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/*
* Submitted by David Pacheco (dp.spambait@gmail.com)
*
* Copyright 2006-2007 Niels Provos
* Copyright 2007-2012 Niels Provos and Nick Mathewson
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY SUN MICROSYSTEMS, INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL SUN MICROSYSTEMS, INC. BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* Copyright (c) 2007 Sun Microsystems. All rights reserved.
* Use is subject to license terms.
*/
/*
* evport.c: event backend using Solaris 10 event ports. See port_create(3C).
* This implementation is loosely modeled after the one used for select(2) (in
* select.c).
*
* The outstanding events are tracked in a data structure called evport_data.
* Each entry in the ed_fds array corresponds to a file descriptor, and contains
* pointers to the read and write events that correspond to that fd. (That is,
* when the file is readable, the "read" event should handle it, etc.)
*
* evport_add and evport_del update this data structure. evport_dispatch uses it
* to determine where to callback when an event occurs (which it gets from
* port_getn).
*
* Helper functions are used: grow() grows the file descriptor array as
* necessary when large fd's come in. reassociate() takes care of maintaining
* the proper file-descriptor/event-port associations.
*
* As in the select(2) implementation, signals are handled by evsignal.
*/
#include "event2/event-config.h"
#include "evconfig-private.h"
#ifdef EVENT__HAVE_EVENT_PORTS
#include <sys/time.h>
#include <sys/queue.h>
#include <errno.h>
#include <poll.h>
#include <port.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include "event2/thread.h"
#include "evthread-internal.h"
#include "event-internal.h"
#include "log-internal.h"
#include "evsignal-internal.h"
#include "evmap-internal.h"
#define INITIAL_EVENTS_PER_GETN 8
#define MAX_EVENTS_PER_GETN 4096
/*
* Per-file-descriptor information about what events we're subscribed to. These
* fields are NULL if no event is subscribed to either of them.
*/
struct fd_info {
/* combinations of EV_READ and EV_WRITE */
short fdi_what;
/* Index of this fd within ed_pending, plus 1. Zero if this fd is
* not in ed_pending. (The +1 is a hack so that memset(0) will set
* it to a nil index. */
int pending_idx_plus_1;
};
#define FDI_HAS_READ(fdi) ((fdi)->fdi_what & EV_READ)
#define FDI_HAS_WRITE(fdi) ((fdi)->fdi_what & EV_WRITE)
#define FDI_HAS_EVENTS(fdi) (FDI_HAS_READ(fdi) || FDI_HAS_WRITE(fdi))
#define FDI_TO_SYSEVENTS(fdi) (FDI_HAS_READ(fdi) ? POLLIN : 0) | \
(FDI_HAS_WRITE(fdi) ? POLLOUT : 0)
struct evport_data {
int ed_port; /* event port for system events */
/* How many elements of ed_pending should we look at? */
int ed_npending;
/* How many elements are allocated in ed_pending and pevtlist? */
int ed_maxevents;
/* fdi's that we need to reassoc */
int *ed_pending;
/* storage space for incoming events. */
port_event_t *ed_pevtlist;
};
static void* evport_init(struct event_base *);
static int evport_add(struct event_base *, int fd, short old, short events, void *);
static int evport_del(struct event_base *, int fd, short old, short events, void *);
static int evport_dispatch(struct event_base *, struct timeval *);
static void evport_dealloc(struct event_base *);
static int grow(struct evport_data *, int min_events);
const struct eventop evportops = {
"evport",
evport_init,
evport_add,
evport_del,
evport_dispatch,
evport_dealloc,
1, /* need reinit */
0, /* features */
sizeof(struct fd_info), /* fdinfo length */
};
/*
* Initialize the event port implementation.
