Revert "example/python: avoid falling back to CLOCK_MONOTONIC"

This breaks client tests on avery old kernel (2.6.32, RHEL 6).

  Traceback (most recent call last):
    File "./clients/tests/test-client.py", line 699, in setUp
      self.srv = NMStubServer(self._testMethodName)
    File "./clients/tests/test-client.py", line 309, in __init__
      start = nmex.nm_boot_time_ns()
    File "/builddir/build/BUILD/NetworkManager-1.11.4/examples/python/nmex.py", line 54, in nm_boot_time_ns
      return sys_clock_gettime_ns(CLOCK_BOOTTIME)
    File "/builddir/build/BUILD/NetworkManager-1.11.4/examples/python/nmex.py", line 50, in sys_clock_gettime_ns
      return _sys_clock_gettime_ns(clock_id)
    File "/builddir/build/BUILD/NetworkManager-1.11.4/examples/python/nmex.py", line 39, in f
      raise OSError(errno_, os.strerror(errno_))
  OSError: [Errno 22] Invalid argument

This reverts commit 119e828dbeeeab134e83890b18d0b7a0c1838786.

1 files changed, 12 insertions, 2 deletions

diff --git a/examples/python/nmex.py b/examples/python/nmex.py
index 78489efeb3..a85eecaf87 100644
--- a/examples/python/nmex.py
+++ b/examples/python/nmex.py
@@ -50,8 +50,18 @@ def sys_clock_gettime_ns(clock_id):
     return _sys_clock_gettime_ns(clock_id)
 
 def nm_boot_time_ns():
-    CLOCK_BOOTTIME = 7
-    return sys_clock_gettime_ns(CLOCK_BOOTTIME)
+    # NetworkManager exposes some timestamps as CLOCK_BOOTTIME.
+    # Try that first (number 7).
+    try:
+        return sys_clock_gettime_ns(7)
+    except OSError as e:
+        # On systems, where this is not available, fallback to
+        # CLOCK_MONOTONIC (numeric 1).
+        # That is what NetworkManager does as well.
+        import errno
+        if e.errno == errno.EINVAL:
+            return sys_clock_gettime_ns(1)
+        raise
 def nm_boot_time_us():
     return nm_boot_time_ns() / 1000
 def nm_boot_time_ms():