diff options
Diffstat (limited to 'libevent/rtsig.c')
| -rw-r--r-- | libevent/rtsig.c | 985 |
1 files changed, 0 insertions, 985 deletions
diff --git a/libevent/rtsig.c b/libevent/rtsig.c deleted file mode 100644 index 29aade6..0000000 --- a/libevent/rtsig.c +++ /dev/null @@ -1,985 +0,0 @@ -/* - * Copyright (c) 2006 Mathew Mills <mathewmills@mac.com> - * 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. - */ -/* - * Meta-level comments: You know that a kernel interface is wrong if - * supporting it requires three times more code than any of the other - * kernel interfaces supported in libevent. Niels - 2006-02-22 - */ -/** - - "RTSIG" is a shorthand for using O_ASYNC to make descriptors send - signals when readable/writable and to use POSIX real-time signals - witch are queued unlike normal signals. At first blush this may - seem like a alternative to epoll, but a number of problems arise - when attempting to build an eventloop entirely out of rtsig. - Still, we can use rtsig in combination with poll() to - provide an eventloop that allows for many thousands of sockets - without huge overheads implicit with using select() or poll() - alone. epoll and kqueue are far superior to rtsig and should be - used where available, but rtsig has been in standard Linux kernels - for a long time and have a huge installation base. epoll requires - special patches for 2.4 kernels and 2.6 kernels are not yet nearly - so ubiquitous. - - rtsig problems: - - O_ASYNC mechanisms work only on sockets - not pipes or tty's - - - O_ASYNC signals are edge-triggered, POLLIN on packet arriving - or socket close; POLLOUT when a socket transitions from - non-writable to writable. Being edge-triggered means the - event-handler callbacks must transition the level ( reading - completely the socket buffer contents ) or it will be unable to - reliably receive notification again. - - - rtsig implementations must be intimately involved in how a - process dispatches signals. - - - delivering signals per-event can be expensive, CPU-wise, but - sigtimedwait() blocks on signals only and means non-sockets - cannot be serviced. - - Theory of operation: - This libevent module uses rtsig to allow us to manage a set of - poll-event descriptors. We can drop uninteresting fd's from the - pollset if the fd will send a signal when it becomes interesting - again. - - poll() offers us level-triggering and, when we have verified the - level of a socket, we can trust the edge-trigger nature of the - ASYNC signal. - - As an eventloop we must poll for external events but leverage - kernel functionality to sleep between events ( until the loop's - next scheduled timed event ). - - If we are polling on any non-sockets then we simply have no choice - about blocking on the poll() call. If we blocked on the - sigtimedwait() call as rtsig papers recommend we will not wake on - non-socket state transitions. As part of libevent, this module - must support non-socket polling. - - Many applications, however, do not need to poll on non-sockets and - so this module should be able to optimize this case by using - sigtimedwait(). For this reason this module can actually trigger - events in each of three different ways: - - poll() returning ready events from descriptors in the pollset - - - real-time signals dequeued via sigtimedwait() - - - real-time signals that call an installed signal handler which in - turn writes the contents of siginfo to one