Need some basic help! about asio-grpc HOT 9 CLOSED

Hi, thanks for your detailed report. I personally do not use conan but I have a little project where I smoketest asio-grpc with conan. Using default setting with MSVC it builds static libraries for me, for you it seems like you have selected shared libraries (at least for protobuf) and now tries to link with both libprotobuf-lite and regular libprotobuf. I tried to reproduce that without luck.

Here is the conanfile.txt that I used for the reproduction:

[requires]
asio-grpc/2.9.2

[generators]
CMakeDeps
CMakeToolchain

[layout]
cmake_layout

[options]
protobuf/*:shared=True

After running the conan install command, I do

cmake --build --preset conan-release

from asio-grpc.

Thank you so much @Tradias for your quick response!
Further, I moved to CMake instead, and still face a last bit of problems as stated below in getting my feet wet on this package:

I followed the below instructions of the README.md, and it was successful in installing the library.
Though I do not understand the significance of "lib" folder inside the install directory is filled with many cmake files. Maybe that got anything to with my problem, not sure...

In stage 2, where I wanted to integrate the library to my target. Here is the snippet of CMakeLists.txt that builds my target linking asio-grpc:

set (CMAKE_PREFIX_PATH C:/Users/Downloads/asio-grpc/install)
find_package(asio-grpc)

## ...

add_executable(WT    hello-world-server.cpp ${HEADERS}  ${SOURCES} )

##...


# Specify include directories if your project has header files in multiple directories.
target_include_directories(WT 
    PRIVATE
     #asio-grpc
    ${CMAKE_PREFIX_PATH}/include
    ${CMAKE_SOURCE_DIR}/helper
  
    #... 
)

target_link_libraries(WT 
        PUBLIC  
       
        asio-grpc::asio-grpc
        Boost::headers

        #..
)
 

After configuring my CMakeLists.txt, when I build it, I get the below error:

C:\thavi\CPP_WS\asio-grpc-experiment\helper\awaitable_server_rpc.hpp(24,41): error C2039: 'use_awaitable_t': is not a member of 'boost::asio' [C:\TH
ARMA\CPP_WS\asio-grpc-experiment\build64\WT.vcxproj]
C:/thavi/vcpkg/installed/x64-windows/include\boost/asio/ssl/stream.hpp(39,11): message : see declaration of 'boost::asio' [C:\thavi\CPP_WS\mt5\manager\mt5_ib_to 
olstandalone\build64\WT.vcxproj]
C:\thavi\CPP_WS\asio-grpc-experiment\helper\awaitable_server_rpc.hpp(24): error C2061: syntax error: identifier 'use_awaitable_t' [C:\thavi\CPP_WS\ 
asio-grpc-experiment\build64\WT.vcxproj]
C:\thavi\CPP_WS\asio-grpc-experiment\helper\awaitable_server_rpc.hpp(24,60): error C2039: 'as_default_on_t': is not a member of '`global namespace'' 
 [C:\thavi\CPP_WS\asio-grpc-experiment\build64\WT.vcxproj]
C:\thavi\CPP_WS\asio-grpc-experiment\hello-world-server.cpp(16,1): fatal  error C1083: Cannot open include file: 'helloworld/helloworld.grpc.pb.h':  
No such file or directory [C:\thavi\CPP_WS\asio-grpc-experiment\build64\WT.vcxproj]

Primarily the issue is about missing "use_awaitable_t"... not clear if my verion of Boost::asio (1.75) is missing it perhaps?
Maybe you can take a look at my environment (snapshot below):

Other general question:
Since it is a header-only library, why do we need to link "asio-grpc::asio-grpc". Sorry for the basic question.

Thanks for your help in advance!

Thanks,
Tharma

from asio-grpc.

In the long run I highly recommend using a package manager. At work and personally I use vcpkg.

I assume in your CMake you forgot to add:

target_compile_features(WT PRIVATE cxx_std_20)

Specifying a target in target_link_libraries is CMake's magic way of propagating any kind of build requirements to your target. This includes: libraries to link, directories to include, pre-processor definitions, compile features/flags, .... In the case of asio-grpc that would be linking with gRPC::grpc++, enabling compile feature cxx_std_17 and adding pre-processor definition AGRPC_BOOST_ASIO. In general it is a good idea to specify all direct dependencies in a target_link_libraries call, regardless of whether they are header-only or compiled.

Also at some point you will have to generate source code from .proto files. You can do so using asio-grpc's helper function:

asio_grpc_protobuf_generate(
    GENERATE_GRPC
    TARGET WT
    OUT_DIR "${CMAKE_CURRENT_BINARY_DIR}/generated"
    IMPORT_DIRS "${CMAKE_CURRENT_SOURCE_DIR}/proto"
    PROTOS "${CMAKE_CURRENT_SOURCE_DIR}/proto/helloworld/helloworld.proto")

from asio-grpc.

