_POLL_GETSZ(e) LTTNG_REF(e)->events_size | |
beaad64c DG |
109 | #define LTTNG_POLL_GET_PREV_FD(e, i, nb_fd) \ |
110 | __lttng_epoll_get_prev_fd(LTTNG_REF(e), i, nb_fd) | |
5eb91c98 DG |
111 | |
112 | /* | |
113 | * Create the epoll set. No memory allocation is done here. | |
114 | */ | |
115 | extern int compat_epoll_create(struct lttng_poll_event *events, | |
116 | int size, int flags); | |
117 | #define lttng_poll_create(events, size, flags) \ | |
65b1b198 | 118 | compat_epoll_create(events, size, flags) |
5eb91c98 DG |
119 | |
120 | /* | |
121 | * Wait on epoll set with the number of fd registered to the lttng_poll_event | |
122 | * data structure (events). | |
123 | */ | |
124 | extern int compat_epoll_wait(struct lttng_poll_event *events, int timeout); | |
125 | #define lttng_poll_wait(events, timeout) \ | |
65b1b198 | 126 | compat_epoll_wait(events, timeout) |
5eb91c98 DG |
127 | |
128 | /* | |
129 | * Add a fd to the epoll set and resize the epoll_event structure if needed. | |
130 | */ | |
131 | extern int compat_epoll_add(struct lttng_poll_event *events, | |
132 | int fd, uint32_t req_events); | |
133 | #define lttng_poll_add(events, fd, req_events) \ | |
65b1b198 | 134 | compat_epoll_add(events, fd, req_events) |
5eb91c98 DG |
135 | |
136 | /* | |
137 | * Remove a fd from the epoll set. | |
138 | */ | |
139 | extern int compat_epoll_del(struct lttng_poll_event *events, int fd); | |
140 | #define lttng_poll_del(events, fd) \ | |
65b1b198 | 141 | compat_epoll_del(events, fd) |
5eb91c98 DG |
142 | |
143 | /* | |
144 | * Set up the poll set limits variable poll_max_size | |
145 | */ | |
146 | extern void compat_epoll_set_max_size(void); | |
65b1b198 MD |
147 | #define lttng_poll_set_max_size() \ |
148 | compat_epoll_set_max_size() | |
5eb91c98 DG |
149 | |
150 | /* | |
151 | * This function memset with zero the structure since it can be reused at each | |
152 | * round of a main loop. Being in a loop and using a non static number of fds, | |
153 | * this function must be called to insure coherent events with associted fds. | |
154 | */ | |
155 | static inline void lttng_poll_reset(struct lttng_poll_event *events) | |
156 | { | |
157 | if (events && events->events) { | |
158 | memset(events->events, 0, | |
159 | events->nb_fd * sizeof(struct epoll_event)); | |
160 | } | |
161 | } | |
162 | ||
163 | /* | |
164 | * Clean the events structure of a lttng_poll_event. It's the caller | |
165 | * responsability to free the lttng_poll_event memory. | |
166 | */ | |
167 | static inline void lttng_poll_clean(struct lttng_poll_event *events) | |
168 | { | |
76d7553f MD |
169 | int ret; |
170 | ||
5eb91c98 | 171 | if (events) { |
76d7553f MD |
172 | ret = close(events->epfd); |
173 | if (ret) { | |
174 | perror("close"); | |
175 | } | |
5eb91c98 DG |
176 | __lttng_poll_free((void *) events->events); |
177 | } | |
178 | } | |
179 | ||
180 | #else /* HAVE_EPOLL */ | |
181 | /* | |
182 | * Fallback on poll(2) API | |
183 | */ | |
184 | ||
185 | /* Needed for some poll event values */ | |
186 | #ifndef __USE_XOPEN | |
187 | #define __USE_XOPEN | |
188 | #endif | |
189 | ||
190 | /* Needed for some poll event values */ | |
191 | #ifndef __USE_GNU | |
192 | #define __USE_GNU | |
193 | #endif | |
194 | ||
195 | #include <poll.h> | |
196 | #include <stdint.h> | |
197 | ||
198 | enum { | |
199 | /* Polling variables compatibility for poll */ | |
200 | LPOLLIN = POLLIN, | |
201 | LPOLLPRI = POLLPRI, | |
202 | LPOLLOUT = POLLOUT, | |
203 | LPOLLRDNORM = POLLRDNORM, | |
204 | LPOLLRDBAND = POLLRDBAND, | |
205 | LPOLLWRNORM = POLLWRNORM, | |
206 | LPOLLWRBAND = POLLWRBAND, | |
1268b9d6 | 207 | #if __linux__ |
5eb91c98 | 208 | LPOLLMSG = POLLMSG, |
1268b9d6 | 209 | LPOLLRDHUP = POLLRDHUP, |
3247be18 | 210 | #elif (defined(__FreeBSD__) || defined(__CYGWIN__)) |
1268b9d6 DG |
211 | LPOLLMSG = 0, |
212 | LPOLLRDHUP = 0, | |
b2c3836f MD |
213 | #else |
214 | #error "Please add support for your OS." | |
1268b9d6 | 215 | #endif /* __linux__ */ |
5eb91c98 DG |
216 | LPOLLERR = POLLERR, |
217 | LPOLLHUP = POLLHUP | POLLNVAL, | |
5eb91c98 DG |
218 | /* Close on exec feature does not exist for poll(2) */ |
219 | LTTNG_CLOEXEC = 0xdead, | |
220 | }; | |
221 | ||
d21b0d71 | 222 | struct compat_poll_event_array { |
5eb91c98 | 223 | uint32_t nb_fd; /* Current number of fd in events */ |
d21b0d71 DG |
