Timestamp: Add recent(), now_steady(), and recent_steady().

The steady() functions return the current time as measured by a steady clock: a monotonic clock that never moves backwards. We call the clock "steady" rather than "monotonic" or "up" because C++0x calls this clock the steady_clock, and that's a good name. The recent() functions return a cached copy of a recent now() or now_steady(). At userlevel at the moment, these functions actually just call now() or now_steady(). In the kernels, though, they will be faster than now() or now_steady(). Signed-off-by: Eddie Kohler <[email protected]>
tbarbette · Aug 23, 2011 · a96e410 · a96e410
1 parent fdd2b39
commit a96e410
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Showing 7 changed files with 280 additions and 93 deletions.
diff --git a/config-linuxmodule.h.in b/config-linuxmodule.h.in
@@ -52,6 +52,9 @@
 /* Define if your Linux kernel has devinet_ioctl. */
 #undef HAVE_LINUX_DEVINET_IOCTL
 
+/* Define if your Linux kernel exports get_monotonic_coarse. */
+#undef HAVE_LINUX_GET_MONOTONIC_COARSE
+
 /* Define if your Linux kernel has inet_ctl_sock_create. */
 #undef HAVE_LINUX_INET_CTL_SOCK_CREATE
 

diff --git a/configure b/configure
@@ -11317,6 +11317,22 @@ $as_echo "$ac_cv_linux_netdev_rx_handler_register" >&6; }
 
     fi
 
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for get_monotonic_coarse kernel symbol" >&5
+$as_echo_n "checking for get_monotonic_coarse kernel symbol... " >&6; }
+if ${ac_cv_linux_get_monotonic_coarse+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  if grep "__ksymtab_get_monotonic_coarse" $linux_system_map >/dev/null 2>&1; then
+        ac_cv_linux_get_monotonic_coarse=yes
+    else ac_cv_linux_get_monotonic_coarse=no; fi
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_linux_get_monotonic_coarse" >&5
+$as_echo "$ac_cv_linux_get_monotonic_coarse" >&6; }
+    if test $ac_cv_linux_get_monotonic_coarse = yes; then
+        $as_echo "#define HAVE_LINUX_GET_MONOTONIC_COARSE 1" >>confdefs.h
+
+    fi
+
     CC="$save_cc"
     CXX="$save_cxx"
     CPPFLAGS="$save_cppflags"

diff --git a/configure.in b/configure.in
@@ -1475,6 +1475,14 @@ void f1(int64_t) { // will fail if long long and int64_t are the same type
         AC_DEFINE(HAVE_LINUX_NETDEV_RX_HANDLER_REGISTER)
     fi
 
+    AC_CACHE_CHECK([for get_monotonic_coarse kernel symbol], [ac_cv_linux_get_monotonic_coarse],
+    [if grep "__ksymtab_get_monotonic_coarse" $linux_system_map >/dev/null 2>&1; then
+        ac_cv_linux_get_monotonic_coarse=yes
+    else ac_cv_linux_get_monotonic_coarse=no; fi])
+    if test $ac_cv_linux_get_monotonic_coarse = yes; then
+        AC_DEFINE(HAVE_LINUX_GET_MONOTONIC_COARSE)
+    fi
+
     CC="$save_cc"
     CXX="$save_cxx"
     CPPFLAGS="$save_cppflags"

diff --git a/include/click/timerset.hh b/include/click/timerset.hh
@@ -93,7 +93,7 @@ inline Timestamp
 TimerSet::next_timer_expiry_adjusted() const
 {
     Timestamp e = _timer_expiry;
-#if CLICK_USERLEVEL
+#if TIMESTAMP_WARPABLE
     if (likely(!Timestamp::warp_jumping())) {
 #endif
     if (_timer_stride >= 8 || e.sec() == 0)
@@ -102,7 +102,7 @@ TimerSet::next_timer_expiry_adjusted() const
 	e -= Timer::adjustment();
     else
 	e -= Timer::adjustment() + Timer::adjustment();
-#if CLICK_USERLEVEL
+#if TIMESTAMP_WARPABLE
     }
 #endif
     return e;