seastar::concrete_execution_stage< ReturnType, Args > Class Template Reference

Detailed Description

template<typename ReturnType, typename... Args>
requires std::is_nothrow_move_constructible_v<std::tuple<Args...>>
class seastar::concrete_execution_stage< ReturnType, Args >

Concrete execution stage class.

Note

The recommended way of creating execution stages is to use make_execution_stage().

Template Parameters

ReturnType	return type of the function object
Args	argument pack containing arguments to the function object, needs to have move constructor that doesn't throw

#include <seastar/core/execution_stage.hh>

Inheritance diagram for seastar::concrete_execution_stage< ReturnType, Args >:

Public Member Functions
	concrete_execution_stage (const sstring &name, scheduling_group sg, noncopyable_function< ReturnType(Args...)> f)
	concrete_execution_stage (const sstring &name, noncopyable_function< ReturnType(Args...)> f)
return_type	operator() (typename internal::wrap_for_es< Args >::type... args)
const sstring &	name () const noexcept
	Returns execution stage name.
const stats &	get_stats () const noexcept
	Returns execution stage usage statistics.
bool	flush () noexcept
bool	poll () const noexcept

Protected Attributes
bool	_empty = true
bool	_flush_scheduled = false
scheduling_group	_sg
stats	_stats
sstring	_name
metrics::metric_group	_metric_group

Member Function Documentation

flush()

bool seastar::execution_stage::flush ( )

noexceptinherited

Flushes execution stage

Ensures that a task which would execute all queued operations is scheduled. Does not schedule a new task if there is one already pending or the queue is empty.

Returns

true if a new task has been scheduled

operator()()

template<typename ReturnType , typename... Args>

return_type seastar::concrete_execution_stage< ReturnType, Args >::operator() ( typename internal::wrap_for_es< Args >::type...  args )

inline

Enqueues a call to the stage's function

Adds a function call to the queue. Objects passed by value are moved, rvalue references are decayed and the objects are moved, lvalue references need to be explicitly wrapped using seastar::ref().

Usage example:

void do_something(int&, int, std::vector<int>&&);
thread_local auto stage = seastar::make_execution_stage("execution-stage", do_something);
 
int global_value;
 
future<> func(std::vector<int> vec) {
    //return stage(global_value, 42, std::move(vec)); // fail: use seastar::ref to pass references
    return stage(seastar::ref(global_value), 42, std::move(vec)); // ok
}

Parameters

args	arguments passed to the stage's function

Returns

future containing the result of the call to the stage's function

poll()

bool seastar::execution_stage::poll ( ) const

inlinenoexceptinherited

Checks whether there are pending operations.

Returns

true if there is at least one queued operation

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

• seastar/core/execution_stage.hh