W3cubDocs

/Crystal

struct Atomic::Flag

Overview

An atomic flag, that can be set or not.

Concurrency safe. If many fibers try to set the atomic in parallel, only one will succeed.

Example:

flag = Atomic::Flag.new
flag.test_and_set # => true
flag.test_and_set # => false
flag.clear
flag.test_and_set # => true

Defined in:

atomic.cr

Constructors

Instance Method Summary

Instance methods inherited from struct Struct

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

Instance methods inherited from struct 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?(*values : Object) : Bool
in?(collection) : Bool in?, inspect : String
inspect(io : IO) : Nil inspect, is_a?(type : Class) : Bool is_a?, itself itself, nil? : Bool nil?, 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)
to_json to_json, to_pretty_json(io : IO, indent : String = " ")
to_pretty_json(indent : String = " ") to_pretty_json, to_s : String
to_s(io : IO) : Nil to_s, to_yaml(io : IO)
to_yaml to_yaml, try(&) try, unsafe_as(type : T.class) forall T unsafe_as

Class methods inherited from class Object

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

Constructor Detail

def self.newSource

Instance Method Detail

def clear : NilSource

Atomically clears the flag.

def test_and_set : BoolSource

Atomically tries to set the flag. Only succeeds and returns true if the flag wasn't previously set; returns false otherwise.

© 2012–2020 Manas Technology Solutions.
Licensed under the Apache License, Version 2.0.
https://crystal-lang.org/api/0.35.1/Atomic/Flag.html