v2.8.0

Features

• Add agrpc::register_callback_rpc_handler for setting up request handling with agrpc::ServerRPCPtr, a dynamically allocated ServerRPC which can be used to implement non-coroutine based gRPC servers.
• Add experimental support for P2300R7 (std::execution) in the form of a new CMake target asio-grpc::asio-grpc-stdexec.
• Breaking change: Certain completion token like asio::experimental::use_promise might now return a different type due to the implementation of Asio's optional requirement on asynchronous operations: The operation's associated I/O executor may be exposed via the Initiation function object's executor_type type alias and get_executor() member function.

Fixes

• Removed all usage of pointer tagging. Although Asio uses it, it is technically undefined behavior.

Performance

• Use Asio's immediate_executor in ServerRPC::wait_for_done and Waiter::wait.

Documentation

• Use Asio's default completion token mechanism in examples.
• Avoid using asio::detached in examples since it swallows exceptions.
• Document how register_awaitable_rpc_handler and register_yield_rpc_handler obtain the executor used to spawn the coroutine.
• Removed documentation of deprecated CMake options.

Chore

• Remove codeql pipeline

v2.7.0

This release prepares asio-grpc for a large trim down in the next major release by adding an API that follows Asio's I/O object model more closely, avoids the pitfalls of the current API and provides more customization options.

The following headers should be considered deprecated:
bind_allocator.hpp, cancel_safe.hpp, default_completion_token.hpp, get_completion_queue.hpp, grpc_initiate.hpp, grpc_stream.hpp, notify_when_done.hpp, repeatedly_request_context.hpp, repeatedly_request.hpp, rpc.hpp, use_awaitable.hpp, wait.hpp

Features

• Add agrpc::ServerRPC, new API for asynchronous servers.
• Add agrpc::register_awaitable_rpc_handler, agrpc::register_yield_rpc_handler and agrpc::register_sender_rpc_handler functions for setting up request handling with agrpc::ServerRPC.
• Breaking change in experimental agrpc::ClientRPC API:
  • Rename agrpc::ClientRPCGenericUnary to agrpc::GenericUnaryClientRPC.
  • Rename agrpc::ClientRPCGenericStreaming to agrpc::GenericStreamingClientRPC.
• Make unary ClientRPCs constructible and add start, read_initial_metadata and finish member functions.

Fixes

• Avoid UB from casting function pointer to void* in ClientRPC, BasicAlarm and notify_one_state_change asynchronous operations.
• Consistently take CompletionToken by forwarding-reference.

Performance

• Improve compile times of ClientRPC, BasicAlarm and notify_one_state_change asynchronous operations.

Documentation

• Remove documentation of old API.

Chore

• Run sonarscanner on Ubuntu 22.04 with GCC 11 and Java 17.
• Use vcpkg binarycaching with Github Caches.

v2.6.0

Features

• Breaking change in experimental agrpc::RPC API:
  • Rename to agrpc::ClientRPC and agrpc::ClientRPCType.
  • Header name changed to client_rpc.hpp.
  • asio::use_awaitable is no longer the default completion token.
  • Remove third template parameter.
  • For streaming specializations:
    • ClientRPC now creates and owns the grpc::ClientContext, it can be customized during construction or later access using context().
    • Must now be started by calling start(), request() has been removed.
    • finish() and writes_done() no longer guard against being called multiple times.
  • For generic specializations:
    • Replace marker values agrpc::CLIENT_GENERIC_X_RPC with agrpc::ClientRPCType::GENERIC_X.
    • Add type aliases agrpc::ClientRPCGenericUnary<Executor> and agrpc::ClientRPCGenericStreaming<Executor>.
• De-experimentalize agrpc::HealthCheckService.
• Add cancel() to agrpc::Alarm.
• Add support for libunifex v0.2.0 to agrpc::repeatedly_request.

Fixes

• Typo in NotfiyWhenDoneFn

Documentation

• Simplify file-transfer example.

