/* $NetBSD: evport.c,v 1.1.1.1 2013/04/11 16:43:25 christos Exp $ */ /* * 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 __RCSID("$NetBSD: evport.c,v 1.1.1.1 2013/04/11 16:43:25 christos Exp $"); #include #include #include #include #include #include #include #include #include #include #include #include "event2/thread.h" #include "evthread-internal.h" #include "event-internal.h" #include "log-internal.h" #include "evsignal-internal.h" #include "evmap-internal.h" /* * 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 { short fdi_what; /* combinations of EV_READ and EV_WRITE */ }; #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 */ int ed_nevents; /* number of allocated fdi's */ struct fd_info *ed_fds; /* allocated fdi table */ /* fdi's that we need to reassoc */ int ed_pending[EVENTS_PER_GETN]; /* fd's with pending events */ }; 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 *); const struct eventop evportops = { "evport", evport_init, evport_add, evport_del, evport_dispatch, evport_dealloc, 1, /* need reinit */ 0, /* features */ 0, /* fdinfo length */ }; /* * Initialize the event port implementation. */ static void* evport_init(struct event_base *base) { struct evport_data *evpd; int i; if (!(evpd = mm_calloc(1, sizeof(struct evport_data)))) return (NULL); if ((evpd->ed_port = port_create()) == -1) { mm_free(evpd); return (NULL); } /* * Initialize file descriptor structure */ evpd->ed_fds = mm_calloc(DEFAULT_NFDS, sizeof(struct fd_info)); if (evpd->ed_fds == NULL) { close(evpd->ed_port); mm_free(evpd); return (NULL); } evpd->ed_nevents = DEFAULT_NFDS; for (i = 0; i < EVENTS_PER_GETN; i++) evpd->ed_pending[i] = -1; evsig_init(base); 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) { EVUTIL_ASSERT(evpd); EVUTIL_ASSERT(evpd->ed_nevents > 0); EVUTIL_ASSERT(evpd->ed_port > 0); EVUTIL_ASSERT(evpd->ed_fds > 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); EVUTIL_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; EVUTIL_ASSERT(factor > 1); check_evportop(epdp); tmp = mm_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 (port_associate(epdp->ed_port, PORT_SOURCE_FD, fd, sysevents, NULL) == -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[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). 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 < EVENTS_PER_GETN; ++i) { struct fd_info *fdi = NULL; if (epdp->ed_pending[i] != -1) { fdi = &(epdp->ed_fds[epdp->ed_pending[i]]); } if (fdi != NULL && FDI_HAS_EVENTS(fdi)) { int fd = epdp->ed_pending[i]; reassociate(epdp, fdi, fd); epdp->ed_pending[i] = -1; } } EVBASE_RELEASE_LOCK(base, th_base_lock); res = port_getn(epdp->ed_port, pevtlist, EVENTS_PER_GETN, (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) { struct fd_info *fdi; port_event_t *pevt = &pevtlist[i]; int fd = (int) pevt->portev_object; check_evportop(epdp); check_event(pevt); epdp->ed_pending[i] = fd; /* * 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; EVUTIL_ASSERT(epdp->ed_nevents > fd); fdi = &(epdp->ed_fds[fd]); evmap_io_active(base, fd, res); } /* end of all events gotten */ 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; int factor; (void)p; check_evportop(evpd); /* * If necessary, grow the file descriptor info table */ factor = 1; while (fd >= factor * evpd->ed_nevents) factor *= 2; if (factor > 1) { if (-1 == grow(evpd, factor)) { return (-1); } } fdi = &evpd->ed_fds[fd]; 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; int i; int associated = 1; (void)p; check_evportop(evpd); if (evpd->ed_nevents < fd) { return (-1); } for (i = 0; i < EVENTS_PER_GETN; ++i) { if (evpd->ed_pending[i] == fd) { associated = 0; break; } } fdi = &evpd->ed_fds[fd]; if (events & EV_READ) fdi->fdi_what &= ~EV_READ; if (events & EV_WRITE) fdi->fdi_what &= ~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) { evpd->ed_pending[i] = -1; } } 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_fds) mm_free(evpd->ed_fds); mm_free(evpd); }