blob: d87dddc2a5615a45c4c79c9a6c961b7ae7c6fa09 [file] [log] [blame]
/*
* File descriptors management functions.
*
* Copyright 2000-2014 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.
*
* This code implements an events cache for file descriptors. It remembers the
* readiness of a file descriptor after a return from poll() and the fact that
* an I/O attempt failed on EAGAIN. Events in the cache which are still marked
* ready and active are processed just as if they were reported by poll().
*
* This serves multiple purposes. First, it significantly improves performance
* by avoiding to subscribe to polling unless absolutely necessary, so most
* events are processed without polling at all, especially send() which
* benefits from the socket buffers. Second, it is the only way to support
* edge-triggered pollers (eg: EPOLL_ET). And third, it enables I/O operations
* that are backed by invisible buffers. For example, SSL is able to read a
* whole socket buffer and not deliver it to the application buffer because
* it's full. Unfortunately, it won't be reported by a poller anymore until
* some new activity happens. The only way to call it again thus is to keep
* this readiness information in the cache and to access it without polling
* once the FD is enabled again.
*
* One interesting feature of the cache is that it maintains the principle
* of speculative I/O introduced in haproxy 1.3 : the first time an event is
* enabled, the FD is considered as ready so that the I/O attempt is performed
* via the cache without polling. And the polling happens only when EAGAIN is
* first met. This avoids polling for HTTP requests, especially when the
* defer-accept mode is used. It also avoids polling for sending short data
* such as requests to servers or short responses to clients.
*
* The cache consists in a list of active events and a list of updates.
* Active events are events that are expected to come and that we must report
* to the application until it asks to stop or asks to poll. Updates are new
* requests for changing an FD state. Updates are the only way to create new
* events. This is important because it means that the number of cached events
* cannot increase between updates and will only grow one at a time while
* processing updates. All updates must always be processed, though events
* might be processed by small batches if required.
*
* There is no direct link between the FD and the updates list. There is only a
* bit in the fdtab[] to indicate than a file descriptor is already present in
* the updates list. Once an fd is present in the updates list, it will have to
* be considered even if its changes are reverted in the middle or if the fd is
* replaced.
*
* It is important to understand that as long as all expected events are
* processed, they might starve the polled events, especially because polled
* I/O starvation quickly induces more cached I/O. One solution to this
* consists in only processing a part of the events at once, but one drawback
* is that unhandled events will still wake the poller up. Using an edge-
* triggered poller such as EPOLL_ET will solve this issue though.
*
* Since we do not want to scan all the FD list to find cached I/O events,
* we store them in a list consisting in a linear array holding only the FD
* indexes right now. Note that a closed FD cannot exist in the cache, because
* it is closed by fd_delete() which in turn calls fd_release_cache_entry()
* which always removes it from the list.
*
* The FD array has to hold a back reference to the cache. This reference is
* always valid unless the FD is not in the cache and is not updated, in which
* case the reference points to index 0.
*
* The event state for an FD, as found in fdtab[].state, is maintained for each
* direction. The state field is built this way, with R bits in the low nibble
* and W bits in the high nibble for ease of access and debugging :
*
* 7 6 5 4 3 2 1 0
* [ 0 | PW | RW | AW | 0 | PR | RR | AR ]
*
* A* = active *R = read
* P* = polled *W = write
* R* = ready
*
* An FD is marked "active" when there is a desire to use it.
* An FD is marked "polled" when it is registered in the polling.
* An FD is marked "ready" when it has not faced a new EAGAIN since last wake-up
* (it is a cache of the last EAGAIN regardless of polling changes).
