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Willy Tarreau4f60f162007-04-08 16:39:58 +02001/*
2 * FD polling functions for generic poll()
3 *
Willy Tarreauf817e9f2014-01-10 16:58:45 +01004 * Copyright 2000-2014 Willy Tarreau <w@1wt.eu>
Willy Tarreau4f60f162007-04-08 16:39:58 +02005 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 *
11 */
12
Willy Tarreau3c8a8962017-03-13 17:14:51 +010013#define _GNU_SOURCE // for POLLRDHUP on Linux
14
Willy Tarreau4f60f162007-04-08 16:39:58 +020015#include <unistd.h>
Willy Tarreau3c8a8962017-03-13 17:14:51 +010016#include <poll.h>
Willy Tarreau4f60f162007-04-08 16:39:58 +020017#include <sys/time.h>
18#include <sys/types.h>
19
20#include <common/compat.h>
21#include <common/config.h>
Willy Tarreau0c303ee2008-07-07 00:09:58 +020022#include <common/ticks.h>
Willy Tarreau4f60f162007-04-08 16:39:58 +020023#include <common/time.h>
24
Willy Tarreau4f60f162007-04-08 16:39:58 +020025#include <types/global.h>
26
27#include <proto/fd.h>
Willy Tarreau4f60f162007-04-08 16:39:58 +020028
Willy Tarreau3c8a8962017-03-13 17:14:51 +010029
30#ifndef POLLRDHUP
31/* POLLRDHUP was defined late in libc, and it appeared in kernel 2.6.17 */
32#define POLLRDHUP 0
33#endif
Willy Tarreau4f60f162007-04-08 16:39:58 +020034
Willy Tarreau80da05a2013-03-31 14:06:57 +020035static unsigned int *fd_evts[2];
Willy Tarreau4f60f162007-04-08 16:39:58 +020036
37/* private data */
38static struct pollfd *poll_events = NULL;
39
40
Willy Tarreau80da05a2013-03-31 14:06:57 +020041static inline void hap_fd_set(int fd, unsigned int *evts)
42{
43 evts[fd / (8*sizeof(*evts))] |= 1U << (fd & (8*sizeof(*evts) - 1));
44}
45
46static inline void hap_fd_clr(int fd, unsigned int *evts)
47{
48 evts[fd / (8*sizeof(*evts))] &= ~(1U << (fd & (8*sizeof(*evts) - 1)));
49}
50
51REGPRM1 static void __fd_clo(int fd)
52{
53 hap_fd_clr(fd, fd_evts[DIR_RD]);
54 hap_fd_clr(fd, fd_evts[DIR_WR]);
55}
56
Willy Tarreau4f60f162007-04-08 16:39:58 +020057/*
58 * Poll() poller
59 */
Willy Tarreau0c303ee2008-07-07 00:09:58 +020060REGPRM2 static void _do_poll(struct poller *p, int exp)
Willy Tarreau4f60f162007-04-08 16:39:58 +020061{
62 int status;
63 int fd, nbfd;
Willy Tarreaud825eef2007-05-12 22:35:00 +020064 int wait_time;
Willy Tarreaucc7e3f72012-11-11 17:25:15 +010065 int updt_idx, en, eo;
Willy Tarreau4f60f162007-04-08 16:39:58 +020066 int fds, count;
67 int sr, sw;
68 unsigned rn, wn; /* read new, write new */
69
Willy Tarreaucc7e3f72012-11-11 17:25:15 +010070 /* first, scan the update list to find changes */
