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-rw-r--r--libevent/evport.c509
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diff --git a/libevent/evport.c b/libevent/evport.c
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+/*
+ * Submitted by David Pacheco (dp.spambait@gmail.com)
+ *
+ * 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 THE AUTHOR ``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 THE AUTHOR 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) 2006 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, and
+ * evport_recalc does almost nothing.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#ifdef HAVE_SYS_TIME_H
+#include <sys/time.h>
+#else
+#include <sys/_time.h>
+#endif
+#include <assert.h>
+#include <sys/queue.h>
+#include <sys/tree.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>
+#ifdef CHECK_INVARIANTS
+#include <assert.h>
+#endif
+
+#include "event.h"
+#include "event-internal.h"
+#include "log.h"
+#include "evsignal.h"
+
+extern volatile sig_atomic_t evsignal_caught;
+
+
+/*
+ * Default value for ed_nevents, which is the maximum file descriptor number we
+ * can handle. If an event comes in for a file descriptor F > nevents, we will
+ * grow the array of file descriptors, doubling its size.
+ */
+#define DEFAULT_NFDS	16
+
+
+/*
+ * EVENTS_PER_GETN is the maximum number of events to retrieve from port_getn on
+ * any particular call. You can speed things up by increasing this, but it will
+ * (obviously) require more memory.
+ */
+#define EVENTS_PER_GETN 8
+
+/*
+ * 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 {
+	struct event* fdi_revt; /* the event responsible for the "read"  */
+	struct event* fdi_wevt; /* the event responsible for the "write" */
+};
+
+#define FDI_HAS_READ(fdi)  ((fdi)->fdi_revt != NULL)
+#define FDI_HAS_WRITE(fdi) ((fdi)->fdi_wevt != NULL)
+#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  */
+	sigset_t 	ed_sigmask;	/* for evsignal 		 */
+	int		ed_nevents;	/* number of allocated fdi's 	 */
+	struct fd_info *ed_fds;		/* allocated fdi table 		 */
+	/* fdi's that we need to reassoc */
+	struct fd_info *ed_pending[EVENTS_PER_GETN];
+};
+
+static void*	evport_init	(void);
+static int 	evport_add	(void *, struct event *);
+static int 	evport_del	(void *, struct event *);
+static int 	evport_recalc	(struct event_base *, void *, int);
+static int 	evport_dispatch	(struct event_base *, void *, struct timeval *);
+
+const struct eventop evportops = {
+	"event ports",
+	evport_init,
+	evport_add,
+	evport_del,
+	evport_recalc,
+	evport_dispatch
+};
+
+/*
+ * Initialize the event port implementation.
+ */
+
+static void*
+evport_init(void)
+{
+	struct evport_data *evpd;
+	/*
+	 * Disable event ports when this environment variable is set 
+	 */
+	if (getenv("EVENT_NOEVPORT"))
+		return (NULL);
+
+	if (!(evpd = calloc(1, sizeof(struct evport_data))))
+		return (NULL);
+
+	if ((evpd->ed_port = port_create()) == -1) {
+		free(evpd);
+		return (NULL);
+	}
+
+	/*
+	 * Initialize file descriptor structure
+	 */
+	evpd->ed_fds = calloc(DEFAULT_NFDS, sizeof(struct fd_info));
+	if (evpd->ed_fds == NULL) {
+		close(evpd->ed_port);
+		free(evpd);
+		return (NULL);
+	}
+	evpd->ed_nevents = DEFAULT_NFDS;
+	memset(&evpd->ed_pending, 0, EVENTS_PER_GETN * sizeof(struct fd_info*));
+
+	evsignal_init(&evpd->ed_sigmask);
+
+	return (evpd);
+}
+
+#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)
+{
+	assert(evpd);
+	assert(evpd->ed_nevents > 0);
+	assert(evpd->ed_port > 0);
+	assert(evpd->ed_fds > 0);
+
+	/*
+	 * Verify the integrity of the fd_info struct as well as the events to
+	 * which it points (at least, that they're valid references and correct
+	 * for their position in the structure).
