X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=lib%2Ftimeval.c;h=3f12b501209f681f345e4108eb7b8fae53548925;hb=734ec5ec13499a2e7112626564cc9bd0c2d06600;hp=c8c02bdc425746648998d74df27a3677e466eae3;hpb=6197af6e4b9890f43380e0a0159886ba3275c75c;p=openvswitch

diff --git a/lib/timeval.c b/lib/timeval.c
index c8c02bdc..3f12b501 100644
--- a/lib/timeval.c
+++ b/lib/timeval.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2009, 2010, 2011 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010, 2011, 2012 Nicira Networks.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -51,8 +51,12 @@ static volatile sig_atomic_t monotonic_tick = true;
 static struct timespec wall_time;
 static struct timespec monotonic_time;
 
-/* Fixed monotonic time offset, for use by unit tests. */
-static struct timespec warp_offset;
+/* The monotonic time at which the time module was initialized. */
+static long long int boot_time;
+
+/* features for use by unit tests. */
+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;
@@ -71,10 +75,7 @@ static void refresh_rusage(void);
 static void timespec_add(struct timespec *sum,
                          const struct timespec *a, const struct timespec *b);
 
-/* Initializes the timetracking module.
- *
- * It is not necessary to call this function directly, because other time
- * functions will call it automatically, but it doesn't hurt. */
+/* Initializes the timetracking module, if not already initialized. */
 static void
 time_init(void)
 {
@@ -95,6 +96,7 @@ time_init(void)
 
     set_up_signal(SA_RESTART);
     set_up_timer();
+    boot_time = time_msec();
 }
 
 static void
@@ -182,15 +184,17 @@ refresh_monotonic(void)
 {
     time_init();
 
-    if (monotonic_clock == CLOCK_MONOTONIC) {
-        clock_gettime(monotonic_clock, &monotonic_time);
-    } else {
-        refresh_wall_if_ticked();
-        monotonic_time = wall_time;
-    }
-    timespec_add(&monotonic_time, &monotonic_time, &warp_offset);
+    if (!time_stopped) {
+        if (monotonic_clock == CLOCK_MONOTONIC) {
+            clock_gettime(monotonic_clock, &monotonic_time);
+        } else {
+            refresh_wall_if_ticked();
+            monotonic_time = wall_time;
+        }
+        timespec_add(&monotonic_time, &monotonic_time, &warp_offset);
 
-    monotonic_tick = false;
+        monotonic_tick = false;
+    }
 }
 
 /* Forces a refresh of the current time from the kernel.  It is not usually
@@ -402,6 +406,15 @@ timeval_to_msec(const struct timeval *tv)
     return (long long int) tv->tv_sec * 1000 + tv->tv_usec / 1000;
 }
 
+/* Returns the monotonic time at which the "time" module was initialized, in
+ * milliseconds(). */
+long long int
+time_boot_msec(void)
+{
+    time_init();
+    return boot_time;
+}
+
 void
 xgettimeofday(struct timeval *tv)
 {
@@ -551,6 +564,22 @@ get_cpu_usage(void)
 
 /* Unixctl interface. */
 
+/* "time/stop" stops the monotonic time returned by e.g. time_msec() from
+ * advancing, except due to later calls to "time/warp". */
+static void
+timeval_stop_cb(struct unixctl_conn *conn,
+                 int argc OVS_UNUSED, const char *argv[] OVS_UNUSED,
+                 void *aux OVS_UNUSED)
+{
+    time_stopped = true;
+    unixctl_command_reply(conn, NULL);
+}
+
+/* "time/warp MSECS" advances the current monotonic time by the specified
+ * number of milliseconds.  Unless "time/stop" has also been executed, the
+ * monotonic clock continues to tick forward at the normal rate afterward.
+ *
+ * Does not affect wall clock readings. */
 static void
 timeval_warp_cb(struct unixctl_conn *conn,
                 int argc OVS_UNUSED, const char *argv[], void *aux OVS_UNUSED)
@@ -560,19 +589,21 @@ timeval_warp_cb(struct unixctl_conn *conn,
 
     msecs = atoi(argv[1]);
     if (msecs <= 0) {
-        unixctl_command_reply(conn, 501, "invalid MSECS");
+        unixctl_command_reply_error(conn, "invalid MSECS");
         return;
     }
 
     ts.tv_sec = msecs / 1000;
     ts.tv_nsec = (msecs % 1000) * 1000 * 1000;
     timespec_add(&warp_offset, &warp_offset, &ts);
-    unixctl_command_reply(conn, 200, "warped");
+    timespec_add(&monotonic_time, &monotonic_time, &ts);
+    unixctl_command_reply(conn, "warped");
 }
 
 void
 timeval_dummy_register(void)
 {
+    unixctl_command_register("time/stop", "", 0, 0, timeval_stop_cb, NULL);
     unixctl_command_register("time/warp", "MSECS", 1, 1,
                              timeval_warp_cb, NULL);
 }