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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 | ||
21 | #include <string.h> | |
22 | #include <unistd.h> | |
23 | ||
990570ed | 24 | #include <common/common.h> |
5eb91c98 DG |
25 | |
26 | /* | |
27 | * Maximum number of fd we can monitor. | |
28 | * | |
29 | * For epoll(7), /proc/sys/fs/epoll/max_user_watches (since Linux 2.6.28) will | |
30 | * be used for the maximum size of the poll set. If this interface is not | |
31 | * available, according to the manpage, the max_user_watches value is 1/25 (4%) | |
32 | * of the available low memory divided by the registration cost in bytes which | |
33 | * is 90 bytes on a 32-bit kernel and 160 bytes on a 64-bit kernel. | |
34 | * | |
35 | * For poll(2), the max fds must not exceed RLIMIT_NOFILE given by | |
36 | * getrlimit(2). | |
37 | */ | |
38 | extern unsigned int poll_max_size; | |
39 | ||
40 | /* | |
41 | * Used by lttng_poll_clean to free the events structure in a lttng_poll_event. | |
42 | */ | |
43 | static inline void __lttng_poll_free(void *events) | |
44 | { | |
b3066218 DG |
45 | if (events) { |
46 | free(events); | |
47 | } | |
5eb91c98 DG |
48 | } |
49 | ||
50 | /* | |
51 | * epoll(7) implementation. | |
52 | */ | |
53 | #ifdef HAVE_EPOLL | |
54 | #include <sys/epoll.h> | |
76d7553f | 55 | #include <stdio.h> |
5eb91c98 DG |
56 | |
57 | /* See man epoll(7) for this define path */ | |
990570ed | 58 | #define COMPAT_EPOLL_PROC_PATH "/proc/sys/fs/epoll/max_user_watches" |
5eb91c98 DG |
59 | |
60 | enum { | |
61 | /* Polling variables compatibility for epoll */ | |
62 | LPOLLIN = EPOLLIN, | |
63 | LPOLLPRI = EPOLLPRI, | |
64 | LPOLLOUT = EPOLLOUT, | |
65 | LPOLLRDNORM = EPOLLRDNORM, | |
66 | LPOLLRDBAND = EPOLLRDBAND, | |
67 | LPOLLWRNORM = EPOLLWRNORM, | |
68 | LPOLLWRBAND = EPOLLWRBAND, | |
69 | LPOLLMSG = EPOLLMSG, | |
70 | LPOLLERR = EPOLLERR, | |
71 | LPOLLHUP = EPOLLHUP, | |
72 | LPOLLNVAL = EPOLLHUP, | |
73 | LPOLLRDHUP = EPOLLRDHUP, | |
74 | /* Close on exec feature of epoll */ | |
75 | LTTNG_CLOEXEC = EPOLL_CLOEXEC, | |
76 | }; | |
77 | ||
78 | struct compat_epoll_event { | |
79 | int epfd; | |
80 | uint32_t nb_fd; /* Current number of fd in events */ | |
81 | uint32_t events_size; /* Size of events array */ | |
82 | struct epoll_event *events; | |
83 | }; | |
84 | #define lttng_poll_event compat_epoll_event | |
85 | ||
86 | /* | |
87 | * For the following calls, consider 'e' to be a lttng_poll_event pointer and i | |
88 | * being the index of the events array. | |
89 | */ | |
90 | #define LTTNG_POLL_GETFD(e, i) LTTNG_REF(e)->events[i].data.fd | |
91 | #define LTTNG_POLL_GETEV(e, i) LTTNG_REF(e)->events[i].events | |
92 | #define LTTNG_POLL_GETNB(e) LTTNG_REF(e)->nb_fd | |
93 | #define LTTNG_POLL_GETSZ(e) LTTNG_REF(e)->events_size | |
94 | ||
95 | /* | |
96 | * Create the epoll set. No memory allocation is done here. | |
97 | */ | |
98 | extern int compat_epoll_create(struct lttng_poll_event *events, | |
99 | int size, int flags); | |
100 | #define lttng_poll_create(events, size, flags) \ | |
65b1b198 | 101 | compat_epoll_create(events, size, flags) |
5eb91c98 DG |
102 | |
103 | /* | |
104 | * Wait on epoll set with the number of fd registered to the lttng_poll_event | |
105 | * data structure (events). | |
