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::start_new(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 (int32 initial_count)
	Initializes a new instance of xtd::threading::countdown_event class with the specified count.

Public Properties
int32	current_count () const
	Gets the number of remaining signals required to set the event.
int32	initial_count () const
	Gets the numbers of signals initially required to set the event.
bool	is_set () const
	ndicates whether the xtd::threading::countdown_event object's current count has reached zero.
const xtd::threading::wait_handle &	wait_handle () const
	Gets a xtd::threading::wait_handle that is used to wait for the event to be set.
xtd::threading::wait_handle &	wait_handle ()
	Gets a xtd::threading::wait_handle that is used to wait for the event to be set.

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

int32 xtd::threading::countdown_event::current_count

(

)

const

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()

int32 xtd::threading::countdown_event::initial_count

(

)

const

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()

bool xtd::threading::countdown_event::is_set

(

)

const

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]

const xtd::threading::wait_handle & xtd::threading::countdown_event::wait_handle

(

)

const

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]

xtd::threading::wait_handle & xtd::threading::countdown_event::wait_handle

(

)

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]

void xtd::threading::countdown_event::add_count

(

)

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]

void xtd::threading::countdown_event::add_count

(

int32

count

)

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()

void xtd::threading::countdown_event::close

(

)

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

reset() [1/2]

void xtd::threading::countdown_event::reset

(

)

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

(

int32

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]

bool xtd::threading::countdown_event::signal

(

)

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]

bool xtd::threading::countdown_event::signal

(

int32

signal_count

)

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]

bool xtd::threading::countdown_event::try_add_count ( )

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]

bool xtd::threading::countdown_event::try_add_count ( int32 count )

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]

void xtd::threading::countdown_event::wait

(

)

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]

bool xtd::threading::countdown_event::wait

(

int32

milliseconds_timeout

)

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]

void xtd::threading::countdown_event::wait

(

const cancellation_token &

cancellation_token

)

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]

bool xtd::threading::countdown_event::wait

(

const time_span &

timeout

)

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]

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

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]

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

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