Edit
kc3-lang/libevent/select.c
Nick Mathewson
- select.c
-
/* $OpenBSD: select.c,v 1.2 2002/06/25 15:50:15 mickey Exp $ */ /* * Copyright 2000-2002 Niels Provos <provos@citi.umich.edu> * All rights reserved. * * 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. */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include <sys/types.h> #ifdef HAVE_SYS_TIME_H #include <sys/time.h> #else #include <sys/_time.h> #endif #ifdef HAVE_SYS_SELECT_H #include <sys/select.h> #endif #include <sys/queue.h> #include <signal.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <errno.h> #ifdef CHECK_INVARIANTS #include <assert.h> #endif #include "event.h" #include "event-internal.h" #include "evsignal.h" #include "log.h" #ifndef howmany #define howmany(x, y) (((x)+((y)-1))/(y)) #endif struct selectop { int event_fds; /* Highest fd in fd set */ int event_fdsz; fd_set *event_readset_in; fd_set *event_writeset_in; fd_set *event_readset_out; fd_set *event_writeset_out; struct event **event_r_by_fd; struct event **event_w_by_fd; }; void *select_init (struct event_base *); int select_add (void *, struct event *); int select_del (void *, struct event *); int select_recalc (struct event_base *, void *, int); int select_dispatch (struct event_base *, void *, struct timeval *); void select_dealloc (struct event_base *, void *); const struct eventop selectops = { "select", select_init, select_add, select_del, select_recalc, select_dispatch, select_dealloc }; static int select_resize(struct selectop *sop, int fdsz); void * select_init(struct event_base *base) { struct selectop *sop; /* Disable select when this environment variable is set */ if (getenv("EVENT_NOSELECT")) return (NULL); if (!(sop = event_calloc(1, sizeof(struct selectop)))) return (NULL); select_resize(sop, howmany(32 + 1, NFDBITS)*sizeof(fd_mask)); evsignal_init(base); return (sop); } #ifdef CHECK_INVARIANTS static void check_selectop(struct selectop *sop) { int i; for (i = 0; i <= sop->event_fds; ++i) { if (FD_ISSET(i, sop->event_readset_in)) { assert(sop->event_r_by_fd[i]); assert(sop->event_r_by_fd[i]->ev_events & EV_READ); assert(sop->event_r_by_fd[i]->ev_fd == i); } else { assert(! sop->event_r_by_fd[i]); } if (FD_ISSET(i, sop->event_writeset_in)) { assert(sop->event_w_by_fd[i]); assert(sop->event_w_by_fd[i]->ev_events & EV_WRITE); assert(sop->event_w_by_fd[i]->ev_fd == i); } else { assert(! sop->event_w_by_fd[i]); } } } #else #define check_selectop(sop) do { (void) sop; } while (0) #endif /* * Called with the highest fd that we know about. If it is 0, completely * recalculate everything. */ int select_recalc(struct event_base *base, void *arg, int max) { struct selectop *sop = arg; check_selectop(sop); return (0); } int select_dispatch(struct event_base *base, void *arg, struct timeval *tv) { int res, i; struct selectop *sop = arg; check_selectop(sop); memcpy(sop->event_readset_out, sop->event_readset_in, sop->event_fdsz); memcpy(sop->event_writeset_out, sop->event_writeset_in, sop->event_fdsz); res = select(sop->event_fds + 1, sop->event_readset_out, sop->event_writeset_out, NULL, tv); check_selectop(sop); if (res == -1) { if (errno != EINTR) { event_warn("select"); return (-1); } evsignal_process(base); return (0); } else if (base->sig.evsignal_caught) { evsignal_process(base); } event_debug(("%s: select reports %d", __func__, res)); check_selectop(sop); for (i = 0; i <= sop->event_fds; ++i) { struct event *r_ev = NULL, *w_ev = NULL; res = 0; if (FD_ISSET(i, sop->event_readset_out)) { r_ev = sop->event_r_by_fd[i]; res |= EV_READ; } if (FD_ISSET(i, sop->event_writeset_out)) { w_ev = sop->event_w_by_fd[i]; res |= EV_WRITE; } if (r_ev && (res & r_ev->ev_events)) { if (!