sess.run分布式脚本迁移

具体方法为，在变量初始化之后，训练之前，通过集合通信接口broadcast进行变量广播。

from npu_bridge.npu_init import *

def broadcast_global_variables(root_rank, index):
"""Broadcasts all global variables from root rank to all other processes.
Arguments:
root_rank: rank of the process from which global variables will be broadcasted
to all other processes. 
index: rank_id
"""
op_list = []
for var in tf.global_variables():
# the input and out tensor of HCOMBroadcast interface are list
if "float" in var.dtype.name:
inputs = [var]
outputs=hccl_ops.broadcast(tensor=inputs,root_rank=root_rank)
if outputs is not None:
op_list.append(outputs[0].op)
op_list.append(tf.assign(var, outputs[0]))

return tf.group(op_list)

...
bcast_op = broadcast_global_variables(root_rank, index)
sess = tf.Session()
...
sess.run(bcast_op)