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5eb91c98 DG |
1 | /* |
2 | * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca> | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify it | |
5 | * under the terms of the GNU General Public License as published by the Free | |
6 | * Software Foundation; only version 2 of the License. | |
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 | * | |
13 | * You should have received a copy of the GNU General Public License along with | |
14 | * this program; if not, write to the Free Software Foundation, Inc., 59 Temple | |
15 | * Place - Suite 330, Boston, MA 02111-1307, USA. | |
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 | { | |
45 | free(events); | |
46 | } | |
47 | ||
48 | /* | |
49 | * epoll(7) implementation. | |
50 | */ | |
51 | #ifdef HAVE_EPOLL | |
52 | #include <sys/epoll.h> | |
53 | ||
54 | /* See man epoll(7) for this define path */ | |
990570ed | 55 | #define COMPAT_EPOLL_PROC_PATH "/proc/sys/fs/epoll/max_user_watches" |
5eb91c98 DG |
56 | |
57 | enum { | |
58 | /* Polling variables compatibility for epoll */ | |
59 | LPOLLIN = EPOLLIN, | |
60 | LPOLLPRI = EPOLLPRI, | |
61 | LPOLLOUT = EPOLLOUT, | |
62 | LPOLLRDNORM = EPOLLRDNORM, | |
63 | LPOLLRDBAND = EPOLLRDBAND, | |
64 | LPOLLWRNORM = EPOLLWRNORM, | |
65 | LPOLLWRBAND = EPOLLWRBAND, | |
66 | LPOLLMSG = EPOLLMSG, | |
67 | LPOLLERR = EPOLLERR, | |
68 | LPOLLHUP = EPOLLHUP, | |
69 | LPOLLNVAL = EPOLLHUP, | |
70 | LPOLLRDHUP = EPOLLRDHUP, | |
71 | /* Close on exec feature of epoll */ | |
72 | LTTNG_CLOEXEC = EPOLL_CLOEXEC, | |
73 | }; | |
74 | ||
75 | struct compat_epoll_event { | |
76 | int epfd; | |
77 | uint32_t nb_fd; /* Current number of fd in events */ | |
78 | uint32_t events_size; /* Size of events array */ | |
79 | struct epoll_event *events; | |
80 | }; | |
81 | #define lttng_poll_event compat_epoll_event | |
82 | ||
83 | /* | |
84 | * For the following calls, consider 'e' to be a lttng_poll_event pointer and i | |
85 | * being the index of the events array. | |
86 | */ | |
87 | #define LTTNG_POLL_GETFD(e, i) LTTNG_REF(e)->events[i].data.fd | |
88 | #define LTTNG_POLL_GETEV(e, i) LTTNG_REF(e)->events[i].events | |
89 | #define LTTNG_POLL_GETNB(e) LTTNG_REF(e)->nb_fd | |
90 | #define LTTNG_POLL_GETSZ(e) LTTNG_REF(e)->events_size | |
91 | ||
92 | /* | |
93 | * Create the epoll set. No memory allocation is done here. | |
94 | */ | |
95 | extern int compat_epoll_create(struct lttng_poll_event *events, | |
96 | int size, int flags); | |
97 | #define lttng_poll_create(events, size, flags) \ | |
65b1b198 | 98 | compat_epoll_create(events, size, flags) |
5eb91c98 DG |
99 | |
100 | /* | |
101 | * Wait on epoll set with the number of fd registered to the lttng_poll_event | |
102 | * data structure (events). | |
103 | */ | |
104 | extern int compat_epoll_wait(struct lttng_poll_event *events, int timeout); | |
105 | #define lttng_poll_wait(events, timeout) \ | |
65b1b198 | 106 | compat_epoll_wait(events, timeout) |
5eb91c98 DG |
107 | |
108 | /* | |
109 | * Add a fd to the epoll set and resize the epoll_event structure if needed. | |
110 | */ | |
111 | extern int compat_epoll_add(struct lttng_poll_event *events, | |
112 | int fd, uint32_t req_events); | |
113 | #define lttng_poll_add(events, fd, req_events) \ | |
65b1b198 | 114 | compat_epoll_add(events, fd, req_events) |
5eb91c98 DG |
115 | |
116 | /* | |
117 | * Remove a fd from the epoll set. | |
118 | */ | |
119 | extern int compat_epoll_del(struct lttng_poll_event *events, int fd); | |
120 | #define lttng_poll_del(events, fd) \ | |
65b1b198 | 121 | compat_epoll_del(events, fd) |
5eb91c98 DG |
122 | |
123 | /* | |
124 | * Set up the poll set limits variable poll_max_size | |
125 | */ | |
126 | extern void compat_epoll_set_max_size(void); | |
65b1b198 MD |
127 | #define lttng_poll_set_max_size() \ |
128 | compat_epoll_set_max_size() | |
5eb91c98 DG |
129 | |
130 | /* | |
131 | * This function memset with zero the structure since it can be reused at each | |
132 | * round of a main loop. Being in a loop and using a non static number of fds, | |
133 | * this function must be called to insure coherent events with associted fds. | |
134 | */ | |
135 | static inline void lttng_poll_reset(struct lttng_poll_event *events) | |
136 | { | |
137 | if (events && events->events) { | |
138 | memset(events->events, 0, | |
139 | events->nb_fd * sizeof(struct epoll_event)); | |
140 | } | |
141 | } | |
142 | ||
143 | /* | |
144 | * Clean the events structure of a lttng_poll_event. It's the caller | |
145 | * responsability to free the lttng_poll_event memory. | |
