* AsyncExecutor: C++ side

* Google naming conventions

* Rename MultiExecutor to AsyncExecutor

* pybind with async_executor

* Naming convention

* remove some flags and unused code

* add refactored file of async_executor and data_feed

* clear async executor interface and add data feed factory

* split async executor into executor_thread_worker and async_executor, refactor pybind, add datafeed and corresponding proto

* Fix async_executor interfaces: 1) Remove all protobufs; 2) Stop after each epoch

* refine async_executor_refactor.cc

* add some files about datafeed

* Revert "add some files about datafeed"

This reverts commit 8ee8133a.

* Interface rework

* add MultiSlotDataFeed

* Creating DataFeedDesc from .proto file, then manipulate it (add/del fields etc) from python side

* update data_feed for add MultiSlotDataFeed

* update datafeed and async_executor to run bow_net demo

* fix bug that finish_set_filelist failed in multithread

* delete finish_binding_memory_(flag), because it can not be marked under the current interface

* Fix bug

* update async_executor.py for support set_use_slots

* update async_executor.py for support set_use_slots and set set_dense_slots

* fix bug that when the number of files is less than the number of threads, it will fetch nan

* remove redundant code, and make executor exit when set a illegal queue size

* add batch_size check

* add MultiSlotDesc

* Revert "add MultiSlotDesc"

This reverts commit 2e72ebfa.

* add some checkpoint in DataFeedDesc

* add CheckFile function in MultiSlotDataFeed

* update something error info

* fix deaded lock bug

* Fix fetch variable

* Merge error

* fix code style in async_executor

* using one lock blocking queue replace two lock blocking queue because of some bugs

* update code style

* add utest for data_feed

* Fix fetch var

* update utest for data_feed for multithread

* update SetFileList info

* fix bug in utest of data_feed

* Add comments for python

* Add comments for python code

* Fix pybind.cc with new pybind11 version

* add note for DataFeedDesc's set_use_slots function

* Add save_model

* update data_feed_test for multi-type

* add comment for executor_thread_worker

* Remove unused code

* update data_feed_test for generate test data file

* removed unnecessary interfaces and add comments

* c++ style check

* update data_feed.cc

* AsyncExecutor: C++ side

Google naming conventions

Rename MultiExecutor to AsyncExecutor

pybind with async_executor

Naming convention

remove some flags and unused code

add refactored file of async_executor and data_feed

clear async executor interface and add data feed factory

split async executor into executor_thread_worker and async_executor, refactor pybind, add datafeed and corresponding proto

Fix async_executor interfaces: 1) Remove all protobufs; 2) Stop after each epoch

refine async_executor_refactor.cc

add some files about datafeed

Revert "add some files about datafeed"

This reverts commit 8ee8133a.

add MultiSlotDataFeed

Interface rework

Creating DataFeedDesc from .proto file, then manipulate it (add/del fields etc) from python side

update datafeed and async_executor to run bow_net demo

update async_executor.py for support set_use_slots

Fix bug

update async_executor.py for support set_use_slots and set set_dense_slots

fix bug that when the number of files is less than the number of threads, it will fetch nan

remove redundant code, and make executor exit when set a illegal queue size

add MultiSlotDesc

Revert "add MultiSlotDesc"

This reverts commit 2e72ebfa.

add some checkpoint in DataFeedDesc

Fix fetch variable

fix code style in async_executor

Fix fetch var

add utest for data_feed

Add comments for python

update utest for data_feed for multithread

fix bug in utest of data_feed

Add comments for python code

Fix pybind.cc with new pybind11 version

add note for DataFeedDesc's set_use_slots function

update data_feed_test for multi-type

Add save_model

update data_feed_test for generate test data file

removed unnecessary interfaces and add comments

add comment for executor_thread_worker

Remove unused code

update data_feed.cc

c++ style check

* commit for code style

* commit for code style

* commit for code style

* commit for code style

* Comment away __init__ in async_executor.py

* clang-format fix test=develop

* use PADDLE_THROW instead of exit(-1); use unique_ptr to manage scope var in data_feed_test.cc

* commit for update code style

* commit for update code style

* Add async_executor demo; Remove some methods
test=develop

* commit for update code style

* commit for update code style

* commit for update code style

* update API.spec

* AsyncExecutor
test=develop

* AsyncExecutor
test=develop

* AsyncExecutor
test=develop

* AsyncExecutor
test=develop

* Fix API.spec
test=develop

* Fix API.spec
test=develop

* Fix windows build error
test=develop

* FIx windows build error
test=develop

* FIx windows build error
test=develop

* FIx windows build error
test=develop

* Fix Windows Build
test=develop

* Fix Windows Build
test=develop

* Fix Windows Build
test=develop

* Fix code style
test=develop

* Fix code style
test=develop

* update datafeed

* Fix code style
test=develop

* update data_feed_test for test Tensor test=develop

* Fix code style
test=develop

* Fix windows build failure
test=develop

* Fix code style and windows build failure
test=develop

* Fix PYTHON3.5 build failure
test=develop

* AsyncExecutor API
test=develop

* wip

* use executor.complete to end trainer

* fix build

* fix build with distribute off

* fix typo

* fix cmake typo

* fix build

* listen_and_serv use localscope

* fix ut

Add an argument in Executor.Run to allow users to choose whether to create and destroy variables every time. (#9242)

optimize executor.run

* initial commit

* add new executor run function

* fix bug

* fix multiple definition of feed_fetch_method issue

* fix cmake

* fix tensor copy error

* refine executor code

* add comments

* temporary modification

* address comments

* fix bug

* test dist word2vec

* multiple trainers work

* create tensor in recv op

* static global function to global function

* "change operator interface"

* "move devicepool to device_context"

* "fix operator test"

* "fix op_registry Run interface"

* "net op passed. Need to fix nccl multi-Context"

* "add nccl group function"

* "add nccl group function"

* "fix gpu count exceed 32 error"

* "fix recurrent op, nccl op"

* "change the other operators interface with Place"

* "fix typo"

* "fix pybind"

* "fix device in python side"

* "fix pybind failed"

* "add init for test"

* "fix CI"

* "remove GPU Sync Interface"

* "fix typo"

* "fix type cast error"

* "fix related Copy with stream"

* "fix failed tests with DevicePool"

* "fix stupid removed position error"

* Rename XXDescBind --> XXDesc

* Fix Compile

* "add DeviceContextPool"

* "add devicecontextpool in pybind"

* "add comments in python side "

* "fix static link error"

* "fix CI error"

* "add executor.py"

* "fix CI error"

* "add with gpu macro"

* "remove comment out codes"

* "add TODO items"

* "update init devices"