[BACKPORT] Fix random execute that a random tensor can have different…

… results when executed in different sessions (#178)

mars/_version.py

@@ -16,7 +16,7 @@
 import os
 import sys
 
-version_info = (0, 1, 0, 'b1')
+version_info = (0, 1, 0)
 _num_index = max(idx if isinstance(v, int) else 0
                  for idx, v in enumerate(version_info))
 __version__ = '.'.join(map(str, version_info[:_num_index + 1])) + \

mars/tensor/expressions/random/core.py

@@ -33,7 +33,6 @@
 class RandomState(object):
     def __init__(self, seed=None):
         self._random_state = np.random.RandomState(seed=seed)
-        self._curr_seed = seed
 
     def seed(self, seed=None):
         """
@@ -53,11 +52,10 @@ def seed(self, seed=None):
         RandomState
         """
         self._random_state.seed(seed=seed)
-        self._curr_seed = seed
 
     @property
     def _state(self):
-        return State(self._random_state) if self._curr_seed is not None else None
+        return State(self._random_state)
 
     @classmethod
     def _handle_size(cls, size):

mars/tests/test_session.py

@@ -183,3 +183,14 @@ def testArrayProtocol(self):
 
         result = np.asarray(arr4, dtype=np.float_)
         np.testing.assert_array_equal(result, np.asarray(200, dtype=np.float_))
+
+    def testRandomExecuteInSessions(self):
+        arr = mt.random.rand(20, 20)
+
+        sess1 = new_session()
+        res1 = sess1.run(arr)
+
+        sess2 = new_session()
+        res2 = sess2.run(arr)
+
+        np.testing.assert_array_equal(res1, res2)