fix dist transpile with memopt (#12974)

* fix dist transpile with memopt

* update api.spec

* polish dist transpile api

* update apispec

* update apispec

paddle/fluid/API.spec

@@ -55,9 +55,10 @@ paddle.fluid.Inferencer.__init__ ArgSpec(args=['self', 'infer_func', 'param_path
 paddle.fluid.Inferencer.infer ArgSpec(args=['self', 'inputs', 'return_numpy'], varargs=None, keywords=None, defaults=(True,))
 paddle.fluid.DistributeTranspiler.__init__ ArgSpec(args=['self', 'config'], varargs=None, keywords=None, defaults=(None,))
 paddle.fluid.DistributeTranspiler.get_pserver_program ArgSpec(args=['self', 'endpoint'], varargs=None, keywords=None, defaults=None)
-paddle.fluid.DistributeTranspiler.get_startup_program ArgSpec(args=['self', 'endpoint', 'pserver_program', 'startup_program'], varargs=None, keywords=None, defaults=(None,))
+paddle.fluid.DistributeTranspiler.get_pserver_programs ArgSpec(args=['self', 'endpoint'], varargs=None, keywords=None, defaults=None)
+paddle.fluid.DistributeTranspiler.get_startup_program ArgSpec(args=['self', 'endpoint', 'pserver_program', 'startup_program'], varargs=None, keywords=None, defaults=(None, None))
 paddle.fluid.DistributeTranspiler.get_trainer_program ArgSpec(args=['self'], varargs=None, keywords=None, defaults=None)
-paddle.fluid.DistributeTranspiler.transpile ArgSpec(args=['self', 'trainer_id', 'program', 'pservers', 'trainers', 'sync_mode'], varargs=None, keywords=None, defaults=(None, '127.0.0.1:6174', 1, True))
+paddle.fluid.DistributeTranspiler.transpile ArgSpec(args=['self', 'trainer_id', 'program', 'pservers', 'trainers', 'sync_mode', 'startup_program'], varargs=None, keywords=None, defaults=(None, '127.0.0.1:6174', 1, True, None))
 paddle.fluid.InferenceTranspiler.__init__ 
 paddle.fluid.InferenceTranspiler.transpile ArgSpec(args=['self', 'program', 'place', 'scope'], varargs=None, keywords=None, defaults=(None,))
 paddle.fluid.memory_optimize ArgSpec(args=['input_program', 'skip_opt_set', 'print_log', 'level'], varargs=None, keywords=None, defaults=(None, False, 0))
@@ -329,9 +330,10 @@ paddle.fluid.contrib.BeamSearchDecoder.update_array ArgSpec(args=['self', 'array
 paddle.fluid.contrib.memory_usage ArgSpec(args=['program', 'batch_size'], varargs=None, keywords=None, defaults=None)
 paddle.fluid.transpiler.DistributeTranspiler.__init__ ArgSpec(args=['self', 'config'], varargs=None, keywords=None, defaults=(None,))
 paddle.fluid.transpiler.DistributeTranspiler.get_pserver_program ArgSpec(args=['self', 'endpoint'], varargs=None, keywords=None, defaults=None)
-paddle.fluid.transpiler.DistributeTranspiler.get_startup_program ArgSpec(args=['self', 'endpoint', 'pserver_program', 'startup_program'], varargs=None, keywords=None, defaults=(None,))
+paddle.fluid.transpiler.DistributeTranspiler.get_pserver_programs ArgSpec(args=['self', 'endpoint'], varargs=None, keywords=None, defaults=None)
+paddle.fluid.transpiler.DistributeTranspiler.get_startup_program ArgSpec(args=['self', 'endpoint', 'pserver_program', 'startup_program'], varargs=None, keywords=None, defaults=(None, None))
 paddle.fluid.transpiler.DistributeTranspiler.get_trainer_program ArgSpec(args=['self'], varargs=None, keywords=None, defaults=None)
-paddle.fluid.transpiler.DistributeTranspiler.transpile ArgSpec(args=['self', 'trainer_id', 'program', 'pservers', 'trainers', 'sync_mode'], varargs=None, keywords=None, defaults=(None, '127.0.0.1:6174', 1, True))
+paddle.fluid.transpiler.DistributeTranspiler.transpile ArgSpec(args=['self', 'trainer_id', 'program', 'pservers', 'trainers', 'sync_mode', 'startup_program'], varargs=None, keywords=None, defaults=(None, '127.0.0.1:6174', 1, True, None))
 paddle.fluid.transpiler.InferenceTranspiler.__init__ 
 paddle.fluid.transpiler.InferenceTranspiler.transpile ArgSpec(args=['self', 'program', 'place', 'scope'], varargs=None, keywords=None, defaults=(None,))
 paddle.fluid.transpiler.memory_optimize ArgSpec(args=['input_program', 'skip_opt_set', 'print_log', 'level'], varargs=None, keywords=None, defaults=(None, False, 0))

python/paddle/fluid/transpiler/distribute_transpiler.py

@@ -31,7 +31,7 @@ Steps to transpile pserver:
 """
 
 import math
-import random
+import sys
 import numpy as np
 import collections
 
@@ -181,7 +181,8 @@ class DistributeTranspiler(object):
                   program=None,
                   pservers="127.0.0.1:6174",
                   trainers=1,
-                  sync_mode=True):
+                  sync_mode=True,
+                  startup_program=None):
         """
         Run the transpiler.
 