71 for (updt_idx = 0; updt_idx < fd_nbupdt; updt_idx++) {
72 fd = fd_updt[updt_idx];
Willy Tarreauf817e9f2014-01-10 16:58:45 +010073 fdtab[fd].updated = 0;
74 fdtab[fd].new = 0;
Willy Tarreaucc7e3f72012-11-11 17:25:15 +010075
Willy Tarreauf817e9f2014-01-10 16:58:45 +010076 if (!fdtab[fd].owner)
77 continue;
Willy Tarreaucc7e3f72012-11-11 17:25:15 +010078
Willy Tarreau25002d22014-01-25 10:32:56 +010079 eo = fdtab[fd].state;
80 en = fd_compute_new_polled_status(eo);
Willy Tarreauf817e9f2014-01-10 16:58:45 +010081
82 if ((eo ^ en) & FD_EV_POLLED_RW) {
83 /* poll status changed, update the lists */
84 fdtab[fd].state = en;
85
86 if ((eo & ~en) & FD_EV_POLLED_R)
87 hap_fd_clr(fd, fd_evts[DIR_RD]);
88 else if ((en & ~eo) & FD_EV_POLLED_R)
89 hap_fd_set(fd, fd_evts[DIR_RD]);
90
91 if ((eo & ~en) & FD_EV_POLLED_W)
92 hap_fd_clr(fd, fd_evts[DIR_WR]);
93 else if ((en & ~eo) & FD_EV_POLLED_W)
94 hap_fd_set(fd, fd_evts[DIR_WR]);
95 }
Willy Tarreaucc7e3f72012-11-11 17:25:15 +010096 }
97 fd_nbupdt = 0;
98
Willy Tarreau4f60f162007-04-08 16:39:58 +020099 nbfd = 0;
Willy Tarreau80da05a2013-03-31 14:06:57 +0200100 for (fds = 0; (fds * 8*sizeof(**fd_evts)) < maxfd; fds++) {
101 rn = fd_evts[DIR_RD][fds];
102 wn = fd_evts[DIR_WR][fds];
Willy Tarreau4f60f162007-04-08 16:39:58 +0200103
Willy Tarreau80da05a2013-03-31 14:06:57 +0200104 if (!(rn|wn))
105 continue;
Willy Tarreau4f60f162007-04-08 16:39:58 +0200106
Willy Tarreau80da05a2013-03-31 14:06:57 +0200107 for (count = 0, fd = fds * 8*sizeof(**fd_evts); count < 8*sizeof(**fd_evts) && fd < maxfd; count++, fd++) {
108 sr = (rn >> count) & 1;
109 sw = (wn >> count) & 1;
110 if ((sr|sw)) {
111 poll_events[nbfd].fd = fd;
Willy Tarreau3c8a8962017-03-13 17:14:51 +0100112 poll_events[nbfd].events = (sr ? (POLLIN | POLLRDHUP) : 0) | (sw ? POLLOUT : 0);
Willy Tarreau80da05a2013-03-31 14:06:57 +0200113 nbfd++;
Willy Tarreau4f60f162007-04-08 16:39:58 +0200114 }
115 }
116 }
117
118 /* now let's wait for events */
Willy Tarreau10146c92015-04-13 20:44:19 +0200119 if (!exp)
Willy Tarreaub0b37bc2008-06-23 14:00:57 +0200120 wait_time = MAX_DELAY_MS;
Willy Tarreau0c303ee2008-07-07 00:09:58 +0200121 else if (tick_is_expired(exp, now_ms))
Willy Tarreaubdefc512007-05-14 02:02:04 +0200122 wait_time = 0;
Willy Tarreaub0b37bc2008-06-23 14:00:57 +0200123 else {
Willy Tarreau0c303ee2008-07-07 00:09:58 +0200124 wait_time = TICKS_TO_MS(tick_remain(now_ms, exp)) + 1;
Willy Tarreaub0b37bc2008-06-23 14:00:57 +0200125 if (wait_time > MAX_DELAY_MS)
126 wait_time = MAX_DELAY_MS;
