Describe dummy test model. Work on OpenFlow intro.

[openvswitch] / lib / timeval.h

diff --git a/lib/timeval.h b/lib/timeval.h
index d9eb3c7a61be526f245f08821577514e08a2aa46..5a7b6e25c62aeabc09b3b1089913446a828a8576 100644 (file)
--- a/lib/timeval.h
+++ b/lib/timeval.h
@@ -25,6 +25,7 @@
 extern "C" {
 #endif
 
+struct ds;
 struct pollfd;
 struct timespec;
 struct timeval;
@@ -44,6 +45,24 @@ BUILD_ASSERT_DECL(TYPE_IS_SIGNED(time_t));
  * much time will be wasted in signal handlers and calls to clock_gettime(). */
 #define TIME_UPDATE_INTERVAL 100
 
+/* True on systems (particularly x86-64 Linux) where clock_gettime() is
+ * inexpensive.  On these systems, we don't bother caching the current time.
+ * Instead, we consult clock_gettime() directly when needed.
+ *
+ * False on systems where clock_gettime() is relatively expensive.  On these
+ * systems, we cache the current time and set up a periodic SIGALRM to remind
+ * us to update it.
+ *
+ * Also false on systems (e.g. ESX) that don't support setting up timers based
+ * on a monotonically increasing clock. */
+#ifndef CACHE_TIME
+#if defined ESX || (defined __x86_64__ && defined LINUX_DATAPATH)
+#define CACHE_TIME 0
+#else
+#define CACHE_TIME 1
+#endif
+#endif /* ifndef CACHE_TIME */
+
 void time_disable_restart(void);
 void time_enable_restart(void);
 void time_postfork(void);
@@ -65,6 +84,7 @@ long long int timeval_to_msec(const struct timeval *);
 void xgettimeofday(struct timeval *);
 
 int get_cpu_usage(void);
+void format_backtraces(struct ds *, size_t min_count);
 
 long long int time_boot_msec(void);