Edit
kc3-lang/libevent/poll.c
Niels Provos
- poll.c
-
/* $OpenBSD: poll.c,v 1.2 2002/06/25 15:50:15 mickey Exp $ */ /* * Copyright 2000-2003 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 #include <sys/queue.h> #include <sys/tree.h> #include <poll.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" extern volatile sig_atomic_t evsignal_caught; struct pollop { int event_count; /* Highest number alloc */ int nfds; /* Size of event_* */ int fd_count; /* Size of idxplus1_by_fd */ struct pollfd *event_set; struct event **event_r_back; struct event **event_w_back; int *idxplus1_by_fd; /* Index into event_set by fd; we add 1 so * that 0 (which is easy to memset) can mean * "no entry." */ sigset_t evsigmask; }; void *poll_init (void); int poll_add (void *, struct event *); int poll_del (void *, struct event *); int poll_recalc (struct event_base *, void *, int); int poll_dispatch (struct event_base *, void *, struct timeval *); struct eventop pollops = { "poll", poll_init, poll_add, poll_del, poll_recalc, poll_dispatch }; void * poll_init(void) { struct pollop *pollop; /* Disable kqueue when this environment variable is set */ if (getenv("EVENT_NOPOLL")) return (NULL); if (!(pollop = calloc(1, sizeof(struct pollop)))) return (NULL); evsignal_init(&pollop->evsigmask); return (pollop); } /* * Called with the highest fd that we know about. If it is 0, completely * recalculate everything. */ int poll_recalc(struct event_base *base, void *arg, int max) { struct pollop *pop = arg; return (evsignal_recalc(&pop->evsigmask)); } #ifdef CHECK_INVARIANTS static void poll_check_ok(struct pollop *pop) { int i, idx; struct event *ev; for (i = 0; i < pop->fd_count; ++i) { idx = pop->idxplus1_by_fd[i]-1; if (idx < 0) continue; assert(pop->event_set[idx].fd == i); if (pop->event_set[idx].events & POLLIN) { ev = pop->event_r_back[idx]; assert(ev); assert(ev->ev_events & EV_READ); assert(ev->ev_fd == i); } if (pop->event_set[idx].events & POLLOUT) { ev = pop->event_w_back[idx]; assert(ev); assert(ev->ev_events & EV_WRITE); assert(ev->ev_fd == i); } } for (i = 0; i < pop->nfds; ++i) { struct pollfd *pfd = &pop->event_set[i]; assert(pop->idxplus1_by_fd[pfd->fd] == i+1); } } #else #define poll_check_ok(pop) #endif int poll_dispatch(struct event_base *base, void *arg, struct timeval *tv) { int res, i, sec, nfds; struct pollop *pop = arg; if (evsignal_deliver(&pop->evsigmask) == -1) return (-1); poll_check_ok(pop); sec = tv->tv_sec * 1000 + (tv->tv_usec + 999) / 1000; nfds = pop->nfds; res = poll(pop->event_set, nfds, sec); if (evsignal_recalc(&pop->evsigmask) == -1) return (-1); if (res == -1) { if (errno != EINTR) { event_warn("poll"); return (-1); } evsignal_process(); return (0); } else if (evsignal_caught) evsignal_process(); event_debug(("%s: poll reports %d", __func__, res)); if (res == 0) return (0); for (i = 0; i < nfds; i++) { int what = pop->event_set[i].revents; struct event *r_ev = NULL, *w_ev = NULL; if (!what) continue; res = 0; /* If the file gets closed notify */ if (what & (POLLHUP|POLLERR)) what |= POLLIN|POLLOUT; if (what & POLLIN) { res |= EV_READ; r_ev = pop->event_r_back[i]; } if (what & POLLOUT) { res |= EV_WRITE; w_ev = pop->event_w_back[i]; } if (res == 0) continue; 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); } } return (0); } int poll_add(void *arg, struct event *ev) { struct pollop *pop = arg; struct pollfd *pfd = NULL; int i; if (ev->ev_events & EV_SIGNAL) return (evsignal_add(&pop->evsigmask, ev)); if (!(ev->ev_events & (EV_READ|EV_WRITE))) return (0); poll_check_ok(pop); if (pop->nfds + 1 >= pop->event_count) { if (pop->event_count < 32) pop->event_count = 32; else pop->event_count *= 2; /* We need more file descriptors */ pop->event_set = realloc(pop->event_set, pop->event_count * sizeof(struct pollfd)); if (pop->event_set == NULL) { event_warn("realloc"); return (-1); } pop->event_r_back = realloc(pop->event_r_back, pop->event_count * sizeof(struct event *)); pop->event_w_back = realloc(pop->event_w_back, pop->event_count * sizeof(struct event *)); if (pop->event_r_back == NULL || pop->event_w_back == NULL) { event_warn("realloc"); return (-1); } } if (ev->ev_fd >= pop->fd_count) { int new_count; if (pop->fd_count < 32) new_count = 32; else new_count = pop->fd_count * 2; while (new_count <= ev->ev_fd) new_count *= 2; pop->idxplus1_by_fd = realloc(pop->idxplus1_by_fd, new_count*sizeof(int)); if (pop->idxplus1_by_fd == NULL) { event_warn("realloc"); return (-1); } memset(pop->idxplus1_by_fd + pop->fd_count, 0, sizeof(int)*(new_count - pop->fd_count)); pop->fd_count = new_count; } i = pop->idxplus1_by_fd[ev->ev_fd] - 1; if (i >= 0) { pfd = &pop->event_set[i]; } else { i = pop->nfds++; pfd = &pop->event_set[i]; pfd->events = 0; pfd->fd = ev->ev_fd; pop->event_w_back[i] = pop->event_r_back[i] = NULL; pop->idxplus1_by_fd[ev->ev_fd] = i + 1; } pfd->revents = 0; if (ev->ev_events & EV_WRITE) { pfd->events |= POLLOUT; pop->event_w_back[i] = ev; } if (ev->ev_events & EV_READ) { pfd->events |= POLLIN; pop->event_r_back[i] = ev; } poll_check_ok(pop); return (0); } /* * Nothing to be done here. */ int poll_del(void *arg, struct event *ev) { struct pollop *pop = arg; struct pollfd *pfd = NULL; int i; if (ev->ev_events & EV_SIGNAL) return (evsignal_del(&pop->evsigmask, ev)); if (!(ev->ev_events & (EV_READ|EV_WRITE))) return (0); poll_check_ok(pop); i = pop->idxplus1_by_fd[ev->ev_fd] - 1; if (i < 0) return (-1); /* Do we still want to read or write? */ pfd = &pop->event_set[i]; if (ev->ev_events & EV_READ) { pfd->events &= ~POLLIN; pop->event_r_back[i] = NULL; } if (ev->ev_events & EV_WRITE) { pfd->events &= ~POLLOUT; pop->event_w_back[i] = NULL; } poll_check_ok(pop); if (pfd->events) /* Another event cares about that fd. */ return (0); /* Okay, so we aren't interested in that fd anymore. */ pop->idxplus1_by_fd[ev->ev_fd] = 0; --pop->nfds; if (i != pop->nfds) { /* * Shift the last pollfd down into the now-unoccupied * position. */ memcpy(&pop->event_set[i], &pop->event_set[pop->nfds], sizeof(struct pollfd)); pop->event_r_back[i] = pop->event_r_back[pop->nfds]; pop->event_w_back[i] = pop->event_w_back[pop->nfds]; pop->idxplus1_by_fd[pop->event_set[i].fd] = i + 1; } poll_check_ok(pop); return (0); }