/*
- * Copyright (c) 2008, 2009, 2010, 2011, 2012 Nicira, Inc.
+ * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013 Nicira, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
+#include "ovs-thread.h"
#include "poll-loop.h"
#include "shash.h"
#include "sset.h"
VLOG_DEFINE_THIS_MODULE(fatal_signal);
/* Signals to catch. */
+#ifndef _WIN32
static const int fatal_signals[] = { SIGTERM, SIGINT, SIGHUP, SIGALRM };
-
-/* Signals to catch as a sigset_t. */
-static sigset_t fatal_signal_set;
+#else
+static const int fatal_signals[] = { SIGTERM };
+#endif
/* Hooks to call upon catching a signal */
struct hook {
static size_t n_hooks;
static int signal_fds[2];
+static HANDLE wevent;
static volatile sig_atomic_t stored_sig_nr = SIG_ATOMIC_MAX;
-static void fatal_signal_init(void);
+static struct ovs_mutex mutex;
+
static void atexit_handler(void);
static void call_hooks(int sig_nr);
+#ifdef _WIN32
+static BOOL WINAPI ConsoleHandlerRoutine(DWORD dwCtrlType);
+#endif
-static void
+/* Initializes the fatal signal handling module. Calling this function is
+ * optional, because calling any other function in the module will also
+ * initialize it. However, in a multithreaded program, the module must be
+ * initialized while the process is still single-threaded. */
+void
fatal_signal_init(void)
{
static bool inited = false;
if (!inited) {
size_t i;
+ assert_single_threaded();
inited = true;
+ ovs_mutex_init_recursive(&mutex);
+#ifndef _WIN32
xpipe_nonblocking(signal_fds);
+#else
+ wevent = CreateEvent(NULL, TRUE, FALSE, NULL);
+ if (!wevent) {
+ char *msg_buf = ovs_lasterror_to_string();
+ VLOG_FATAL("Failed to create a event (%s).", msg_buf);
+ }
+
+ /* Register a function to handle Ctrl+C. */
+ SetConsoleCtrlHandler(ConsoleHandlerRoutine, true);
+#endif
- sigemptyset(&fatal_signal_set);
for (i = 0; i < ARRAY_SIZE(fatal_signals); i++) {
int sig_nr = fatal_signals[i];
+#ifndef _WIN32
struct sigaction old_sa;
- sigaddset(&fatal_signal_set, sig_nr);
xsigaction(sig_nr, NULL, &old_sa);
if (old_sa.sa_handler == SIG_DFL
&& signal(sig_nr, fatal_signal_handler) == SIG_ERR) {
- VLOG_FATAL("signal failed (%s)", strerror(errno));
+ VLOG_FATAL("signal failed (%s)", ovs_strerror(errno));
}
+#else
+ if (signal(sig_nr, fatal_signal_handler) == SIG_ERR) {
+ VLOG_FATAL("signal failed (%s)", ovs_strerror(errno));
+ }
+#endif
}
atexit(atexit_handler);
}
}
-/* Registers 'hook_cb' to be called when a process termination signal is
- * raised. If 'run_at_exit' is true, 'hook_cb' is also called during normal
- * process termination, e.g. when exit() is called or when main() returns.
+/* Registers 'hook_cb' to be called from inside poll_block() following a fatal
+ * signal. 'hook_cb' does not need to be async-signal-safe. In a
+ * multithreaded program 'hook_cb' might be called from any thread, with
+ * threads other than the one running 'hook_cb' in unknown states.
*
- * 'hook_cb' is not called immediately from the signal handler but rather the
- * next time the poll loop iterates, so it is freed from the usual restrictions
- * on signal handler functions.
+ * If 'run_at_exit' is true, 'hook_cb' is also called during normal process
+ * termination, e.g. when exit() is called or when main() returns.
