blob: 30df9285bac4b0f2a881666365592c25a2a789c2 [file] [log] [blame]
/*
* FD polling functions for generic select()
*
* Copyright 2000-2008 Willy Tarreau <w@1wt.eu>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
*/
#include <unistd.h>
#include <sys/time.h>
#include <sys/types.h>
#include <common/compat.h>
#include <common/config.h>
#include <common/time.h>
#include <types/fd.h>
#include <types/global.h>
#include <proto/fd.h>
#include <proto/task.h>
static fd_set *fd_evts[2];
static fd_set *tmp_evts[2];
/*
* Benchmarks performed on a Pentium-M notebook show that using functions
* instead of the usual macros improve the FD_* performance by about 80%,
* and that marking them regparm(2) adds another 20%.
*/
REGPRM2 static int __fd_is_set(const int fd, int dir)
{
return FD_ISSET(fd, fd_evts[dir]);
}
REGPRM2 static int __fd_set(const int fd, int dir)
{
FD_SET(fd, fd_evts[dir]);
return 0;
}
REGPRM2 static int __fd_clr(const int fd, int dir)
{
FD_CLR(fd, fd_evts[dir]);
return 0;
}
REGPRM2 static int __fd_cond_s(const int fd, int dir)
{
int ret;
ret = !FD_ISSET(fd, fd_evts[dir]);
if (ret)
FD_SET(fd, fd_evts[dir]);
return ret;
}
REGPRM2 static int __fd_cond_c(const int fd, int dir)
{
int ret;
ret = FD_ISSET(fd, fd_evts[dir]);
if (ret)
FD_CLR(fd, fd_evts[dir]);
return ret;
}
REGPRM1 static void __fd_rem(int fd)
{
FD_CLR(fd, fd_evts[DIR_RD]);
FD_CLR(fd, fd_evts[DIR_WR]);
}
/*
* Select() poller
*/
REGPRM2 static void _do_poll(struct poller *p, struct timeval *exp)
{
const struct timeval max_delay = {
.tv_sec = MAX_DELAY_MS / 1000,
.tv_usec = (MAX_DELAY_MS % 1000) * 1000
};
int status;
int fd, i;
struct timeval delta;
int delta_ms;
int readnotnull, writenotnull;
int fds;
char count;
/* allow select to return immediately when needed */
delta.tv_sec = delta.tv_usec = 0;
delta_ms = 0;
if (!run_queue) {
if (!tv_isset(exp)) {
delta = max_delay;
delta_ms = MAX_DELAY_MS;
}
else if (tv_islt(&now, exp)) {
tv_remain(&now, exp, &delta);
/* To avoid eventual select loops due to timer precision */
delta.tv_usec += SCHEDULER_RESOLUTION * 1000;
if (delta.tv_usec >= 1000000) {
delta.tv_usec -= 1000000;
delta.tv_sec ++;
}
if (__tv_isge(&delta, &max_delay)) {
delta = max_delay;
delta_ms = MAX_DELAY_MS;
} else {
delta_ms = delta.tv_sec * 1000 + delta.tv_usec / 1000;
}
}
}
/* let's restore fdset state */
readnotnull = 0; writenotnull = 0;
for (i = 0; i < (maxfd + FD_SETSIZE - 1)/(8*sizeof(int)); i++) {
readnotnull |= (*(((int*)tmp_evts[DIR_RD])+i) = *(((int*)fd_evts[DIR_RD])+i)) != 0;
writenotnull |= (*(((int*)tmp_evts[DIR_WR])+i) = *(((int*)fd_evts[DIR_WR])+i)) != 0;
}
// /* just a verification code, needs to be removed for performance */
// for (i=0; i<maxfd; i++) {
// if (FD_ISSET(i, tmp_evts[DIR_RD]) != FD_ISSET(i, fd_evts[DIR_RD]))
// abort();
// if (FD_ISSET(i, tmp_evts[DIR_WR]) != FD_ISSET(i, fd_evts[DIR_WR]))
// abort();
//
// }
status = select(maxfd,
readnotnull ? tmp_evts[DIR_RD] : NULL,
writenotnull ? tmp_evts[DIR_WR] : NULL,
NULL,
&delta);
tv_update_date(delta_ms, status);
if (status <= 0)
return;
for (fds = 0; (fds << INTBITS) < maxfd; fds++) {
if ((((int *)(tmp_evts[DIR_RD]))[fds] | ((int *)(tmp_evts[DIR_WR]))[fds]) == 0)
continue;
for (count = 1<<INTBITS, fd = fds << INTBITS; count && fd < maxfd; count--, fd++) {
/* if we specify read first, the accepts and zero reads will be
* seen first. Moreover, system buffers will be flushed faster.
