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Add documentation for Ractor (#3895)

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Victor Shepelev 2020-12-19 20:04:40 +02:00 committed by GitHub
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Notes: git 2020-12-20 03:05:06 +09:00
Merged-By: marcandre <github@marc-andre.ca>
3 changed files with 702 additions and 89 deletions

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@ -20,6 +20,7 @@ kernel.rb
pack.rb
trace_point.rb
warning.rb
ractor.rb
# the lib/ directory (which has its own .document file)
lib

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@ -1933,6 +1933,100 @@ ractor_moved_missing(int argc, VALUE *argv, VALUE self)
rb_raise(rb_eRactorMovedError, "can not send any methods to a moved object");
}
/*
* Document-class: Ractor::ClosedError
*
* Raised when an attempt is made to take something from the Ractor's outgoing port,
* but it is closed with Ractor#close_outgoing, or to send something to Ractor's
* incoming port, and it is closed with Ractor#close_incoming, or an attempt to
* send/take something with ractor which was already terminated.
*
* r = Ractor.new { sleep(500) }
* r.close_outgoing
* r.take # Ractor::ClosedError
*
* ClosedError is a descendant of StopIteration, so the closing of the ractor will break
* the loops without propagating the error:
*
* r = Ractor.new { 3.times { puts "Received: " + receive } }
*
* loop { r.send "test" }
* puts "Continue successfully"
*
* This will print:
*
* Received: test
* Received: test
* Received: test
* Continue successfully
*/
/*
* Document-class: Ractor::RemoteError
*
* Raised on attempt to Ractor#take if there was an uncaught exception in the Ractor.
* Its +cause+ will contain the original exception, and +ractor+ is the original ractor
* it was raised in.
*
* r = Ractor.new { raise "Something weird happened" }
*
* begin
* r.take
* rescue => e
* p e # => #<Ractor::RemoteError: thrown by remote Ractor.>
* p e.ractor == r # => true
* p e.cause # => #<RuntimeError: Something weird happened>
* end
*
*/
/*
* Document-class: Ractor::MovedError
*
* Raised on an attempt to access an object which was moved in Ractor#send or Ractor.yield.
*
* r = Ractor.new { sleep }
*
* ary = [1, 2, 3]
* r.send(ary, move: true)
* ary.inspect
* # Ractor::MovedError (can not send any methods to a moved object)
*
*/
/*
* Document-class: Ractor::MovedObject
*
* A special object which replaces any value that was moved to another ractor in Ractor#send
* or Ractor.yield. Any attempt to access the object results in Ractor::MovedError.
*
* r = Ractor.new { receive }
*
* ary = [1, 2, 3]
* r.send(ary, move: true)
* p Ractor::MovedObject === ary
* # => true
* ary.inspect
* # Ractor::MovedError (can not send any methods to a moved object)
*
* The class MovedObject is frozen to avoid tampering with it:
*
* class Ractor::MovedObject
* def inspect
* "<MyMovedObject>"
* end
* end
* # FrozenError (can't modify frozen class: Ractor::MovedObject)
*/
// Main docs are in ractor.rb, but without this clause there are weird artifacts
// in their rendering.
/*
* Document-class: Ractor
*
*/
void
Init_Ractor(void)
{

696
ractor.rb
View file

