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 switch kernel https://github.com/PaddlePaddle/Paddle/blob/develop/doc/design/switch_kernel.md

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