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/*
* include/types/fd.h
* File descriptors states - check src/fd.c for explanations.
*
* Copyright (C) 2000-2014 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 _TYPES_FD_H
#define _TYPES_FD_H
#include <common/config.h>
#include <common/hathreads.h>
#include <common/ist.h>
#include <types/port_range.h>
/* Direction for each FD event update */
enum {
DIR_RD=0,
DIR_WR=1,
};
/* Polling status flags returned in fdtab[].ev :
* FD_POLL_IN remains set as long as some data is pending for read.
* FD_POLL_OUT remains set as long as the fd accepts to write data.
* FD_POLL_ERR and FD_POLL_ERR remain set forever (until processed).
*/
#define FD_POLL_IN 0x01
#define FD_POLL_PRI 0x02
#define FD_POLL_OUT 0x04
#define FD_POLL_ERR 0x08
#define FD_POLL_HUP 0x10
#define FD_POLL_DATA (FD_POLL_IN | FD_POLL_OUT)
#define FD_POLL_STICKY (FD_POLL_ERR | FD_POLL_HUP)
/* FD bits used for different polling states in each direction */
#define FD_EV_ACTIVE 1U
#define FD_EV_READY 2U
/* bits positions for a few flags */
#define FD_EV_READY_R_BIT 1
#define FD_EV_READY_W_BIT 5
#define FD_EV_STATUS (FD_EV_ACTIVE | FD_EV_READY)
#define FD_EV_STATUS_R (FD_EV_STATUS)
#define FD_EV_STATUS_W (FD_EV_STATUS << 4)
#define FD_EV_ACTIVE_R (FD_EV_ACTIVE)
#define FD_EV_ACTIVE_W (FD_EV_ACTIVE << 4)
#define FD_EV_ACTIVE_RW (FD_EV_ACTIVE_R | FD_EV_ACTIVE_W)
#define FD_EV_READY_R (FD_EV_READY)
#define FD_EV_READY_W (FD_EV_READY << 4)
#define FD_EV_READY_RW (FD_EV_READY_R | FD_EV_READY_W)
/* This is the value used to mark a file descriptor as dead. This value is
* negative, this is important so that tests on fd < 0 properly match. It
* also has the nice property of being highly negative but neither overflowing
* nor changing sign on 32-bit machines when multiplied by sizeof(fdtab).
* This ensures that any unexpected dereference of such an uninitialized
* file descriptor will lead to so large a dereference that it will crash
* the process at the exact location of the bug with a clean stack trace
* instead of causing silent manipulation of other FDs. And it's readable
* when found in a dump.
*/
#define DEAD_FD_MAGIC 0xFDDEADFD
/* fdlist_entry: entry used by the fd cache.
* >= 0 means we're in the cache and gives the FD of the next in the cache,
* -1 means we're in the cache and the last element,
* -2 means the entry is locked,
* <= -3 means not in the cache, and next element is -4-fd
*
* It must remain 8-aligned so that aligned CAS operations may be done on both
* entries at once.
*/
struct fdlist_entry {
int next;
int prev;
} __attribute__ ((aligned(8)));
/* head of the fd cache */
struct fdlist {
int first;
int last;
} __attribute__ ((aligned(8)));
/* info about one given fd */
struct fdtab {
__decl_hathreads(HA_SPINLOCK_T lock);
unsigned long thread_mask; /* mask of thread IDs authorized to process the task */
unsigned long update_mask; /* mask of thread IDs having an update for fd */
struct fdlist_entry update; /* Entry in the global update list */
void (*iocb)(int fd); /* I/O handler */
void *owner; /* the connection or listener associated with this fd, NULL if closed */
unsigned char state; /* FD state for read and write directions (2*3 bits) */
unsigned char ev; /* event seen in return of poll() : FD_POLL_* */
unsigned char linger_risk:1; /* 1 if we must kill lingering before closing */
unsigned char cloned:1; /* 1 if a cloned socket, requires EPOLL_CTL_DEL on close */
unsigned char initialized:1; /* 1 if init phase was done on this fd (e.g. set non-blocking) */
}
#ifdef USE_THREAD
/* only align on cache lines when using threads; 32-bit small archs
* can put everything in 32-bytes when threads are disabled.
*/
__attribute__((aligned(64)))
#endif
;
/* less often used information */
struct fdinfo {
struct port_range *port_range; /* optional port range to bind to */
int local_port; /* optional local port */
};
/*
* Poller descriptors.
* - <name> is initialized by the poller's register() function, and should not
* be allocated, just linked to.
* - <pref> is initialized by the poller's register() function. It is set to 0
* by default, meaning the poller is disabled. init() should set it to 0 in
* case of failure. term() must set it to 0. A generic unoptimized select()
* poller should set it to 100.
* - <private> is initialized by the poller's init() function, and cleaned by
* the term() function.
* - clo() should be used to do indicate the poller that fd will be closed.
* - poll() calls the poller, expiring at <exp>, or immediately if <wake> is set
* - flags indicate what the poller supports (HAP_POLL_F_*)
*/
#define HAP_POLL_F_RDHUP 0x00000001 /* the poller notifies of HUP with reads */
struct poller {
void *private; /* any private data for the poller */
void REGPRM1 (*clo)(const int fd); /* mark <fd> as closed */
void REGPRM3 (*poll)(struct poller *p, int exp, int wake); /* the poller itself */
int REGPRM1 (*init)(struct poller *p); /* poller initialization */
void REGPRM1 (*term)(struct poller *p); /* termination of this poller */
int REGPRM1 (*test)(struct poller *p); /* pre-init check of the poller */
int REGPRM1 (*fork)(struct poller *p); /* post-fork re-opening */
const char *name; /* poller name */
unsigned int flags; /* HAP_POLL_F_* */
int pref; /* try pollers with higher preference first */
};
extern struct poller cur_poller; /* the current poller */
extern int nbpollers;
#define MAX_POLLERS 10
extern struct poller pollers[MAX_POLLERS]; /* all registered pollers */
extern struct fdtab *fdtab; /* array of all the file descriptors */
extern struct fdinfo *fdinfo; /* less-often used infos for file descriptors */
extern int totalconn; /* total # of terminated sessions */
extern int actconn; /* # of active sessions */
#endif /* _TYPES_FD_H */
/*
* Local variables:
* c-indent-level: 8
* c-basic-offset: 8
* End:
*/