Chore

• Update libunifex to v0.2.0. Version 0.3.0 is also supported by held back due to an ICE in clang 10.

v2.5.1

Fixes

• Remove Intellisense workaround from agrpc::RPC's RPCType deduction because it causes ICE since Visual Studio 17.5 (C++20 only). See bug report.
• Bump asio-grpc version in CMakeLists file.

v2.5.0

Features

• Implement a pool memory resource based on Boost.Container's unsynchronized_pool_resource. This makes selecting between <memory_resource>, Boost.Container and asio::recycling_allocator obsolete. All related CMake options have been marked deprecated and only affect uses_allocator specializations now. They will be removed in version 3 which will always use std::uses_allocator.
• Deprecated: Due to the above, all typedefs in the agrpc::pmr namespace are deprecated and will be removed in v3.
• Add a new CMake option called ASIO_GRPC_BUILD_EXAMPLES which enables compilation of just examples without tests. Also, libunifex is now treated as an optional dependency.

Fixes

• agrpc::run* consumes a high amount of CPU resources when the GrpcContext had already stopped while the second argument (typically an io_context) had work left to do. To resolve that, agrpc::run* will now end when both contexts are stopped using new functions that were added to the RunTraits.

Documentation

• Create an article on the use of asio::io_context.

Chore

• Treat compiler warnings as error in CI.

v2.4.0

Features

• Add cancellation support to agrpc::RPC.
• Add a new install option to use asio::recycling_allocator instead of <memory_resource> or Boost.Container. This can be handy in combination with libc++ and standalone Asio to avoid taking a dependency on Boost.
• Deprecated: Constructor agrpc::GrpcContext{std::make_unique<grpc::CompletionQueue>()}, use the new default constructor instead.
• Deprecated: Member function agrpc::CancelSafe::is_running has been renamed to is_wait_pending() because it never reported whether the asynchronous operation is still running but instead whether a wait is currently pending.

Fixes

• A failed write with grpc::WriteOptions::set_last_message on a high-level client streaming RPC incorrectly completes with true.
• The operation state obtained by connecting a receiver to the sender returned by agprc::notify_when_done is deallocated during GrpcContext destruction, leading to double free because the lifetime of the operation state is expected to be handled by the connector.
• Using asio::deferred for agrpc::RPC::finish and agrpc::RPC::writes_done does not compile.
• The rvalue-overload of agrpc::Alarm::wait does not extend the lifetime of the alarm correctly when using completion tokens like asio::deferred.
• Honor ASIO_GRPC_USE_BOOST_CONTAINER CMake variable when using asio-grpc with add_subdirectory.
• Compatibility of sender/receiver with Asio 1.25/Boost 1.81.

Performance

• Improve performance of high-level client read_initial_metadata, read, write and finish by replacing some if-conditions with compile time dispatch.
• Reduce allocation size of each health check watch request.
• Reduce size of all sender operation states by one pointer and the notify_when_done operation state by two pointers.

Documentation

• Correctly state that agrpc::RPC::read_initial_metadata may not be called concurrently with write.

Chore

• Adjust .clang-tidy rules.
• Fix CMAKE_UNITY_BUILD and enable it for some CI builds.
• Add test for add_subdirectory-consumption of asio-grpc.
• Update doxygen and doxygen-awesome.

v2.3.0

Features

• Add agrpc::notify_when_done, a function for grpc::ServerContext::AsyncNotifyWhenDone that does not suffer from memory leaks like a agrpc::grpc_initiate version would.
• Add agrpc::notify_on_state_change, a function for grpc::ChannelInterface::NotifyOnStateChange.
• Deprecate agrpc::grpc_initiate, use the above functions instead.
• Add a CompletionQueue-based implementation of grpc::HealthCheckServiceInterface. GRPC's default health check service is implemented with the callback API which significantly reduces the performance of a server that also uses the CompletionQueue API (aka. any functionality of this library).

Chore

• Update libunifex to 2022-10-10 and gRPC to 1.50.1

v2.2.0

Features

• Add agrpc::RPC<>::service/method_name():

package example.v1;
 
service Example { rpc Unary(Request) returns (Response) {} }

using RPC = agrpc::RPC<&example::v1::Example::Stub::PrepareAsyncUnary>;
static_assert(RPC::service_name() == "example.v1.Example");
static_assert(RPC::method_name() == "Unary");

• Add agrpc::Alarm, an I/O object that wraps grpc::Alarm. A safer alternative to the agrpc::wait free function. Additionally supports ad-hoc waits which automatically extend the lifetime of the underlying gRPC alarm, for example with a callback:

agrpc::Alarm(grpc_context).wait(deadline, [](bool ok, agrpc::Alarm&& alarm) {});

Fixes

• Leak of uncompleted sender operation states and asynchronous operations started by the high-level client API upon destruction of the GrpcContext.
• For each request in the sender overload of agrpc::repeatedly_request, make a copy of the request handler to avoid lifetime surprises when the handler returns unifex::task<>.

