/* * include/haproxy/fd-t.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 _HAPROXY_FD_T_H #define _HAPROXY_FD_T_H #include #include #include /* Direction for each FD event update */ enum { DIR_RD=0, DIR_WR=1, }; /* fdtab[].state is a composite state describing what is known about the FD. * For now, the following information are stored in it: * - event configuration and status for each direction (R,W) split into * active, ready, shutdown categories (FD_EV_*). These are known by their * bit values as well so that test-and-set bit operations are possible. * * - last known polling status (FD_POLL_*). For ease of troubleshooting, * avoid visually mixing these ones with the other ones above. 3 of these * flags are updated on each poll() report (FD_POLL_IN, FD_POLL_OUT, * FD_POLL_PRI). FD_POLL_HUP and FD_POLL_ERR are "sticky" in that once they * are reported, they will not be cleared until the FD is closed. */ /* bits positions for a few flags */ #define FD_EV_ACTIVE_R_BIT 0 #define FD_EV_READY_R_BIT 1 #define FD_EV_SHUT_R_BIT 2 /* unused: 3 */ #define FD_EV_ACTIVE_W_BIT 4 #define FD_EV_READY_W_BIT 5 #define FD_EV_SHUT_W_BIT 6 #define FD_EV_ERR_RW_BIT 7 #define FD_POLL_IN_BIT 8 #define FD_POLL_PRI_BIT 9 #define FD_POLL_OUT_BIT 10 #define FD_POLL_ERR_BIT 11 #define FD_POLL_HUP_BIT 12 /* info/config bits */ #define FD_LINGER_RISK_BIT 16 /* must kill lingering before closing */ #define FD_CLONED_BIT 17 /* cloned socket, requires EPOLL_CTL_DEL on close */ #define FD_INITIALIZED_BIT 18 /* init phase was done (e.g. output pipe set non-blocking) */ #define FD_ET_POSSIBLE_BIT 19 /* edge-triggered is possible on this FD */ #define FD_EXPORTED_BIT 20 /* FD is exported and must not be closed */ #define FD_EXCL_SYSCALL_BIT 21 /* a syscall claims exclusivity on this FD */ #define FD_DISOWN_BIT 22 /* this fd will be closed by some external code */ #define FD_MUST_CLOSE_BIT 23 /* this fd will be closed by some external code */ /* and flag values */ #define FD_EV_ACTIVE_R (1U << FD_EV_ACTIVE_R_BIT) #define FD_EV_ACTIVE_W (1U << FD_EV_ACTIVE_W_BIT) #define FD_EV_ACTIVE_RW (FD_EV_ACTIVE_R | FD_EV_ACTIVE_W) #define FD_EV_READY_R (1U << FD_EV_READY_R_BIT) #define FD_EV_READY_W (1U << FD_EV_READY_W_BIT) #define FD_EV_READY_RW (FD_EV_READY_R | FD_EV_READY_W) /* note that when FD_EV_SHUT is set, ACTIVE and READY are cleared */ #define FD_EV_SHUT_R (1U << FD_EV_SHUT_R_BIT) #define FD_EV_SHUT_W (1U << FD_EV_SHUT_W_BIT) #define FD_EV_SHUT_RW (FD_EV_SHUT_R | FD_EV_SHUT_W) /* note that when FD_EV_ERR is set, SHUT is also set. Also, ERR is for both * directions at once (write error, socket dead, etc). */ #define FD_EV_ERR_RW (1U << FD_EV_ERR_RW_BIT) /* mask covering all use cases above */ #define FD_EV_ANY (FD_EV_ACTIVE_RW | FD_EV_READY_RW | FD_EV_SHUT_RW | FD_EV_ERR_RW) /* polling status */ #define FD_POLL_IN (1U << FD_POLL_IN_BIT) #define FD_POLL_PRI (1U << FD_POLL_PRI_BIT) #define FD_POLL_OUT (1U << FD_POLL_OUT_BIT) #define FD_POLL_ERR (1U << FD_POLL_ERR_BIT) #define FD_POLL_HUP (1U << FD_POLL_HUP_BIT) #define FD_POLL_UPDT_MASK (FD_POLL_IN | FD_POLL_PRI | FD_POLL_OUT) #define FD_POLL_ANY_MASK (FD_POLL_IN | FD_POLL_PRI | FD_POLL_OUT | FD_POLL_ERR | FD_POLL_HUP) /* information/configuration flags */ #define FD_LINGER_RISK (1U << FD_LINGER_RISK_BIT) #define FD_CLONED (1U << FD_CLONED_BIT) #define FD_INITIALIZED (1U << FD_INITIALIZED_BIT) #define FD_ET_POSSIBLE (1U << FD_ET_POSSIBLE_BIT) #define FD_EXPORTED (1U << FD_EXPORTED_BIT) #define FD_EXCL_SYSCALL (1U << FD_EXCL_SYSCALL_BIT) #define FD_DISOWN (1U << FD_DISOWN_BIT) #define FD_MUST_CLOSE (1U << FD_MUST_CLOSE_BIT) /* This function is used to report flags in debugging tools. Please reflect * below any single-bit flag addition above in the same order via the * __APPEND_FLAG macro. The new end of the buffer is returned. */ static forceinline char *fd_show_flags(char *buf, size_t len, const char *delim, uint flg) { #define _(f, ...) __APPEND_FLAG(buf, len, delim, flg, f, #f, __VA_ARGS__) /* prologue */ _(0); /* flags */ _(FD_EV_ACTIVE_R, _(FD_EV_ACTIVE_W, _(FD_EV_READY_R, _(FD_EV_READY_W, _(FD_EV_SHUT_R, _(FD_EV_SHUT_W, _(FD_EV_ERR_RW, _(FD_POLL_IN, _(FD_POLL_PRI, _(FD_POLL_OUT, _(FD_POLL_ERR, _(FD_POLL_HUP, _(FD_LINGER_RISK, _(FD_CLONED, _(FD_INITIALIZED, _(FD_ET_POSSIBLE, _(FD_EXPORTED, _(FD_EXCL_SYSCALL, _(FD_DISOWN))))))))))))))))))); /* epilogue */ _(~0U); return buf; #undef _ } /* FD update status after fd_update_events() */ enum { FD_UPDT_DONE = 0, // update done, nothing else to be done FD_UPDT_CLOSED, // FD was closed FD_UPDT_MIGRATED, // FD was migrated, ignore it now }; /* 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; } ALIGNED(8); /* head of the fd cache, per-group */ struct fdlist { int first; int last; } ALIGNED(64); /* info about one given fd. Note: only align on cache lines when using threads; * 32-bit small archs can put everything in 32-bytes when threads are disabled. * refc_tgid is an atomic 32-bit composite value made of 16 higher bits * containing a refcount on tgid and the running_mask, and 16 lower bits * containing a thread group ID and a lock bit on the 16th. The tgid may only * be changed when refc is zero and running may only be checked/changed when * refc is held and shows the reader is alone. An FD with tgid zero belongs to * nobody. */ struct fdtab { unsigned long running_mask; /* mask of thread IDs currently using the fd */ unsigned long thread_mask; /* mask of thread IDs authorized to process the fd */ 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 int state; /* FD state for read and write directions (FD_EV_*) + FD_POLL_* */ unsigned int refc_tgid; /* refcounted tgid, updated atomically */ #ifdef DEBUG_FD unsigned int event_count; /* number of events reported */ #endif } THREAD_ALIGNED(64); /* polled mask, one bit per thread and per direction for each FD */ struct polled_mask { unsigned long poll_recv; unsigned long poll_send; }; /* 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. * - is initialized by the poller's register() function, and should not * be allocated, just linked to. * - 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. * - 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 , or immediately if is set * - flags indicate what the poller supports (HAP_POLL_F_*) */ #define HAP_POLL_F_RDHUP 0x00000001 /* the poller notifies of HUP with reads */ #define HAP_POLL_F_ERRHUP 0x00000002 /* the poller reports ERR and HUP */ struct poller { void *private; /* any private data for the poller */ void (*clo)(const int fd); /* mark as closed */ void (*poll)(struct poller *p, int exp, int wake); /* the poller itself */ int (*init)(struct poller *p); /* poller initialization */ void (*term)(struct poller *p); /* termination of this poller */ int (*test)(struct poller *p); /* pre-init check of the poller */ int (*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 */ }; #endif /* _HAPROXY_FD_T_H */ /* * Local variables: * c-indent-level: 8 * c-basic-offset: 8 * End: */