add api in distribute transpiler

python/paddle/fluid/transpiler/distribute_transpiler.py

@@ -315,10 +315,21 @@ class DistributeTranspiler:
                 "sync_mode": self.sync_mode
             })
 
+        serial_var = program.global_block().create_var(
+            name="SERIAL_NUMBER",
+            persistable=True,
+            type=core.VarDesc.VarType.RAW)
+
+        save_vars = []
+        for var in self.origin_program.list_vars():
+            if self.is_persistable(var):
+                save_vars.append(var.name)
+
         program.global_block().append_op(
             type="checkpoint_save",
-            inputs={"X": send_outputs},
-            attrs={"overwrite": True,
+            inputs={"X": save_vars},
+            outputs={"Serial": serial_var},
+            attrs={"overwrite": False,
                    "dir": "/workspace/ckpt/"})
 
         # step4: Concat the parameters splits together after recv.
@@ -501,6 +512,27 @@ class DistributeTranspiler:
         pserver_program.sync_with_cpp()
         return pserver_program
 
+    def is_persistable(self, var):
+        if var.desc.type() == core.VarDesc.VarType.FEED_MINIBATCH or \
+                var.desc.type() == core.VarDesc.VarType.FETCH_LIST or \
+                var.desc.type() == core.VarDesc.VarType.RAW :
+            return False
+        return var.persistable
+
+    def get_train_startup_program(self, checkpoint_load_dir=None):
+        startup_prog = default_startup_program()
+
+        if not checkpoint_load_dir:
+            return startup_prog
+
+        for var in startup_prog.list_vars():
+            if self.is_persistable(var):
+                print("var: %s" % var.name)
+
+        startup_prog.global_block().append_op(
+            type="checkpoint_load", attrs={"dir": checkpoint_load_dir})
+        return startup_prog
+
     def get_startup_program(self, endpoint, pserver_program):
         """
         Get startup program for current parameter server.