+	 */
+	int i;
+	for (i = 0; i < evpd->ed_nevents; ++i) {
+		struct event 	*ev;
+		struct fd_info 	*fdi;
+
+		fdi = &evpd->ed_fds[i];
+		if ((ev = fdi->fdi_revt) != NULL) {
+			assert(ev->ev_fd == i);
+		}
+		if ((ev = fdi->fdi_wevt) != NULL) {
+			assert(ev->ev_fd == i);
+		}
+	}
+}
+
+/*
+ * 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.
+	 */
+	assert(pevt->portev_source == PORT_SOURCE_FD);
+	assert(pevt->portev_user == NULL);
+}
+
+#else
+#define check_evportop(epop)
+#define check_event(pevt)
+#endif /* CHECK_INVARIANTS */
+
+/*
+ * Doubles the size of the allocated file descriptor array.
+ */
+static int
+grow(struct evport_data *epdp, int factor)
+{
+	struct fd_info *tmp;
+	int oldsize = epdp->ed_nevents;
+	int newsize = factor * oldsize;
+	assert(factor > 1);
+
+	check_evportop(epdp);
+
+	tmp = realloc(epdp->ed_fds, sizeof(struct fd_info) * newsize);
+	if (NULL == tmp)
+		return -1;
+	epdp->ed_fds = tmp;
+	memset((char*) (epdp->ed_fds + oldsize), 0, 
+	    (newsize - oldsize)*sizeof(struct fd_info));
+	epdp->ed_nevents = newsize;
+
+	check_evportop(epdp);
+
+	return 0;
+}
+
+
+/*
+ * (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 ((-1 == port_associate(epdp->ed_port, PORT_SOURCE_FD,
+		    fd, sysevents, NULL))) {
+			perror("port_associate");
+			return (-1);
+		}
+	} else {
+		if (-1 == port_dissociate(epdp->ed_port, PORT_SOURCE_FD, fd)) {
+			perror("port_dissociate");
+			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, void *arg, struct timeval *tv)
+{
+	int i, res;
+	struct evport_data *epdp = arg;
+	port_event_t pevtlist[EVENTS_PER_GETN];
+
+	/*
+	 * 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 (EVENTS_PER_GETN)) in
+	 * nevents.
+	 */
+	int nevents = 1;
+
+	/*
+	 * We have to convert a struct timeval to a struct timespec
+	 * (only difference is nanoseconds vs. microseconds)
+	 */
+	struct timespec ts = {tv->tv_sec, tv->tv_usec * 1000};
+
+	/*
+	 * 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 < EVENTS_PER_GETN; ++i) {
+		struct fd_info *fdi = epdp->ed_pending[i];
+
+		if (fdi != NULL && FDI_HAS_EVENTS(fdi)) {
+			int fd = FDI_HAS_READ(fdi) ? fdi->fdi_revt->ev_fd : 
+			    fdi->fdi_wevt->ev_fd;
+			reassociate(epdp, fdi, fd);
+			epdp->ed_pending[i] = NULL;
+		}
+	}
+
+	
+
+	if (evsignal_deliver(&epdp->ed_sigmask) == -1)
+		return (-1);
+
+	if ((res = port_getn(epdp->ed_port, pevtlist, EVENTS_PER_GETN, 
+		    &nevents, &ts)) == -1) {
+		if (errno == EINTR) {
+			evsignal_process();
+			return (0);
+		} else if (errno == ETIME) {
+			if (nevents == 0)
+				return (0);
+		} else {
+			perror("port_getn");
+			return (-1);
+		}
+	} else if (evsignal_caught) {
+		evsignal_process();
+	}
+	
+	event_debug(("%s: port_getn reports %d events", __func__, nevents));
+
+	for (i = 0; i < nevents; ++i) {
+		struct event *ev;
+		struct fd_info *fdi;
+		port_event_t *pevt = &pevtlist[i];
+		int fd = (int) pevt->portev_object;
+
+		check_evportop(epdp);
+		check_event(pevt);
+
+		/*
+		 * Figure out what kind of event it was 
+		 * (because we have to pass this to the callback)
+		 */
+		res = 0;
+		if (pevt->portev_events & POLLIN)
+			res |= EV_READ;
+		if (pevt->portev_events & POLLOUT)
+			res |= EV_WRITE;
+
+		assert(epdp->ed_nevents > fd);
+		fdi = &(epdp->ed_fds[fd]);
+
+		/*
+		 * We now check for each of the possible events (READ or WRITE).