@ -1,34 +1,242 @@
# Ractor is a Actor-model abstraction for Ruby that provides thread-safe parallel execution.
#
# To achieve this, ractors severely limit data sharing between different ractors.
# Unlike threads, ractors can't access each other's data, nor any data through variables of
# the outer scope.
#
# # The simplest ractor
# r = Ractor.new {puts "I am in Ractor!"}
# r.take # allow it to finish
# # here "I am in Ractor!" would be printed
#
# a = 1
# r = Ractor.new {puts "I am in Ractor! a=#{a}"}
# # fails immediately with
# # ArgumentError (can not isolate a Proc because it accesses outer variables (a).)
#
# On CRuby (the default implementation), Global Virtual Machine Lock (GVL) is held per ractor, so
# ractors are performed in parallel without locking each other.
#
# Instead of accessing the shared state, the data should be passed to and from ractors via
# sending and receiving messages, thus making them _actors_ ("Ractor" stands for "Ruby Actor").
#
# a = 1
# r = Ractor.new do
# a_in_ractor = receive # receive blocks till somebody will pass message
# puts "I am in Ractor! a=#{a_in_ractor}"
# end
# r.send(a) # pass it
# r.take
# # here "I am in Ractor! a=1" would be printed
#
# There are two pairs of methods for sending/receiving messages:
#
# * Ractor#send and Ractor.receive for when the _sender_ knows the receiver (push);
# * Ractor.yield and Ractor#take for when the _receiver_ knows the sender (pull);
#
# In addition to that, an argument to Ractor.new would be passed to block and available there
# as if received by Ractor.receive, and the last block value would be sent outside of the
# ractor as if sent by Ractor.yield.
#
# A little demonstration on a classic ping-pong:
#
# server = Ractor.new do
# puts "Server starts: #{self.inspect}"
# puts "Server sends: ping"
# Ractor.yield 'ping' # The server doesn't know the receiver and sends to whoever interested
# received = Ractor.receive # The server doesn't know the sender and receives from whoever sent
# puts "Server received: #{received}"
# end
#
# client = Ractor.new(server) do |srv| # The server is sent inside client, and available as srv
# puts "Client starts: #{self.inspect}"
# received = srv.take # The Client takes a message specifically from the server
# puts "Client received from " \
# "#{srv.inspect}: #{received}"
# puts "Client sends to " \
# "#{srv.inspect}: pong"
# srv.send 'pong' # The client sends a message specifically to the server
# end
#
# [client, server].each(&:take) # Wait till they both finish
#
# This will output:
#
# Server starts: #<Ractor:#2 test.rb:1 running>
# Server sends: ping
# Client starts: #<Ractor:#3 test.rb:8 running>
# Client received from #<Ractor:#2 rac.rb:1 blocking>: ping
# Client sends to #<Ractor:#2 rac.rb:1 blocking>: pong
# Server received: pong
#
# It is said that Ractor receives messages via the <em>incoming port</em>, and sends them
# to the <em>outgoing port</em>. Either one can be disabled with Ractor#close_incoming and
# Ractor#close_outgoing respectively.
#
# == Shareable and unshareable objects
#
# When the object is sent to and from the ractor, it is important to understand whether the
# object is shareable or not. Shareable objects are basically those which can be used by several
# threads without compromising thread-safety; e.g. immutable ones. Ractor.shareable? allows to
# check this, and Ractor.make_shareable tries to make object shareable if it is not.
#
# Ractor.shareable?(1) #=> true -- numbers and other immutable basic values are
# Ractor.shareable?('foo') #=> false, unless the string is frozen due to # freeze_string_literals: true
# Ractor.shareable?('foo'.freeze) #=> true
#
# ary = ['hello', 'world']
# ary.frozen? #=> false
# ary[0].frozen? #=> false
# Ractor.make_shareable(ary)
# ary.frozen? #=> true
# ary[0].frozen? #=> true
# ary[1].frozen? #=> true
#
# When a shareable object is sent (via #send or Ractor.yield), no additional processing happens,
# and it just becomes usable by both ractors. When an unshareable object is sent, it can be
# either _copied_ or _moved_. The first is the default, and it makes the object's full copy by
# deep cloning of non-shareable parts of its structure.
