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Willy Tarreau4f60f162007-04-08 16:39:58 +02001/*
2 * FD polling functions for generic select()
3 *
Willy Tarreaub7f694f2008-06-22 17:18:02 +02004 * Copyright 2000-2008 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
13#include <unistd.h>
14#include <sys/time.h>
15#include <sys/types.h>
16
17#include <common/compat.h>
18#include <common/config.h>
Willy Tarreau0c303ee2008-07-07 00:09:58 +020019#include <common/ticks.h>
Willy Tarreau4f60f162007-04-08 16:39:58 +020020#include <common/time.h>
21
Willy Tarreau4f60f162007-04-08 16:39:58 +020022#include <types/global.h>
23
24#include <proto/fd.h>
Willy Tarreau4f60f162007-04-08 16:39:58 +020025#include <proto/task.h>
26
27
Willy Tarreau28d86862007-04-08 17:42:27 +020028static fd_set *fd_evts[2];
29static fd_set *tmp_evts[2];
Willy Tarreau4f60f162007-04-08 16:39:58 +020030
31
32/*
33 * Benchmarks performed on a Pentium-M notebook show that using functions
34 * instead of the usual macros improve the FD_* performance by about 80%,
35 * and that marking them regparm(2) adds another 20%.
36 */
Willy Tarreau63455a92007-04-09 15:34:49 +020037REGPRM2 static int __fd_is_set(const int fd, int dir)
Willy Tarreau4f60f162007-04-08 16:39:58 +020038{
Willy Tarreau28d86862007-04-08 17:42:27 +020039 return FD_ISSET(fd, fd_evts[dir]);
Willy Tarreau4f60f162007-04-08 16:39:58 +020040}
41
Willy Tarreau97129b52007-04-09 00:54:46 +020042REGPRM2 static int __fd_set(const int fd, int dir)
Willy Tarreau4f60f162007-04-08 16:39:58 +020043{
Willy Tarreau28d86862007-04-08 17:42:27 +020044 FD_SET(fd, fd_evts[dir]);
Willy Tarreau97129b52007-04-09 00:54:46 +020045 return 0;
Willy Tarreau4f60f162007-04-08 16:39:58 +020046}
47
Willy Tarreau97129b52007-04-09 00:54:46 +020048REGPRM2 static int __fd_clr(const int fd, int dir)
Willy Tarreau4f60f162007-04-08 16:39:58 +020049{
Willy Tarreau28d86862007-04-08 17:42:27 +020050 FD_CLR(fd, fd_evts[dir]);
Willy Tarreau97129b52007-04-09 00:54:46 +020051 return 0;
Willy Tarreau4f60f162007-04-08 16:39:58 +020052}
53
Willy Tarreau97129b52007-04-09 00:54:46 +020054REGPRM2 static int __fd_cond_s(const int fd, int dir)
Willy Tarreau4f60f162007-04-08 16:39:58 +020055{
56 int ret;
Willy Tarreau28d86862007-04-08 17:42:27 +020057 ret = !FD_ISSET(fd, fd_evts[dir]);
Willy Tarreau4f60f162007-04-08 16:39:58 +020058 if (ret)
Willy Tarreau28d86862007-04-08 17:42:27 +020059 FD_SET(fd, fd_evts[dir]);
Willy Tarreau4f60f162007-04-08 16:39:58 +020060 return ret;
61}
62
Willy Tarreau97129b52007-04-09 00:54:46 +020063REGPRM2 static int __fd_cond_c(const int fd, int dir)
Willy Tarreau4f60f162007-04-08 16:39:58 +020064{
65 int ret;
Willy Tarreau28d86862007-04-08 17:42:27 +020066 ret = FD_ISSET(fd, fd_evts[dir]);
Willy Tarreau4f60f162007-04-08 16:39:58 +020067 if (ret)
Willy Tarreau28d86862007-04-08 17:42:27 +020068 FD_CLR(fd, fd_evts[dir]);
Willy Tarreau4f60f162007-04-08 16:39:58 +020069 return ret;
70}
71
Willy Tarreau97129b52007-04-09 00:54:46 +020072REGPRM1 static void __fd_rem(int fd)
Willy Tarreau4f60f162007-04-08 16:39:58 +020073{
Willy Tarreau28d86862007-04-08 17:42:27 +020074 FD_CLR(fd, fd_evts[DIR_RD]);
75 FD_CLR(fd, fd_evts[DIR_WR]);
Willy Tarreau4f60f162007-04-08 16:39:58 +020076}
77
Willy Tarreau4f60f162007-04-08 16:39:58 +020078/*
79 * Select() poller
80 */