(r_ev->ev_events & EV_PERSIST)) event_del(r_ev); event_active(r_ev, res & r_ev->ev_events, 1); } if (w_ev && w_ev != r_ev && (res & w_ev->ev_events)) { if (!(w_ev->ev_events & EV_PERSIST)) event_del(w_ev); event_active(w_ev, res & w_ev->ev_events, 1); } } check_selectop(sop); return (0); } static int select_resize(struct selectop *sop, int fdsz) { int n_events, n_events_old; fd_set *readset_in = NULL; fd_set *writeset_in = NULL; fd_set *readset_out = NULL; fd_set *writeset_out = NULL; struct event **r_by_fd = NULL; struct event **w_by_fd = NULL; n_events = (fdsz/sizeof(fd_mask)) * NFDBITS; n_events_old = (sop->event_fdsz/sizeof(fd_mask)) * NFDBITS; if (sop->event_readset_in) check_selectop(sop); if ((readset_in = event_realloc(sop->event_readset_in, fdsz)) == NULL) goto error; sop->event_readset_in = readset_in; if ((readset_out = event_realloc(sop->event_readset_out, fdsz)) == NULL) goto error; sop->event_readset_out = readset_out; if ((writeset_in = event_realloc(sop->event_writeset_in, fdsz)) == NULL) goto error; sop->event_writeset_in = writeset_in; if ((writeset_out = event_realloc(sop->event_writeset_out, fdsz)) == NULL) goto error; sop->event_writeset_out = writeset_out; if ((r_by_fd = event_realloc(sop->event_r_by_fd, n_events*sizeof(struct event*))) == NULL) goto error; sop->event_r_by_fd = r_by_fd; if ((w_by_fd = event_realloc(sop->event_w_by_fd, n_events * sizeof(struct event*))) == NULL) goto error; sop->event_w_by_fd = w_by_fd; memset((char *)sop->event_readset_in + sop->event_fdsz, 0, fdsz - sop->event_fdsz); memset((char *)sop->event_writeset_in + sop->event_fdsz, 0, fdsz - sop->event_fdsz); memset(sop->event_r_by_fd + n_events_old, 0, (n_events-n_events_old) * sizeof(struct event*)); memset(sop->event_w_by_fd + n_events_old, 0, (n_events-n_events_old) * sizeof(struct event*)); sop->event_fdsz = fdsz; check_selectop(sop); return (0); error: event_warn("malloc"); return (-1); } int select_add(void *arg, struct event *ev) { struct selectop *sop = arg; if (ev->ev_events & EV_SIGNAL) return (evsignal_add(ev)); check_selectop(sop); /* * Keep track of the highest fd, so that we can calculate the size * of the fd_sets for select(2) */ if (sop->event_fds < ev->ev_fd) { int fdsz = sop->event_fdsz; if (fdsz < sizeof(fd_mask)) fdsz = sizeof(fd_mask); while (fdsz < (howmany(ev->ev_fd + 1, NFDBITS) * sizeof(fd_mask))) fdsz *= 2; if (fdsz != sop->event_fdsz) { if (select_resize(sop, fdsz)) { check_selectop(sop); return (-1); } } sop->event_fds = ev->ev_fd; } if (ev->ev_events & EV_READ) { FD_SET(ev->ev_fd, sop->event_readset_in); sop->event_r_by_fd[ev->ev_fd] = ev; } if (ev->ev_events & EV_WRITE) { FD_SET(ev->ev_fd, sop->event_writeset_in); sop->event_w_by_fd[ev->ev_fd] = ev; } check_selectop(sop); return (0); } /* * Nothing to be done here. */ int select_del(void *arg, struct event *ev) { struct selectop *sop = arg; check_selectop(sop); if (ev->ev_events & EV_SIGNAL) return (evsignal_del(ev)); if (sop->event_fds < ev->ev_fd) { check_selectop(sop); return (0); } if (ev->ev_events & EV_READ) { FD_CLR(ev->ev_fd, sop->event_readset_in); sop->event_r_by_fd[ev->ev_fd] = NULL; } if (ev->ev_events & EV_WRITE) { FD_CLR(ev->ev_fd, sop->event_writeset_in); sop->event_w_by_fd[ev->ev_fd] = NULL; } check_selectop(sop); return (0); } void select_dealloc(struct event_base *base, void *arg) { struct selectop *sop = arg; evsignal_dealloc(base); if (sop->event_readset_in) event_free(sop->event_readset_in); if (sop->event_writeset_in) event_free(sop->event_writeset_in); if (sop->event_readset_out) event_free(sop->event_readset_out); if (sop->event_writeset_out) event_free(sop->event_writeset_out); if (sop->event_r_by_fd) event_free(sop->event_r_by_fd); if (sop->event_w_by_fd) event_free(sop->event_w_by_fd); memset(sop, 0, sizeof(struct selectop)); event_free(sop); }