*
* We have 8 possible states for each direction based on these 3 flags :
*
* +---+---+---+----------+---------------------------------------------+
* | P | R | A | State | Description |
* +---+---+---+----------+---------------------------------------------+
* | 0 | 0 | 0 | DISABLED | No activity desired, not ready. |
* | 0 | 0 | 1 | MUSTPOLL | Activity desired via polling. |
* | 0 | 1 | 0 | STOPPED | End of activity without polling. |
* | 0 | 1 | 1 | ACTIVE | Activity desired without polling. |
* | 1 | 0 | 0 | ABORT | Aborted poll(). Not frequently seen. |
* | 1 | 0 | 1 | POLLED | FD is being polled. |
* | 1 | 1 | 0 | PAUSED | FD was paused while ready (eg: buffer full) |
* | 1 | 1 | 1 | READY | FD was marked ready by poll() |
* +---+---+---+----------+---------------------------------------------+
*
* The transitions are pretty simple :
* - fd_want_*() : set flag A
* - fd_stop_*() : clear flag A
* - fd_cant_*() : clear flag R (when facing EAGAIN)
* - fd_may_*() : set flag R (upon return from poll())
* - sync() : if (A) { if (!R) P := 1 } else { P := 0 }
*
* The PAUSED, ABORT and MUSTPOLL states are transient for level-trigerred
* pollers and are fixed by the sync() which happens at the beginning of the
* poller. For event-triggered pollers, only the MUSTPOLL state will be
* transient and ABORT will lead to PAUSED. The ACTIVE state is the only stable
* one which has P != A.
*
* The READY state is a bit special as activity on the FD might be notified
* both by the poller or by the cache. But it is needed for some multi-layer
* protocols (eg: SSL) where connection activity is not 100% linked to FD
* activity. Also some pollers might prefer to implement it as ACTIVE if
* enabling/disabling the FD is cheap. The READY and ACTIVE states are the
* two states for which a cache entry is allocated.
*
* The state transitions look like the diagram below. Only the 4 right states
* have polling enabled :
*
* (POLLED=0) (POLLED=1)
*
* +----------+ sync +-------+
* | DISABLED | <----- | ABORT | (READY=0, ACTIVE=0)
* +----------+ +-------+
* clr | ^ set | ^
* | | | |
* v | set v | clr
* +----------+ sync +--------+
* | MUSTPOLL | -----> | POLLED | (READY=0, ACTIVE=1)
* +----------+ +--------+
* ^ poll | ^
* | | |
* | EAGAIN v | EAGAIN
* +--------+ +-------+
* | ACTIVE | | READY | (READY=1, ACTIVE=1)
* +--------+ +-------+
* clr | ^ set | ^
* | | | |
* v | set v | clr
* +---------+ sync +--------+
* | STOPPED | <------ | PAUSED | (READY=1, ACTIVE=0)
* +---------+ +--------+
*/
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/resource.h>
#if defined(USE_POLL)
#include <poll.h>
#include <errno.h>
#endif
#include <common/compat.h>
#include <common/config.h>
#include <types/global.h>
#include <proto/fd.h>
#include <proto/log.h>
#include <proto/port_range.h>
struct fdtab *fdtab = NULL; /* array of all the file descriptors */
unsigned long *polled_mask = NULL; /* Array for the polled_mask of each fd */
struct fdinfo *fdinfo = NULL; /* less-often used infos for file descriptors */
int totalconn; /* total # of terminated sessions */
int actconn; /* # of active sessions */
struct poller pollers[MAX_POLLERS];
struct poller cur_poller;
int nbpollers = 0;
volatile struct fdlist fd_cache ; // FD events cache
volatile struct fdlist fd_cache_local[MAX_THREADS]; // FD events local for each thread
volatile struct fdlist update_list; // Global update list
unsigned long fd_cache_mask = 0; // Mask of threads with events in the cache
THREAD_LOCAL int *fd_updt = NULL; // FD updates list
THREAD_LOCAL int fd_nbupdt = 0; // number of updates in the list
THREAD_LOCAL int poller_rd_pipe = -1; // Pipe to wake the thread
int poller_wr_pipe[MAX_THREADS]; // Pipe to wake the threads
volatile int ha_used_fds = 0; // Number of FD we're currently using
#define _GET_NEXT(fd, off) ((struct fdlist_entry *)(void *)((char *)(&fdtab[fd]) + off))->next
#define _GET_PREV(fd, off) ((struct fdlist_entry *)(void *)((char *)(&fdtab[fd]) + off))->prev
/* adds fd <fd> to fd list <list> if it was not yet in it */
void fd_add_to_fd_list(volatile struct fdlist *list, int fd, int off)
{
int next;
int new;
int old;
int last;
redo_next:
next = _GET_NEXT(fd, off);
/* Check that we're not already in the cache, and if not, lock us. */
if (next >= -2)
goto done;
if (!_HA_ATOMIC_CAS(&_GET_NEXT(fd, off), &next, -2))
goto redo_next;
__ha_barrier_atomic_store();
new = fd;
redo_last:
/* First, insert in the linked list */
last = list->last;
old = -1;
_GET_PREV(fd, off) = -2;
/* Make sure the "prev" store is visible before we update the last entry */
__ha_barrier_store();
if (unlikely(last == -1)) {
/* list is empty, try to add ourselves alone so that list->last=fd */
if (unlikely(!_HA_ATOMIC_CAS(&list->last, &old, new)))
goto redo_last;
/* list->first was necessary -1, we're guaranteed to be alone here */
list->first = fd;
} else {
/* adding ourselves past the last element
* The CAS will only succeed if its next is -1,
* which means it's in the cache, and the last element.
