fluid design doc summary

Overview design:

https://github.com/PaddlePaddle/Paddle/blob/develop/doc/design/fluid.md

Compile time:

Program desc —> main data structures https://github.com/PaddlePaddle/Paddle/blob/develop/paddle/framework/framework.proto Program https://github.com/PaddlePaddle/Paddle/blob/develop/doc/design/program.md Block https://github.com/PaddlePaddle/Paddle/blob/develop/doc/design/block.md var_desc https://github.com/PaddlePaddle/Paddle/blob/develop/doc/design/var_desc.md op_desc https://github.com/PaddlePaddle/Paddle/blob/develop/paddle/framework/framework.proto#L33

Run time:

Tensor       https://github.com/PaddlePaddle/Paddle/blob/develop/paddle/framework/tensor.md Scope https://github.com/PaddlePaddle/Paddle/blob/develop/doc/design/scope.md Variable https://github.com/PaddlePaddle/Paddle/blob/develop/paddle/framework/variable.md Executor https://github.com/PaddlePaddle/Paddle/blob/develop/doc/design/executor.md Operator (to-be-added)

Other key modules

Backward 

https://github.com/PaddlePaddle/Paddle/blob/develop/doc/design/backward.md

Optimizer

https://github.com/PaddlePaddle/Paddle/blob/develop/doc/design/optimizer.md

Parallel design:

https://github.com/PaddlePaddle/Paddle/blob/develop/doc/design/concurrent_programming.md