* update config

* re-blacken python code

* temporarily disable date and diff_py_file

* skip a format

* [CodeStyle] remove all future import

* revert test_error.py

* restore future import in example code

* add simple reformated ci files

* update

* add radme for new unitetsts

* add radme for new unitetsts

* add radme for new unitetsts

* reset mlu

* update for samples

* add base api

* reset some dist unit tests

* add warning in grenerated cmakelists file

* update readme for new dist unit tests

* add all collective tests

* remain base file and launcher file

* Update README.md

* Update README.md

* fix env PYTHONPATH

* Update gen_ut_cmakelists.py

* add all collective tests

* add docs for gen_ut_cmakelists.py

* pretify codes

* commont name == "name"

* update for comments

* update function's help

* update for run type

* update readme

* add all collective tests

* add all collective tests

* mv  collective test files

* update for all collective tests

* update

* update

* update

* update for all tests

* update for checking name

* Update Cmakelists.txt

* update testlist.csv

* remain test_parallel_dygraph_dataparallel in unittests

* set broadcast op all platforms

* update

* remain test_broadcast_tensors_op

* fix

* rm some collective files

* update more colective tests

* update

* update

* update
gen_ut_supports recursion

* update

* update

* update

* update

* fix nccl version

* update

* update

* update

* update

* fix a bug and try to pass

* update

* add csv

* update for timeout

* remove tcp store

* fix

* fix

* update

* update

* update for more dist tests

* move multi node tests

* update

* update

* update

* fix for auto parallele

* update

* update path in python file

* update

* reset some test in unittests

* fix

* update readme

* fix

* update

* fix port

* use yapf to format all python file

* yapf exclude two unittests file for they rely on writing and reading file, and format will break them

* disable diff_py_file because too many diff files cause command following failed

* fix find_unused_parameters default value

* support control flow

* supoort sync_parameters_buffers

* fix the bug of sparse embedding

paddle.distributed.fleet supports dynamic graph execution.

* add dygraph parallel run interface

* polish implement & unified env property name

* add print config arg

* refactor init_parallel_env function

* Compatible with multiprocessing and launch modes

* set default trainer start port

* support run in python 2

* polish python2 support code

* remove python2 support

* refine launch import

* polish dome design details

* refactor api implemention & path

* use new method _set_expected_place

* add spawn unittest framework & mnist test

* add more unittests & doc

* fix unittest failed

* polish english doc

* self review and polish details

* refactor code by reviewer's comments

* fix unittest failed

* fix parallel_env unittest

* fix several typos

* fix error introduced when fixing typos

* add unpublic note for start_processes

* polish details by xiaoguang's comment

* verify correctly when spawn nprocs=-1

* refactor spawn & init_parallel_env design

* polish doc details

* open spawn unittests

* try to fix doc compile error

* try to fix unknown doc format error

* add skip unittest when not gpu

* update parallel.py
test=develop

* add print log for unittest of distributed training
test=develop

* add var grad hook test=develop

implement dygraph.parallel.DataParallel to hook reduce op.

* fix compile issue with_distribute test=develop

* simplified logic test=develop

* use ngraph dependency test=develop

* set cpu only test=develop

* update test and eliminate fp16 test test=develop

test=develop

Currently, our tests run with 2 GPUs, the init time is absurdly long:
about 4s for each process.  Currently, we run each OP test on
different processes. This PR:

1. create cmake function py_test_modules which will generate the
Makefile that runs a list of Python unittest module in a single Python
process.

2. move all "python unittest compatible" (e.g., used the unittest
package, not just a regular python file). from fluid/tests to
fluid/tests/unittests.

3. cmake now will run all OP tests in fluid/tests/unittests in a
single process, except the time-consuming tests, they are separated
into different processes to utilize parallelism. Please make sure to
use the unittest package if you put the python test file in
fluid/tests/unittests

4. remove all exit(0) from fluid/tests/unittests/*.py, exit(0) is used
to disable unittest, we can not do it when running all tests in a
single process since it will terminate the process without running the
other tests. Instead, the test is disabled in
fluid/tests/unittests/CMakeLists.txt. FIXME is added for each disabled
item. Please disable the unittest from
fluid/tests/unittests/CMakeLists.txt, instead of adding exit(0) to the
Python file, for all Python file in fluid/tests/unittests/.

5. add an option WITH_FAST_BUNDLE_TEST. When OFF, will run the unit
tests in separate process so that they can be tested individually.

* "fix decode bug"

* "follow commnet"

* "fix error"

* "fix hook bug"

* fix based comment

* fix copyright

* fix based on comment

* add copyright hook

* add copyright hook

* refine copyright hook

* "test copyright hook"

* fix check style

* fix ci

* init commit

* change some dir name