*/
if (unlikely(!_HA_ATOMIC_CAS(&_GET_NEXT(last, off), &old, new)))
goto redo_last;
/* Then, update the last entry */
list->last = fd;
}
__ha_barrier_store();
/* since we're alone at the end of the list and still locked(-2),
* we know noone tried to add past us. Mark the end of list.
*/
_GET_PREV(fd, off) = last;
_GET_NEXT(fd, off) = -1;
__ha_barrier_store();
done:
return;
}
/* removes fd <fd> from fd list <list> */
void fd_rm_from_fd_list(volatile struct fdlist *list, int fd, int off)
{
#if defined(HA_HAVE_CAS_DW) || defined(HA_CAS_IS_8B)
volatile struct fdlist_entry cur_list, next_list;
#endif
int old;
int new = -2;
int prev;
int next;
int last;
lock_self:
#if (defined(HA_CAS_IS_8B) || defined(HA_HAVE_CAS_DW))
next_list.next = next_list.prev = -2;
cur_list = *(volatile struct fdlist_entry *)(((char *)&fdtab[fd]) + off);
/* First, attempt to lock our own entries */
do {
/* The FD is not in the FD cache, give up */
if (unlikely(cur_list.next <= -3))
return;
if (unlikely(cur_list.prev == -2 || cur_list.next == -2))
goto lock_self;
} while (
#ifdef HA_CAS_IS_8B
unlikely(!_HA_ATOMIC_CAS(((void **)(void *)&_GET_NEXT(fd, off)), ((void **)(void *)&cur_list), (*(void **)(void *)&next_list))))
#else
unlikely(!_HA_ATOMIC_DWCAS(((void **)(void *)&_GET_NEXT(fd, off)), ((void **)(void *)&cur_list), (*(void **)(void *)&next_list))))
#endif
;
next = cur_list.next;
prev = cur_list.prev;
#else
lock_self_next:
next = ({ volatile int *next = &_GET_NEXT(fd, off); *next; });
if (next == -2)
goto lock_self_next;
if (next <= -3)
goto done;
if (unlikely(!_HA_ATOMIC_CAS(&_GET_NEXT(fd, off), &next, -2)))
goto lock_self_next;
lock_self_prev:
prev = ({ volatile int *prev = &_GET_PREV(fd, off); *prev; });
if (prev == -2)
goto lock_self_prev;
if (unlikely(!_HA_ATOMIC_CAS(&_GET_PREV(fd, off), &prev, -2)))
goto lock_self_prev;
#endif
__ha_barrier_atomic_store();
/* Now, lock the entries of our neighbours */
if (likely(prev != -1)) {
redo_prev:
old = fd;
if (unlikely(!_HA_ATOMIC_CAS(&_GET_NEXT(prev, off), &old, new))) {
if (unlikely(old == -2)) {
/* Neighbour already locked, give up and
* retry again once he's done
*/
_GET_PREV(fd, off) = prev;
__ha_barrier_store();
_GET_NEXT(fd, off) = next;
__ha_barrier_store();
goto lock_self;
}
goto redo_prev;
}
}
if (likely(next != -1)) {
redo_next:
old = fd;
if (unlikely(!_HA_ATOMIC_CAS(&_GET_PREV(next, off), &old, new))) {
if (unlikely(old == -2)) {
/* Neighbour already locked, give up and
* retry again once he's done
*/
if (prev != -1) {
_GET_NEXT(prev, off) = fd;
__ha_barrier_store();
}
_GET_PREV(fd, off) = prev;
__ha_barrier_store();
_GET_NEXT(fd, off) = next;
__ha_barrier_store();
goto lock_self;
}
goto redo_next;
}
}
if (list->first == fd)
list->first = next;
__ha_barrier_store();
last = list->last;
while (unlikely(last == fd && (!_HA_ATOMIC_CAS(&list->last, &last, prev))))
__ha_compiler_barrier();
/* Make sure we let other threads know we're no longer in cache,
* before releasing our neighbours.