*
* If the current process forks, fatal_signal_fork() may be called to clear the
* parent process's fatal signal hooks, so that 'hook_cb' is only called when
{
fatal_signal_init();
+ ovs_mutex_lock(&mutex);
ovs_assert(n_hooks < MAX_HOOKS);
hooks[n_hooks].hook_cb = hook_cb;
hooks[n_hooks].cancel_cb = cancel_cb;
hooks[n_hooks].aux = aux;
hooks[n_hooks].run_at_exit = run_at_exit;
n_hooks++;
+ ovs_mutex_unlock(&mutex);
}
/* Handles fatal signal number 'sig_nr'.
void
fatal_signal_handler(int sig_nr)
{
+#ifndef _WIN32
ignore(write(signal_fds[1], "", 1));
+#else
+ SetEvent(wevent);
+#endif
stored_sig_nr = sig_nr;
}
if (sig_nr != SIG_ATOMIC_MAX) {
char namebuf[SIGNAL_NAME_BUFSIZE];
+ ovs_mutex_lock(&mutex);
+
+#ifndef _WIN32
VLOG_WARN("terminating with signal %d (%s)",
(int)sig_nr, signal_name(sig_nr, namebuf, sizeof namebuf));
+#else
+ VLOG_WARN("terminating with signal %d", (int)sig_nr);
+#endif
call_hooks(sig_nr);
/* Re-raise the signal with the default handling so that the program
* termination status reflects that we were killed by this signal */
signal(sig_nr, SIG_DFL);
raise(sig_nr);
+
+ ovs_mutex_unlock(&mutex);
+ OVS_NOT_REACHED();
}
}
fatal_signal_wait(void)
{
fatal_signal_init();
- poll_fd_wait(signal_fds[0], POLLIN);
+ poll_fd_wait_event(signal_fds[0], wevent, POLLIN);
+}
+
+void
+fatal_ignore_sigpipe(void)
+{
+#ifndef _WIN32
+ signal(SIGPIPE, SIG_IGN);
+#endif
}
static void
}
}
}
+
+#ifdef _WIN32
+BOOL WINAPI ConsoleHandlerRoutine(DWORD dwCtrlType)
+{
+ stored_sig_nr = SIGINT;
+ SetEvent(wevent);
+ return true;
+}
+#endif
\f
/* Files to delete on exit. */
static struct sset files = SSET_INITIALIZER(&files);
void
fatal_signal_add_file_to_unlink(const char *file)
{
+ fatal_signal_init();
+
+ ovs_mutex_lock(&mutex);
if (!added_hook) {
added_hook = true;
fatal_signal_add_hook(unlink_files, cancel_files, NULL, true);
}
sset_add(&files, file);
+ ovs_mutex_unlock(&mutex);
}
/* Unregisters 'file' from being unlinked when the program terminates via
void
fatal_signal_remove_file_to_unlink(const char *file)
{
+ fatal_signal_init();
+
+ ovs_mutex_lock(&mutex);
sset_find_and_delete(&files, file);
+ ovs_mutex_unlock(&mutex);
}
/* Like fatal_signal_remove_file_to_unlink(), but also unlinks 'file'.
int
fatal_signal_unlink_file_now(const char *file)
{
- int error = unlink(file) ? errno : 0;
+ int error;
+
+ fatal_signal_init();
+
+ ovs_mutex_lock(&mutex);
+
+ error = unlink(file) ? errno : 0;
if (error) {
- VLOG_WARN("could not unlink \"%s\" (%s)", file, strerror(error));
+ VLOG_WARN("could not unlink \"%s\" (%s)", file, ovs_strerror(error));
}
fatal_signal_remove_file_to_unlink(file);
+ ovs_mutex_unlock(&mutex);
+
return error;
}
{
size_t i;
+ assert_single_threaded();
+
for (i = 0; i < n_hooks; i++) {
struct hook *h = &hooks[i];
if (h->cancel_cb) {
git://git.onelab.eu / sliver-openvswitch.git / blobdiff