xtd::threading::countdown_event Class Reference

Inheritance diagram for xtd::threading::countdown_event:

Definition

Represents a synchronization primitive that is signaled when its count reaches zero.

class countdown_event : public xtd::object

Header

#include <xtd/threading/countdown_event>

Namespace

xtd::threading

Library

xtd.core

Examples

The following example shows how to use a xtd::threading::countdown_event:

#include <xtd/xtd>
 
namespace monitor_lock_example {
  class program {
  public:
    static void main() {
      auto countdown_event = threading::countdown_event {5};
      auto thread_proc = [&] {
        console::write_line("Thread {} signals countdown_event", thread::current_thread().managed_thread_id());
        countdown_event.signal();
      };
      
      for (auto i = 0; i < 5; ++i)
        thread_pool::queue_user_work_item(thread_proc);
      
      countdown_event.wait();
      console::write_line("All threads have signaled countdown_event");
    }
  };
}
 
startup_(monitor_lock_example::program::main);
 
// This example produces output similar to the following:
//
// Thread 2 signals countdown_event
// Thread 3 signals countdown_event
// Thread 4 signals countdown_event
// Thread 6 signals countdown_event
// Thread 5 signals countdown_event
// All threads have signaled countdown_event

Public Constructors
	countdown_event (xtd::size initial_count)
	Initializes a new instance of xtd::threading::countdown_event class with the specified count.

Public Properties
auto	current_count () const -> xtd::size
	Gets the number of remaining signals required to set the event.
auto	initial_count () const -> xtd::size
	Gets the numbers of signals initially required to set the event.
auto	is_set () const -> bool
	ndicates whether the xtd::threading::countdown_event object's current count has reached zero.
auto	wait_handle () const -> const xtd::threading::wait_handle &
	Gets a xtd::threading::wait_handle that is used to wait for the event to be set.
auto	wait_handle () -> xtd::threading::wait_handle &
	Gets a xtd::threading::wait_handle that is used to wait for the event to be set.

Public Methods
auto	add_count () -> void
	Increments the xtd::threading::countdown_event's current count by one.
auto	add_count (xtd::size count) -> void
	Increments the xtd::threading::countdown_event's current count by one.
auto	close () -> void
	Close the current instance of the xtd::threading::countdown_event class.
auto	reset () -> void
	Resets the xtd::threading::countdown_event to the value of xtd::threading::countdown_event::initial_count.
void	reset (xtd::size count)
	Resets the xtd::threading::countdown_event::initial_count property to a specified value.
auto	signal () -> bool
	Registers a signal with the xtd::threading::countdown_event, decrementing the value of xtd::threading::countdown_event::current_count.
auto	signal (xtd::size signal_count) -> bool
	Registers multiple signals with the xtd::threading::countdown_event, decrementing the value of xtd::threading::countdown_event::current_count by the specified amount.
auto	try_add_count () noexcept -> bool
	Attempts to increment xtd::threading::countdown_event::current_count by one.
auto	try_add_count (xtd::size count) noexcept -> bool
	Attempts to increment xtd::threading::countdown_event::current_count by by a specified value.
auto	wait () -> void
	Blocks the current thread until the xtd::threading::countdown_event is set.
auto	wait (xtd::int32 milliseconds_timeout) -> bool
	Blocks the current thread until the xtd::threading::countdown_event is set, using a 32-bit signed integer to measure the timeout.
auto	wait (const cancellation_token &cancellation_token) -> void
	Blocks the current thread until the xtd::threading::countdown_event is set, while observing a xtd::threading::cancellation_token.
auto	wait (const xtd::time_span &timeout) -> bool
	Blocks the current thread until the xtd::threading::countdown_event is set, using a xtd::time_span to measure the timeout.
auto	wait (xtd::int32 milliseconds_timeout, const cancellation_token &cancellation_token) -> bool
	Blocks the current thread until the xtd::threading::countdown_event is set, using a 32-bit signed integer to measure the timeout, while observing a xtd::threading::cancellation_token.
auto	wait (const xtd::time_span &timeout, const cancellation_token &cancellation_token) -> bool
	Blocks the current thread until the xtd::threading::countdown_event is set, using a xtd::time_span to measure the timeout, while observing a xtd::threading::cancellation_token.

Additional Inherited Members
	object ()=default
	Create a new instance of the ultimate base class object.
virtual bool	equals (const object &obj) const noexcept
	Determines whether the specified object is equal to the current object.
virtual xtd::size	get_hash_code () const noexcept
	Serves as a hash function for a particular type.
virtual type_object	get_type () const noexcept
	Gets the type of the current instance.
template<class object_t>
xtd::unique_ptr_object< object_t >	memberwise_clone () const
	Creates a shallow copy of the current object.
virtual xtd::string	to_string () const
	Returns a xtd::string that represents the current object.
template<class object_a_t, class object_b_t>
static bool	equals (const object_a_t &object_a, const object_b_t &object_b) noexcept
	Determines whether the specified object instances are considered equal.
template<class object_a_t, class object_b_t>
static bool	reference_equals (const object_a_t &object_a, const object_b_t &object_b) noexcept
	Determines whether the specified object instances are the same instance.

