X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=lib%2Ftimeval.h;h=1384848a1cec8f9b19087ce3c83413dd64e651a9;hb=1e3f34c7693bcabae8e443ac1b246680ef9b60e2;hp=e57f7ac7b83aa6147eb8343dd6b0ab3ef61fb4eb;hpb=cee03df4f53a9629f1f18b6c9948362f55a3ae27;p=sliver-openvswitch.git

diff --git a/lib/timeval.h b/lib/timeval.h
index e57f7ac7b..1384848a1 100644
--- a/lib/timeval.h
+++ b/lib/timeval.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2009, 2010, 2011 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.
@@ -36,6 +36,21 @@ BUILD_ASSERT_DECL(TYPE_IS_INTEGER(time_t));
  * ever encounter such a platform. */
 BUILD_ASSERT_DECL(TYPE_IS_SIGNED(time_t));
 
+/* On x86-64 systems, Linux avoids using syscalls for clock_gettime().
+ *
+ * For systems which do invoke a system call we wait at least
+ * TIME_UPDATE_INTERVAL ms between clock_gettime() calls and cache the time for
+ * the interim.
+ *
+ * For systems which do not invoke a system call, we just call clock_gettime()
+ * whenever the time is requested.  As a result we don't start the background
+ * SIGALRM timer unless explicitly needed by time_alarm() */
+#if defined __x86_64__ && defined __linux__
+#define CACHE_TIME 0
+#else
+#define CACHE_TIME 1
+#endif
+
 #define TIME_MAX TYPE_MAXIMUM(time_t)
 #define TIME_MIN TYPE_MINIMUM(time_t)
 
@@ -65,6 +80,8 @@ void xgettimeofday(struct timeval *);
 
 int get_cpu_usage(void);
 
+long long int time_boot_msec(void);
+
 #ifdef  __cplusplus
 }
 #endif