[coro_rdma][coro_ucx][feat] add rdmapp ucxpp libraries, examples and tests

[howardlau1999]

Why

Preliminary support of RDMA transport

What is changing

• Add rdmapp for coroutine adaptation for ibverbs
• Add a minimal example integrating RDMA communication with asio

Example

See src/coro_rdma/examples/example.cpp

[CLAassistant]

All committers have signed the CLA.

[helintongh]

不使用ucx的原因能阐述一下吗？谢谢

[howardlau1999]

不使用ucx的原因能阐述一下吗？谢谢

UCX 我也打算支持，因为 RDMA 的接口和 Socket 接口有很大不同，目前是打算先调通 RDMA 相关功能的流程，后面可以对 RDMA 相关的抽象增加 UCX 支持

[howardlau1999]

不使用ucx的原因能阐述一下吗？谢谢

已添加 UCX 相关实现，不过似乎无法在 softroce 环境下测试，在物理真实 roce 硬件下测试可以跑通

[qicosmos]

demo pseudocode code to show rpc with rdma:

struct rdma_service_t {
  pingpong_context ctx;
  pingpong_dest get_pingpong_test(pingpong_dest from_peer) {
    ELOG_INFO << "remote gid: " << from_peer.gid
              << ", remote qp_num: " << from_peer.qpn;

    pingpong_dest dest{};
    dest.lid = ctx.lid;
    dest.qpn = ctx.qp->qp_num;
    dest.psn = g_psn++;
    memcpy(dest.gid, ctx.str_gid, 33);

    modify_qp_to_rts(ctx.qp, from_peer);
    return dest;
  }
};

struct pingpong_dest {
  int lid;
  int qpn;
  int psn;
  char gid[33];
};

int main() {
  coro_rpc_server server(/*thread=*/std::thread::hardware_concurrency(),
                         /*port=*/8801);

  auto ctx = create_rdma_ctx();
  rdma_service_t rdma_srv{ctx};
  server.register_handler<&rdma_service_t::get_pingpong_test>(&rdma_srv);
  server.start();
}

//client
Lazy<void> show_rpc_call() {
  auto ctx = create_rdma_ctx();

  coro_rpc_client client;

  [[maybe_unused]] auto ec = co_await client.connect("127.0.0.1", "8801");
  assert(!ec);

  pingpong_dest dest{};
  dest.lid = ctx.lid;
  dest.qpn = ctx.qp->qp_num;
  dest.psn = ++g_psn;
  memcpy(dest.gid, ctx.str_gid, 33);

  auto ret1 = co_await client.call<&rdma_service_t::get_pingpong_test>(dest);
  auto peer = ret1.value();
  modify_qp_to_rts(ctx.qp, peer);
}