X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=lib%2Ftimeval.c;h=d3b6685e00bb4d8b5f3b375a2f39079fc70c757a;hb=b10a4760be32849e33a2b85084491b7ab058efcd;hp=9829100303dbad775e4dceba18e1c96418ff650a;hpb=c563de0e389f42164d4f7bf76845dced4590a18c;p=openvswitch

diff --git a/lib/timeval.c b/lib/timeval.c
index 98291003..d3b6685e 100644
--- a/lib/timeval.c
+++ b/lib/timeval.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2009, 2010, 2011, 2012 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010, 2011, 2012 Nicira, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -40,7 +40,7 @@ VLOG_DEFINE_THIS_MODULE(timeval);
  * to CLOCK_REALTIME. */
 static clockid_t monotonic_clock;
 
-/* Has a timer tick occurred?
+/* Has a timer tick occurred? Only relevant if CACHE_TIME is true.
  *
  * We initialize these to true to force time_init() to get called on the first
  * call to time_msec() or another function that queries the current time. */
@@ -58,15 +58,14 @@ static long long int boot_time;
 static struct timespec warp_offset; /* Offset added to monotonic_time. */
 static bool time_stopped;           /* Disables real-time updates, if true. */
 
-/* Time at which to die with SIGALRM (if not TIME_MIN). */
-static time_t deadline = TIME_MIN;
+/* Time in milliseconds at which to die with SIGALRM (if not LLONG_MAX). */
+static long long int deadline = LLONG_MAX;
 
 static void set_up_timer(void);
 static void set_up_signal(int flags);
 static void sigalrm_handler(int);
 static void refresh_wall_if_ticked(void);
 static void refresh_monotonic_if_ticked(void);
-static time_t time_add(time_t, time_t);
 static void block_sigalrm(sigset_t *);
 static void unblock_sigalrm(const sigset_t *);
 static void log_poll_interval(long long int last_wakeup);
@@ -96,6 +95,7 @@ time_init(void)
 
     set_up_signal(SA_RESTART);
     set_up_timer();
+
     boot_time = time_msec();
 }
 
@@ -146,6 +146,10 @@ set_up_timer(void)
     static timer_t timer_id;    /* "static" to avoid apparent memory leak. */
     struct itimerspec itimer;
 
+    if (!CACHE_TIME) {
+        return;
+    }
+
     if (timer_create(monotonic_clock, NULL, &timer_id)) {
         VLOG_FATAL("timer_create failed (%s)", strerror(errno));
     }
@@ -199,7 +203,9 @@ refresh_monotonic(void)
 
 /* 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. */
+ * automatically at least every TIME_UPDATE_INTERVAL milliseconds.  If
+ * CACHE_TIME is false, we will always refresh the current time so this
+ * function has no effect. */
 void
 time_refresh(void)
 {
@@ -214,17 +220,6 @@ time_now(void)
     return monotonic_time.tv_sec;
 }
 
-/* Same as time_now() except does not write to static variables, for use in
- * signal handlers.  */
-static time_t
-time_now_sig(void)
-{
-    struct timespec cur_time;
-
-    clock_gettime(monotonic_clock, &cur_time);
-    return cur_time.tv_sec;
-}
-
 /* Returns the current time, in seconds. */
 time_t
 time_wall(void)
@@ -272,11 +267,19 @@ time_wall_timespec(struct timespec *ts)
 void
 time_alarm(unsigned int secs)
 {
+    long long int now;
+    long long int msecs;
+
     sigset_t oldsigs;
 
     time_init();
+    time_refresh();
+
+    now = time_msec();
+    msecs = secs * 1000;
+
     block_sigalrm(&oldsigs);
-    deadline = secs ? time_add(time_now(), secs) : TIME_MIN;
+    deadline = now < LLONG_MAX - msecs ? now + msecs : LLONG_MAX;
     unblock_sigalrm(&oldsigs);
 }
 
@@ -309,6 +312,9 @@ time_poll(struct pollfd *pollfds, int n_pollfds, long long int timeout_when,
     coverage_clear();
     start = time_msec();
     blocked = false;
+
+    timeout_when = MIN(timeout_when, deadline);
+
     for (;;) {
         long long int now = time_msec();
         int time_left;
@@ -325,12 +331,21 @@ time_poll(struct pollfd *pollfds, int n_pollfds, long long int timeout_when,
         if (retval < 0) {
             retval = -errno;
         }
+
         time_refresh();
+        if (deadline <= time_msec()) {
+            fatal_signal_handler(SIGALRM);
+            if (retval < 0) {
+                retval = 0;
+            }
+            break;
+        }
+
         if (retval != -EINTR) {
             break;
         }
 
-        if (!blocked && deadline == TIME_MIN) {
+        if (!blocked && !CACHE_TIME) {
             block_sigalrm(&oldsigs);
             blocked = true;
         }
@@ -344,29 +359,17 @@ time_poll(struct pollfd *pollfds, int n_pollfds, long long int timeout_when,
     return retval;
 }
 
-/* Returns the sum of 'a' and 'b', with saturation on overflow or underflow. */
-static time_t
-time_add(time_t a, time_t b)
-{
-    return (a >= 0
-            ? (b > TIME_MAX - a ? TIME_MAX : a + b)
-            : (b < TIME_MIN - a ? TIME_MIN : a + b));
-}
-
 static void
-sigalrm_handler(int sig_nr)
+sigalrm_handler(int sig_nr OVS_UNUSED)
 {
     wall_tick = true;
     monotonic_tick = true;
-    if (deadline != TIME_MIN && time_now_sig() > deadline) {
-        fatal_signal_handler(sig_nr);
-    }
 }
 
 static void
 refresh_wall_if_ticked(void)
 {
-    if (wall_tick) {
+    if (!CACHE_TIME || wall_tick) {
         refresh_wall();
     }
 }
@@ -374,7 +377,7 @@ refresh_wall_if_ticked(void)
 static void
 refresh_monotonic_if_ticked(void)
 {
-    if (monotonic_tick) {
+    if (!CACHE_TIME || monotonic_tick) {
         refresh_monotonic();
     }
 }
@@ -499,11 +502,7 @@ log_poll_interval(long long int last_wakeup)
                           rusage.ru_nivcsw - last_rusage->ru_nivcsw);
             }
         }
-        /* 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);
+        coverage_log();
     }
 
     /* Update exponentially weighted moving average.  With these parameters, a