Make Channel API accept buffer structs rather than raw pointers. (#45014)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/45014
Pull Request resolved: https://github.com/pytorch/tensorpipe/pull/219
Pull Request resolved: https://github.com/pytorch/tensorpipe/pull/212
+ Introduce buffer.h defining the buffer struct(s). The `CpuBuffer`
struct is always defined, while the `CudaBuffer` struct is defined
only when `TENSORPIPE_SUPPORTS_CUDA` is true.
+ Update all channels to take a `CpuBuffer` or `CudaBuffer` for
`send`/`recv` rather than a raw pointer and a length.
+ Make the base `Channel`/`Context` classes templated on `TBuffer`,
effectively creating two channel hierarchies (one for CPU channels,
one for CUDA channels).
+ Update the Pipe and the generic channel tests to use the new API. So
far, generic channel tests are CPU only, and tests for the CUDA IPC
channel are (temporarily) disabled. A subsequent PR will take care of
refactoring tests so that generic tests work for CUDA channels. An
other PR will add support for CUDA tensors in the Pipe.
Differential Revision: D23598033
Test Plan: Imported from OSS
Reviewed By: lw
Pulled By: beauby
fbshipit-source-id: 1d6c3f91e288420858835cd5e7962e8da051b44b
