# class Thread

- Thread
- Reference
- Object

##
Overview

Match data is unique per thread.

Match data contains a buffer for backtracking when matching in interpreted mode (non-JIT). This buffer is heap-allocated and should be re-used for subsequent matches.

Only a single `match` function can run per thread at any given time, so there can't be any concurrent access to the match data buffer.

##
Included Modules

- Crystal::System::Thread

##
Defined in:

crystal/system/thread.cr
crystal/system/thread_condition_variable.cr
crystal/system/thread_linked_list.cr
crystal/system/thread_mutex.cr
crystal/system/unix/pthread_condition_variable.cr
crystal/system/unix/pthread_mutex.cr
random.cr
regex/pcre2.cr:241
regex/pcre2.cr:255

##
Constructors

- .current : Thread

  Returns the Thread object associated to the running system thread.

- .new(name : String | Nil = nil, &func : Thread -> )

  Creates and starts a new system thread.

- .new

  Used once to initialize the thread object representing the main thread of the process (that already exists).

##
Class Method Summary

- .delay(backoff : Int32) : Int32

  Delays execution for a brief moment.

- .each(&)
- .init : Nil
- .lock : Nil
- .name=(name : String) : String

  Changes the name of the current thread.

- .sleep(time : Time::Span) : Nil

  Blocks the current thread for the duration of time.

- .start_world : Nil
- .stop_world : Nil
- .unlock : Nil
- .unsafe_each(&)
- .yield : Nil

  Yields the currently running thread.

##
Instance Method Summary

- #current_fiber : Fiber

  Returns the Fiber currently running on the thread.

- #current_fiber=(current_fiber : Fiber)

  Returns the Fiber currently running on the thread.

- #current_fiber? : Fiber | Nil

  Returns the Fiber currently running on the thread.

- #gc_thread_handler : Pointer(Void)

  Holds the GC thread handler

- #gc_thread_handler=(gc_thread_handler : Pointer(Void))

  Holds the GC thread handler

- #inspect(io : IO) : Nil

  Appends a String representation of this object which includes its class name, its object address and the values of all instance variables.

- #internal_name=(name : String)

  Changes the Thread#name property but doesn't update the system name.

- #join : Nil

  Suspends the current thread until this thread terminates.

- #main_fiber : Fiber

  Returns the Fiber representing the thread's main stack.

- #main_fiber? : Fiber | Nil

  Returns the Fiber representing the thread's main stack.

- #name : String | Nil
- #resume : Nil
- #suspend : Nil
- #to_s(io : IO) : Nil

  Appends a short String representation of this object which includes its class name and its object address.

- #wait_suspended : Nil

### Instance methods inherited from module `Crystal::System::Thread`

to_unsafe to_unsafe

### Class methods inherited from module `Crystal::System::Thread`

current_handle : Handle current_handle, current_thread : ::Thread current_thread, current_thread=(current_thread : ::Thread) current_thread=, current_thread? : ::Thread | Nil current_thread?, init : Nil init, init_suspend_resume : Nil init_suspend_resume, sig_resume : ::Signal sig_resume, sig_suspend : ::Signal sig_suspend, sleep(time : ::Time::Span) : Nil sleep, thread_proc(data : Pointer(Void)) : Pointer(Void) thread_proc, yield_current : Nil yield_current

### Instance methods inherited from class `Reference`

==(other : self)
==(other : JSON::Any)
==(other : YAML::Any)
==(other) ==, dup dup, hash(hasher) hash, initialize initialize, inspect(io : IO) : Nil inspect, object_id : UInt64 object_id, pretty_print(pp) : Nil pretty_print, same?(other : Reference) : Bool
same?(other : Nil) same?, to_s(io : IO) : Nil to_s

### Constructor methods inherited from class `Reference`

new new, unsafe_construct(address : Pointer, *args, **opts) : self unsafe_construct

### Class methods inherited from class `Reference`

pre_initialize(address : Pointer) pre_initialize

### 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.current : Thread #

Returns the Thread object associated to the running system thread.

def self.new(name : String | Nil = nil, &func : Thread -> ) #

Creates and starts a new system thread.

def self.new #

Used once to initialize the thread object representing the main thread of the process (that already exists).

##
Class Method Detail

def self.delay(backoff : Int32) : Int32 #

Delays execution for a brief moment.

def self.each(&) #
def self.init : Nil #
def self.lock : Nil #
def self.name=(name : String) : String #

Changes the name of the current thread.

def self.sleep(time : Time::Span) : Nil #

Blocks the current thread for the duration of time. Clock precision is dependent on the operating system and hardware.

def self.start_world : Nil #
def self.stop_world : Nil #
def self.unlock : Nil #
def self.unsafe_each(&) #
def self.yield : Nil #

Yields the currently running thread.

##
Instance Method Detail

def current_fiber : Fiber #

Returns the Fiber currently running on the thread.

def current_fiber=(current_fiber : Fiber) #

Returns the Fiber currently running on the thread.

def current_fiber? : Fiber | Nil #

Returns the Fiber currently running on the thread.

def gc_thread_handler : Pointer(Void) #

Holds the GC thread handler

def gc_thread_handler=(gc_thread_handler : Pointer(Void)) #

Holds the GC thread handler

def inspect(io : IO) : Nil #
Description copied from class Reference

Appends a String representation of this object which includes its class name, its object address and the values of all instance variables.

    class Person
      def initialize(@name : String, @age : Int32)
      end
    end

    Person.new("John", 32).inspect # => #<Person:0x10fd31f20 @name="John", @age=32>

def internal_name=(name : String) #

Changes the Thread#name property but doesn't update the system name. Useful on the main thread where we'd change the process name (e.g. top, ps, ...).

def join : Nil #

Suspends the current thread until this thread terminates.

def main_fiber : Fiber #

Returns the Fiber representing the thread's main stack.

def main_fiber? : Fiber | Nil #

Returns the Fiber representing the thread's main stack.

def name : String | Nil #
def resume : Nil #
def suspend : Nil #
def to_s(io : IO) : Nil #
Description copied from class Reference

Appends a short String representation of this object which includes its class name and its object address.

    class Person
      def initialize(@name : String, @age : Int32)
      end
    end

    Person.new("John", 32).to_s # => #<Person:0x10a199f20>

def wait_suspended : Nil #