#
# data = ['foo', 'bar'.freeze]
# r = Ractor.new do
# data2 = Ractor.receive
# puts "In ractor: #{data2.object_id}, #{data2[0].object_id}, #{data2[1].object_id}"
# end
# r.send(data)
# r.take
# puts "Outside : #{data.object_id}, #{data[0].object_id}, #{data[1].object_id}"
#
# This will output:
#
# In ractor: 340, 360, 320
# Outside : 380, 400, 320
#
# (Note that object id of both array and non-frozen string inside array have changed inside
# the ractor, showing it is different objects. But the second array's element, which is a
# shareable frozen string, has the same object_id.)
#
# Deep cloning of the data may be slow, and sometimes impossible. Alternatively,
# <tt>move: true</tt> may be used on sending. This will <em>move</em> the object to the
# receiving ractor, making it inaccessible for a sending ractor.
#
# data = ['foo', 'bar']
# r = Ractor.new do
# data_in_ractor = Ractor.receive
# puts "In ractor: #{data_in_ractor.object_id}, #{data_in_ractor[0].object_id}"
# end
# r.send(data, move: true)
# r.take
# puts "Outside: moved? #{Ractor::MovedObject === data}"
# puts "Outside: #{data.inspect}"
#
# This will output:
#
# In ractor: 100, 120
# Outside: moved? true
# test.rb:9:in `method_missing': can not send any methods to a moved object (Ractor::MovedError)
#
# Notice that even +inspect+ (and more basic methods like <tt>__id__</tt>) is inaccessible
# on a moved object.
#
# Besides frozen objects, shareable objects are instances of Module, Class and Ractor itself. Modules
# and classes, though, can not access instance variables from ractors other than main:
#
# class C
# class << self
# attr_accessor :tricky
# end
# end
#
# C.tricky = 'test'
#
# r = Ractor.new(C) do |cls|
# puts "I see #{cls}"
# puts "I can't see #{cls.tricky}"
# end
# r.take
# # I see C
# # can not access instance variables of classes/modules from non-main Ractors (RuntimeError)
#
# Ractors can access constants if they are shareable. The main Ractor is the only one that can
# access non-shareable constants.
#
# GOOD = 'good'.freeze
# BAD = 'bad'
#
# r = Ractor.new do
# puts "GOOD=#{GOOD}"
# puts "BAD=#{BAD}"
# end
# r.take
# # GOOD=good
# # can not access non-shareable objects in constant Object::BAD by non-main Ractor. (NameError)
#
# # Consider the same C class from above
#
# r = Ractor.new do
# puts "I see #{C}"
# puts "I can't see #{C.tricky}"
# end
# r.take
# # I see C
# # can not access instance variables of classes/modules from non-main Ractors (RuntimeError)
#
# See also the description of <tt># shareable_constant_value</tt> pragma in
# {Comments syntax}[rdoc-ref:doc/syntax/comments.rdoc] explanation.
#
# == Ractors vs threads
#
# Each ractor creates its own thread. New threads can be created from inside ractor, having the full
# access to its data (and, on CRuby, sharing GVL with other threads of this ractor).
#
# r = Ractor.new do
# a = 1
# Thread.new {puts "Thread in ractor: a=#{a}"}.join
# end
# r.take
# # Here "Thread in ractor: a=1" will be printed
#
# == Note on code examples
#
# In examples below, sometimes we use the following method to wait till ractors that
# are not currently blocked will finish (or process till next blocking) method.
#
# def wait
# sleep(0.1)
# end
#
# It is **only for demonstration purposes** and shouldn't be used in a real code.
# Most of the times, just #take is used to wait till ractor will finish.
#
class Ractor
# Create a new Ractor with args and a block.
# args are passed via incoming channel.
# A block (Proc) will be isolated (can't access to outer variables)
#
# A ractor has default two channels:
# an incoming channel and an outgoing channel.
# A block (Proc) will be isolated (can't access to outer variables). +self+
# inside the block will refer to the current Ractor.
#
# Other ractors send objects to the ractor via the incoming channel and
# the ractor receives them.
# The ractor send objects via the outgoing channel and other ractors can
# receive them.
