# struct Crystal::EventLoop::Polling::Event

- Crystal::EventLoop::Polling::Event
- Struct
- Value
- Object

##
Overview

Information about the event that a `Fiber` is waiting on.

The event can be waiting for `IO` with or without a timeout, or be a timed event such as sleep or a select timeout (without IO).

The events can be found in different queues, for example `Timers` and/or `Waiters` depending on their type.

##
Included Modules

- Crystal::PointerLinkedList::Node
- Crystal::PointerPairingHeap::Node

##
Defined in:

crystal/event_loop/polling/event.cr

##
Constructors

- .new(type : Type, fiber : Fiber, index : Crystal::EventLoop::Polling::Arena::Index | Nil = nil, timeout : Time::Span | Nil = nil)

##
Instance Method Summary

- #fiber : Fiber

  The `Fiber` that is waiting on the event and that the `EventLoop` shall resume.

- #heap_child=(heap_child : Pointer(self))
- #heap_child? : Pointer(self)
- #heap_compare(other : Pointer(self)) : Bool

  Compare self with other.

- #heap_next=(heap_next : Pointer(self))
- #heap_next? : Pointer(self)
- #heap_previous=(heap_previous : Pointer(self))
- #heap_previous? : Pointer(self)
- #index : Arena::Index | Nil

  Arena index to access the associated `PollDescriptor` when processing an IO event.

- #index? : Arena::Index | Nil | Nil

  Arena index to access the associated `PollDescriptor` when processing an IO event.

- #next : Pointer(self)
- #next=(next __arg0 : Pointer(self))
- #previous : Pointer(self)
- #previous=(previous : Pointer(self))
- #timed_out! : Bool

  Mark the IO event as timed out.

- #timed_out? : Bool

  True if an IO event has timed out (i.e.

- #type : Type
- #wake_at : Time::Instant

  The absolute time, against the monotonic clock, at which a timed event shall trigger.

- #wake_at=(wake_at : Time::Instant | Nil)

  Manually set the absolute time (against the monotonic clock).

- #wake_at? : Time::Instant | Nil

  The absolute time, against the monotonic clock, at which a timed event shall trigger.

### Instance methods inherited from module `Crystal::PointerPairingHeap::Node`

heap_compare(other : Pointer(self)) : Bool heap_compare

### Instance methods inherited from struct `Struct`

==(other : YAML::Any)
==(other) : Bool ==, hash(hasher) hash, inspect(io : IO) : Nil inspect, pretty_print(pp) : Nil pretty_print, to_s(io : IO) : Nil to_s

### Class methods inherited from struct `Struct`

pre_initialize(address : Pointer) : Nil pre_initialize

### Instance methods inherited from struct `Value`

==(other : Log::Metadata::Value)
==(other : JSON::Any)
==(other : YAML::Any)
==(other) ==, dup dup

### Instance methods inherited from class `Object`

! : Bool !, !=(other) !=, !~(other) !~, ==(other) ==, ===(other : JSON::Any)
===(other : YAML::Any)
===(other) ===, =~(other) =~, as(type : Class) as, as?(type : Class) as?, class class, dup dup, hash(hasher)
hash hash, in?(collection : Object) : Bool
in?(*values : Object) : Bool in?, inspect(io : IO) : Nil
inspect : String inspect, is_a?(type : Class) : Bool is_a?, itself itself, nil? : Bool nil?, not_nil!(message)
not_nil! not_nil!, pretty_inspect(width = 79, newline = "\n", indent = 0) : String pretty_inspect, pretty_print(pp : PrettyPrint) : Nil pretty_print, responds_to?(name : Symbol) : Bool responds_to?, tap(&) tap, to_json(io : IO) : Nil
to_json : String to_json, to_pretty_json(indent : String = " ") : String
to_pretty_json(io : IO, indent : String = " ") : Nil to_pretty_json, to_s(io : IO) : Nil
to_s : String to_s, to_yaml(io : IO) : Nil
to_yaml : String to_yaml, try(&) try, unsafe_as(type : T.class) forall T unsafe_as

### Class methods inherited from class `Object`

from_json(string_or_io : String | IO, root : String)
from_json(string_or_io : String | IO) from_json, from_yaml(string_or_io : String | IO) from_yaml

### Macros inherited from class `Object`

class_getter(*names, &block) class_getter, class_getter!(*names) class_getter!, class_getter?(*names, &block) class_getter?, class_property(*names, &block) class_property, class_property!(*names) class_property!, class_property?(*names, &block) class_property?, class_setter(*names) class_setter, def_clone def_clone, def_equals(*fields) def_equals, def_equals_and_hash(*fields) def_equals_and_hash, def_hash(*fields) def_hash, delegate(*methods, to object) delegate, forward_missing_to(delegate) forward_missing_to, getter(*names, &block) getter, getter!(*names) getter!, getter?(*names, &block) getter?, property(*names, &block) property, property!(*names) property!, property?(*names, &block) property?, setter(*names) setter

##
Constructor Detail

def self.new(type : Type, fiber : Fiber, index : Crystal::EventLoop::Polling::Arena::Index | Nil = nil, timeout : Time::Span | Nil = nil) #

##
Instance Method Detail

def fiber : Fiber #

The `Fiber` that is waiting on the event and that the `EventLoop` shall resume.

def heap_child=(heap_child : Pointer(self)) #
def heap_child? : Pointer(self) #
def heap_compare(other : Pointer(self)) : Bool #
Description copied from module Crystal::PointerPairingHeap::Node

Compare self with other. For example:

Use `<` to create a min heap. Use `>` to create a max heap.

def heap_next=(heap_next : Pointer(self)) #
def heap_next? : Pointer(self) #
def heap_previous=(heap_previous : Pointer(self)) #
def heap_previous? : Pointer(self) #
def index : Arena::Index | Nil #

Arena index to access the associated `PollDescriptor` when processing an IO event. Nil for timed events (sleep, select timeout).

def index? : Arena::Index | Nil | Nil #

Arena index to access the associated `PollDescriptor` when processing an IO event. Nil for timed events (sleep, select timeout).

def next : Pointer(self) #
def next=(next __arg0 : Pointer(self)) #
def previous : Pointer(self) #
def previous=(previous : Pointer(self)) #
def timed_out! : Bool #

Mark the IO event as timed out.

def timed_out? : Bool #

True if an IO event has timed out (i.e. we're past `#wake_at`).

def type : Type #
def wake_at : Time::Instant #

The absolute time, against the monotonic clock, at which a timed event shall trigger. Nil for IO events without a timeout.

def wake_at=(wake_at : Time::Instant | Nil) #

Manually set the absolute time (against the monotonic clock). This is meant for `FiberEvent` to set and cancel its inner sleep or select timeout; these objects are allocated once per `Fiber`.

NOTE musn't be changed after registering the event into `Timers`!

def wake_at? : Time::Instant | Nil #

The absolute time, against the monotonic clock, at which a timed event shall trigger. Nil for IO events without a timeout.