Call the functor associated with asynchronous operations when they complete. More...

#include <google/cloud/completion_queue.h>

Public Member Functions
	CompletionQueue ()

	CompletionQueue (std::shared_ptr< internal::CompletionQueueImpl > impl)

void	Run ()
	Run the completion queue event loop. More...

void	Shutdown ()
	Terminate the completion queue event loop. More...

void	CancelAll ()
	Cancel all pending operations. More...

google::cloud::future< StatusOr< std::chrono::system_clock::time_point > >	MakeDeadlineTimer (std::chrono::system_clock::time_point deadline)
	Create a timer that fires at `deadline`. More...

template<typename Rep , typename Period >
future< StatusOr< std::chrono::system_clock::time_point > >	MakeRelativeTimer (std::chrono::duration< Rep, Period > duration)
	Create a timer that fires after the `duration`. More...

template<typename AsyncCallType , typename Request , typename Sig = internal::AsyncCallResponseType<AsyncCallType, Request>, typename Response = typename Sig::type, typename std::enable_if< Sig::value, int >::type = 0>
future< StatusOr< Response > >	MakeUnaryRpc (AsyncCallType async_call, Request const &request, std::unique_ptr< grpc::ClientContext > context)
	Make an asynchronous unary RPC. More...

template<typename AsyncCallType , typename Request , typename Response = typename internal:: AsyncStreamingReadResponseType<AsyncCallType, Request>::type, typename OnReadHandler , typename OnFinishHandler >
std::shared_ptr< AsyncOperation >	MakeStreamingReadRpc (AsyncCallType &&async_call, Request const &request, std::unique_ptr< grpc::ClientContext > context, OnReadHandler &&on_read, OnFinishHandler &&on_finish)
	Make an asynchronous streaming read RPC. More...

template<typename Functor , typename std::enable_if< internal::CheckRunAsyncCallback< Functor >::value, int >::type = 0>
void	RunAsync (Functor &&functor)
	Asynchronously run a functor on a thread `Run()`ning the `CompletionQueue`. More...

template<typename Functor , typename std::enable_if< internal::is_invocable< Functor >::value, int >::type = 0>
void	RunAsync (Functor &&functor)
	Asynchronously run a functor on a thread `Run()`ning the `CompletionQueue`. More...

future< Status >	AsyncWaitConnectionReady (std::shared_ptr< grpc::Channel > channel, std::chrono::system_clock::time_point deadline)
	Asynchronously wait for a connection to become ready. More...

Detailed Description

Call the functor associated with asynchronous operations when they complete.

Constructor & Destructor Documentation

◆ CompletionQueue() [1/2]

google::cloud::CompletionQueue::CompletionQueue ( )

◆ CompletionQueue() [2/2]

google::cloud::CompletionQueue::CompletionQueue ( std::shared_ptr< internal::CompletionQueueImpl > impl )

inlineexplicit

Member Function Documentation

◆ AsyncWaitConnectionReady()

future< Status > google::cloud::CompletionQueue::AsyncWaitConnectionReady	(	std::shared_ptr< grpc::Channel >	channel,
		std::chrono::system_clock::time_point	deadline
	)

Asynchronously wait for a connection to become ready.

Parameters

channel	the channel on which to wait for state changes
deadline	give up waiting for the state change if this deadline passes

Returns: future<> which will be satisfied when either of these events happen: (a) the connection is ready, (b) the connection permanently failed, (c) deadline passes before (a) or (b) happen; the future will be satisfied with StatusCode::kOk for (a), StatusCode::kCancelled for (b) and StatusCode::kDeadlineExceeded for (c)

◆ CancelAll()

void google::cloud::CompletionQueue::CancelAll ( )

inline

Cancel all pending operations.

◆ MakeDeadlineTimer()

google::cloud::future< StatusOr< std::chrono::system_clock::time_point > > google::cloud::CompletionQueue::MakeDeadlineTimer ( std::chrono::system_clock::time_point deadline )

inline

Create a timer that fires at deadline.

Parameters

deadline when should the timer expire.

Returns: a future that becomes satisfied after deadline. The result of the future is the time at which it expired, or an error Status if the timer did not run to expiration (e.g. it was cancelled).

◆ MakeRelativeTimer()

template<typename Rep , typename Period >

future< StatusOr< std::chrono::system_clock::time_point > > google::cloud::CompletionQueue::MakeRelativeTimer ( std::chrono::duration< Rep, Period > duration )

inline

Create a timer that fires after the duration.

Template Parameters

Rep	a placeholder to match the Rep tparam for `duration` type, the semantics of this template parameter are documented in `std::chrono::duration<>` (in brief, the underlying arithmetic type used to store the number of ticks), for our purposes it is simply a formal parameter.
Period	a placeholder to match the Period tparam for `duration` type, the semantics of this template parameter are documented in `std::chrono::duration<>` (in brief, the length of the tick in seconds, expressed as a `std::ratio<>`), for our purposes it is simply a formal parameter.

