/*
- * Copyright (c) 2008, 2009 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010 Nicira Networks.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
/* Time at which to die with SIGALRM (if not TIME_MIN). */
static time_t deadline = TIME_MIN;
-static void setup_timer(void);
+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;
if (inited) {
return;
}
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");
}
+}
- /* Set up periodic signal. */
- setup_timer();
+/* 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
-setup_timer(void)
+set_up_timer(void)
{
struct itimerval itimer;
void
time_postfork(void)
{
- setup_timer();
+ set_up_timer();
}
/* Forces a refresh of the current time from the kernel. It is not usually
}
}
-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;
struct rusage rusage;
getrusage(RUSAGE_SELF, &rusage);
- VLOG_WARN("%u ms poll interval (%lld ms user, %lld ms system) "
+ VLOG_WARN("%lld ms poll interval (%lld ms user, %lld ms system) "
"is over %u times the weighted mean interval %u ms "
"(%u samples)",
- (interval + 8) / 16,
+ now - last_wakeup,
timeval_diff_msec(&rusage.ru_utime, &last_rusage->ru_utime),
timeval_diff_msec(&rusage.ru_stime, &last_rusage->ru_stime),
interval / mean_interval,