146 | */ | |
147 | static inline void lttng_poll_clean(struct lttng_poll_event *events) | |
148 | { | |
149 | if (events) { | |
150 | close(events->epfd); | |
151 | __lttng_poll_free((void *) events->events); | |
152 | } | |
153 | } | |
154 | ||
155 | #else /* HAVE_EPOLL */ | |
156 | /* | |
157 | * Fallback on poll(2) API | |
158 | */ | |
159 | ||
160 | /* Needed for some poll event values */ | |
161 | #ifndef __USE_XOPEN | |
162 | #define __USE_XOPEN | |
163 | #endif | |
164 | ||
165 | /* Needed for some poll event values */ | |
166 | #ifndef __USE_GNU | |
167 | #define __USE_GNU | |
168 | #endif | |
169 | ||
170 | #include <poll.h> | |
171 | #include <stdint.h> | |
172 | ||
173 | enum { | |
174 | /* Polling variables compatibility for poll */ | |
175 | LPOLLIN = POLLIN, | |
176 | LPOLLPRI = POLLPRI, | |
177 | LPOLLOUT = POLLOUT, | |
178 | LPOLLRDNORM = POLLRDNORM, | |
179 | LPOLLRDBAND = POLLRDBAND, | |
180 | LPOLLWRNORM = POLLWRNORM, | |
181 | LPOLLWRBAND = POLLWRBAND, | |
1268b9d6 | 182 | #if __linux__ |
5eb91c98 | 183 | LPOLLMSG = POLLMSG, |
1268b9d6 | 184 | LPOLLRDHUP = POLLRDHUP, |
b2c3836f | 185 | #elif defined(__FreeBSD__) |
1268b9d6 DG |
186 | LPOLLMSG = 0, |
187 | LPOLLRDHUP = 0, | |
b2c3836f MD |
188 | #else |
189 | #error "Please add support for your OS." | |
1268b9d6 | 190 | #endif /* __linux__ */ |
5eb91c98 DG |
191 | LPOLLERR = POLLERR, |
192 | LPOLLHUP = POLLHUP | POLLNVAL, | |
5eb91c98 DG |
193 | /* Close on exec feature does not exist for poll(2) */ |
194 | LTTNG_CLOEXEC = 0xdead, | |
195 | }; | |
196 | ||
197 | struct compat_poll_event { | |
198 | uint32_t nb_fd; /* Current number of fd in events */ | |
199 | uint32_t events_size; /* Size of events array */ | |
200 | struct pollfd *events; | |
201 | }; | |
202 | #define lttng_poll_event compat_poll_event | |
203 | ||
204 | /* | |
205 | * For the following calls, consider 'e' to be a lttng_poll_event pointer and i | |
206 | * being the index of the events array. | |
207 | */ | |
208 | #define LTTNG_POLL_GETFD(e, i) LTTNG_REF(e)->events[i].fd | |
209 | #define LTTNG_POLL_GETEV(e, i) LTTNG_REF(e)->events[i].revents | |
210 | #define LTTNG_POLL_GETNB(e) LTTNG_REF(e)->nb_fd | |
211 | #define LTTNG_POLL_GETSZ(e) LTTNG_REF(e)->events_size | |
212 | ||
213 | /* | |
214 | * Create a pollfd structure of size 'size'. | |
215 | */ | |
216 | extern int compat_poll_create(struct lttng_poll_event *events, int size); | |
217 | #define lttng_poll_create(events, size, flags) \ | |
65b1b198 | 218 | compat_poll_create(events, size) |
5eb91c98 DG |
219 | |
220 | /* | |
221 | * Wait on poll(2) event with nb_fd registered to the lttng_poll_event data | |
222 | * structure. | |
223 | */ | |
224 | extern int compat_poll_wait(struct lttng_poll_event *events, int timeout); | |
225 | #define lttng_poll_wait(events, timeout) \ | |
65b1b198 | 226 | compat_poll_wait(events, timeout) |
5eb91c98 DG |
227 | |
228 | /* | |
229 | * Add the fd to the pollfd structure. Resize if needed. | |
230 | */ | |
231 | extern int compat_poll_add(struct lttng_poll_event *events, | |
232 | int fd, uint32_t req_events); | |
233 | #define lttng_poll_add(events, fd, req_events) \ | |
65b1b198 | 234 | compat_poll_add(events, fd, req_events) |
5eb91c98 DG |
235 | |
236 | /* | |
237 | * Remove the fd from the pollfd. Memory allocation is done to recreate a new | |
238 | * pollfd, data is copied from the old pollfd to the new and, finally, the old | |
239 | * one is freed(). | |
240 | */ | |
241 | extern int compat_poll_del(struct lttng_poll_event *events, int fd); | |
242 | #define lttng_poll_del(events, fd) \ | |
65b1b198 | 243 | compat_poll_del(events, fd) |
5eb91c98 DG |
244 | |
245 | /* | |
246 | * Set up the poll set limits variable poll_max_size | |
247 | */ | |
248 | extern void compat_poll_set_max_size(void); | |
65b1b198 MD |
249 | #define lttng_poll_set_max_size() \ |
250 | compat_poll_set_max_size() | |
5eb91c98 DG |
251 | |
252 | /* | |
253 | * No need to reset a pollfd structure for poll(2) | |
254 | */ | |
255 | static inline void lttng_poll_reset(struct lttng_poll_event *events) | |
256 | {} | |
257 | ||
258 | /* | |
259 | * Clean the events structure of a lttng_poll_event. It's the caller | |
260 | * responsability to free the lttng_poll_event memory. | |
261 | */ | |
262 | static inline void lttng_poll_clean(struct lttng_poll_event *events) | |
263 | { | |
264 | if (events) { | |
265 | __lttng_poll_free((void *) events->events); | |
266 | } | |
267 | } | |
268 | ||
269 | #endif /* HAVE_EPOLL */ | |
270 | ||
271 | #endif /* _LTT_POLL_H */ |