end of a socketpair - DGRAM socket. The other end of the socket is always in the - pollset so poll will be guaranteed to return even if the signal is - received before entering poll(). - - non-socket descriptors force us to block on the poll() for the - duration of a dispatch. In this case we unblock (w/ sigprocmask) - the managed signals just before polling. Each managed signal is - handled by signal_handler() which send()'s the contents of siginfo - over the socketpair. Otherwise, we call poll() with a timeout of - 0ms so it checks the levels of the fd's in the pollset and returns - immediately. Any fd that is a socket and has no active state is - removed from the pollset for the next pass -- we will rely on - getting a signal for events on these fd's. - - The receiving end of the siginfo socketpair is in the pollset - (permanently) so if we are polling on non-sockets, the delivery of - signals immediately following sigprocmask( SIG_UNBLOCK...) will - result in a readable op->signal_recv_fd which ensures the poll() - will return immediately. If the poll() call is blocking and a - signal arrives ( possibly a real-time signal from a socket not in - the pollset ) its handler will write the data to the socketpair - and interrupt the poll(). - - After every poll call we attempt a non-blocking recv from the - signal_recv_fd and continue to recv and dispatch the events until - recv indicates the socket buffer is empty. - - One might raise concerns about receiving event activations from - both poll() and from the rtsig data in the signal_recv_fd. - Fortunately, libevent is already structured for event coalescing, - so this issue is mitigated ( though we do some work twice for the - same event making us less efficient ). I suspect that the cost of - turning off the O_ASYNC flag on fd's in the pollset is more - expensive than handling some events twice. Looking at the - kernel's source code for setting O_ASYNC, it looks like it takes a - global kernel lock... - - After a poll and recv-loop for the signal_recv_fd, we finally do a - sigtimedwait(). sigtimedwait will only block if we haven't - blocked in poll() and we have not enqueued events from either the - poll or the recv-loop. Because sigtimedwait blocks all signals - that are not in the set of signals to be dequeued, we need to - dequeue almost all signals and make sure we dispatch them - correctly. We dequeue any signal that is not blocked as well as - all libevent-managed signals. If we get a signal that is not - managed by libevent we lookup the sigaction for the specific - signal and call that function ourselves. - - Finally, I should mention that getting a SIGIO signal indicates - that the rtsig buffer has overflowed and we have lost events. - This forces us to add _every_ descriptor to the pollset to recover. - -*/ - - -#ifdef HAVE_CONFIG_H -#include "config.h" -#endif - -/* Enable F_SETSIG and F_SETOWN */ -#define _GNU_SOURCE - -#include <sys/types.h> -#ifdef HAVE_SYS_TIME_H -#include <sys/time.h> -#else -#include <sys/_time.h> -#endif -#include <assert.h> -#include <errno.h> -#include <fcntl.h> -#include <signal.h> -#include <stdio.h> -#include <stdlib.h> -#include <string.h> -#include <sys/poll.h> -#include <sys/queue.h> -#include <sys/tree.h> -#include <unistd.h> -#include <sys/socket.h> - -#include "event.h" -#include "event-internal.h" -#include "log.h" -extern struct event_list signalqueue; - -#include <linux/unistd.h> -#ifndef __NR_gettid -#define gettid() getpid() -#else - -#if ((__GLIBC__ > 2) || ((__GLIBC__ == 2) && (__GLIBC_MINOR__ >= 3))) -_syscall0(pid_t,gettid) -#endif - -#endif - -#define EVLIST_NONSOCK 0x1000 /* event is for a non-socket file-descriptor */ -#define EVLIST_DONTDEL 0x2000 /* event should always be in the pollset */ -#define MAXBUFFERSIZE (1024 * 1024 * 2) /* max socketbuffer for signal-spair */ -#define INIT_MAX 16 /* init/min # of fd positions in our pollset */ - -static int signal_send_fd[_NSIG]; /* the globalend of the signal socketpair */ -static int trouble[_NSIG]; /* 1 when signal-handler cant send to signal_send_fd */ - -struct rtdata; -TAILQ_HEAD(rtdata_list, rtdata); - -struct rtsigop { - sigset_t sigs; /* signal mask for all _managed_ signals */ - struct pollfd *poll; /* poll structures */ - struct rtdata **ptodat; /* map poll_position to rtdata */ - int cur; /* cur # fd's in a poll set */ - int max; /* max # fd's in a poll set, start at 16 and grow as needed */ - int total; /* count of fd's we are watching now */ - int signo; /* the signo we use for ASYNC fd notifications */ - int nonsock; /* number of non-socket fd's we are watching */ - int highestfd; /* highest fd accomodated by fdtodat */ - struct rtdata_list **fdtodat; /* map fd to rtdata ( and thus to event ) */ - int signal_recv_fd; /* recv side of the signal_send_fd */ - int signal_send_fd; /* recv side of the signal_send_fd */ - struct event sigfdev; /* our own event structure for the signal fd */ -}; - -struct rtdata { - /* rtdata holds rtsig-private state on each event */ - TAILQ_ENTRY (rtdata) next; - struct event *ev; - int poll_position; -}; - -void *rtsig_init(void); -int rtsig_add(void *, struct event *); -int rtsig_del(void *, struct event *); -int rtsig_recalc(struct event_base *, void *, int); -int rtsig_dispatch(struct event_base *, void *, struct timeval *); - -struct eventop rtsigops = { - "rtsig", - rtsig_init, - rtsig_add, - rtsig_del, - rtsig_recalc, - rtsig_dispatch -}; - -static void -signal_handler(int sig, siginfo_t *info, void *ctx) -{ - /* - * the signal handler for all libevent-managed signals only - * used if we need to do a blocking poll() call due to - * non-socket fd's in the pollset. - */ - - siginfo_t *i = info; - siginfo_t i_local; - - if (trouble[sig - 1]) { - i_local.si_signo = SIGIO; - i_local.si_errno = 0; - i_local.si_code = 0; - i = &i_local; - trouble[sig - 1] = 0; - } - - if (send(signal_send_fd[sig - 1], i, sizeof(*i), - MSG_DONTWAIT|MSG_NOSIGNAL) == -1) - trouble[sig - 1] = 1; -} - -static void -donothing(int fd, short event, void *arg) -{ - /* - * callback for our signal_recv_fd event structure - * we don't want to act on these events, we just want to wake the poll() - */ -}; - -static void -signotset(sigset_t *set) -{ - int i, l; - l = sizeof(*set) / 4; - for (i = 0; i < l; i++) { - ((unsigned *)set)[i] = ~((unsigned *)set)[i]; - } -} - -/* The next three functions manage our private data about each event struct */ - -static int -grow_fdset(struct rtsigop *op, int newhigh) -{ - /* - * grow the fd -> rtdata array because we have encountered a - * new fd too high to fit in the existing array - */ - - struct rtdata_list **p; - struct rtdata_list *datset; - int i,x; - int newcnt = (newhigh + 1) << 1; - - if (newhigh <= op->highestfd) - return (0); - - p = op->fdtodat; - p = realloc(op->fdtodat, sizeof(struct rtdata_list *) * newcnt); - if (p == NULL) - return (-1); - op->fdtodat = p; - - datset = calloc(newcnt - (op->highestfd + 1), - sizeof(struct rtdata_list)); - if (datset == NULL) - return (-1); - - for (i = op->highestfd + 1, x = 0; i < newcnt; i++, x++) { - op->fdtodat[i] = &(datset[x]); - TAILQ_INIT(op->fdtodat[i]); - } - - op->highestfd = newcnt - 1; - return (0); -} - -static struct rtdata * -ev2dat(struct rtsigop *op, struct event *ev, int create) -{ - /* - * given an event struct, find the dat structure that - * corresponds to it if create is non-zero and the rtdata - * structure does not exist, create it return NULL if not - * found - */ - - int found = 0; - int fd = ev->ev_fd; - struct rtdata *ret = NULL; - - if (op->highestfd < fd && create) - if (grow_fdset(op, fd) == -1) - return (NULL); - - TAILQ_FOREACH(ret, op->fdtodat[fd], next) { - if (ret->ev == ev) { - found = 1; - break; - } - } - - if (!found) { - if (!create) - return (NULL); - - ret = calloc(1, sizeof(struct rtdata)); - if (ret == NULL) - return (NULL); - ret->ev = ev; - ret->poll_position = -1; - TAILQ_INSERT_TAIL(op->fdtodat[fd], ret, next); - } - - return (ret); -} - -static void -dat_del(struct rtsigop *op, struct rtdata *dat) -{ - /* - * delete our private notes about a given event struct - * called from rtsig_del() only - */ - int fd; - if (dat == NULL) - return; - fd = dat->ev->ev_fd; - - TAILQ_REMOVE(op->fdtodat[fd], dat, next); - memset(dat, 0, sizeof(*dat)); - free(dat); -} - - -static void -set_sigaction(int sig) -{ - /* - * set the standard handler for any libevent-managed signal, - * including the rtsig used for O_ASYNC notifications - */ - struct sigaction act; - - act.sa_flags = SA_RESTART | SA_SIGINFO; - sigfillset(&(act.sa_mask)); - act.sa_sigaction = &signal_handler; - sigaction(sig, &act, NULL); -} - -static int -find_rt_signal() -{ - /* find an unused rtsignal */ - struct sigaction act; - int sig = SIGRTMIN; - - while (sig <= SIGRTMAX) { - if (sigaction(sig, NULL, &act) != 0) { - if (errno == EINTR) - continue; - } else { - if (act.sa_flags & SA_SIGINFO) { - if (act.sa_sigaction == NULL) - return (sig); - } else { - if (act.sa_handler == SIG_DFL) - return (sig); - } - } - sig++; - } - return (0); -} - -/* - * the next three functions manage our pollset and the memory management for - * fd -> rtdata -> event -> poll_position maps - */ - -static int -poll_add(struct rtsigop *op, struct event *ev, struct rtdata *dat) -{ - struct pollfd *pfd; - int newmax = op->max << 1; - int pp; - - if (op->poll == NULL) - return (0); - - if (dat == NULL) - dat = ev2dat(op, ev, 0); - - if (dat == NULL) - return (0); - - pp = dat->poll_position; - - if (pp != -1) { - pfd = &op->poll[pp]; - if (ev->ev_events & EV_READ) - pfd->events |= POLLIN; - - if (ev->ev_events & EV_WRITE) - pfd->events |= POLLOUT; - - return (0); - } - - if (op->cur == op->max) { - void *p = realloc(op->poll, sizeof(*op->poll) * newmax); - if (p == NULL) { - errno = ENOMEM; - return (-1); - } - op->poll = p; - - p = realloc(op->ptodat, sizeof(*op->ptodat) * newmax); - if (p == NULL) { - /* shrink the pollset back down */ - op->poll = realloc(op->poll, - sizeof(*op->poll) * op->max); - errno = ENOMEM; - return (-1); - } - op->ptodat = p; - op->max = newmax; - } - - pfd = &op->poll[op->cur]; - pfd->fd = ev->ev_fd; - pfd->revents = 0; - pfd->events = 0; - - if (ev->ev_events & EV_READ) - pfd->events |= POLLIN; - - if (ev->ev_events & EV_WRITE) - pfd->events |= POLLOUT; - - op->ptodat[op->cur] = dat; - dat->poll_position = op->cur; - op->cur++; - - return (0); -} - -static void -poll_free(struct rtsigop *op, int n) -{ - if (op->poll == NULL) - return; - - op->cur--; - - if (n < op->cur) { - memcpy(&op->poll[n], &op->poll[op->cur], sizeof(*op->poll)); - op->ptodat[n] = op->ptodat[op->cur]; - op->ptodat[n]->poll_position = n; - } - - - /* less then half the max in use causes us to shrink */ - if (op->max > INIT_MAX && op->cur < op->max >> 1) { - op->max >>= 1; - op->poll = realloc(op->poll, sizeof(*op->poll) * op->max); - op->ptodat = realloc(op->ptodat, sizeof(*op->ptodat) * op->max); - } -} - -static void -poll_remove(struct rtsigop *op, struct event *ev, struct rtdata *dat) -{ - int pp; - if (dat == NULL) - dat = ev2dat(op, ev, 0); - - if (dat == NULL) return; - - pp = dat->poll_position; - if (pp != -1) { - poll_free(op, pp); - dat->poll_position = -1; - } -} - -static void -activate(struct event *ev, int flags) -{ - /* activate an event, possibly removing one-shot events */ - if (!(ev->ev_events & EV_PERSIST)) - event_del(ev); - event_active(ev, flags, 1); -} - -#define FD_CLOSEONEXEC(x) do { \ - if (fcntl(x, F_SETFD, 1) == -1) \ - event_warn("fcntl(%d, F_SETFD)", x); \ -} while (0) - -void * -rtsig_init(void) -{ - struct rtsigop *op; - int sockets[2]; - int optarg; - struct rtdata *dat; - int flags; - - if (getenv("EVENT_NORTSIG")) - goto err; - - op = calloc(1, sizeof(*op)); - if (op == NULL) - goto err; - - op->max = INIT_MAX; - op->poll = malloc(sizeof(*op->poll) * op->max); - if (op->poll == NULL) - goto err_free_op; - - op->signo = find_rt_signal(); - if (op->signo == 0) - goto err_free_poll; - - op->nonsock = 0; - - if (socketpair(PF_UNIX, SOCK_DGRAM, 0, sockets) != 0) - goto err_free_poll; - - FD_CLOSEONEXEC(sockets[0]); - FD_CLOSEONEXEC(sockets[1]); - - signal_send_fd[op->signo - 1] = sockets[0]; - trouble[op->signo - 1] = 0; - op->signal_send_fd = sockets[0]; - op->signal_recv_fd = sockets[1]; - flags = fcntl(op->signal_recv_fd, F_GETFL); - fcntl(op->signal_recv_fd, F_SETFL, flags | O_NONBLOCK); - - optarg = MAXBUFFERSIZE; - setsockopt(signal_send_fd[op->signo - 1], - SOL_SOCKET, SO_SNDBUF, - &optarg, sizeof(optarg)); - - optarg = MAXBUFFERSIZE; - setsockopt(op->signal_recv_fd, - SOL_SOCKET, SO_RCVBUF, - &optarg, sizeof(optarg)); - - op->highestfd = -1; - op->fdtodat = NULL; - if (grow_fdset(op, 1) == -1) - goto err_close_pair; - - op->ptodat = malloc(sizeof(*op->ptodat) * op->max); - if (op->ptodat == NULL) - goto err_close_pair; - - sigemptyset(&op->sigs); - sigaddset(&op->sigs, SIGIO); - sigaddset(&op->sigs, op->signo); - sigprocmask(SIG_BLOCK, &op->sigs, NULL); - set_sigaction(SIGIO); - set_sigaction(op->signo); - - event_set(&(op->sigfdev), op->signal_recv_fd, EV_READ|EV_PERSIST, - donothing, NULL); - op->sigfdev.ev_flags |= EVLIST_DONTDEL; - dat = ev2dat(op, &(op->sigfdev), 1); - poll_add(op, &(op->sigfdev), dat); - - return (op); - - err_close_pair: - close(op->signal_recv_fd); - close(signal_send_fd[op->signo - 1]); - - err_free_poll: - free(op->poll); - - err_free_op: - free(op); - err: - return (NULL); -} - -int -rtsig_add(void *arg, struct event *ev) -{ - struct rtsigop *op = (struct rtsigop *) arg; - int flags, i; - struct stat statbuf; - struct rtdata *dat; - - if (ev->ev_events & EV_SIGNAL) { - int signo = EVENT_SIGNAL(ev); - - sigaddset(&op->sigs, EVENT_SIGNAL(ev)); - if (sigprocmask(SIG_BLOCK, &op->sigs, NULL) == -1) - return (-1); - - set_sigaction(signo); - - signal_send_fd[signo - 1] = op->signal_send_fd; - trouble[signo - 1] = 0; - - return (0); - } - - if (!