*/
static void*
evport_init(struct event_base *base)
{
struct evport_data *evpd;
if (!(evpd = mm_calloc(1, sizeof(struct evport_data))))
return (NULL);
if ((evpd->ed_port = port_create()) == -1) {
mm_free(evpd);
return (NULL);
}
if (grow(evpd, INITIAL_EVENTS_PER_GETN) < 0) {
close(evpd->ed_port);
mm_free(evpd);
return NULL;
}
evpd->ed_npending = 0;
evsig_init_(base);
return (evpd);
}
static int
grow(struct evport_data *data, int min_events)
{
int newsize;
int *new_pending;
port_event_t *new_pevtlist;
if (data->ed_maxevents) {
newsize = data->ed_maxevents;
do {
newsize *= 2;
} while (newsize < min_events);
} else {
newsize = min_events;
}
new_pending = mm_realloc(data->ed_pending, sizeof(int)*newsize);
if (new_pending == NULL)
return -1;
data->ed_pending = new_pending;
new_pevtlist = mm_realloc(data->ed_pevtlist, sizeof(port_event_t)*newsize);
if (new_pevtlist == NULL)
return -1;
data->ed_pevtlist = new_pevtlist;
data->ed_maxevents = newsize;
return 0;
}
#ifdef CHECK_INVARIANTS
/*
* Checks some basic properties about the evport_data structure. Because it
* checks all file descriptors, this function can be expensive when the maximum
* file descriptor ever used is rather large.
*/
static void
check_evportop(struct evport_data *evpd)
{
EVUTIL_ASSERT(evpd);
EVUTIL_ASSERT(evpd->ed_port > 0);
}
/*
* Verifies very basic integrity of a given port_event.
*/
static void
check_event(port_event_t* pevt)
{
/*
* We've only registered for PORT_SOURCE_FD events. The only
* other thing we can legitimately receive is PORT_SOURCE_ALERT,
* but since we're not using port_alert either, we can assume
* PORT_SOURCE_FD.
*/
EVUTIL_ASSERT(pevt->portev_source == PORT_SOURCE_FD);
}
#else
#define check_evportop(epop)
#define check_event(pevt)
#endif /* CHECK_INVARIANTS */
/*
* (Re)associates the given file descriptor with the event port. The OS events
* are specified (implicitly) from the fd_info struct.
*/
static int
reassociate(struct evport_data *epdp, struct fd_info *fdip, int fd)
{
int sysevents = FDI_TO_SYSEVENTS(fdip);
if (sysevents != 0) {
if (port_associate(epdp->ed_port, PORT_SOURCE_FD,
fd, sysevents, fdip) == -1) {
event_warn("port_associate");
return (-1);
}
}
check_evportop(epdp);
return (0);
}
/*
* Main event loop - polls port_getn for some number of events, and processes
* them.
*/
static int
evport_dispatch(struct event_base *base, struct timeval *tv)
{
int i, res;
struct evport_data *epdp = base->evbase;
port_event_t *pevtlist = epdp->ed_pevtlist;
/*
* port_getn will block until it has at least nevents events. It will
* also return how many it's given us (which may be more than we asked
* for, as long as it's less than our maximum (ed_maxevents)) in
* nevents.
*/
int nevents = 1;
/*
* We have to convert a struct timeval to a struct timespec
* (only difference is nanoseconds vs. microseconds). If no time-based
* events are active, we should wait for I/O (and tv == NULL).
*/
struct timespec ts;
struct timespec *ts_p = NULL;
if (tv != NULL) {
ts.tv_sec = tv->tv_sec;
ts.tv_nsec = tv->tv_usec * 1000;
ts_p = &ts;
}
/*
* Before doing anything else, we need to reassociate the events we hit
* last time which need reassociation. See comment at the end of the
* loop below.