Thank you so much! I had a valuable learning experience with this cmake function, target_compile_features. Additionally, I proceeded with "vcpkg" as you suggested, and I must say, I found it to be incredibly user-friendly.

Regarding the linking errors, you were absolutely correct! When I replaced cxx_std_17 with cxx_std_20 in the code below, the issues were resolved:

target_compile_features(WT PRIVATE cxx_std_20)

With that, I could "configure" (cmake . -B ./build) without any error.
But when I "build" ( cmake --build ./build --config Release or cmake --build ./build --config Debug ),
I face just these two errors (details below):

C:/Users/thavi/Downloads/asio-grpc/install/include\agrpc/detail/register_awaitable_rpc_handler.hpp(58,15): error C2672: 'co_spawn': 
no matching overloaded function found

C:\thavi\build\generated\helloworld\helloworld.pb.cc(43,80): error C2127: 'helloworld::_HelloReply 
_default_instance_': illegal initialization of 'constinit' entity with a non-constant expression

I was wondering if you could provide guidance on this as well? Thanks for your help, in advance.

Thanks,
Tharma

from asio-grpc.

Here is a complete minimal gRPC helloworld example: https://github.com/Tradias/example-vcpkg-grpc/tree/asio-grpc-97

The register_awaitable_rpc_handler.hpp error seems to be a Boost 1.75 specific thing where asio forgot to add type traits for executor_with_default of asio::use_awaitable_t and misdetects MSVC's decltype capabilities. Nothing I can do on my side but if you use the example above that won't be an issue (because it will use Boost 1.83).

The protobuf error is this one protocolbuffers/protobuf#8688 and was fixed in a later protobuf release. Again, none issue if you use my example.

from asio-grpc.

@Tradias :

The minimal gRPC "helloworld" example worked seamlessly! Interestingly, while examining that example, I gained insights into certain concepts related to both CMake and VCPKG as well :) I truly appreciate your guidance throughout this process. BTW, I've successfully upgraded my Boost version to the latest release (1.84.0).

However, upon attempting to integrate the success into my production application, I encountered the following linking error:

It has been quite perplexing, and I've spent a significant amount of time troubleshooting since yesterday. I understand that I've already taken your valuable time, so if you have a chance to provide any insight or guidance into this error, I'd be grateful. Otherwise, no worries; I sincerely appreciate all the assistance you've provided thus far. You are the best!

grpc_unsecure.lib(bdp_estimator.cc.obj) : error LNK2001: unresolved external symbol __imp_rand [C:\thavi\experiment\asio-grpc-prod\build64\src\WT...] 

Here is the complete list of .obj files that have linking problem due to missing the exact sample symbol:

grpc_unsecure.lib(bdp_estimator.cc.obj) 
grpc_unsecure.lib(stream_map.cc.obj) 
grpc_unsecure.lib(server.cc.obj 
grpc_unsecure.lib(dns_resolver_ares.cc.obj) 
grpc_unsecure.lib(channel_idle_filter.cc.obj) 
grpc_unsecure.lib(round_robin.cc.obj) 
grpc_unsecure.lib(flow_control.cc.obj)

Thanks,
Tharma

from asio-grpc.

@Tradias : Sorry to bother you. This issue has become a roadblock for me. I tried on another project too, but I ran into exactly the same issue. I looked at your [Documentation] (https://tradias.github.io/asio-grpc/md_doc_v3_migration.html) and I tried like this, but with no luck:

set(ASIO_GRPC_DISABLE_AUTOLINK on)
find_package(asio-grpc)
find_package(gRPC)
 
target_link_libraries(your_app PUBLIC asio-grpc::asio-grpc gRPC::grpc++_unsecure)

I am unable to proceed and got stuck for almost 2 days! Any quick help will be really appreciated.

Thanks,
Tharma

from asio-grpc.

It very much sounds like a gRPC issue, I don't think I am the right person to help here. I suspect it has something to do with the flags you used when compiling gRPC, maybe a mix of /MD and /MT. You could try the following, but I doubt it will help:

set(ASIO_GRPC_DISABLE_AUTOLINK on)
find_package(asio-grpc)
find_package(gRPC)
 
target_link_libraries(your_app PUBLIC asio-grpc::asio-grpc gRPC::grpc++)

from asio-grpc.

Sure, thank you, @Tradias. I will dig further into this.

Thanks,
Tharma

from asio-grpc.