106 | */ | |
107 | extern int compat_epoll_wait(struct lttng_poll_event *events, int timeout); | |
108 | #define lttng_poll_wait(events, timeout) \ | |
65b1b198 | 109 | compat_epoll_wait(events, timeout) |
5eb91c98 DG |
110 | |
111 | /* | |
112 | * Add a fd to the epoll set and resize the epoll_event structure if needed. | |
113 | */ | |
114 | extern int compat_epoll_add(struct lttng_poll_event *events, | |
115 | int fd, uint32_t req_events); | |
116 | #define lttng_poll_add(events, fd, req_events) \ | |
65b1b198 | 117 | compat_epoll_add(events, fd, req_events) |
5eb91c98 DG |
118 | |
119 | /* | |
120 | * Remove a fd from the epoll set. | |
121 | */ | |
122 | extern int compat_epoll_del(struct lttng_poll_event *events, int fd); | |
123 | #define lttng_poll_del(events, fd) \ | |
65b1b198 | 124 | compat_epoll_del(events, fd) |
5eb91c98 DG |
125 | |
126 | /* | |
127 | * Set up the poll set limits variable poll_max_size | |
128 | */ | |
129 | extern void compat_epoll_set_max_size(void); | |
65b1b198 MD |
130 | #define lttng_poll_set_max_size() \ |
131 | compat_epoll_set_max_size() | |
5eb91c98 DG |
132 | |
133 | /* | |
134 | * This function memset with zero the structure since it can be reused at each | |
135 | * round of a main loop. Being in a loop and using a non static number of fds, | |
136 | * this function must be called to insure coherent events with associted fds. | |
137 | */ | |
138 | static inline void lttng_poll_reset(struct lttng_poll_event *events) | |
139 | { | |
140 | if (events && events->events) { | |
141 | memset(events->events, 0, | |
142 | events->nb_fd * sizeof(struct epoll_event)); | |
143 | } | |
144 | } | |
145 | ||
146 | /* | |
147 | * Clean the events structure of a lttng_poll_event. It's the caller | |
148 | * responsability to free the lttng_poll_event memory. | |
149 | */ | |
150 | static inline void lttng_poll_clean(struct lttng_poll_event *events) | |
151 | { | |
76d7553f MD |
152 | int ret; |
153 | ||
5eb91c98 | 154 | if (events) { |
76d7553f MD |
155 | ret = close(events->epfd); |
156 | if (ret) { | |
157 | perror("close"); | |
158 | } | |
5eb91c98 DG |
159 | __lttng_poll_free((void *) events->events); |
160 | } | |
161 | } | |
162 | ||
163 | #else /* HAVE_EPOLL */ | |
164 | /* | |
165 | * Fallback on poll(2) API | |
166 | */ | |
167 | ||
168 | /* Needed for some poll event values */ | |
169 | #ifndef __USE_XOPEN | |
170 | #define __USE_XOPEN | |
171 | #endif | |
172 | ||
173 | /* Needed for some poll event values */ | |
174 | #ifndef __USE_GNU | |
175 | #define __USE_GNU | |
176 | #endif | |
177 | ||
178 | #include <poll.h> | |
179 | #include <stdint.h> | |
180 | ||
181 | enum { | |
182 | /* Polling variables compatibility for poll */ | |
183 | LPOLLIN = POLLIN, | |
184 | LPOLLPRI = POLLPRI, | |
185 | LPOLLOUT = POLLOUT, | |
186 | LPOLLRDNORM = POLLRDNORM, | |
187 | LPOLLRDBAND = POLLRDBAND, | |
188 | LPOLLWRNORM = POLLWRNORM, | |
189 | LPOLLWRBAND = POLLWRBAND, | |
1268b9d6 | 190 | #if __linux__ |
5eb91c98 | 191 | LPOLLMSG = POLLMSG, |
1268b9d6 | 192 | LPOLLRDHUP = POLLRDHUP, |
3247be18 | 193 | #elif (defined(__FreeBSD__) || defined(__CYGWIN__)) |
1268b9d6 DG |
194 | LPOLLMSG = 0, |
195 | LPOLLRDHUP = 0, | |
b2c3836f MD |
196 | #else |
197 | #error "Please add support for your OS." | |