*/
for (i = 0; i < epdp->ed_npending; ++i) {
struct fd_info *fdi = NULL;
const int fd = epdp->ed_pending[i];
if (fd != -1) {
/* We might have cleared out this event; we need
* to be sure that it's still set. */
fdi = evmap_io_get_fdinfo_(&base->io, fd);
}
if (fdi != NULL && FDI_HAS_EVENTS(fdi)) {
reassociate(epdp, fdi, fd);
/* epdp->ed_pending[i] = -1; */
fdi->pending_idx_plus_1 = 0;
}
}
EVBASE_RELEASE_LOCK(base, th_base_lock);
res = port_getn(epdp->ed_port, pevtlist, epdp->ed_maxevents,
(unsigned int *) &nevents, ts_p);
EVBASE_ACQUIRE_LOCK(base, th_base_lock);
if (res == -1) {
if (errno == EINTR || errno == EAGAIN) {
return (0);
} else if (errno == ETIME) {
if (nevents == 0)
return (0);
} else {
event_warn("port_getn");
return (-1);
}
}
event_debug(("%s: port_getn reports %d events", __func__, nevents));
for (i = 0; i < nevents; ++i) {
port_event_t *pevt = &pevtlist[i];
int fd = (int) pevt->portev_object;
struct fd_info *fdi = pevt->portev_user;
/*EVUTIL_ASSERT(evmap_io_get_fdinfo_(&base->io, fd) == fdi);*/
check_evportop(epdp);
check_event(pevt);
epdp->ed_pending[i] = fd;
fdi->pending_idx_plus_1 = i + 1;
/*
* Figure out what kind of event it was
* (because we have to pass this to the callback)
*/
res = 0;
if (pevt->portev_events & (POLLERR|POLLHUP)) {
res = EV_READ | EV_WRITE;
} else {
if (pevt->portev_events & POLLIN)
res |= EV_READ;
if (pevt->portev_events & POLLOUT)
res |= EV_WRITE;
}
/*
* Check for the error situations or a hangup situation
*/
if (pevt->portev_events & (POLLERR|POLLHUP|POLLNVAL))
res |= EV_READ|EV_WRITE;
evmap_io_active_(base, fd, res);
} /* end of all events gotten */
epdp->ed_npending = nevents;
if (nevents == epdp->ed_maxevents &&
epdp->ed_maxevents < MAX_EVENTS_PER_GETN) {
/* we used all the space this time. We should be ready
* for more events next time around. */
grow(epdp, epdp->ed_maxevents * 2);
}
check_evportop(epdp);
return (0);
}
/*
* Adds the given event (so that you will be notified when it happens via
* the callback function).
*/
static int
evport_add(struct event_base *base, int fd, short old, short events, void *p)
{
struct evport_data *evpd = base->evbase;
struct fd_info *fdi = p;
check_evportop(evpd);
fdi->fdi_what |= events;
return reassociate(evpd, fdi, fd);
}
/*
* Removes the given event from the list of events to wait for.
*/
static int
evport_del(struct event_base *base, int fd, short old, short events, void *p)
{
struct evport_data *evpd = base->evbase;
struct fd_info *fdi = p;
int associated = ! fdi->pending_idx_plus_1;
check_evportop(evpd);
fdi->fdi_what &= ~(events &(EV_READ|EV_WRITE));
if (associated) {
if (!FDI_HAS_EVENTS(fdi) &&
port_dissociate(evpd->ed_port, PORT_SOURCE_FD, fd) == -1) {
/*
* Ignore EBADFD error the fd could have been closed
* before event_del() was called.
*/
if (errno != EBADFD) {
event_warn("port_dissociate");
return (-1);
}
} else {
if (FDI_HAS_EVENTS(fdi)) {
return (reassociate(evpd, fdi, fd));
}
}
} else {
if ((fdi->fdi_what & (EV_READ|EV_WRITE)) == 0) {
const int i = fdi->pending_idx_plus_1 - 1;
EVUTIL_ASSERT(evpd->ed_pending[i] == fd);
evpd->ed_pending[i] = -1;
fdi->pending_idx_plus_1 = 0;
}
}
return 0;
}
static void
evport_dealloc(struct event_base *base)
{
struct evport_data *evpd = base->evbase;
evsig_dealloc_(base);
close(evpd->ed_port);
if (evpd->ed_pending)
mm_free(evpd->ed_pending);
if (evpd->ed_pevtlist)
mm_free(evpd->ed_pevtlist);
mm_free(evpd);
}
#endif /* EVENT__HAVE_EVENT_PORTS */
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