X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=lib%2Ftimeval.c;h=8097ce806b413f21e429ebbca4fcef01555c6a94;hb=2953097759d3baaf22223b876d0028be8df78d3d;hp=88a6679eab039f97676bb44710dc211cb0e51f75;hpb=959ec62e324d88e47930379d3f0d196119595de9;p=openvswitch

diff --git a/lib/timeval.c b/lib/timeval.c
index 88a6679e..8097ce80 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.
@@ -20,13 +20,16 @@
 #include <errno.h>
 #include <poll.h>
 #include <signal.h>
+#include <stdlib.h>
 #include <string.h>
 #include <sys/time.h>
 #include <sys/resource.h>
 #include <unistd.h>
 #include "coverage.h"
+#include "dummy.h"
 #include "fatal-signal.h"
 #include "signals.h"
+#include "unixctl.h"
 #include "util.h"
 #include "vlog.h"
 
@@ -48,6 +51,12 @@ static volatile sig_atomic_t monotonic_tick = true;
 static struct timespec wall_time;
 static struct timespec monotonic_time;
 
+/* The monotonic time at which the time module was initialized. */
+static long long int boot_time;
+
+/* Fixed monotonic time offset, for use by unit tests. */
+static struct timespec warp_offset;
+
 /* Time at which to die with SIGALRM (if not TIME_MIN). */
 static time_t deadline = TIME_MIN;
 
@@ -62,11 +71,10 @@ static void unblock_sigalrm(const sigset_t *);
 static void log_poll_interval(long long int last_wakeup);
 static struct rusage *get_recent_rusage(void);
 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)
 {
@@ -87,6 +95,7 @@ time_init(void)
 
     set_up_signal(SA_RESTART);
     set_up_timer();
+    boot_time = time_msec();
 }
 
 static void
@@ -180,6 +189,7 @@ refresh_monotonic(void)
         refresh_wall_if_ticked();
         monotonic_time = wall_time;
     }
+    timespec_add(&monotonic_time, &monotonic_time, &warp_offset);
 
     monotonic_tick = false;
 }
@@ -268,17 +278,22 @@ time_alarm(unsigned int secs)
 }
 
 /* Like poll(), except:
+ *
+ *      - The timeout is specified as an absolute time, as defined by
+ *        time_msec(), instead of a duration.
  *
  *      - On error, returns a negative error code (instead of setting errno).
  *
  *      - If interrupted by a signal, retries automatically until the original
- *        'timeout' expires.  (Because of this property, this function will
+ *        timeout is reached.  (Because of this property, this function will
  *        never return -EINTR.)
  *
  *      - As a side effect, refreshes the current time (like time_refresh()).
- */
+ *
+ * Stores the number of milliseconds elapsed during poll in '*elapsed'. */
 int
-time_poll(struct pollfd *pollfds, int n_pollfds, int timeout)
+time_poll(struct pollfd *pollfds, int n_pollfds, long long int timeout_when,
+          int *elapsed)
 {
     static long long int last_wakeup;
     long long int start;
@@ -292,12 +307,15 @@ time_poll(struct pollfd *pollfds, int n_pollfds, int timeout)
     start = time_msec();
     blocked = false;
     for (;;) {
+        long long int now = time_msec();
         int time_left;
-        if (timeout > 0) {
-            long long int elapsed = time_msec() - start;
-            time_left = timeout >= elapsed ? timeout - elapsed : 0;
+
+        if (now >= timeout_when) {
+            time_left = 0;
+        } else if ((unsigned long long int) timeout_when - now > INT_MAX) {
+            time_left = INT_MAX;
         } else {
-            time_left = timeout;
+            time_left = timeout_when - now;
         }
 
         retval = poll(pollfds, n_pollfds, time_left);
@@ -319,6 +337,7 @@ time_poll(struct pollfd *pollfds, int n_pollfds, int timeout)
     }
     last_wakeup = time_msec();
     refresh_rusage();
+    *elapsed = last_wakeup - start;
     return retval;
 }
 
@@ -384,6 +403,15 @@ 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)
 {
@@ -398,6 +426,23 @@ timeval_diff_msec(const struct timeval *a, const struct timeval *b)
     return timeval_to_msec(a) - timeval_to_msec(b);
 }
 
+static void
+timespec_add(struct timespec *sum,
+             const struct timespec *a,
+             const struct timespec *b)
+{
+    struct timespec tmp;
+
+    tmp.tv_sec = a->tv_sec + b->tv_sec;
+    tmp.tv_nsec = a->tv_nsec + b->tv_nsec;
+    if (tmp.tv_nsec >= 1000 * 1000 * 1000) {
+        tmp.tv_nsec -= 1000 * 1000 * 1000;
+        tmp.tv_sec++;
+    }
+
+    *sum = tmp;
+}
+
 static void
 log_poll_interval(long long int last_wakeup)
 {
@@ -513,3 +558,31 @@ get_cpu_usage(void)
 {
     return cpu_usage;
 }
+
+/* Unixctl interface. */
+
+static void
+timeval_warp_cb(struct unixctl_conn *conn,
+                int argc OVS_UNUSED, const char *argv[], void *aux OVS_UNUSED)
+{
+    struct timespec ts;
+    int msecs;
+
+    msecs = atoi(argv[1]);
+    if (msecs <= 0) {
+        unixctl_command_reply(conn, 501, "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");
+}
+
+void
+timeval_dummy_register(void)
+{
+    unixctl_command_register("time/warp", "MSECS", 1, 1,
+                             timeval_warp_cb, NULL);
+}