From: @luoyang42
Reviewed-by: 
Signed-off-by:

fix sampler

From: @ezphlow
Reviewed-by: @robingrosman,@nsyca,@robingrosman
Signed-off-by: @robingrosman

Added validator checks

Added builtin sampler check

Added proper input check for samplers

From: @hfarahat
Reviewed-by: @robingrosman,@nsyca
Signed-off-by: @robingrosman

From: @luoyang42
Reviewed-by: @liucunwei
Signed-off-by: @liucunwei

From: @ms_yan
Reviewed-by: @lilongfei15
Signed-off-by:

From: @hfarahat
Reviewed-by: 
Signed-off-by:

DistributedSampler with GeneratorOp bug
Issue#2:
GeneratorOp with iterable source doesn't respect num_samples
Issue#3:
Generator with schemas does not take samplers

From: @tina_mengting_zhang
Reviewed-by: 
Signed-off-by:

From: @jonyguo
Reviewed-by: @pandoublefeng,@liucunwei
Signed-off-by: @pandoublefeng

From: @lixiachen
Reviewed-by: 
Signed-off-by:

add hostpush part modify

optimize previous code

provide aclhandle access method

modify CMakeList format

add device_id parameter into TransferNode

update copyright

add examples to CacheClient docstring

From: @ming__blue
Reviewed-by: 
Signed-off-by:

fix rebase confict

add operator profiling part

add op_id param when create task

repair bugs in op cpu sampling

fix wrong order of write and parse cpu_info

add process cpu profiling part

add multiprocessing part(part 1)

adapter cpu_sampling c layer

fix little error in sampling

descrease cirle complex in voc

descrease cirle complex in device_que

From: @tiancixiao
Reviewed-by: @liucunwei,@heleiwang
Signed-off-by: @liucunwei

From: @hfarahat
Reviewed-by: 
Signed-off-by:

From: @heleiwang
Reviewed-by: @liucunwei
Signed-off-by: @liucunwei

From: @luoyang42
Reviewed-by: 
Signed-off-by:

1. description of num_shard in datasets.py
2. add param validation for sampler
3. add description for add_child in sampler.py

From: @hfarahat
Reviewed-by: 
Signed-off-by:

From: @alexyuyue
Reviewed-by: 
Signed-off-by:

Signed-off-by: alex-yuyue <yue.yu1@huawei.com>

From: @tiancixiao
Reviewed-by: @liucunwei,@heleiwang
Signed-off-by: @liucunwei

From: @tina_mengting_zhang
Reviewed-by: 
Signed-off-by:

From: @ezphlow
Reviewed-by: 
Signed-off-by: