update docs (#2523)

doc/fluid/api_cn/distributed_cn/all_gather_cn.rst

@@ -22,14 +22,15 @@ all_gather
 :::::::::
 .. code-block:: python
 
+        import numpy as np
         import paddle
-        import paddle.prepare_context as prepare_context
+        from paddle.distributed import init_parallel_env
 
         paddle.disable_static()
-        paddle.set_device('gpu:%d'%paddle.ParallelEnv().dev_id)
-        prepare_context()
+        paddle.set_device('gpu:%d'%paddle.distributed.ParallelEnv().dev_id)
+        init_parallel_env()
         tensor_list = []
-        if paddle.ParallelEnv().local_rank == 0:
+        if paddle.distributed.ParallelEnv().local_rank == 0:
             np_data1 = np.array([[4, 5, 6], [4, 5, 6]])
             np_data2 = np.array([[4, 5, 6], [4, 5, 6]])
             data1 = paddle.to_tensor(np_data1)
@@ -40,4 +41,4 @@ all_gather
             np_data2 = np.array([[1, 2, 3], [1, 2, 3]])
             data1 = paddle.to_tensor(np_data1)
             data2 = paddle.to_tensor(np_data2)
-            out = paddle.distributed.all_gather(tensor_list, data2)
+            paddle.distributed.all_gather(tensor_list, data2)

doc/fluid/api_cn/distributed_cn/all_reduce_cn.rst

@@ -22,17 +22,19 @@ all_reduce
 :::::::::
 .. code-block:: python
 
+        import numpy as np
         import paddle
         from paddle.distributed import ReduceOp
-        import paddle.prepare_context as prepare_context
+        from paddle.distributed import init_parallel_env
 
         paddle.disable_static()
-        paddle.set_device('gpu:%d'%paddle.ParallelEnv().dev_id)
-        prepare_context()
-        if paddle.ParallelEnv().local_rank == 0:
+        paddle.set_device('gpu:%d'%paddle.distributed.ParallelEnv().dev_id)
+        init_parallel_env()
+        if paddle.distributed.ParallelEnv().local_rank == 0:
             np_data = np.array([[4, 5, 6], [4, 5, 6]])
         else:
             np_data = np.array([[1, 2, 3], [1, 2, 3]])
         data = paddle.to_tensor(np_data)
         paddle.distributed.all_reduce(data)
         out = data.numpy()
+        # [[5, 7, 9], [5, 7, 9]]

doc/fluid/api_cn/distributed_cn/barrier_cn.rst

@@ -21,9 +21,9 @@ barrier
 .. code-block:: python
 
         import paddle
-        import paddle.prepare_context as prepare_context
+        from paddle.distributed import init_parallel_env
 
         paddle.disable_static()
-        paddle.set_device('gpu:%d'%paddle.ParallelEnv().dev_id)
-        prepare_context()
+        paddle.set_device('gpu:%d'%paddle.distributed.ParallelEnv().dev_id)
+        init_parallel_env()
         paddle.distributed.barrier()

doc/fluid/api_cn/distributed_cn/broadcast_cn.rst

@@ -22,13 +22,14 @@ broadcast
 :::::::::
 .. code-block:: python
 
+        import numpy as np
         import paddle
-        import paddle.prepare_context as prepare_context
+        from paddle.distributed import init_parallel_env
 
         paddle.disable_static()
-        paddle.set_device('gpu:%d'%paddle.ParallelEnv().dev_id)
-        prepare_context()
-        if paddle.ParallelEnv().local_rank == 0:
+        paddle.set_device('gpu:%d'%paddle.distributed.ParallelEnv().dev_id)
+        init_parallel_env()
+        if paddle.distributed.ParallelEnv().local_rank == 0:
             np_data = np.array([[4, 5, 6], [4, 5, 6]])
         else:
             np_data = np.array([[1, 2, 3], [1, 2, 3]])

doc/fluid/api_cn/distributed_cn/reduce_cn.rst

@@ -23,13 +23,14 @@ reduce
 :::::::::
 .. code-block:: python
 
+        import numpy as np
         import paddle
-        import paddle.prepare_context as prepare_context
+        from paddle.distributed import init_parallel_env
 
         paddle.disable_static()
-        paddle.set_device('gpu:%d'%paddle.ParallelEnv().dev_id)
-        prepare_context()
-        if paddle.ParallelEnv().local_rank == 0:
+        paddle.set_device('gpu:%d'%paddle.distributed.ParallelEnv().dev_id)
+        init_parallel_env()
+        if paddle.distributed.ParallelEnv().local_rank == 0:
             np_data = np.array([[4, 5, 6], [4, 5, 6]])
         else:
             np_data = np.array([[1, 2, 3], [1, 2, 3]])

doc/fluid/api_cn/distributed_cn/scatter_cn.rst

@@ -23,13 +23,14 @@ scatter
 :::::::::
 .. code-block:: python
 
+        import numpy as np
         import paddle
-        import paddle.prepare_context as prepare_context
+        from paddle.distributed import init_parallel_env
 
         paddle.disable_static()
-        paddle.set_device('gpu:%d'%paddle.ParallelEnv().dev_id)
-        prepare_context()
-        if paddle.ParallelEnv().local_rank == 0:
+        paddle.set_device('gpu:%d'%paddle.distributed.ParallelEnv().dev_id)
+        init_parallel_env()
+        if paddle.distributed.ParallelEnv().local_rank == 0:
             np_data1 = np.array([7, 8, 9])
             np_data2 = np.array([10, 11, 12])
         else:
@@ -37,7 +38,7 @@ scatter
             np_data2 = np.array([4, 5, 6])
         data1 = paddle.to_tensor(np_data1)
         data2 = paddle.to_tensor(np_data2)
-        if paddle.ParallelEnv().local_rank == 0:
+        if paddle.distributed.ParallelEnv().local_rank == 0:
             paddle.distributed.scatter(data1, src=1)
         else:
             paddle.distributed.scatter(data1, tensor_list=[data1, data2], src=1)