*/
__ha_barrier_store();
if (likely(prev != -1))
_GET_NEXT(prev, off) = next;
__ha_barrier_store();
if (likely(next != -1))
_GET_PREV(next, off) = prev;
__ha_barrier_store();
/* Ok, now we're out of the fd cache */
_GET_NEXT(fd, off) = -(next + 4);
__ha_barrier_store();
done:
return;
}
#undef _GET_NEXT
#undef _GET_PREV
/* Deletes an FD from the fdsets.
* The file descriptor is also closed.
*/
static void fd_dodelete(int fd, int do_close)
{
unsigned long locked = atleast2(fdtab[fd].thread_mask);
if (locked)
HA_SPIN_LOCK(FD_LOCK, &fdtab[fd].lock);
if (fdtab[fd].linger_risk) {
/* this is generally set when connecting to servers */
setsockopt(fd, SOL_SOCKET, SO_LINGER,
(struct linger *) &nolinger, sizeof(struct linger));
}
if (cur_poller.clo)
cur_poller.clo(fd);
fd_release_cache_entry(fd);
fdtab[fd].state = 0;
port_range_release_port(fdinfo[fd].port_range, fdinfo[fd].local_port);
fdinfo[fd].port_range = NULL;
fdtab[fd].owner = NULL;
fdtab[fd].thread_mask = 0;
if (do_close) {
polled_mask[fd] = 0;
close(fd);
_HA_ATOMIC_SUB(&ha_used_fds, 1);
}
if (locked)
HA_SPIN_UNLOCK(FD_LOCK, &fdtab[fd].lock);
}
/* Deletes an FD from the fdsets.
* The file descriptor is also closed.
*/
void fd_delete(int fd)
{
fd_dodelete(fd, 1);
}
/* Deletes an FD from the fdsets.
* The file descriptor is kept open.
*/
void fd_remove(int fd)
{
fd_dodelete(fd, 0);
}
static inline void fdlist_process_cached_events(volatile struct fdlist *fdlist)
{
int fd, old_fd, e;
unsigned long locked;
for (old_fd = fd = fdlist->first; fd != -1; fd = fdtab[fd].cache.next) {
if (fd == -2) {
fd = old_fd;
continue;
} else if (fd <= -3)
fd = -fd - 4;
if (fd == -1)
break;
old_fd = fd;
if (!(fdtab[fd].thread_mask & tid_bit))
continue;
if (fdtab[fd].cache.next < -3)
continue;
_HA_ATOMIC_OR(&fd_cache_mask, tid_bit);
locked = atleast2(fdtab[fd].thread_mask);
if (locked && HA_SPIN_TRYLOCK(FD_LOCK, &fdtab[fd].lock)) {
activity[tid].fd_lock++;
continue;
}
e = fdtab[fd].state;
fdtab[fd].ev &= FD_POLL_STICKY;
if ((e & (FD_EV_READY_R | FD_EV_ACTIVE_R)) == (FD_EV_READY_R | FD_EV_ACTIVE_R))
fdtab[fd].ev |= FD_POLL_IN;
if ((e & (FD_EV_READY_W | FD_EV_ACTIVE_W)) == (FD_EV_READY_W | FD_EV_ACTIVE_W))
fdtab[fd].ev |= FD_POLL_OUT;
if (fdtab[fd].iocb && fdtab[fd].owner && fdtab[fd].ev) {
if (locked)
HA_SPIN_UNLOCK(FD_LOCK, &fdtab[fd].lock);
fdtab[fd].iocb(fd);
}
else {
fd_release_cache_entry(fd);
if (locked)
HA_SPIN_UNLOCK(FD_LOCK, &fdtab[fd].lock);
}
}
}
/* Scan and process the cached events. This should be called right after
* the poller. The loop may cause new entries to be created, for example
* if a listener causes an accept() to initiate a new incoming connection
* wanting to attempt an recv().