127 }
Willy Tarreaud825eef2007-05-12 22:35:00 +0200128
Willy Tarreau45a12512011-09-10 16:56:42 +0200129 gettimeofday(&before_poll, NULL);
Willy Tarreau4f60f162007-04-08 16:39:58 +0200130 status = poll(poll_events, nbfd, wait_time);
Willy Tarreaub0b37bc2008-06-23 14:00:57 +0200131 tv_update_date(wait_time, status);
Willy Tarreau45a12512011-09-10 16:56:42 +0200132 measure_idle();
Willy Tarreau4f60f162007-04-08 16:39:58 +0200133
134 for (count = 0; status > 0 && count < nbfd; count++) {
Christopher Fauletab62f512017-08-30 10:34:36 +0200135 unsigned int n;
Willy Tarreau491c4982012-07-06 11:16:01 +0200136 int e = poll_events[count].revents;
Willy Tarreau4f60f162007-04-08 16:39:58 +0200137 fd = poll_events[count].fd;
138
Willy Tarreau3c8a8962017-03-13 17:14:51 +0100139 if (!(e & ( POLLOUT | POLLIN | POLLERR | POLLHUP | POLLRDHUP )))
Willy Tarreau4f60f162007-04-08 16:39:58 +0200140 continue;
141
Willy Tarreau076be252012-07-06 16:02:29 +0200142 /* ok, we found one active fd */
143 status--;
144
145 if (!fdtab[fd].owner)
146 continue;
147
Willy Tarreau462c7202012-12-13 22:26:37 +0100148 /* it looks complicated but gcc can optimize it away when constants
149 * have same values... In fact it depends on gcc :-(
150 */
Willy Tarreau462c7202012-12-13 22:26:37 +0100151 if (POLLIN == FD_POLL_IN && POLLOUT == FD_POLL_OUT &&
152 POLLERR == FD_POLL_ERR && POLLHUP == FD_POLL_HUP) {
Christopher Fauletab62f512017-08-30 10:34:36 +0200153 n = e & (POLLIN|POLLOUT|POLLERR|POLLHUP);
Willy Tarreau462c7202012-12-13 22:26:37 +0100154 }
155 else {
Christopher Fauletab62f512017-08-30 10:34:36 +0200156 n = ((e & POLLIN ) ? FD_POLL_IN : 0) |
Willy Tarreau462c7202012-12-13 22:26:37 +0100157 ((e & POLLOUT) ? FD_POLL_OUT : 0) |
158 ((e & POLLERR) ? FD_POLL_ERR : 0) |
159 ((e & POLLHUP) ? FD_POLL_HUP : 0);
160 }
Willy Tarreau491c4982012-07-06 11:16:01 +0200161
Willy Tarreau3c8a8962017-03-13 17:14:51 +0100162 /* always remap RDHUP to HUP as they're used similarly */
163 if (e & POLLRDHUP) {
164 cur_poller.flags |= HAP_POLL_F_RDHUP;
Christopher Fauletab62f512017-08-30 10:34:36 +0200165 n |= FD_POLL_HUP;
Willy Tarreau3c8a8962017-03-13 17:14:51 +0100166 }
167
Christopher Fauletab62f512017-08-30 10:34:36 +0200168 fd_update_events(fd, n);
Willy Tarreau4f60f162007-04-08 16:39:58 +0200169 }
170
Willy Tarreaue54e9172007-04-09 09:23:31 +0200171}
172
173/*
174 * Initialization of the poll() poller.
175 * Returns 0 in case of failure, non-zero in case of success. If it fails, it
176 * disables the poller by setting its pref to 0.
