X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=lib%2Fsignals.c;h=27da5d6f9139bb4e89c1d4da51a9b7cce20df943;hb=c4e976db1343aac88dec4b457bdf5d0277f247e6;hp=26eebcdb62a3824225905daff16c6e117c30724f;hpb=064af42167bf4fc9aaea2702d80ce08074b889c0;p=sliver-openvswitch.git diff --git a/lib/signals.c b/lib/signals.c index 26eebcdb6..27da5d6f9 100644 --- a/lib/signals.c +++ b/lib/signals.c @@ -1,29 +1,33 @@ /* - * Copyright (c) 2008, 2009 Nicira Networks. + * Copyright (c) 2008, 2009, 2011, 2012, 2013 Nicira, Inc. * - * Permission to use, copy, modify, and/or distribute this software for any - * purpose with or without fee is hereby granted, provided that the above - * copyright notice and this permission notice appear in all copies. + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at: * - * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES - * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF - * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR - * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES - * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN - * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF - * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. */ #include #include "signals.h" -#include #include #include #include +#include #include #include "poll-loop.h" #include "socket-util.h" +#include "type-props.h" #include "util.h" +#include "vlog.h" + +VLOG_DEFINE_THIS_MODULE(signals); #if defined(_NSIG) #define N_SIGNALS _NSIG @@ -36,59 +40,36 @@ #endif struct signal { - int signr; + int fds[2]; }; -static volatile sig_atomic_t signaled[N_SIGNALS]; - -static int fds[2]; +static struct signal signals[N_SIGNALS]; static void signal_handler(int signr); -/* Initializes the signals subsystem (if it is not already initialized). Calls - * exit() if initialization fails. - * - * Calling this function is optional; it will be called automatically by - * signal_start() if necessary. Calling it explicitly allows the client to - * prevent the process from exiting at an unexpected time. */ -void -signal_init(void) -{ - static bool inited; - if (!inited) { - inited = true; - if (pipe(fds)) { - ovs_fatal(errno, "could not create pipe"); - } - set_nonblocking(fds[0]); - set_nonblocking(fds[1]); - } -} - /* Sets up a handler for 'signr' and returns a structure that represents it. * - * Only one handler for a given signal may be registered at a time. */ + * Only one handler for a given signal may be registered. */ struct signal * signal_register(int signr) { struct sigaction sa; struct signal *s; - signal_init(); + ovs_assert(signr >= 1 && signr < N_SIGNALS); + + /* Create a pipe. */ + s = &signals[signr]; + ovs_assert(!s->fds[0] && !s->fds[1]); + xpipe_nonblocking(s->fds); - /* Set up signal handler. */ - assert(signr >= 1 && signr < N_SIGNALS); + /* Install signal handler. */ memset(&sa, 0, sizeof sa); sa.sa_handler = signal_handler; sigemptyset(&sa.sa_mask); sa.sa_flags = SA_RESTART; - if (sigaction(signr, &sa, NULL)) { - ovs_fatal(errno, "sigaction(%d) failed", signr); - } + xsigaction(signr, &sa, NULL); - /* Return structure. */ - s = xmalloc(sizeof *s); - s->signr = signr; return s; } @@ -98,12 +79,8 @@ bool signal_poll(struct signal *s) { char buf[_POSIX_PIPE_BUF]; - read(fds[0], buf, sizeof buf); - if (signaled[s->signr]) { - signaled[s->signr] = 0; - return true; - } - return false; + + return read(s->fds[0], buf, sizeof buf) > 0; } /* Causes the next call to poll_block() to wake up when signal_poll(s) would @@ -111,18 +88,57 @@ signal_poll(struct signal *s) void signal_wait(struct signal *s) { - if (signaled[s->signr]) { - poll_immediate_wake(); - } else { - poll_fd_wait(fds[0], POLLIN); - } + poll_fd_wait(s->fds[0], POLLIN); } static void signal_handler(int signr) { if (signr >= 1 && signr < N_SIGNALS) { - write(fds[1], "", 1); - signaled[signr] = true; + ignore(write(signals[signr].fds[1], "", 1)); + } +} + +/* Returns the name of signal 'signum' as a string. The return value is either + * a statically allocated constant string or the 'bufsize'-byte buffer + * 'namebuf'. 'bufsize' should be at least SIGNAL_NAME_BUFSIZE. + * + * The string is probably a (possibly multi-word) description of the signal + * (e.g. "Hangup") instead of just the stringified version of the macro + * (e.g. "SIGHUP"). */ +const char * +signal_name(int signum, char *namebuf, size_t bufsize) +{ +#if HAVE_DECL_SYS_SIGLIST + if (signum >= 0 && signum < N_SIGNALS) { + const char *name = sys_siglist[signum]; + if (name) { + return name; + } + } +#endif + + snprintf(namebuf, bufsize, "signal %d", signum); + return namebuf; +} + +void +xsigaction(int signum, const struct sigaction *new, struct sigaction *old) +{ + if (sigaction(signum, new, old)) { + char namebuf[SIGNAL_NAME_BUFSIZE]; + + VLOG_FATAL("sigaction(%s) failed (%s)", + signal_name(signum, namebuf, sizeof namebuf), + ovs_strerror(errno)); + } +} + +void +xpthread_sigmask(int how, const sigset_t *new, sigset_t *old) +{ + int error = pthread_sigmask(how, new, old); + if (error) { + VLOG_FATAL("pthread_sigmask failed (%s)", ovs_strerror(error)); } }