*/
void fd_process_cached_events()
{
_HA_ATOMIC_AND(&fd_cache_mask, ~tid_bit);
fdlist_process_cached_events(&fd_cache_local[tid]);
fdlist_process_cached_events(&fd_cache);
}
#if defined(USE_CLOSEFROM)
void my_closefrom(int start)
{
closefrom(start);
}
#elif defined(USE_POLL)
/* This is a portable implementation of closefrom(). It closes all open file
* descriptors starting at <start> and above. It relies on the fact that poll()
* will return POLLNVAL for each invalid (hence close) file descriptor passed
* in argument in order to skip them. It acts with batches of FDs and will
* typically perform one poll() call per 1024 FDs so the overhead is low in
* case all FDs have to be closed.
*/
void my_closefrom(int start)
{
struct pollfd poll_events[1024];
struct rlimit limit;
int nbfds, fd, ret, idx;
int step, next;
if (getrlimit(RLIMIT_NOFILE, &limit) == 0)
step = nbfds = limit.rlim_cur;
else
step = nbfds = 0;
if (nbfds <= 0) {
/* set safe limit */
nbfds = 1024;
step = 256;
}
if (step > sizeof(poll_events) / sizeof(poll_events[0]))
step = sizeof(poll_events) / sizeof(poll_events[0]);
while (start < nbfds) {
next = (start / step + 1) * step;
for (fd = start; fd < next && fd < nbfds; fd++) {
poll_events[fd - start].fd = fd;
poll_events[fd - start].events = 0;
}
do {
ret = poll(poll_events, fd - start, 0);
if (ret >= 0)
break;
} while (errno == EAGAIN || errno == EINTR || errno == ENOMEM);
if (ret)
ret = fd - start;
for (idx = 0; idx < ret; idx++) {
if (poll_events[idx].revents & POLLNVAL)
continue; /* already closed */
fd = poll_events[idx].fd;
close(fd);
}
start = next;
}
}
#else // defined(USE_POLL)
/* This is a portable implementation of closefrom(). It closes all open file
* descriptors starting at <start> and above. This is a naive version for use
* when the operating system provides no alternative.
*/
void my_closefrom(int start)
{
struct rlimit limit;
int nbfds;
if (getrlimit(RLIMIT_NOFILE, &limit) == 0)
nbfds = limit.rlim_cur;
else
nbfds = 0;
if (nbfds <= 0)
nbfds = 1024; /* safe limit */
while (start < nbfds)
close(start++);
}
#endif // defined(USE_POLL)
/* disable the specified poller */
void disable_poller(const char *poller_name)
{
int p;
for (p = 0; p < nbpollers; p++)
if (strcmp(pollers[p].name, poller_name) == 0)
pollers[p].pref = 0;
}
void poller_pipe_io_handler(int fd)
{
char buf[1024];
/* Flush the pipe */
while (read(fd, buf, sizeof(buf)) > 0);
fd_cant_recv(fd);
}
/* allocate the per-thread fd_updt thus needs to be called early after
* thread creation.
*/
static int alloc_pollers_per_thread()
{
fd_updt = calloc(global.maxsock, sizeof(*fd_updt));
return fd_updt != NULL;
}
/* Initialize the pollers per thread.*/
static int init_pollers_per_thread()
{
int mypipe[2];
if (pipe(mypipe) < 0)
return 0;
poller_rd_pipe = mypipe[0];
poller_wr_pipe[tid] = mypipe[1];
fcntl(poller_rd_pipe, F_SETFL, O_NONBLOCK);
fd_insert(poller_rd_pipe, poller_pipe_io_handler, poller_pipe_io_handler,
tid_bit);
fd_want_recv(poller_rd_pipe);
return 1;
}
/* Deinitialize the pollers per thread */
static void deinit_pollers_per_thread()
{
/* rd and wr are init at the same place, but only rd is init to -1, so
we rely to rd to close. */
if (poller_rd_pipe > -1) {
close(poller_rd_pipe);
poller_rd_pipe = -1;
close(poller_wr_pipe[tid]);
poller_wr_pipe[tid] = -1;
}
}
/* Release the pollers per thread, to be called late */
static void free_pollers_per_thread()
{
free(fd_updt);
fd_updt = NULL;
}
/*
* Initialize the pollers till the best one is found.
