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" 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." */ }; void *poll_init (struct event_base *); 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 *); void poll_dealloc (struct event_base *, void *); const struct eventop pollops = { "poll", poll_init, poll_add, poll_del, poll_recalc, poll_dispatch, poll_dealloc }; void * poll_init(struct event_base *base) { struct pollop *pollop; /* Disable poll when this environment variable is set */ if (getenv("EVENT_NOPOLL")) return (NULL); if (!(pollop = calloc(1, sizeof(struct pollop)))) return (NULL); evsignal_init(base); 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) { return (0); } #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, msec = -1, nfds; struct pollop *pop = arg; poll_check_ok(pop); if (tv != NULL) msec = tv->tv_sec * 1000 + (tv->tv_usec + 999) / 1000; nfds = pop->nfds; res = poll(pop->event_set, nfds, msec); if (res == -1) { if (errno != EINTR) { event_warn("poll"); return (-1); } evsignal_process(base); return (0); } else if (base->sig.evsignal_caught) { evsignal_process(base); } 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(ev)); if (!(ev->ev_events & (EV_READ|EV_WRITE))) return (0); poll_check_ok(pop); if (pop->nfds + 1 >= pop->event_count) { struct pollfd *tmp_event_set; struct event **tmp_event_r_back; struct event **tmp_event_w_back; int tmp_event_count; if (pop->event_count < 32) tmp_event_count = 32; else tmp_event_count = pop->event_count * 2; /* We need more file descriptors */ tmp_event_set = realloc(pop->event_set, tmp_event_count * sizeof(struct pollfd)); if (tmp_event_set == NULL) { event_warn("realloc"); return (-1); } pop->event_set = tmp_event_set; tmp_event_r_back = realloc(pop->event_r_back, tmp_event_count * sizeof(struct event *)); if (tmp_event_r_back == NULL) { /* event_set overallocated; that's okay. */ event_warn("realloc"); return (-1); } pop->event_r_back = tmp_event_r_back; tmp_event_w_back = realloc(pop->event_w_back, tmp_event_count * sizeof(struct event *)); if (tmp_event_w_back == NULL) { /* event_set and event_r_back overallocated; that's * okay. */ event_warn("realloc"); return (-1); } pop->event_w_back = tmp_event_w_back; pop->event_count = tmp_event_count; } if (ev->ev_fd >= pop->fd_count) { int *tmp_idxplus1_by_fd; 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; tmp_idxplus1_by_fd = realloc(pop->idxplus1_by_fd, new_count * sizeof(int)); if (tmp_idxplus1_by_fd == NULL) { event_warn("realloc"); return (-1); } pop->idxplus1_by_fd = tmp_idxplus1_by_fd; 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(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); } void poll_dealloc(struct event_base *base, void *arg) { struct pollop *pop = arg; evsignal_dealloc(base); if (pop->event_set) free(pop->event_set); if (pop->event_r_back) free(pop->event_r_back); if (pop->event_w_back) free(pop->event_w_back); if (pop->idxplus1_by_fd) free(pop->idxplus1_by_fd); memset(pop, 0, sizeof(struct pollop)); free(pop); }