+		 * If the event is not persistent, then we delete it. Then, we
+		 * activate the event (which will cause its callback to be
+		 * executed).
+		 */
+
+		if ((res & EV_READ) && ((ev = fdi->fdi_revt) != NULL)) {
+			if (!(ev->ev_events & EV_PERSIST))
+				event_del(ev);
+			event_active(ev, res, 1);
+		}
+
+		if ((res & EV_WRITE) && ((ev = fdi->fdi_wevt) != NULL)) {
+			if (!(ev->ev_events & EV_PERSIST))
+				event_del(ev);
+			event_active(ev, res, 1);
+		}
+
+		/*
+		 * If there are still events (they haven't been deleted), then
+		 * we must reassociate the port, since the event port interface
+		 * dissociates them automatically. 
+		 *
+		 * But we can't do it right away, because the event hasn't
+		 * handled this event yet, so of course there's still data
+		 * waiting!
+		 */
+		if(FDI_HAS_EVENTS(fdi)) {
+			epdp->ed_pending[i] = fdi;
+		}
+	} /* end of all events gotten */
+
+	check_evportop(epdp);
+
+	if (evsignal_recalc(&epdp->ed_sigmask) == -1)
+		return (-1);
+
+	return (0);
+}
+
+
+/*
+ * Copied from the version in select.c
+ */
+
+static int
+evport_recalc(struct event_base *base, void *arg, int max)
+{
+	struct evport_data *evpd = arg;
+	check_evportop(evpd);
+	return (evsignal_recalc(&evpd->ed_sigmask));
+}
+
+
+/*
+ * Adds the given event (so that you will be notified when it happens via
+ * the callback function).
+ */
+
+static int
+evport_add(void *arg, struct event *ev)
+{
+	struct evport_data *evpd = arg;
+	struct fd_info *fdi;
+	int factor;
+
+	check_evportop(evpd);
+
+	/*
+	 * Delegate, if it's not ours to handle.
+	 */
+	if (ev->ev_events & EV_SIGNAL)
+		return (evsignal_add(&evpd->ed_sigmask, ev));
+
+	/*
+	 * If necessary, grow the file descriptor info table
+	 */
+
+	factor = 1;
+	while (ev->ev_fd >= factor * evpd->ed_nevents)
+		factor *= 2;
+
+	if (factor > 1) {
+		if (-1 == grow(evpd, factor)) {
+			return (-1);
+		}
+	}
+
+	fdi = &evpd->ed_fds[ev->ev_fd];
+	if (ev->ev_events & EV_READ)
+		fdi->fdi_revt = ev;
+	if (ev->ev_events & EV_WRITE)
+		fdi->fdi_wevt = ev;
+
+	return reassociate(evpd, fdi, ev->ev_fd);
+}
+
+/*
+ * Removes the given event from the list of events to wait for.
+ */
+
+static int
+evport_del(void *arg, struct event *ev)
+{
+	struct evport_data *evpd = arg;
+	struct fd_info *fdi;
+
+	check_evportop(evpd);
+
+	/*
+	 * Delegate, if it's not ours to handle
+	 */
+	if (ev->ev_events & EV_SIGNAL) {
+		return (evsignal_del(&evpd->ed_sigmask, ev));
+	}
+
+	if (evpd->ed_nevents < ev->ev_fd) {
+		return (-1);
+	}
+
+
+	fdi = &evpd->ed_fds[ev->ev_fd];
+	if (ev->ev_events & EV_READ)
+		fdi->fdi_revt = NULL;
+	if (ev->ev_events & EV_WRITE)
+		fdi->fdi_wevt = NULL;
+
+	return reassociate(evpd, fdi, ev->ev_fd);
+}
+
+
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