--- /dev/null
+/*
+ * Copyright (c) 2006 Sun Microsystems.
+ * All rights reserved.
+ * 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.
+ */
+
+/*
+ * 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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