1268b9d6 | 198 | #endif /* __linux__ */ |
5eb91c98 DG |
199 | LPOLLERR = POLLERR, |
200 | LPOLLHUP = POLLHUP | POLLNVAL, | |
5eb91c98 DG |
201 | /* Close on exec feature does not exist for poll(2) */ |
202 | LTTNG_CLOEXEC = 0xdead, | |
203 | }; | |
204 | ||
205 | struct compat_poll_event { | |
206 | uint32_t nb_fd; /* Current number of fd in events */ | |
207 | uint32_t events_size; /* Size of events array */ | |
208 | struct pollfd *events; | |
209 | }; | |
210 | #define lttng_poll_event compat_poll_event | |
211 | ||
212 | /* | |
213 | * For the following calls, consider 'e' to be a lttng_poll_event pointer and i | |
214 | * being the index of the events array. | |
215 | */ | |
216 | #define LTTNG_POLL_GETFD(e, i) LTTNG_REF(e)->events[i].fd | |
217 | #define LTTNG_POLL_GETEV(e, i) LTTNG_REF(e)->events[i].revents | |
218 | #define LTTNG_POLL_GETNB(e) LTTNG_REF(e)->nb_fd | |
219 | #define LTTNG_POLL_GETSZ(e) LTTNG_REF(e)->events_size | |
220 | ||
221 | /* | |
222 | * Create a pollfd structure of size 'size'. | |
223 | */ | |
224 | extern int compat_poll_create(struct lttng_poll_event *events, int size); | |
225 | #define lttng_poll_create(events, size, flags) \ | |
65b1b198 | 226 | compat_poll_create(events, size) |
5eb91c98 DG |
227 | |
228 | /* | |
229 | * Wait on poll(2) event with nb_fd registered to the lttng_poll_event data | |
230 | * structure. | |
231 | */ | |
232 | extern int compat_poll_wait(struct lttng_poll_event *events, int timeout); | |
233 | #define lttng_poll_wait(events, timeout) \ | |
65b1b198 | 234 | compat_poll_wait(events, timeout) |
5eb91c98 DG |
235 | |
236 | /* | |
237 | * Add the fd to the pollfd structure. Resize if needed. | |
238 | */ | |
239 | extern int compat_poll_add(struct lttng_poll_event *events, | |
240 | int fd, uint32_t req_events); | |
241 | #define lttng_poll_add(events, fd, req_events) \ | |
65b1b198 | 242 | compat_poll_add(events, fd, req_events) |
5eb91c98 DG |
243 | |
244 | /* | |
245 | * Remove the fd from the pollfd. Memory allocation is done to recreate a new | |
246 | * pollfd, data is copied from the old pollfd to the new and, finally, the old | |
247 | * one is freed(). | |
248 | */ | |
249 | extern int compat_poll_del(struct lttng_poll_event *events, int fd); | |
250 | #define lttng_poll_del(events, fd) \ | |
65b1b198 | 251 | compat_poll_del(events, fd) |
5eb91c98 DG |
252 | |
253 | /* | |
254 | * Set up the poll set limits variable poll_max_size | |
255 | */ | |
256 | extern void compat_poll_set_max_size(void); | |
65b1b198 MD |
257 | #define lttng_poll_set_max_size() \ |
258 | compat_poll_set_max_size() | |
5eb91c98 DG |
259 | |
260 | /* | |
261 | * No need to reset a pollfd structure for poll(2) | |
262 | */ | |
263 | static inline void lttng_poll_reset(struct lttng_poll_event *events) | |
264 | {} | |
265 | ||
266 | /* | |
267 | * Clean the events structure of a lttng_poll_event. It's the caller | |
268 | * responsability to free the lttng_poll_event memory. | |
269 | */ | |
270 | static inline void lttng_poll_clean(struct lttng_poll_event *events) | |
271 | { | |
272 | if (events) { | |
273 | __lttng_poll_free((void *) events->events); | |
274 | } | |
275 | } | |
276 | ||
277 | #endif /* HAVE_EPOLL */ | |
278 | ||
279 | #endif /* _LTT_POLL_H */ |