177 */
Willy Tarreauef1d1f82007-04-16 00:25:25 +0200178REGPRM1 static int _do_init(struct poller *p)
Willy Tarreaue54e9172007-04-09 09:23:31 +0200179{
180 __label__ fail_swevt, fail_srevt, fail_pe;
Willy Tarreau80da05a2013-03-31 14:06:57 +0200181 int fd_evts_bytes;
Willy Tarreaue54e9172007-04-09 09:23:31 +0200182
183 p->private = NULL;
Willy Tarreau80da05a2013-03-31 14:06:57 +0200184 fd_evts_bytes = (global.maxsock + sizeof(**fd_evts) - 1) / sizeof(**fd_evts) * sizeof(**fd_evts);
Willy Tarreaue54e9172007-04-09 09:23:31 +0200185
Willy Tarreau80da05a2013-03-31 14:06:57 +0200186 poll_events = calloc(1, sizeof(struct pollfd) * global.maxsock);
Willy Tarreaue54e9172007-04-09 09:23:31 +0200187
188 if (poll_events == NULL)
189 goto fail_pe;
190
Willy Tarreau80da05a2013-03-31 14:06:57 +0200191 if ((fd_evts[DIR_RD] = calloc(1, fd_evts_bytes)) == NULL)
Willy Tarreaue54e9172007-04-09 09:23:31 +0200192 goto fail_srevt;
193
Willy Tarreau80da05a2013-03-31 14:06:57 +0200194 if ((fd_evts[DIR_WR] = calloc(1, fd_evts_bytes)) == NULL)
Willy Tarreaue54e9172007-04-09 09:23:31 +0200195 goto fail_swevt;
196
197 return 1;
198
199 fail_swevt:
200 free(fd_evts[DIR_RD]);
201 fail_srevt:
202 free(poll_events);
203 fail_pe:
204 p->pref = 0;
205 return 0;
206}
207
208/*
209 * Termination of the poll() poller.
210 * Memory is released and the poller is marked as unselectable.
211 */
Willy Tarreauef1d1f82007-04-16 00:25:25 +0200212REGPRM1 static void _do_term(struct poller *p)
Willy Tarreaue54e9172007-04-09 09:23:31 +0200213{
Willy Tarreaua534fea2008-08-03 12:19:50 +0200214 free(fd_evts[DIR_WR]);
215 free(fd_evts[DIR_RD]);
216 free(poll_events);
Willy Tarreaue54e9172007-04-09 09:23:31 +0200217 p->private = NULL;
218 p->pref = 0;
Willy Tarreau4f60f162007-04-08 16:39:58 +0200219}
220
221/*
Willy Tarreau2ff76222007-04-09 19:29:56 +0200222 * Check that the poller works.
223 * Returns 1 if OK, otherwise 0.
224 */
Willy Tarreauef1d1f82007-04-16 00:25:25 +0200225REGPRM1 static int _do_test(struct poller *p)
Willy Tarreau2ff76222007-04-09 19:29:56 +0200226{
227 return 1;
228}
229
230/*
Willy Tarreauef1d1f82007-04-16 00:25:25 +0200231 * It is a constructor, which means that it will automatically be called before
232 * main(). This is GCC-specific but it works at least since 2.95.
233 * Special care must be taken so that it does not need any uninitialized data.
Willy Tarreau4f60f162007-04-08 16:39:58 +0200234 */
Willy Tarreauef1d1f82007-04-16 00:25:25 +0200235__attribute__((constructor))
236static void _do_register(void)
Willy Tarreau4f60f162007-04-08 16:39:58 +0200237{
Willy Tarreauef1d1f82007-04-16 00:25:25 +0200238 struct poller *p;
239
240 if (nbpollers >= MAX_POLLERS)
241 return;
242 p = &pollers[nbpollers++];
243
Willy Tarreau4f60f162007-04-08 16:39:58 +0200244 p->name = "poll";
245 p->pref = 200;
Willy Tarreau5a767692017-03-13 11:38:28 +0100246 p->flags = 0;
Willy Tarreau4f60f162007-04-08 16:39:58 +0200247 p->private = NULL;
248
Willy Tarreau70c6fd82012-11-11 21:02:34 +0100249 p->clo = __fd_clo;
Willy Tarreauef1d1f82007-04-16 00:25:25 +0200250 p->test = _do_test;
251 p->init = _do_init;
252 p->term = _do_term;
253 p->poll = _do_poll;
Willy Tarreau4f60f162007-04-08 16:39:58 +0200254}
255
256
257/*
258 * Local variables:
259 * c-indent-level: 8
260 * c-basic-offset: 8
261 * End:
262 */