Parameters

duration when should the timer expire relative to the current time.

Returns: a future that becomes satisfied after duration time has elapsed. The result of the future is the time at which it expired, or an error Status if the timer did not run to expiration (e.g. it was cancelled).

◆ MakeStreamingReadRpc()

template<typename AsyncCallType , typename Request , typename Response = typename internal:: AsyncStreamingReadResponseType<AsyncCallType, Request>::type, typename OnReadHandler , typename OnFinishHandler >

std::shared_ptr< AsyncOperation > google::cloud::CompletionQueue::MakeStreamingReadRpc	(	AsyncCallType &&	async_call,
		Request const &	request,
		std::unique_ptr< grpc::ClientContext >	context,
		OnReadHandler &&	on_read,
		OnFinishHandler &&	on_finish
	)

inline

Make an asynchronous streaming read RPC.

Reading from the stream starts automatically, and the handler is notified of all interesting events in the stream. Note that then handler is called by any thread blocked on this object's Run() member function. However, only one callback in the handler is called at a time.

Parameters

async_call	a callable to start the asynchronous RPC.
request	the contents of the request.
context	an initialized request context to make the call.
on_read	the callback to be invoked on each successful Read().
on_finish	the callback to be invoked when the stream is closed.

Template Parameters

AsyncCallType	the type of async_call. It must be invocable with parameters `(grpc::ClientContext, RequestType const&, grpc::CompletionQueue)`. Furthermore, it should return a type convertible to `std::unique_ptr<grpc::ClientAsyncReaderInterface<Response>>>`. These requirements are verified by `internal::AsyncStreamingReadRpcUnwrap<>`, and this function is excluded from overload resolution if the parameters do not meet these requirements.
Request	the type of the request in the streaming RPC.
Response	the type of the response in the streaming RPC.
OnReadHandler	the type of the `on_read` callback.
OnFinishHandler	the type of the `on_finish` callback.

◆ MakeUnaryRpc()

template<typename AsyncCallType , typename Request , typename Sig = internal::AsyncCallResponseType<AsyncCallType, Request>, typename Response = typename Sig::type, typename std::enable_if< Sig::value, int >::type = 0>

future< StatusOr< Response > > google::cloud::CompletionQueue::MakeUnaryRpc	(	AsyncCallType	async_call,
		Request const &	request,
		std::unique_ptr< grpc::ClientContext >	context
	)

inline

Make an asynchronous unary RPC.

Parameters

async_call	a callable to start the asynchronous RPC.
request	the contents of the request.
context	an initialized request context to make the call.

Template Parameters

AsyncCallType the type of async_call. It must be invocable with (grpc::ClientContext*, RequestType const&, grpc::CompletionQueue*). Furthermore, it should return a std::unique_ptr<grpc::ClientAsyncResponseReaderInterface<Response>>>. These requirements are verified by internal::CheckAsyncUnaryRpcSignature<>, and this function is excluded from overload resolution if the parameters do not meet these requirements.

Request the type of the request parameter in the gRPC.

Returns: a future that becomes satisfied when the operation completes.

◆ Run()

void google::cloud::CompletionQueue::Run ( )

inline

Run the completion queue event loop.

Note that more than one thread can call this member function, to create a pool of threads completing asynchronous operations.

◆ RunAsync() [1/2]

template<typename Functor , typename std::enable_if< internal::CheckRunAsyncCallback< Functor >::value, int >::type = 0>

void google::cloud::CompletionQueue::RunAsync ( Functor && functor )

inline

Asynchronously run a functor on a thread Run()ning the CompletionQueue.

Template Parameters

Functor the functor to call on the CompletionQueue thread. It must satisfy the void(CompletionQueue&) signature.

Parameters

functor the value of the functor.

◆ RunAsync() [2/2]

template<typename Functor , typename std::enable_if< internal::is_invocable< Functor >::value, int >::type = 0>

void google::cloud::CompletionQueue::RunAsync ( Functor && functor )

inline

Asynchronously run a functor on a thread Run()ning the CompletionQueue.

Template Parameters

Functor the functor to call on the CompletionQueue thread. It must satisfy the void() signature.

Parameters

functor the value of the functor.

◆ Shutdown()

void google::cloud::CompletionQueue::Shutdown ( )

inline

Terminate the completion queue event loop.

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ CompletionQueue() [1/2]

◆ CompletionQueue() [2/2]

Member Function Documentation

◆ AsyncWaitConnectionReady()

◆ CancelAll()

◆ MakeDeadlineTimer()

◆ MakeRelativeTimer()

◆ MakeStreamingReadRpc()

◆ MakeUnaryRpc()

◆ Run()

◆ RunAsync() [1/2]

◆ RunAsync() [2/2]

◆ Shutdown()