*/
if (FD_ISSET(fd, tmp_evts[DIR_RD])) {
if (fdtab[fd].state == FD_STCLOSE)
continue;
fdtab[fd].cb[DIR_RD].f(fd);
}
if (FD_ISSET(fd, tmp_evts[DIR_WR])) {
if (fdtab[fd].state == FD_STCLOSE)
continue;
fdtab[fd].cb[DIR_WR].f(fd);
}
}
}
}
/*
* Initialization of the select() poller.
* Returns 0 in case of failure, non-zero in case of success. If it fails, it
* disables the poller by setting its pref to 0.
*/
REGPRM1 static int _do_init(struct poller *p)
{
__label__ fail_swevt, fail_srevt, fail_wevt, fail_revt;
int fd_set_bytes;
p->private = NULL;
fd_set_bytes = sizeof(fd_set) * (global.maxsock + FD_SETSIZE - 1) / FD_SETSIZE;
if ((tmp_evts[DIR_RD] = (fd_set *)calloc(1, fd_set_bytes)) == NULL)
goto fail_revt;
if ((tmp_evts[DIR_WR] = (fd_set *)calloc(1, fd_set_bytes)) == NULL)
goto fail_wevt;
if ((fd_evts[DIR_RD] = (fd_set *)calloc(1, fd_set_bytes)) == NULL)
goto fail_srevt;
if ((fd_evts[DIR_WR] = (fd_set *)calloc(1, fd_set_bytes)) == NULL)
goto fail_swevt;
return 1;
fail_swevt:
free(fd_evts[DIR_RD]);
fail_srevt:
free(tmp_evts[DIR_WR]);
fail_wevt:
free(tmp_evts[DIR_RD]);
fail_revt:
p->pref = 0;
return 0;
}
/*
* Termination of the select() poller.
* Memory is released and the poller is marked as unselectable.
*/
REGPRM1 static void _do_term(struct poller *p)
{
if (fd_evts[DIR_WR])
free(fd_evts[DIR_WR]);
if (fd_evts[DIR_RD])
free(fd_evts[DIR_RD]);
if (tmp_evts[DIR_WR])
free(tmp_evts[DIR_WR]);
if (tmp_evts[DIR_RD])
free(tmp_evts[DIR_RD]);
p->private = NULL;
p->pref = 0;
}
/*
* Check that the poller works.
* Returns 1 if OK, otherwise 0.
*/
REGPRM1 static int _do_test(struct poller *p)
{
return 1;
}
/*
* It is a constructor, which means that it will automatically be called before
* main(). This is GCC-specific but it works at least since 2.95.
* Special care must be taken so that it does not need any uninitialized data.
*/
__attribute__((constructor))
static void _do_register(void)
{
struct poller *p;
if (nbpollers >= MAX_POLLERS)
return;
p = &pollers[nbpollers++];
p->name = "select";
p->pref = 150;
p->private = NULL;
p->test = _do_test;
p->init = _do_init;
p->term = _do_term;
p->poll = _do_poll;
p->is_set = __fd_is_set;
p->set = __fd_set;
p->clr = __fd_clr;
p->clo = p->rem = __fd_rem;
p->cond_s = __fd_cond_s;
p->cond_c = __fd_cond_c;
}
/*
* Local variables:
* c-indent-level: 8
* c-basic-offset: 8
* End:
*/