Performance

• Improve compile times by no longer instantiating entire operation states with two different allocators, but instead only their completion function. This affects all free functions, like agrpc::read and agrpc::wait, as well as the high-level client API.

Chore

• Use a more meticulous gRPC shutdown sequence in tests to make them less flaky.
• Update tests and examples to Boost 1.80.

v2.1.0

Features

• Add a high-level client API - a new major feature that makes writing asynchronous gRPC clients easier and safer.
• In asio_grpc_protobuf_generate, check the validity of IMPORT_DIRS at CMake configure time instead of build time.
• The asio-grpc source files can now be consumed without CMake. In that case, the compile definition AGRPC_USE_BOOST_CONTAINER can be used to choose between <memory_resource> and Boost.Container.

Fixes

• Enable cancellation support for standalone Asio 1.19.0 instead of 1.20.0. Note that throwing exceptions from the request handler of agrpc::repeatedly_request crashes until 1.19.2.
• Correctly handle .proto filenames that include dots in asio_grpc_protobuf_generate.
• Return correct sender from asio::execution::schedule(GrpcExecutor) when compiling in C++17 using MSVC.

Performance

• Turn cancellation check in agrpc::repeatedly_request to a no-op when the completion handler does not support cancellation.
• Replace most calls to std::move and std::forward with static_cast and use a simpler version of std::tuple to improve compile times.

Documentation

• State that read_initial_metadata will not complete until the server calls write_initial_metadata or the client performs a write/finish.
• Add generic bidirectional streaming example.
• Add dark mode to documentation website.

Chore

• No longer run CodeQL in Github Actions since it stopped working and never diagnosed anything useful.

v2.0.0

Breaking change: All headers now use snake_case instead of camelCase, e.g. #include <agrpc/asioGrpc.hpp> becomes #include <agrpc/asio_grpc.hpp>.

Breaking change: Two overloads for requesting unary RPCs have been removed, example: co_await agrpc::request(&example::v1::Example::Stub::AsyncUnary, stub, client_context, request). Please use other means of obtaining a reference to the agrpc::GrpcContext and then call agrpc::request(&example::v1::Example::Stub::AsyncUnary, stub, client_context, request, grpc_context).

Breaking change: Unsafe overloads of agrpc::get_completion_queue have been removed.

Breaking change: asio-grpcConfig.cmake will now autolink with gRPC::grpc++_unsecure instead of gRPC::grpc++. If you are using encrypted gRPC then you need to explicitly link with gRPC::grpc++ in your CMake files.

Breaking change: If the completion handler passed to an asynchronous operation does not have an associated allocator then asio-grpc will no longer attempt to retrieve one from the associated executor through asio::query(executor, asio::execution::allocator). This behavior had been deprecated in v1.6.0.

Features

• Add run_until(deadline) to agrpc::GrpcContext.
• Add PrepareAsync overloads for requesting RPCs in a thread-safe manner.
• Deprecate the Async overloads for requesting client-side streaming RPCs as they can lead to race-conditions.
• Add agrpc::BasicGrpcStream overload to agrpc::get_completion_queue.
• Make agrpc::AllocatorBinder fully constexpr compatible.

Style

• No longer use std::aligned_storage since it is deprecated in C++23.
• Continue to implement compile time improvements.

Documentation

• Add examples for multi-threaded clients and servers.
• Make the ServerShutdown that is used in examples thread-safe.

Chore

• Asio-grpc is now available on conan-center!
• Use CTest's --build-and-test command for the asio-grpc-cmake test. Also use an older version of CMake (3.16) for that test.
• Remove GCC 9 and Clang 11 pipelines.
• Update doctest, gRPC, gtest, libunifex and liburing in the pipelines.