# r = Ractor.new {puts "Hi, I am #{self.inspect}"}
# r.take
# # Prints "Hi, I am #<Ractor:#2 test.rb:1 running>"
#
# The result of the block is sent via the outgoing channel
# and other
# +args+ passed to the method would be propagated to block args by the same rules as
# objects passed through #send/Ractor.receive: if +args+ are not shareable, they
# will be copied (via deep cloning, which might be inefficient).
#
# r = Ractor.new do
# Ractor.receive # receive via r's mailbox => 1
# Ractor.receive # receive via r's mailbox => 2
# Ractor.yield 3 # yield a message (3) and wait for taking by another ractor.
# 'ok' # the return value will be yielded.
# # and r's incoming/outgoing ports are closed automatically.
# end
# r.send 1 # send a message (1) into r's mailbox.
# r << 2 # << is an alias of `send`.
# p r.take # take a message from r's outgoing port => 3
# p r.take # => 'ok'
# p r.take # raise Ractor::ClosedError
# arg = [1, 2, 3]
# puts "Passing: #{arg} (##{arg.object_id})"
# r = Ractor.new(arg) {|received_arg|
# puts "Received: #{received_arg} (##{received_arg.object_id})"
# }
# r.take
# # Prints:
# # Passing: [1, 2, 3] (#280)
# # Received: [1, 2, 3] (#300)
#
# other options:
# name: Ractor's name
# Ractor's +name+ can be set for debugging purposes:
#
# r = Ractor.new(name: 'my ractor') {}
# p r
# #=> #<Ractor:#3 my ractor test.rb:1 terminated>
#
def self.new(*args, name: nil, &block)
b = block # TODO: builtin bug
@ -38,38 +246,75 @@ class Ractor
__builtin_ractor_create(loc, name, args, b)
end
# return current Ractor
# Returns the currently executing Ractor.
#
# Ractor.current #=> #<Ractor:#1 running>
def self.current
__builtin_cexpr! %q{
rb_ec_ractor_ptr(ec)->self
}
}
end
# Returns total count of Ractors currently running.
#
# Ractor.count #=> 1
# r = Ractor.new(name: 'example') {sleep(0.1)}
# Ractor.count #=> 2 (main + example ractor)
# r.take # wait till r will finish
# Ractor.count #=> 1
def self.count
__builtin_cexpr! %q{
ULONG2NUM(GET_VM()->ractor.cnt);
}
}
end
# Multiplex multiple Ractor communications.
# call-seq: Ractor.select(*ractors, [yield_value:, move: false]) -> [ractor or symbol, obj]
#
# r, obj = Ractor.select(r1, r2)
# #=> wait for taking from r1 or r2
# # returned obj is a taken object from Ractor r
# Waits for the first ractor to have something in its outgoing port, reads from this ractor, and
# returns that ractor and the object received.
#
# r, obj = Ractor.select(r1, r2, Ractor.current)
# #=> wait for taking from r1 or r2
# # or receive from incoming queue
# # If receive is succeed, then obj is received value
# # and r is :receive (Ractor.current)
# r1 = Ractor.new {Ractor.yield 'from 1'}
# r2 = Ractor.new {Ractor.yield 'from 2'}
#
# r, obj = Ractor.select(r1, r2, Ractor.current, yield_value: obj)
# #=> wait for taking from r1 or r2
# # or receive from incoming queue
# # or yield (Ractor.yield) obj
# # If yield is succeed, then obj is nil
# # and r is :yield
# r, obj = Ractor.select(r1, r2)
#
# puts "received #{obj.inspect} from #{r.inspect}"
# # Prints: received "from 1" from #<Ractor:#2 test.rb:1 running>
#
# If one of the given ractors is the current ractor, and it would be selected, +r+ will contain
# +:receive+ symbol instead of the ractor object.
#
# r1 = Ractor.new(Ractor.current) do |main|
# main.send 'to main'
# Ractor.yield 'from 1'
# end
# r2 = Ractor.new do
# Ractor.yield 'from 2'
# end
#
# r, obj = Ractor.select(r1, r2, Ractor.current)
# puts "received #{obj.inspect} from #{r.inspect}"
# # Prints: received "to main" from :receive
#
# If +yield_value+ is provided, that value may be yielded if another Ractor is calling #take.
# In this case, the pair <tt>[:yield, nil]</tt> would be returned:
#
# r1 = Ractor.new(Ractor.current) do |main|
# puts "Received from main: #{main.take}"
# end
#
# puts "Trying to select"
# r, obj = Ractor.select(r1, Ractor.current, yield_value: 123)
# wait
# puts "Received #{obj.inspect} from #{r.inspect}"
#
# This will print:
#
# Trying to select
# Received from main: 123
# Received nil from :yield
#
# +move+ boolean flag defines whether yielded value should be copied (default) or moved.
def self.select(*ractors, yield_value: yield_unspecified = true, move: false)
raise ArgumentError, 'specify at least one ractor or `yield_value`' if yield_unspecified && ractors.empty?
