[3/7] git commit: Added os::bootId.

[bm...@apache.org]

Added os::bootId.

This can be used to identify a reboot, should the boot id change.

For OS X and POSIX systems, the boot time in seconds from sysctl and
utmpx (respectively) are used as a good approximation for a unique
boot id.

Review: https://reviews.apache.org/r/16235


Project: http://git-wip-us.apache.org/repos/asf/mesos/repo
Commit: http://git-wip-us.apache.org/repos/asf/mesos/commit/8d485a68
Tree: http://git-wip-us.apache.org/repos/asf/mesos/tree/8d485a68
Diff: http://git-wip-us.apache.org/repos/asf/mesos/diff/8d485a68

Branch: refs/heads/master
Commit: 8d485a68550e593db3af9244fca876b91597d558
Parents: 83e1547
Author: Benjamin Mahler <bm...@twitter.com>
Authored: Tue Dec 17 14:57:07 2013 -0800
Committer: Benjamin Mahler <bm...@twitter.com>
Committed: Thu Dec 19 14:26:27 2013 -0800

----------------------------------------------------------------------
 .../3rdparty/stout/include/stout/os.hpp         | 22 +++++++++++++++++
 .../3rdparty/stout/tests/os_tests.cpp           | 26 ++++++++++++++++++++
 2 files changed, 48 insertions(+)
----------------------------------------------------------------------


http://git-wip-us.apache.org/repos/asf/mesos/blob/8d485a68/3rdparty/libprocess/3rdparty/stout/include/stout/os.hpp
----------------------------------------------------------------------
diff --git a/3rdparty/libprocess/3rdparty/stout/include/stout/os.hpp b/3rdparty/libprocess/3rdparty/stout/include/stout/os.hpp
index 2382d40..7c1f6ec 100644
--- a/3rdparty/libprocess/3rdparty/stout/include/stout/os.hpp
+++ b/3rdparty/libprocess/3rdparty/stout/include/stout/os.hpp
@@ -885,6 +885,28 @@ inline Try<Bytes> memory()
 }
 
 
+inline Try<std::string> bootId()
+{
+#ifdef __linux__
+  Try<std::string> read = os::read("/proc/sys/kernel/random/boot_id");
+  if (read.isError()) {
+    return read;
+  }
+  return strings::trim(read.get());
+#elif defined(__APPLE__)
+  // For OS X, we use the boot time in seconds as a unique boot id.
+  // Although imperfect, this works quite well in practice.
+  Try<timeval> bootTime = os::sysctl(CTL_KERN, KERN_BOOTTIME).time();
+  if (bootTime.isError()) {
+    return Error(bootTime.error());
+  }
+  return stringify(bootTime.get().tv_sec);
+#else
+  return Error("Not implemented");
+#endif
+}
+
+
 // The structure returned by uname describing the currently running system.
 struct UTSInfo
 {

http://git-wip-us.apache.org/repos/asf/mesos/blob/8d485a68/3rdparty/libprocess/3rdparty/stout/tests/os_tests.cpp
----------------------------------------------------------------------
diff --git a/3rdparty/libprocess/3rdparty/stout/tests/os_tests.cpp b/3rdparty/libprocess/3rdparty/stout/tests/os_tests.cpp
index 33c2ee1..c40c743 100644
--- a/3rdparty/libprocess/3rdparty/stout/tests/os_tests.cpp
+++ b/3rdparty/libprocess/3rdparty/stout/tests/os_tests.cpp
@@ -15,8 +15,10 @@
 #include <stout/foreach.hpp>
 #include <stout/gtest.hpp>
 #include <stout/hashset.hpp>
+#include <stout/numify.hpp>
 #include <stout/os.hpp>
 #include <stout/stopwatch.hpp>
+#include <stout/strings.hpp>
 #include <stout/try.hpp>
 #include <stout/uuid.hpp>
 
@@ -178,6 +180,30 @@ TEST_F(OsTest, find)
 }
 
 
+TEST_F(OsTest, bootId)
+{
+  Try<string> bootId = os::bootId();
+  ASSERT_SOME(bootId);
+  EXPECT_NE("", bootId.get());
+
+#ifdef __linux__
+  Try<string> read = os::read("/proc/sys/kernel/random/boot_id");
+  ASSERT_SOME(read);
+  EXPECT_EQ(bootId.get(), strings::trim(read.get()));
+#elif defined(__APPLE__)
+  // For OS X systems, the boot id is the system boot time in
+  // seconds, so assert it can be numified and is a reasonable value.
+  Try<uint64_t> numified = numify<uint64_t>(bootId.get());
+  ASSERT_SOME(numified);
+
+  timeval time;
+  gettimeofday(&time, NULL);
+  EXPECT_GT(Seconds(numified.get()), Seconds(0));
+  EXPECT_LT(Seconds(numified.get()), Seconds(time.tv_sec));
+#endif
+}
+
+
 TEST_F(OsTest, uname)
 {
   const Try<os::UTSInfo>& info = os::uname();