RPCFuture< R > Class Template Reference

An RPCFuture is a proxy for the result of an asynchronous RPC call. More...

#include <rpc/RPCFuture.h>

Inheritance diagram for RPCFuture< R >:

Public Types
typedef boost::detail::future_traits< R >::move_dest_type	ReturnValue
	The rvalue return value, which essentially can be thought of R&&. More...

Public Member Functions
	RPCFuture ()
	RPCFuture (boost::unique_future< R > other, AbstractRPCClient *client, const std::string &callId)
	internally used by RPCClient More...
	RPCFuture (RPCFuture &&other) noexcept
	move constructor More...
RPCFuture &	operator= (RPCFuture &&other) noexcept
	move assignment operator More...
	operator ReturnValue ()
	Casts the return value of the RPC call associated to this future to R&&. More...
ReturnValue	get (bool throwXRPC=true, bool recursive=true)
	Obtains the return value of the RPC call associated to this future as rvalue R&&. More...
const std::string &	callId ()
	query call ID More...
bool	isReady () const
	Checks to see if the result of the RPC call associated with this future is set. More...
bool	hasException () const
	Returns true if the RPC call associated with this future has finished with an exception rather than a return value. More...
bool	hasValue () const
	Returns true if the RPC call associated with this future has finished with a return value value rather than an exception. More...
void	wait () const
	Waits and blocks the current thread until the result of the associated RPC call is ready. More...
template<typename Duration >
bool	timedWait (Duration const &relTime) const
	Waits and blocks the current thread until the result of the associated RPC call is ready, or the time duration specified by waitDuration has elapsed. More...
bool	timedWaitUntil (boost::system_time const &absTime) const
	Waits and blocks the current thread until the result of the associated RPC call is ready, or the time point specified by waitDuration has passed. More...
void	swap (RPCFutureCommon< R > &other)
	Swaps ownership of the asynchronous results associated with other and *this. More...

Protected Attributes
AbstractRPCClient *	mClient
std::string	mCallId
boost::unique_future< R >	mFuture

Detailed Description

template<typename R>
class mira::RPCFuture< R >

An RPCFuture is a proxy for the result of an asynchronous RPC call.

It can be used to block the calling thread until the RPC call has finished and the result is available. The use of futures dramatically reduces latency in RPC calls, since the caller can decide whether it wants to wait for the result or not and where it wants to wait for the result.

The RPCFuture cannot be shared, however, the ownership can be transferred between different instances using the move constructor or move-assignment operator, but at most one instance holds a reference to a given asynchronous result. When the result is ready, it can be returned using get() by rvalue-reference to allow the result to be moved or copied as appropriate for the type.

See also

Services and Remote Procedure Calls

Member Typedef Documentation

ReturnValue

typedef boost::detail::future_traits<R>::move_dest_type ReturnValue

The rvalue return value, which essentially can be thought of R&&.

Constructor & Destructor Documentation

RPCFuture() [1/3]

RPCFuture ( )

inline

RPCFuture() [2/3]

RPCFuture ( boost::unique_future< R >  other, AbstractRPCClient *  client, const std::string &  callId  )

inline

internally used by RPCClient

RPCFuture() [3/3]

RPCFuture ( RPCFuture< R > &&  other )

inlinenoexcept

move constructor

Member Function Documentation

operator=()

RPCFuture& operator= ( RPCFuture< R > &&  other )

inlinenoexcept

move assignment operator

operator ReturnValue()

operator ReturnValue ( )

inline

Casts the return value of the RPC call associated to this future to R&&.

Note

This cast will block until the result becomes available.

See also

wait(), timedWait(), hasValue()

get()

ReturnValue get ( bool  throwXRPC = true, bool  recursive = true  )

inline

Obtains the return value of the RPC call associated to this future as rvalue R&&.

Parameters

[in]	throwXRPC	throw XRPC instead of original exception that occured in the called function (default = true, for backward compatibility)
[in]	recursive	recurse to innermost exception (for nested XRPC, only if throwXRPC=false)

Note

This method will block until the result becomes available.

This method will throw if an exception occurred on the server side while processing the call.

See also

wait(), timedWait(), hasValue(), hasException()

callId()

const std::string& callId ( )

inlineinherited

query call ID

isReady()

bool isReady ( ) const

inlineinherited

Checks to see if the result of the RPC call associated with this future is set.

hasException()

bool hasException ( ) const

inlineinherited

Returns true if the RPC call associated with this future has finished with an exception rather than a return value.

hasValue()

bool hasValue ( ) const

inlineinherited

Returns true if the RPC call associated with this future has finished with a return value value rather than an exception.

wait()

void wait ( ) const

inlineinherited

Waits and blocks the current thread until the result of the associated RPC call is ready.

This is an interruption point.

timedWait()

bool timedWait ( Duration const &  relTime ) const

inlineinherited

Waits and blocks the current thread until the result of the associated RPC call is ready, or the time duration specified by waitDuration has elapsed.

This is an interruption point.

Returns

false if the call is returning because the time specified was reached, true otherwise.

timedWaitUntil()

bool timedWaitUntil ( boost::system_time const &  absTime ) const

inlineinherited

Waits and blocks the current thread until the result of the associated RPC call is ready, or the time point specified by waitDuration has passed.

This is an interruption point.

Returns

false if the call is returning because the time specified was reached, true otherwise.

swap()

void swap ( RPCFutureCommon< R > &  other )

inlineinherited

Swaps ownership of the asynchronous results associated with other and *this.

Member Data Documentation

mClient

AbstractRPCClient* mClient

protectedinherited

mCallId

std::string mCallId

protectedinherited

mFuture

boost::unique_future<R> mFuture

protectedinherited

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The documentation for this class was generated from the following file:

• base/include/rpc/RPCFuture.h