@ -80,14 +325,68 @@ class Ractor
yield_unspecified == Qtrue ? Qundef : yield_value,
(bool)RTEST(move) ? true : false, &rv);
return rb_ary_new_from_args(2, rv, v);
}
}
end
# Receive an incoming message from Ractor's incoming queue.
# Receive an incoming message from the current Ractor's incoming port's queue, which was
# sent there by #send.
#
# r = Ractor.new do
# v1 = Ractor.receive
# puts "Received: #{v1}"
# end
# r.send('message1')
# r.take
# # Here will be printed: "Received: message1"
#
# Alternatively, private instance method +receive+ may be used:
#
# r = Ractor.new do
# v1 = receive
# puts "Received: #{v1}"
# end
# r.send('message1')
# r.take
# # Here will be printed: "Received: message1"
#
# The method blocks if the queue is empty.
#
# r = Ractor.new do
# puts "Before first receive"
# v1 = Ractor.receive
# puts "Received: #{v1}"
# v2 = Ractor.receive
# puts "Received: #{v2}"
# end
# wait
# puts "Still not received"
# r.send('message1')
# wait
# puts "Still received only one"
# r.send('message2')
# r.take
#
# Output:
#
# Before first receive
# Still not received
# Received: message1
# Still received only one
# Received: message2
#
# If close_incoming was called on the ractor, the method raises Ractor::ClosedError:
#
# Ractor.new do
# close_incoming
# receive
# end
# wait
# # in `receive': The incoming port is already closed => #<Ractor:#2 test.rb:1 running> (Ractor::ClosedError)
#
def self.receive
__builtin_cexpr! %q{
ractor_receive(ec, rb_ec_ractor_ptr(ec))
}
}
end
class << self
@ -98,7 +397,7 @@ class Ractor
private def receive
__builtin_cexpr! %q{
ractor_receive(ec, rb_ec_ractor_ptr(ec))
}
}
end
alias recv receive
@ -107,33 +406,55 @@ class Ractor
# Instead of Ractor.receive, Ractor.receive_if can provide a pattern
# by a block and you can choose the receiving message.
#
# # Example:
# r = Ractor.new do
# p Ractor.receive_if{|msg| /foo/ =~ msg} #=> "foo3"
# p Ractor.receive_if{|msg| /bar/ =~ msg} #=> "bar1"
# p Ractor.receive_if{|msg| /baz/ =~ msg} #=> "baz2"
# end
# r << "bar1"
# r << "baz2"
# r << "foo3"
# r.take
# r = Ractor.new do
# p Ractor.receive_if{|msg| msg.match?(/foo/)} #=> "foo3"
# p Ractor.receive_if{|msg| msg.match?(/bar/)} #=> "bar1"
# p Ractor.receive_if{|msg| msg.match?(/baz/)} #=> "baz2"
# end
# r << "bar1"
# r << "baz2"
# r << "foo3"
# r.take
#
# If the block returns truthy, the message will be removed from incoming queue
# This will output:
#
# foo3
# bar1
# baz2
#
# If the block returns a truthy value, the message will be removed from the incoming queue
# and return this method with the message.
# When the block is escaped by break/return/exception and so on, the message also
# removed from the incoming queue.
# Otherwise, the messsage is remained in the incoming queue and check next received
# message by the given block.
# Otherwise, the messsage remains in the incoming queue and the next received
# message is checked by the given block.
#
# If there is no messages in the incoming queue, wait until arrival of other messages.
# If there is no messages in the incoming queue matching the check, the method will
# block until such message arrives.
#
# r = Ractor.new do
# val = Ractor.receive_if{|msg| msg.is_a?(Array)}
# puts "Received successfully: #{val}"
# end
#
# r.send(1)
# r.send('test')
# wait
# puts "2 non-matching sent, nothing received"
# r.send([1, 2, 3])
# wait
#
# Prints:
#
# 2 non-matching sent, nothing received
# Received successfully: [1, 2, 3]
#
# Note that you can not call receive/receive_if in the given block recursively.
# It means that you should not do any tasks in the block.
#
# # Example:
# Ractor.current << true
# Ractor.receive_if{|msg| Ractor.receive}
# #=> `receive': can not call receive/receive_if recursively (Ractor::Error)
# Ractor.current << true
# Ractor.receive_if{|msg| Ractor.receive}
# #=> `receive': can not call receive/receive_if recursively (Ractor::Error)
#
def self.receive_if &b
Primitive.ractor_receive_if b
@ -143,50 +464,205 @@ class Ractor
Primitive.ractor_receive_if b
end
# Send a message to a Ractor's incoming queue.
# Send a message to a Ractor's incoming queue to be consumed by Ractor.receive.
#
# # Example:
# r = Ractor.new do
# p Ractor.receive #=> 'ok'
# value = Ractor.receive
# puts "Received #{value}"
# end
# r.send 'ok' # send to r's incoming queue.
# r.send 'message'
# # Prints: "Received: message"
#
# The method is non-blocking (will return immediately even if the ractor is not ready
# to receive anything):
#
# r = Ractor.new {sleep(5)}
# r.send('test')
# puts "Sent successfully"
# # Prints: "Sent successfully" immediately
#
# Attempt to send to ractor which already finished its execution will raise Ractor::ClosedError.
#
# r = Ractor.new {}
# r.take
# p r
# # "#<Ractor:#6 (irb):23 terminated>"
# r.send('test')
# # Ractor::ClosedError (The incoming-port is already closed)
#
# If close_incoming was called on the ractor, the method also raises Ractor::ClosedError.
#
# r = Ractor.new do
# sleep(500)
# receive
# end
# r.close_incoming
# r.send('test')
# # Ractor::ClosedError (The incoming-port is already closed)
# # The error would be raised immediately, not when ractor will try to receive
#
# If the +obj+ is unshareable, by default it would be copied into ractor by deep cloning.
# If the <tt>move: true</tt> is passed, object is _moved_ into ractor and becomes
# inaccessible to sender.
#
# r = Ractor.new {puts "Received: #{receive}"}
# msg = 'message'
# r.send(msg, move: true)
# r.take
# p msg
#
# This prints:
#
# Received: message
# in `p': undefined method `inspect' for #<Ractor::MovedObject:0x000055c99b9b69b8>
#
# All references to the object and its parts will become invalid in sender.
#
# r = Ractor.new {puts "Received: #{receive}"}
# s = 'message'
# ary = [s]
# copy = ary.dup
# r.send(ary, move: true)
#
# s.inspect
# # Ractor::MovedError (can not send any methods to a moved object)
# ary.class
# # Ractor::MovedError (can not send any methods to a moved object)
# copy.class
# # => Array, it is different object
# copy[0].inspect
# # Ractor::MovedError (can not send any methods to a moved object)
# # ...but its item was still a reference to `s`, which was moved
#
# If the object was shareable, <tt>move: true</tt> has no effect on it:
#
# r = Ractor.new {puts "Received: #{receive}"}
# s = 'message'.freeze
# r.send(s, move: true)
# s.inspect #=> "message", still available
#
def send(obj, move: false)
__builtin_cexpr! %q{
ractor_send(ec, RACTOR_PTR(self), obj, move)
}
}
end
alias << send
# yield a message to the ractor's outgoing port.
# Send a message to the current ractor's outgoing port to be consumed by #take.
#
# r = Ractor.new {Ractor.yield 'Hello from ractor'}
# puts r.take
# # Prints: "Hello from ractor"
#
# The method is blocking, and will return only when somebody consumes the
# sent message.
#
# r = Ractor.new do
# Ractor.yield 'Hello from ractor'
# puts "Ractor: after yield"
# end
# wait
# puts "Still not taken"
# puts r.take
#
# This will print:
#
# Still not taken
# Hello from ractor
# Ractor: after yield
#
# If the outgoing port was closed with #close_outgoing, the method will raise:
#
# r = Ractor.new do
# close_outgoing
# Ractor.yield 'Hello from ractor'
# end
# wait
# # `yield': The outgoing-port is already closed (Ractor::ClosedError)
#
# The meaning of +move+ argument is the same as for #send.
def self.yield(obj, move: false)
__builtin_cexpr! %q{
ractor_yield(ec, rb_ec_ractor_ptr(ec), obj, move)