(ev->ev_events & (EV_READ|EV_WRITE))) - return (0); - - if (-1 == fstat(ev->ev_fd, &statbuf)) - return (-1); - - if (!S_ISSOCK(statbuf.st_mode)) - ev->ev_flags |= EVLIST_NONSOCK; - - flags = fcntl(ev->ev_fd, F_GETFL); - if (flags == -1) - return (-1); - - if (!(flags & O_ASYNC)) { - if (fcntl(ev->ev_fd, F_SETSIG, op->signo) == -1 || - fcntl(ev->ev_fd, F_SETOWN, (int) gettid()) == -1) - return (-1); - - /* - * the overhead of always handling writeable edges - * isn't going to be that bad... - */ - if (fcntl(ev->ev_fd, F_SETFL, flags | O_ASYNC|O_RDWR)) - return (-1); - } - -#ifdef O_ONESIGFD - /* - * F_SETAUXFL and O_ONESIGFD are defined in a non-standard - * linux kernel patch to coalesce events for fds - */ - fcntl(ev->ev_fd, F_SETAUXFL, O_ONESIGFD); -#endif - - dat = ev2dat(op, ev, 1); - if (dat == NULL) - return (-1); - - op->total++; - if (ev->ev_flags & EVLIST_NONSOCK) - op->nonsock++; - - if (poll_add(op, ev, dat) == -1) { - /* must check the level of new fd's */ - i = errno; - fcntl(ev->ev_fd, F_SETFL, flags); - errno = i; - return (-1); - } - - return (0); -} - -int -rtsig_del(void *arg, struct event *ev) -{ - struct rtdata *dat; - struct rtsigop *op = (struct rtsigop *) arg; - - if (ev->ev_events & EV_SIGNAL) { - sigset_t sigs; - - sigdelset(&op->sigs, EVENT_SIGNAL(ev)); - - sigemptyset(&sigs); - sigaddset(&sigs, EVENT_SIGNAL(ev)); - return (sigprocmask(SIG_UNBLOCK, &sigs, NULL)); - } - - if (!(ev->ev_events & (EV_READ|EV_WRITE))) - return (0); - - dat = ev2dat(op, ev, 0); - poll_remove(op, ev, dat); - dat_del(op, dat); - op->total--; - if (ev->ev_flags & EVLIST_NONSOCK) - op->nonsock--; - - return (0); -} - -int -rtsig_recalc(struct event_base *base, void *arg, int max) -{ - return (0); -} - -/* - * the following do_X functions implement the different stages of a single - * eventloop pass: poll(), recv(sigsock), sigtimedwait() - * - * do_siginfo_dispatch() is a common factor to both do_sigwait() and - * do_signals_from_socket(). - */ - -static inline int -do_poll(struct rtsigop *op, struct timespec *ts) -{ - int res = 0; - int i = 0; - - if (op->cur > 1) { - /* non-empty poll set (modulo the signalfd) */ - if (op->nonsock) { - int timeout = ts->tv_nsec / 1000000 + ts->tv_sec * 1000; - - sigprocmask(SIG_UNBLOCK, &(op->sigs), NULL); - - res = poll(op->poll, op->cur, timeout); - - sigprocmask(SIG_BLOCK, &(op->sigs), NULL); - - ts->tv_sec = 0; - ts->tv_nsec = 0; - } else { - res = poll(op->poll, op->cur, 0); - } - - if (res < 0) { - return (errno == EINTR ? 0 : -1); - } else if (res) { - ts->tv_sec = 0; - ts->tv_nsec = 0; - } - - i = 0; - while (i < op->cur) { - struct rtdata *dat = op->ptodat[i]; - struct event *ev = dat->ev; - - if (op->poll[i].revents) { - int flags = 0; - - if (op->poll[i].revents & (POLLIN | POLLERR)) - flags |= EV_READ; - - if (op->poll[i].revents & POLLOUT) - flags |= EV_WRITE; - - if (!