@@ -194,13 +195,17 @@ class DistributeTranspiler(object):
                 list.
             trainers (int): number of trainers in the distributed job.
             sync_mode (bool): Do sync training or not, default is True.
+            startup_program (Program|None): startup_program to transpile,
+                default is fluid.default_main_program().
         """
         if program is None:
             program = default_main_program()
+        if startup_program is None:
+            startup_program = default_startup_program()
         self.origin_program = program
-        self.origin_startup_program = default_startup_program().clone()
+        self.startup_program = startup_program
+        self.origin_startup_program = self.startup_program.clone()
 
-        self.startup_program = default_startup_program()
         self.trainer_num = trainers
         self.sync_mode = sync_mode
         self.trainer_id = trainer_id
@@ -369,20 +374,17 @@ class DistributeTranspiler(object):
 
         return self.origin_program
 
-    def _get_trainer_startup_program(self,
-                                     recv_vars,
-                                     eplist,
-                                     startup_program=None):
+    def _get_trainer_startup_program(self, recv_vars, eplist):
         """
         Get transpiled trainer side startup program.
 
         Args:
-            startup_program(Program): Startup program.
+            recv_vars (list): Variable list to recv for current trainer_id
+            eplist (list): A list of strings indicating 
 
         Returns:
             Program: trainer side startup program.
         """
-        if startup_program is None:
         startup_program = self.startup_program
 
         # FIXME(gongwb): delete not need ops.
@@ -431,7 +433,18 @@ class DistributeTranspiler(object):
             #add concat ops to merge splited parameters received from parameter servers.
             if len(splited_var) <= 1:
                 continue
+            # NOTE: if enable memory optimization, origin vars maybe removed.
+            if startup_program.global_block().vars.has_key(varname):
                 orig_param = startup_program.global_block().vars[varname]
+            else:
+                origin_param_var = self.origin_program.global_block().vars[
+                    varname]
+                orig_param = startup_program.global_block().create_var(
+                    name=varname,
+                    persistable=origin_param_var.persistable,
+                    type=origin_param_var.type,
+                    dtype=origin_param_var.dtype,
+                    shape=origin_param_var.shape)
             startup_program.global_block().append_op(
                 type="concat",
                 inputs={"X": splited_var},
@@ -454,7 +467,9 @@ class DistributeTranspiler(object):
         # NOTE: assume blocks of the same variable is not distributed
         # on the same pserver, only change param/grad varnames for
         # trainers to fetch.
-
+        sys.stderr.write("get_pserver_program() is deprecated, call\
+            get_pserver_programs() to get pserver main and startup\
+            in a single call.")
         # step1
         pserver_program = Program()
         pserver_program.random_seed = self.origin_program.random_seed
@@ -638,32 +653,58 @@ class DistributeTranspiler(object):
             attrs=attrs)
 
         pserver_program._sync_with_cpp()
+        # save pserver program to generate pserver side startup relatively.
+        self.pserver_program = pserver_program
         return pserver_program
 
+    def get_pserver_programs(self, endpoint):
+        """
+        Get pserver side main program and startup program for distributed training.
+
+        Args:
+            endpoint (str): current pserver endpoint.
+        
+        Returns:
+            tuple: (main_program, startup_program), of type "Program"
+        """
+        pserver_prog = self.get_pserver_program(endpoint)
+        pserver_startup = self.get_startup_program(endpoint)
+        return pserver_prog, pserver_startup
+
     def get_startup_program(self,
                             endpoint,
-                            pserver_program,
+                            pserver_program=None,
                             startup_program=None):
         """
+        **Deprecated**
+
         Get startup program for current parameter server.
         Modify operator input variables if there are variables that
         were split to several blocks.
 
         Args:
             endpoint (str): current pserver endpoint.
-            pserver_program (Program): call get_pserver_program first and
-                pass the result here.
-            startup_program (Program): if pass None, will use
-                default_startup_program
+            pserver_program (Program): deprecated, call get_pserver_program first.
+            startup_program (Program): deprecated, should pass startup_program
+                when initalizing 
 
         Returns:
             Program: parameter server side startup program.
         """
+        sys.stderr.write("get_startup_program() is deprecated, call\
+            get_pserver_programs() to get pserver main and startup\
+            in a single call.")
+        if pserver_program != None:
+            sys.stderr.write("passing pserver_program to get_startup_program()\
+                is deprecated, you can use new API get_pserver_programs() to\
+                get both pserver main program and startup program.")
+        if startup_program != None:
+            sys.stderr.write("passing startup_program to get_startup_program()\
+                is deprecated, use fluid.program_guard() or pass this argument\
+                to transpile() call.")
+
         s_prog = Program()
-        if not startup_program:
-            orig_s_prog = default_startup_program()
-        else:
-            orig_s_prog = startup_program
+        orig_s_prog = self.startup_program
         s_prog.random_seed = orig_s_prog.random_seed
         params = self.param_grad_ep_mapping[endpoint]["params"]