/*
* Copyright (c) 2008, 2009 Nicira Networks.
*
- * 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 <config.h>
/* Time at which to die with SIGALRM (if not TIME_MIN). */
static time_t deadline = TIME_MIN;
+static void set_up_timer(void);
+static void set_up_signal(int flags);
static void sigalrm_handler(int);
static void refresh_if_ticked(void);
static time_t time_add(time_t, time_t);
static void unblock_sigalrm(const sigset_t *);
static void log_poll_interval(long long int last_wakeup,
const struct rusage *last_rusage);
-static long long int timeval_to_msec(const struct timeval *);
/* Initializes the timetracking module. */
void
time_init(void)
{
- struct sigaction sa;
- struct itimerval itimer;
-
if (inited) {
return;
}
+ coverage_init();
+
inited = true;
gettimeofday(&now, NULL);
tick = false;
- /* Set up signal handler. */
+ set_up_signal(SA_RESTART);
+ set_up_timer();
+}
+
+static void
+set_up_signal(int flags)
+{
+ struct sigaction sa;
+
memset(&sa, 0, sizeof sa);
sa.sa_handler = sigalrm_handler;
sigemptyset(&sa.sa_mask);
- sa.sa_flags = SA_RESTART;
+ sa.sa_flags = flags;
if (sigaction(SIGALRM, &sa, NULL)) {
ovs_fatal(errno, "sigaction(SIGALRM) failed");
}
+}
+
+/* Remove SA_RESTART from the flags for SIGALRM, so that any system call that
+ * is interrupted by the periodic timer interrupt will return EINTR instead of
+ * continuing after the signal handler returns.
+ *
+ * time_disable_restart() and time_enable_restart() may be usefully wrapped
+ * around function calls that might otherwise block forever unless interrupted
+ * by a signal, e.g.:
+ *
+ * time_disable_restart();
+ * fcntl(fd, F_SETLKW, &lock);
+ * time_enable_restart();
+ */
+void
+time_disable_restart(void)
+{
+ set_up_signal(0);
+}
+
+/* Add SA_RESTART to the flags for SIGALRM, so that any system call that
+ * is interrupted by the periodic timer interrupt will continue after the
+ * signal handler returns instead of returning EINTR. */
+void
+time_enable_restart(void)
+{
+ set_up_signal(SA_RESTART);
+}
+
+static void
+set_up_timer(void)
+{
+ struct itimerval itimer;
- /* Set up periodic timer. */
itimer.it_interval.tv_sec = 0;
itimer.it_interval.tv_usec = TIME_UPDATE_INTERVAL * 1000;
itimer.it_value = itimer.it_interval;
}
}
+/* Set up the interval timer, to ensure that time advances even without calling
+ * time_refresh().
+ *
+ * A child created with fork() does not inherit the parent's interval timer, so
+ * this function needs to be called from the child after fork(). */
+void
+time_postfork(void)
+{
+ set_up_timer();
+}
+
/* Forces a refresh of the current time from the kernel. It is not usually
* necessary to call this function, since the time will be refreshed
* automatically at least every TIME_UPDATE_INTERVAL milliseconds. */
}
}
-static long long int
+long long int
timeval_to_msec(const struct timeval *tv)
{
return (long long int) tv->tv_sec * 1000 + tv->tv_usec / 1000;
rusage.ru_nvcsw - last_rusage->ru_nvcsw,
rusage.ru_nivcsw - last_rusage->ru_nivcsw);
}
- coverage_log(VLL_WARN);
+
+ /* Care should be taken in the value chosen for logging. Depending
+ * on the configuration, syslog can write changes synchronously,
+ * which can cause the coverage messages to take longer to log
+ * than the processing delay that triggered it. */
+ coverage_log(VLL_INFO, true);
}
/* Update exponentially weighted moving average. With these parameters, a
git://git.onelab.eu / sliver-openvswitch.git / blobdiff