Willy Tarreau0c303ee2008-07-07 00:09:58 +020081REGPRM2 static void _do_poll(struct poller *p, int exp)
Willy Tarreau4f60f162007-04-08 16:39:58 +020082{
83 int status;
84 int fd, i;
85 struct timeval delta;
Willy Tarreaub0b37bc2008-06-23 14:00:57 +020086 int delta_ms;
Willy Tarreau4f60f162007-04-08 16:39:58 +020087 int readnotnull, writenotnull;
88 int fds;
89 char count;
90
Willy Tarreau0c303ee2008-07-07 00:09:58 +020091 delta_ms = 0;
92 delta.tv_sec = 0;
93 delta.tv_usec = 0;
94
Willy Tarreaub0b37bc2008-06-23 14:00:57 +020095 if (!run_queue) {
Willy Tarreau0c303ee2008-07-07 00:09:58 +020096 if (!exp) {
97 delta_ms = MAX_DELAY_MS;
98 delta.tv_sec = (MAX_DELAY_MS / 1000);
99 delta.tv_usec = (MAX_DELAY_MS % 1000) * 1000;
Willy Tarreaub0b37bc2008-06-23 14:00:57 +0200100 }
Willy Tarreau0c303ee2008-07-07 00:09:58 +0200101 else if (!tick_is_expired(exp, now_ms)) {
102 delta_ms = TICKS_TO_MS(tick_remain(now_ms, exp)) + SCHEDULER_RESOLUTION;
103 if (delta_ms > MAX_DELAY_MS)
Willy Tarreaub0b37bc2008-06-23 14:00:57 +0200104 delta_ms = MAX_DELAY_MS;
Willy Tarreau0c303ee2008-07-07 00:09:58 +0200105 delta.tv_sec = (delta_ms / 1000);
106 delta.tv_usec = (delta_ms % 1000) * 1000;
Willy Tarreaud825eef2007-05-12 22:35:00 +0200107 }
Willy Tarreau4f60f162007-04-08 16:39:58 +0200108 }
109
110 /* let's restore fdset state */
111
112 readnotnull = 0; writenotnull = 0;
113 for (i = 0; i < (maxfd + FD_SETSIZE - 1)/(8*sizeof(int)); i++) {
Willy Tarreau28d86862007-04-08 17:42:27 +0200114 readnotnull |= (*(((int*)tmp_evts[DIR_RD])+i) = *(((int*)fd_evts[DIR_RD])+i)) != 0;
115 writenotnull |= (*(((int*)tmp_evts[DIR_WR])+i) = *(((int*)fd_evts[DIR_WR])+i)) != 0;
Willy Tarreau4f60f162007-04-08 16:39:58 +0200116 }
117
118 // /* just a verification code, needs to be removed for performance */
119 // for (i=0; i<maxfd; i++) {
Willy Tarreau28d86862007-04-08 17:42:27 +0200120 // if (FD_ISSET(i, tmp_evts[DIR_RD]) != FD_ISSET(i, fd_evts[DIR_RD]))
Willy Tarreau4f60f162007-04-08 16:39:58 +0200121 // abort();
Willy Tarreau28d86862007-04-08 17:42:27 +0200122 // if (FD_ISSET(i, tmp_evts[DIR_WR]) != FD_ISSET(i, fd_evts[DIR_WR]))
Willy Tarreau4f60f162007-04-08 16:39:58 +0200123 // abort();
124 //
125 // }
126
127 status = select(maxfd,
Willy Tarreau28d86862007-04-08 17:42:27 +0200128 readnotnull ? tmp_evts[DIR_RD] : NULL,
129 writenotnull ? tmp_evts[DIR_WR] : NULL,
Willy Tarreau4f60f162007-04-08 16:39:58 +0200130 NULL,
Willy Tarreaub0b37bc2008-06-23 14:00:57 +0200131 &delta);
Willy Tarreau4f60f162007-04-08 16:39:58 +0200132
Willy Tarreaub0b37bc2008-06-23 14:00:57 +0200133 tv_update_date(delta_ms, status);
Willy Tarreau4f60f162007-04-08 16:39:58 +0200134
135 if (status <= 0)
136 return;
137
Willy Tarreau177e2b02008-07-15 00:36:31 +0200138 for (fds = 0; (fds * BITS_PER_INT) < maxfd; fds++) {
Willy Tarreau28d86862007-04-08 17:42:27 +0200139 if ((((int *)(tmp_evts[DIR_RD]))[fds] | ((int *)(tmp_evts[DIR_WR]))[fds]) == 0)
Willy Tarreau4f60f162007-04-08 16:39:58 +0200140 continue;
141
Willy Tarreau177e2b02008-07-15 00:36:31 +0200142 for (count = BITS_PER_INT, fd = fds * BITS_PER_INT; count && fd < maxfd; count--, fd++) {
Willy Tarreau4f60f162007-04-08 16:39:58 +0200143 /* if we specify read first, the accepts and zero reads will be
144 * seen first. Moreover, system buffers will be flushed faster.