(ev->ev_events & EV_PERSIST)) { - poll_remove(op, ev, op->ptodat[i]); - event_del(ev); - } else { - i++; - } - - event_active(ev, flags, 1); - } else { - if (ev->ev_flags & (EVLIST_NONSOCK|EVLIST_DONTDEL)) { - i++; - } else { - poll_remove(op, ev, op->ptodat[i]); - } - } - } - } - return (res); -} - -static inline int -do_siginfo_dispatch(struct event_base *base, struct rtsigop *op, - siginfo_t *info) -{ - int signum; - struct rtdata *dat, *next_dat; - struct event *ev, *next_ev; - - if (info == NULL) - return (-1); - - signum = info->si_signo; - if (signum == op->signo) { - int flags, sigok = 0; - flags = 0; - - if (info->si_band & (POLLIN|POLLERR)) - flags |= EV_READ; - if (info->si_band & POLLOUT) - flags |= EV_WRITE; - - if (!flags) - return (0); - - if (info->si_fd > op->highestfd) - return (-1); - - dat = TAILQ_FIRST(op->fdtodat[info->si_fd]); - while (dat != TAILQ_END(op->fdtodat[info->si_fd])) { - next_dat = TAILQ_NEXT(dat, next); - if (flags & dat->ev->ev_events) { - ev = dat->ev; - poll_add(op, ev, dat); - activate(ev, flags & ev->ev_events); - sigok = 1; - } - dat = next_dat; - } - } else if (signum == SIGIO) { - TAILQ_FOREACH(ev, &base->eventqueue, ev_next) { - if (ev->ev_events & (EV_READ|EV_WRITE)) - poll_add(op, ev, NULL); - } - return (1); /* 1 means the caller should poll() again */ - - } else if (sigismember(&op->sigs, signum)) { - /* managed signals are queued */ - ev = TAILQ_FIRST(&signalqueue); - while (ev != TAILQ_END(&signalqueue)) { - next_ev = TAILQ_NEXT(ev, ev_signal_next); - if (EVENT_SIGNAL(ev) == signum) - activate(ev, EV_SIGNAL); - ev = next_ev; - } - } else { - /* dispatch unmanaged signals immediately */ - struct sigaction sa; - if (sigaction(signum, NULL, &sa) == 0) { - if ((sa.sa_flags & SA_SIGINFO) && sa.sa_sigaction) { - (*sa.sa_sigaction)(signum, info, NULL); - } else if (sa.sa_handler) { - if ((int)sa.sa_handler != 1) - (*sa.sa_handler)(signum); - } else { - if (signum != SIGCHLD) { - /* non-blocked SIG_DFL */ - kill(gettid(), signum); - } - } - } - } - - return (0); -} - -/* - * return 1 if we should poll again - * return 0 if we are all set - * return -1 on error - */ -static inline int -do_sigwait(struct event_base *base, struct rtsigop *op, struct timespec *ts, - sigset_t *sigs) -{ - for (;;) { - siginfo_t info; - int signum; - - signum = sigtimedwait(sigs, &info, ts); - - ts->tv_sec = 0; - ts->tv_nsec = 0; - - if (signum == -1) { - if (errno == EAGAIN || errno == EINTR) - return (0); - return (-1); - } else if (1 == do_siginfo_dispatch(base, op, &info)) { - return (1); - } - } - - /* NOTREACHED */ -} - -static inline int -do_signals_from_socket(struct event_base *base, struct rtsigop *op, - struct timespec *ts) -{ - int fd = op->signal_recv_fd; - siginfo_t info; - int res; - - for (;;) { - res = recv(fd, &info, sizeof(info), MSG_NOSIGNAL); - if (res == -1) { - if (errno == EAGAIN) - return (0); - if (errno == EINTR) - continue; - return (-1); - } else { - ts->tv_sec = 0; - ts->tv_nsec = 0; - if (1 == do_siginfo_dispatch(base, op, &info)) - return (1); - } - } - /* NOTREACHED */ -} - -int -rtsig_dispatch(struct event_base *base, void *arg, struct timeval *tv) -{ - struct rtsigop *op = (struct rtsigop *) arg; - struct timespec ts; - int res; - sigset_t sigs; - - ts.tv_sec = tv->tv_sec; - ts.tv_nsec = tv->tv_usec * 1000; - - poll_for_level: - res = do_poll(op, &ts); /* ts can be modified in do_XXX() */ - - res = do_signals_from_socket(base, op, &ts); - if (res == 1) - goto poll_for_level; - else if (res == -1) - return (-1); - - /* - * the mask = managed_signals | unblocked-signals - * MM - if this is not blocking do we need to cast the net this wide? - */ - sigemptyset(&sigs); - sigprocmask(SIG_BLOCK, &sigs, &sigs); - signotset(&sigs); - sigorset(&sigs, &sigs, &op->sigs); - - res = do_sigwait(base, op, &ts, &sigs); - - if (res == 1) - goto poll_for_level; - else if (res == -1) - return (-1); - - return (0); -} - |