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/*
* include/proto/fd.h
* File descriptors states.
*
* Copyright (C) 2000-2012 Willy Tarreau - w@1wt.eu
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation, version 2.1
* exclusively.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef _PROTO_FD_H
#define _PROTO_FD_H
#include <stdio.h>
#include <sys/time.h>
#include <sys/types.h>
#include <unistd.h>
#include <common/config.h>
#include <types/fd.h>
/* public variables */
extern int fd_nbspec; // number of speculative events in the list
extern int fd_nbupdt; // number of updates in the list
extern unsigned int *fd_spec; // speculative I/O list
extern unsigned int *fd_updt; // FD updates list
/* Deletes an FD from the fdsets, and recomputes the maxfd limit.
* The file descriptor is also closed.
*/
void fd_delete(int fd);
/* disable the specified poller */
void disable_poller(const char *poller_name);
/*
* Initialize the pollers till the best one is found.
* If none works, returns 0, otherwise 1.
* The pollers register themselves just before main() is called.
*/
int init_pollers();
/*
* Deinitialize the pollers.
*/
void deinit_pollers();
/*
* Some pollers may lose their connection after a fork(). It may be necessary
* to create initialize part of them again. Returns 0 in case of failure,
* otherwise 1. The fork() function may be NULL if unused. In case of error,
* the the current poller is destroyed and the caller is responsible for trying
* another one by calling init_pollers() again.
*/
int fork_poller();
/*
* Lists the known pollers on <out>.
* Should be performed only before initialization.
*/
int list_pollers(FILE *out);
/*
* Runs the polling loop
*/
void run_poller();
/* Scan and process the speculative events. This should be called right after
* the poller.
*/
void fd_process_spec_events();
/* Mark fd <fd> as updated and allocate an entry in the update list for this if
* it was not already there. This can be done at any time.
*/
static inline void updt_fd(const int fd)
{
if (fdtab[fd].updated)
/* already scheduled for update */
return;
fdtab[fd].updated = 1;
fd_updt[fd_nbupdt++] = fd;
}
/* allocate an entry for a speculative event. This can be done at any time. */
static inline void alloc_spec_entry(const int fd)
{
if (fdtab[fd].spec_p)
/* FD already in speculative I/O list */
return;
fd_nbspec++;
fdtab[fd].spec_p = fd_nbspec;
fd_spec[fd_nbspec-1] = fd;
}
/* Removes entry used by fd <fd> from the spec list and replaces it with the
* last one. The fdtab.spec is adjusted to match the back reference if needed.
* If the fd has no entry assigned, return immediately.
*/
static inline void release_spec_entry(int fd)
{
unsigned int pos;
pos = fdtab[fd].spec_p;
if (!pos)
return;
fdtab[fd].spec_p = 0;
fd_nbspec--;
if (likely(pos <= fd_nbspec)) {
/* was not the last entry */
fd = fd_spec[fd_nbspec];
fd_spec[pos - 1] = fd;
fdtab[fd].spec_p = pos;
}
}
/*
* Returns non-zero if <fd> is already monitored for events in direction <dir>.
*/
static inline int fd_ev_is_set(const int fd, int dir)
{
return ((unsigned)fdtab[fd].spec_e >> dir) & FD_EV_STATUS;
}
/* Disable processing of events on fd <fd> for direction <dir>. Note: this
* function was optimized to be used with a constant for <dir>.
*/
static inline void fd_ev_clr(const int fd, int dir)
{
unsigned int i = ((unsigned int)fdtab[fd].spec_e) & (FD_EV_STATUS << dir);
if (i == 0)
return; /* already disabled */
fdtab[fd].spec_e ^= i;
updt_fd(fd); /* need an update entry to change the state */
}
/* Enable polling for events on fd <fd> for direction <dir>. Note: this
* function was optimized to be used with a constant for <dir>.
*/
static inline void fd_ev_wai(const int fd, int dir)
{
unsigned int i = ((unsigned int)fdtab[fd].spec_e) & (FD_EV_STATUS << dir);
if (i == (FD_EV_POLLED << dir))
return; /* already in desired state */
fdtab[fd].spec_e ^= i ^ (FD_EV_POLLED << dir);
updt_fd(fd); /* need an update entry to change the state */
}
/* Enable processing of events on fd <fd> for direction <dir>. Note: this
* function was optimized to be used with a constant for <dir>.
*/
static inline void fd_ev_set(int fd, int dir)
{
unsigned int i = ((unsigned int)fdtab[fd].spec_e) & (FD_EV_STATUS << dir);
/* note that we don't care about disabling the polled state when
* enabling the active state, since it brings no benefit but costs
* some syscalls.
*/
if (i & (FD_EV_ACTIVE << dir))
return; /* already in desired state */
fdtab[fd].spec_e |= (FD_EV_ACTIVE << dir);
updt_fd(fd); /* need an update entry to change the state */
}
/* Disable processing of events on fd <fd> for both directions. */
static inline void fd_ev_rem(const int fd)
{
unsigned int i = ((unsigned int)fdtab[fd].spec_e) & FD_EV_CURR_MASK;
if (i == 0)
return; /* already disabled */
fdtab[fd].spec_e ^= i;
updt_fd(fd); /* need an update entry to change the state */
}
/* event manipulation primitives for use by I/O callbacks */
static inline void fd_want_recv(int fd)
{
return fd_ev_set(fd, DIR_RD);
}
static inline void fd_stop_recv(int fd)
{
return fd_ev_clr(fd, DIR_RD);
}
static inline void fd_poll_recv(int fd)
{
return fd_ev_wai(fd, DIR_RD);
}
static inline void fd_want_send(int fd)
{
return fd_ev_set(fd, DIR_WR);
}
static inline void fd_stop_send(int fd)
{
return fd_ev_clr(fd, DIR_WR);
}
static inline void fd_poll_send(int fd)
{
return fd_ev_wai(fd, DIR_WR);
}
static inline void fd_stop_both(int fd)
{
return fd_ev_rem(fd);
}
/* Prepares <fd> for being polled */
static inline void fd_insert(int fd)
{
fdtab[fd].ev = 0;
fdtab[fd].new = 1;
if (fd + 1 > maxfd)
maxfd = fd + 1;
}
#endif /* _PROTO_FD_H */
/*
* Local variables:
* c-indent-level: 8
* c-basic-offset: 8
* End:
*/