Constructor & Destructor Documentation

countdown_event()

xtd::threading::countdown_event::countdown_event ( xtd::size initial_count )

explicit

Initializes a new instance of xtd::threading::countdown_event class with the specified count.

Parameters

initial_count

he number of signals initially required to set the xtd::threading::countdown_event.

Exceptions

xtd::argument_out_of_range_exception

initial_count is less than 0.

Remarks

If initial_count is 0, the event is created in a signaled state.

Member Function Documentation

current_count()

auto xtd::threading::countdown_event::current_count ( ) const -> xtd::size

nodiscard

Gets the number of remaining signals required to set the event.

Returns

The number of remaining signals required to set the event.

Exceptions

xtd::object_closed_exception

The current instance has already been closed.

initial_count()

auto xtd::threading::countdown_event::initial_count ( ) const -> xtd::size

nodiscard

Gets the numbers of signals initially required to set the event.

Returns

The number of signals initially required to set the event.

Exceptions

xtd::object_closed_exception

The current instance has already been closed.

is_set()

auto xtd::threading::countdown_event::is_set ( ) const -> bool

nodiscard

ndicates whether the xtd::threading::countdown_event object's current count has reached zero.

Returns

true if the current count is zero; otherwise, false.

Exceptions

xtd::object_closed_exception

The current instance has already been closed.

Remarks

The xtd::threading::countdown_event does not raise an event when the countdown has reached zero. Instead, the xtd::threading::countdown_event::current_count property equals zero, and the xtd::threading::countdown_event::is_set property equals true.

wait_handle() [1/2]

auto xtd::threading::countdown_event::wait_handle ( ) const -> const xtd::threading::wait_handle &

nodiscard

Gets a xtd::threading::wait_handle that is used to wait for the event to be set.

Returns

A xtd::threading::wait_handle that is used to wait for the event to be set.

Exceptions

xtd::object_closed_exception

The current instance has already been closed.

wait_handle() [2/2]

auto xtd::threading::countdown_event::wait_handle ( ) -> xtd::threading::wait_handle &

nodiscard

Gets a xtd::threading::wait_handle that is used to wait for the event to be set.

Returns

A xtd::threading::wait_handle that is used to wait for the event to be set.

Exceptions

xtd::object_closed_exception

The current instance has already been closed.

add_count() [1/2]

auto xtd::threading::countdown_event::add_count

(

)

-> void

Increments the xtd::threading::countdown_event's current count by one.

Exceptions

xtd::object_closed_exception	The current instance has already been closed.
xtd::invalid_operation_exception	The current instance is already set.

add_count() [2/2]

auto xtd::threading::countdown_event::add_count

(

xtd::size

count

)

-> void

Increments the xtd::threading::countdown_event's current count by one.

Parameters

count

The value by which to increase xtd::threading::countdown_event::current_count.

Exceptions

xtd::object_closed_exception	The current instance has already been closed.
xtd::invalid_operation_exception	The current instance is already set.
xtd::argument_out_of_range_exception	count is less than 0.

close()

auto xtd::threading::countdown_event::close

(

)

-> void

Close the current instance of the xtd::threading::countdown_event class.

reset() [1/2]

auto xtd::threading::countdown_event::reset

(

)

-> void

Resets the xtd::threading::countdown_event to the value of xtd::threading::countdown_event::initial_count.

Exceptions

xtd::object_closed_exception

The current instance has already been closed.

Remarks

This method resets xtd::threading::countdown_event::initial_count for all subsequent accesses of the property on the current instance.

reset() [2/2]

void xtd::threading::countdown_event::reset

(

xtd::size

count

)

Resets the xtd::threading::countdown_event::initial_count property to a specified value.

Parameters

count

he number of signals required to set the xtd::threading::countdown_event.

Exceptions

xtd::object_closed_exception	The current instance has already been closed.
xtd::argument_out_of_range_exception	count is less than 0.

Remarks

This method resets xtd::threading::countdown_event::initial_count for all subsequent accesses of the property on the current instance.

signal() [1/2]

auto xtd::threading::countdown_event::signal

(

)

-> bool

Registers a signal with the xtd::threading::countdown_event, decrementing the value of xtd::threading::countdown_event::current_count.

Returns

true if the signal caused the count to reach zero and the event was set; otherwise, false.

Exceptions

xtd::object_closed_exception	The current instance has already been closed.
xtd::nvalid_operation_exception	The current instance is already set.

signal() [2/2]

auto xtd::threading::countdown_event::signal

(

xtd::size

signal_count

)

-> bool

Registers multiple signals with the xtd::threading::countdown_event, decrementing the value of xtd::threading::countdown_event::current_count by the specified amount.

Parameters

signal_count

The number of signals to register.

Returns

true if the signal caused the count to reach zero and the event was set; otherwise, false.