145 */
Willy Tarreau28d86862007-04-08 17:42:27 +0200146 if (FD_ISSET(fd, tmp_evts[DIR_RD])) {
Willy Tarreau4f60f162007-04-08 16:39:58 +0200147 if (fdtab[fd].state == FD_STCLOSE)
148 continue;
149 fdtab[fd].cb[DIR_RD].f(fd);
150 }
151
Willy Tarreau28d86862007-04-08 17:42:27 +0200152 if (FD_ISSET(fd, tmp_evts[DIR_WR])) {
Willy Tarreau4f60f162007-04-08 16:39:58 +0200153 if (fdtab[fd].state == FD_STCLOSE)
154 continue;
155 fdtab[fd].cb[DIR_WR].f(fd);
156 }
157 }
158 }
159}
160
161/*
Willy Tarreaue54e9172007-04-09 09:23:31 +0200162 * Initialization of the select() poller.
163 * Returns 0 in case of failure, non-zero in case of success. If it fails, it
164 * disables the poller by setting its pref to 0.
165 */
Willy Tarreauef1d1f82007-04-16 00:25:25 +0200166REGPRM1 static int _do_init(struct poller *p)
Willy Tarreaue54e9172007-04-09 09:23:31 +0200167{
168 __label__ fail_swevt, fail_srevt, fail_wevt, fail_revt;
169 int fd_set_bytes;
170
171 p->private = NULL;
172 fd_set_bytes = sizeof(fd_set) * (global.maxsock + FD_SETSIZE - 1) / FD_SETSIZE;
173
174 if ((tmp_evts[DIR_RD] = (fd_set *)calloc(1, fd_set_bytes)) == NULL)
175 goto fail_revt;
176
177 if ((tmp_evts[DIR_WR] = (fd_set *)calloc(1, fd_set_bytes)) == NULL)
178 goto fail_wevt;
179
180 if ((fd_evts[DIR_RD] = (fd_set *)calloc(1, fd_set_bytes)) == NULL)
181 goto fail_srevt;
182
183 if ((fd_evts[DIR_WR] = (fd_set *)calloc(1, fd_set_bytes)) == NULL)
184 goto fail_swevt;
185
186 return 1;
187
188 fail_swevt:
189 free(fd_evts[DIR_RD]);
190 fail_srevt:
191 free(tmp_evts[DIR_WR]);
192 fail_wevt:
193 free(tmp_evts[DIR_RD]);
194 fail_revt:
195 p->pref = 0;
196 return 0;
197}
198
199/*
200 * Termination of the select() poller.
201 * Memory is released and the poller is marked as unselectable.
202 */
Willy Tarreauef1d1f82007-04-16 00:25:25 +0200203REGPRM1 static void _do_term(struct poller *p)
Willy Tarreaue54e9172007-04-09 09:23:31 +0200204{
Willy Tarreaua534fea2008-08-03 12:19:50 +0200205 free(fd_evts[DIR_WR]);
206 free(fd_evts[DIR_RD]);
207 free(tmp_evts[DIR_WR]);
208 free(tmp_evts[DIR_RD]);
Willy Tarreaue54e9172007-04-09 09:23:31 +0200209 p->private = NULL;
210 p->pref = 0;
211}
212
213/*
Willy Tarreau2ff76222007-04-09 19:29:56 +0200214 * Check that the poller works.
215 * Returns 1 if OK, otherwise 0.
216 */
Willy Tarreauef1d1f82007-04-16 00:25:25 +0200217REGPRM1 static int _do_test(struct poller *p)
Willy Tarreau2ff76222007-04-09 19:29:56 +0200218{
219 return 1;
220}
221
222/*
Willy Tarreauef1d1f82007-04-16 00:25:25 +0200223 * It is a constructor, which means that it will automatically be called before
224 * main(). This is GCC-specific but it works at least since 2.95.
225 * Special care must be taken so that it does not need any uninitialized data.
Willy Tarreau4f60f162007-04-08 16:39:58 +0200226 */
Willy Tarreauef1d1f82007-04-16 00:25:25 +0200227__attribute__((constructor))
228static void _do_register(void)
Willy Tarreau4f60f162007-04-08 16:39:58 +0200229{
Willy Tarreauef1d1f82007-04-16 00:25:25 +0200230 struct poller *p;
231
232 if (nbpollers >= MAX_POLLERS)
233 return;
234 p = &pollers[nbpollers++];
235
Willy Tarreau4f60f162007-04-08 16:39:58 +0200236 p->name = "select";
237 p->pref = 150;
238 p->private = NULL;
239
Willy Tarreauef1d1f82007-04-16 00:25:25 +0200240 p->test = _do_test;
241 p->init = _do_init;
242 p->term = _do_term;
243 p->poll = _do_poll;
Willy Tarreau63455a92007-04-09 15:34:49 +0200244 p->is_set = __fd_is_set;
Willy Tarreau4f60f162007-04-08 16:39:58 +0200245 p->set = __fd_set;
246 p->clr = __fd_clr;
247 p->clo = p->rem = __fd_rem;
248 p->cond_s = __fd_cond_s;
249 p->cond_c = __fd_cond_c;
Willy Tarreau4f60f162007-04-08 16:39:58 +0200250}
251
252
253/*
254 * Local variables:
255 * c-indent-level: 8
256 * c-basic-offset: 8
257 * End:
258 */