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# TVM RPC Server
This folder contains a simple recipe to make RPC server in c++.

## Usage (Non-Windows)
- Configure the tvm cmake build with `config.cmake` ensuring that `USE_CPP_RPC` is set to `ON` in the config.
- If cross compiling for Android, add the following options to the cmake config or specify them when invoking cmake:
```
  # Whether to build the C++ RPC server binary
  set(USE_CPP_RPC ON)
  # Path to the Android NDK cmake toolchain
  set(CMAKE_TOOLCHAIN_FILE $ENV{ANDROID_NDK}/build/cmake/android.toolchain.cmake)
  # The Android ABI and platform to target
  set(ANDROID_ABI "arm64-v8a")
  set(ANDROID_PLATFORM android-28)
  ```
- Similarly, if cross compiling for embedded Linux add the following options to cmake config:
```
  # Needed to ensure pthread is linked
  set(OS Linux)
  # Path to the desired C++ cross compiler
  set(CMAKE_CXX_COMPILER /path/to/cross/compiler/executable)
```
- If linking against a custom device OpenCL library is needed, in the config specify the path to the OpenCL SDK containing the include/CL headers and lib/ or lib64/libOpenCL.so:
```
  set(USE_OPENCL /path/to/opencl-sdk)
```

- From within the configured tvm build directory, compile `tvm_runtime` and the `tvm_rpc` server:
```
  cd $TVM_ROOT/build
  make -jN tvm_runtime tvm_rpc
```
- Use `./tvm_rpc server` to start the RPC server

## Usage (Windows)
- Configure the tvm cmake build with `config.cmake` ensuring that `USE_CPP_RPC` is set to `ON` in the config.
- Install [LLVM pre-build binaries](https://releases.llvm.org/download.html), making sure to select the option to add it to the PATH.
- Verify Python 3.6 or newer is installed and in the PATH.
- Use `<tvm_output_dir>\tvm_rpc.exe` to start the RPC server

## How it works
- The tvm runtime dll is linked along with this executable and when the RPC server starts it will load the tvm runtime library.

```
Command line usage
 server       - Start the server
--host        - The hostname of the server, Default=0.0.0.0
--port        - The port of the RPC, Default=9090
--port-end    - The end search port of the RPC, Default=9199
--tracker     - The RPC tracker address in host:port format e.g. 10.1.1.2:9190 Default=""
--key         - The key used to identify the device type in tracker. Default=""
--custom-addr - Custom IP Address to Report to RPC Tracker. Default=""
--silent      - Whether to run in silent mode. Default=False
  Example
  ./tvm_rpc server --host=0.0.0.0 --port=9000 --port-end=9090 --tracker=127.0.0.1:9190 --key=rasp
```

## Note
Currently support is only there for Linux / Android / Windows environment and proxy mode isn't supported currently.