add monotonic time func for py2 (https://stackoverflow.com/a/1205762)

ilyam8 · ilyam8 · commit 88a027efd94d · 2018-06-01T14:24:19.000+09:00
diff --git a/python.d/python_modules/bases/monotonic.py b/python.d/python_modules/bases/monotonic.py
@@ -0,0 +1,29 @@
+# thx to https://stackoverflow.com/a/1205762
+import ctypes
+# import os
+
+CLOCK_MONOTONIC_RAW = 4  # see <linux/time.h>
+
+
+class _Timespec(ctypes.Structure):
+    _fields_ = [
+        ('tv_sec', ctypes.c_long),
+        ('tv_nsec', ctypes.c_long)
+    ]
+
+
+_librt = ctypes.CDLL('librt.so.1', use_errno=True)
+_clock_gettime = _librt.clock_gettime
+_clock_gettime.argtypes = [ctypes.c_int, ctypes.POINTER(_Timespec)]
+
+
+def time():
+    t = _Timespec()
+    if _clock_gettime(CLOCK_MONOTONIC_RAW, ctypes.pointer(t)) != 0:
+        # errno_ = ctypes.get_errno()
+        # raise OSError(errno_, os.strerror(errno_))
+        return None
+    return t.tv_sec + t.tv_nsec * 1e-9
+
+
+AVAILABLE = bool(time())