Exceptions

xtd::object_closed_exception	The current instance has already been closed.
xtd::argument_out_of_range_exception	signal_count is less than 0.
xtd::nvalid_operation_exception	The current instance is already set.

try_add_count() [1/2]

auto xtd::threading::countdown_event::try_add_count ( ) -> bool

noexcept

Attempts to increment xtd::threading::countdown_event::current_count by one.

Returns

true if the increment succeeded; otherwise, false. If CurrentCount is already at zero, this method will return false.

try_add_count() [2/2]

auto xtd::threading::countdown_event::try_add_count ( xtd::size count ) -> bool

noexcept

Attempts to increment xtd::threading::countdown_event::current_count by by a specified value.

Parameters

count

The value by which to increase xtd::threading::countdown_event::current_count.

Returns

true if the increment succeeded; otherwise, false. If CurrentCount is already at zero, this method will return false.

wait() [1/6]

auto xtd::threading::countdown_event::wait

(

)

-> void

Blocks the current thread until the xtd::threading::countdown_event is set.

Exceptions

xtd::object_closed_exception

The current instance has already been closed.

Remarks

The caller of this method blocks indefinitely until the current instance is set. The caller will return immediately if the event is currently in a set state.

wait() [2/6]

auto xtd::threading::countdown_event::wait

(

xtd::int32

milliseconds_timeout

)

-> bool

Blocks the current thread until the xtd::threading::countdown_event is set, using a 32-bit signed integer to measure the timeout.

Parameters

milliseconds_timeout

The number of milliseconds to wait, or xtd::threading::timeout::ifinite (-1) to wait indefinitely.

Returns

true if the xtd::threading::countdown_event was set; otherwise, false.

Exceptions

xtd::object_closed_exception	The current instance has already been closed.
xtd::argument_out_of_range_exception	milliseconds_timeout is a negative number other than -1, which represents an infinite time-out..

wait() [3/6]

auto xtd::threading::countdown_event::wait

(

const cancellation_token &

cancellation_token

)

-> void

Blocks the current thread until the xtd::threading::countdown_event is set, while observing a xtd::threading::cancellation_token.

Parameters

cancellation_toker

The xtd::threading::cancellation_token to observe.

Exceptions

xtd::object_closed_exception	The current instance has already been closed.
xtd::operation_canceled_exception	cancellation_token has been canceled.

Remarks

The caller of this method blocks indefinitely until the current instance is set. The caller will return immediately if the event is currently in a set state. If the xtd::threading::cancellation_token being observed is canceled during the wait operation, an xtd::operation_canceled_exception will be thrown.

wait() [4/6]

auto xtd::threading::countdown_event::wait

(

const xtd::time_span &

timeout

)

-> bool

Blocks the current thread until the xtd::threading::countdown_event is set, using a xtd::time_span to measure the timeout.

Parameters

timeout

A xtd::time_span that represents the number of milliseconds to wait, or a xtd::time_span that represents -1 milliseconds to wait indefinitely.

Returns

true if the xtd::threading::countdown_event was set; otherwise, false.

Exceptions

xtd::object_closed_exception	The current instance has already been closed.
xtd::argument_out_of_range_exception	milliseconds_timeout is a negative number other than -1, which represents an infinite time-out..

wait() [5/6]

auto xtd::threading::countdown_event::wait	(	xtd::int32	milliseconds_timeout,
		const cancellation_token &	cancellation_token ) -> bool

Blocks the current thread until the xtd::threading::countdown_event is set, using a 32-bit signed integer to measure the timeout, while observing a xtd::threading::cancellation_token.

Parameters

milliseconds_timeout	The number of milliseconds to wait, or xtd::threading::timeout::ifinite (-1) to wait indefinitely.
cancellation_toker	The xtd::threading::cancellation_token to observe.

Returns

true if the xtd::threading::countdown_event was set; otherwise, false.

Exceptions

xtd::object_closed_exception	The current instance has already been closed.
xtd::operation_canceled_exception	cancellation_token has been canceled.
xtd::argument_out_of_range_exception	milliseconds_timeout is a negative number other than -1, which represents an infinite time-out..

wait() [6/6]

auto xtd::threading::countdown_event::wait	(	const xtd::time_span &	timeout,
		const cancellation_token &	cancellation_token ) -> bool

Blocks the current thread until the xtd::threading::countdown_event is set, using a xtd::time_span to measure the timeout, while observing a xtd::threading::cancellation_token.

Parameters

timeout	A xtd::time_span that represents the number of milliseconds to wait, or a xtd::time_span that represents -1 milliseconds to wait indefinitely.
cancellation_toker	The xtd::threading::cancellation_token to observe.

Returns

true if the xtd::threading::countdown_event was set; otherwise, false.

Exceptions

xtd::object_closed_exception	The current instance has already been closed.
xtd::operation_canceled_exception	cancellation_token has been canceled.
xtd::argument_out_of_range_exception	milliseconds_timeout is a negative number other than -1, which represents an infinite time-out..

---

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

• xtd.core/include/xtd/threading/countdown_event.hpp