* If none works, returns 0, otherwise 1.
*/
int init_pollers()
{
int p;
struct poller *bp;
if ((fdtab = calloc(global.maxsock, sizeof(struct fdtab))) == NULL)
goto fail_tab;
if ((polled_mask = calloc(global.maxsock, sizeof(unsigned long))) == NULL)
goto fail_polledmask;
if ((fdinfo = calloc(global.maxsock, sizeof(struct fdinfo))) == NULL)
goto fail_info;
fd_cache.first = fd_cache.last = -1;
update_list.first = update_list.last = -1;
for (p = 0; p < global.maxsock; p++) {
HA_SPIN_INIT(&fdtab[p].lock);
/* Mark the fd as out of the fd cache */
fdtab[p].cache.next = -3;
fdtab[p].update.next = -3;
}
for (p = 0; p < global.nbthread; p++)
fd_cache_local[p].first = fd_cache_local[p].last = -1;
do {
bp = NULL;
for (p = 0; p < nbpollers; p++)
if (!bp || (pollers[p].pref > bp->pref))
bp = &pollers[p];
if (!bp || bp->pref == 0)
break;
if (bp->init(bp)) {
memcpy(&cur_poller, bp, sizeof(*bp));
return 1;
}
} while (!bp || bp->pref == 0);
free(fdinfo);
fail_info:
free(polled_mask);
fail_polledmask:
free(fdtab);
fail_tab:
return 0;
}
/*
* Deinitialize the pollers.
*/
void deinit_pollers() {
struct poller *bp;
int p;
for (p = 0; p < global.maxsock; p++)
HA_SPIN_DESTROY(&fdtab[p].lock);
for (p = 0; p < nbpollers; p++) {
bp = &pollers[p];
if (bp && bp->pref)
bp->term(bp);
}
free(fdinfo); fdinfo = NULL;
free(fdtab); fdtab = NULL;
free(polled_mask); polled_mask = NULL;
}
/*
* Lists the known pollers on <out>.
* Should be performed only before initialization.
*/
int list_pollers(FILE *out)
{
int p;
int last, next;
int usable;
struct poller *bp;
fprintf(out, "Available polling systems :\n");
usable = 0;
bp = NULL;
last = next = -1;
while (1) {
for (p = 0; p < nbpollers; p++) {
if ((next < 0 || pollers[p].pref > next)
&& (last < 0 || pollers[p].pref < last)) {
next = pollers[p].pref;
if (!bp || (pollers[p].pref > bp->pref))
bp = &pollers[p];
}
}
if (next == -1)
break;
for (p = 0; p < nbpollers; p++) {
if (pollers[p].pref == next) {
fprintf(out, " %10s : ", pollers[p].name);
if (pollers[p].pref == 0)
fprintf(out, "disabled, ");
else
fprintf(out, "pref=%3d, ", pollers[p].pref);
if (pollers[p].test(&pollers[p])) {
fprintf(out, " test result OK");
if (next > 0)
usable++;
} else {
fprintf(out, " test result FAILED");
if (bp == &pollers[p])
bp = NULL;
}
fprintf(out, "\n");
}
}
last = next;
next = -1;
};
fprintf(out, "Total: %d (%d usable), will use %s.\n", nbpollers, usable, bp ? bp->name : "none");
return 0;
}
/*
* 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()
{
int fd;
for (fd = 0; fd < global.maxsock; fd++) {
if (fdtab[fd].owner) {
fdtab[fd].cloned = 1;
}
}
if (cur_poller.fork) {
if (cur_poller.fork(&cur_poller))
return 1;
cur_poller.term(&cur_poller);
return 0;
}
return 1;
}
REGISTER_PER_THREAD_ALLOC(alloc_pollers_per_thread);
REGISTER_PER_THREAD_INIT(init_pollers_per_thread);
REGISTER_PER_THREAD_DEINIT(deinit_pollers_per_thread);
REGISTER_PER_THREAD_FREE(free_pollers_per_thread);
/*
* Local variables:
* c-indent-level: 8
* c-basic-offset: 8
* End:
*/