224 | uint32_t alloc_size; /* Size of events array */ |
225 | /* Initial size of the pollset. We never shrink below that. */ | |
226 | uint32_t init_size; | |
5eb91c98 DG |
227 | struct pollfd *events; |
228 | }; | |
d21b0d71 DG |
229 | |
230 | struct compat_poll_event { | |
231 | /* | |
232 | * Modified by the wait action. Updated using current fields if the | |
233 | * need_update flag is set. | |
234 | */ | |
235 | struct compat_poll_event_array wait; | |
236 | /* | |
237 | * This is modified by add/del actions being the _current_ flow of | |
238 | * execution before a poll wait is done. | |
239 | */ | |
240 | struct compat_poll_event_array current; | |
241 | /* Indicate if wait.events needs to be realloc. */ | |
242 | int need_realloc:1; | |
243 | /* Indicate if wait.events need to be updated from current. */ | |
244 | int need_update:1; | |
245 | }; | |
5eb91c98 DG |
246 | #define lttng_poll_event compat_poll_event |
247 | ||
beaad64c DG |
248 | static inline int __lttng_poll_get_prev_fd(struct lttng_poll_event *events, |
249 | int index, uint32_t nb_fd) | |
250 | { | |
251 | assert(events); | |
252 | assert(index != nb_fd); | |
253 | ||
254 | if (index == 0 || nb_fd == 0) { | |
255 | return -1; | |
256 | } else { | |
257 | return events->current.events[index - 1].fd; | |
258 | } | |
259 | } | |
260 | ||
5eb91c98 DG |
261 | /* |
262 | * For the following calls, consider 'e' to be a lttng_poll_event pointer and i | |
263 | * being the index of the events array. | |
264 | */ | |
d21b0d71 DG |
265 | #define LTTNG_POLL_GETFD(e, i) LTTNG_REF(e)->wait.events[i].fd |
266 | #define LTTNG_POLL_GETEV(e, i) LTTNG_REF(e)->wait.events[i].revents | |
267 | #define LTTNG_POLL_GETNB(e) LTTNG_REF(e)->wait.nb_fd | |
268 | #define LTTNG_POLL_GETSZ(e) LTTNG_REF(e)->wait.events_size | |
beaad64c DG |
269 | #define LTTNG_POLL_GET_PREV_FD(e, i, nb_fd) \ |
270 | __lttng_poll_get_prev_fd(LTTNG_REF(e), i, nb_fd) | |
5eb91c98 DG |
271 | |
272 | /* | |
273 | * Create a pollfd structure of size 'size'. | |
274 | */ | |
275 | extern int compat_poll_create(struct lttng_poll_event *events, int size); | |
276 | #define lttng_poll_create(events, size, flags) \ | |
65b1b198 | 277 | compat_poll_create(events, size) |
5eb91c98 DG |
278 | |
279 | /* | |
280 | * Wait on poll(2) event with nb_fd registered to the lttng_poll_event data | |
281 | * structure. | |
282 | */ | |
283 | extern int compat_poll_wait(struct lttng_poll_event *events, int timeout); | |
284 | #define lttng_poll_wait(events, timeout) \ | |
65b1b198 | 285 | compat_poll_wait(events, timeout) |
5eb91c98 DG |
286 | |
287 | /* | |
288 | * Add the fd to the pollfd structure. Resize if needed. | |
289 | */ | |
290 | extern int compat_poll_add(struct lttng_poll_event *events, | |
291 | int fd, uint32_t req_events); | |
292 | #define lttng_poll_add(events, fd, req_events) \ | |
65b1b198 | 293 | compat_poll_add(events, fd, req_events) |
5eb91c98 DG |
294 | |
295 | /* | |
296 | * Remove the fd from the pollfd. Memory allocation is done to recreate a new | |
297 | * pollfd, data is copied from the old pollfd to the new and, finally, the old | |
298 | * one is freed(). | |
299 | */ | |
300 | extern int compat_poll_del(struct lttng_poll_event *events, int fd); | |
301 | #define lttng_poll_del(events, fd) \ | |
65b1b198 | 302 | compat_poll_del(events, fd) |
5eb91c98 DG |
303 | |
304 | /* | |
305 | * Set up the poll set limits variable poll_max_size | |
306 | */ | |
307 | extern void compat_poll_set_max_size(void); | |
65b1b198 MD |
308 | #define lttng_poll_set_max_size() \ |
309 | compat_poll_set_max_size() | |
5eb91c98 DG |
310 | |
311 | /* | |
312 | * No need to reset a pollfd structure for poll(2) | |
313 | */ | |
314 | static inline void lttng_poll_reset(struct lttng_poll_event *events) | |
315 | {} | |
316 | ||
317 | /* | |
318 | * Clean the events structure of a lttng_poll_event. It's the caller | |
319 | * responsability to free the lttng_poll_event memory. | |
320 | */ | |
321 | static inline void lttng_poll_clean(struct lttng_poll_event *events) | |
322 | { | |
323 | if (events) { | |
d21b0d71 DG |
324 | __lttng_poll_free((void *) events->wait.events); |
325 | __lttng_poll_free((void *) events->current.events); | |
5eb91c98 DG |
326 | } |
327 | } | |
328 | ||
329 | #endif /* HAVE_EPOLL */ | |
330 | ||
331 | #endif /* _LTT_POLL_H */ |