}
}
end
# Take a message from ractor's outgoing port.
# Take a message from ractor's outgoing port, which was put there by Ractor.yield or at ractor's
# finalization.
#
# Example:
# r = Ractor.new{ 'oK' }
# p r.take #=> 'ok'
def take
# r = Ractor.new do
# Ractor.yield 'explicit yield'
# 'last value'
# end
# puts r.take #=> 'explicit yield'
# puts r.take #=> 'last value'
# puts r.take # Ractor::ClosedError (The outgoing-port is already closed)
#
# The fact that the last value is also put to outgoing port means that +take+ can be used
# as some analog of Thread#join ("just wait till ractor finishes"), but don't forget it
# will raise if somebody had already consumed everything ractor have produced.
#
# If the outgoing port was closed with #close_outgoing, the method will raise Ractor::ClosedError.
#
# r = Ractor.new do
# sleep(500)
# Ractor.yield 'Hello from ractor'
# end
# r.close_outgoing
# r.take
# # Ractor::ClosedError (The outgoing-port is already closed)
# # The error would be raised immediately, not when ractor will try to receive
#
# If an uncaught exception is raised in the Ractor, it is propagated on take as a
# Ractor::RemoteError.
#
# r = Ractor.new {raise "Something weird happened"}
#
# begin
# r.take
# rescue => e
# p e # => #<Ractor::RemoteError: thrown by remote Ractor.>
# p e.ractor == r # => true
# p e.cause # => #<RuntimeError: Something weird happened>
# end
#
# Ractor::ClosedError is a descendant of StopIteration, so the closing of the ractor will break
# the loops without propagating the error:
#
# r = Ractor.new do
# 3.times {|i| Ractor.yield "message #{i}"}
# "finishing"
# end
#
# loop {puts "Received: " + r.take}
# puts "Continue successfully"
#
# This will print:
#
# Received: message 0
# Received: message 1
# Received: message 2
# Received: finishing
# Continue successfully
def take
__builtin_cexpr! %q{
ractor_take(ec, RACTOR_PTR(self))
}
}
end
def inspect
loc = __builtin_cexpr! %q{ RACTOR_PTR(self)->loc }
name = __builtin_cexpr! %q{ RACTOR_PTR(self)->name }
id = __builtin_cexpr! %q{ INT2FIX(RACTOR_PTR(self)->id) }
def inspect # :nodoc:
loc = __builtin_cexpr! %q{RACTOR_PTR(self)->loc}
name = __builtin_cexpr! %q{RACTOR_PTR(self)->name}
id = __builtin_cexpr! %q{INT2FIX(RACTOR_PTR(self)->id)}
status = __builtin_cexpr! %q{
rb_str_new2(ractor_status_str(RACTOR_PTR(self)->status_))
}
}
"#<Ractor:##{id}#{name ? ' '+name : ''}#{loc ? " " + loc : ''} #{status}>"
end
# The name set in Ractor.new, or +nil+.
def name
__builtin_cexpr! %q{ RACTOR_PTR(self)->name }
__builtin_cexpr! %q{RACTOR_PTR(self)->name}
end
class RemoteError
@ -194,39 +670,81 @@ class Ractor
end
# Closes the incoming port and returns its previous state.
# All further attempts to Ractor.receive in the ractor, and #send to the ractor
# will fail with Ractor::ClosedError.
#
# r = Ractor.new {sleep(500)}
# r.close_incoming #=> false
# r.close_incoming #=> true
# r.send('test')
# # Ractor::ClosedError (The incoming-port is already closed)
def close_incoming
__builtin_cexpr! %q{
ractor_close_incoming(ec, RACTOR_PTR(self));
}
}
end
# Closes the outgoing port and returns its previous state.
# All further attempts to Ractor.yield in the ractor, and #take from the ractor
# will fail with Ractor::ClosedError.
#
# r = Ractor.new {sleep(500)}
# r.close_outgoing #=> false
# r.close_outgoing #=> true
# r.take
# # Ractor::ClosedError (The outgoing-port is already closed)
def close_outgoing
__builtin_cexpr! %q{
ractor_close_outgoing(ec, RACTOR_PTR(self));
}
}
end
# utility method
# Checks if the object is shareable by ractors.
#
# Ractor.shareable?(1) #=> true -- numbers and other immutable basic values are frozen
# Ractor.shareable?('foo') #=> false, unless the string is frozen due to # freeze_string_literals: true
# Ractor.shareable?('foo'.freeze) #=> true
#
# See also the "Shareable and unshareable objects" section in the Ractor class docs.
def self.shareable? obj
__builtin_cexpr! %q{
rb_ractor_shareable_p(obj) ? Qtrue : Qfalse;
}
}
end
# make obj sharable.
# Make +obj+ sharable.
#
# Basically, traverse referring objects from obj and freeze them.
#
# When a sharable object is found in traversing, stop traversing
# from this shareable object.
#
# If copy keyword is true, it makes a deep copied object
# If +copy+ keyword is +true+, it makes a deep copied object
# and make it sharable. This is safer option (but it can take more time).
#
# Note that the specification and implementation of this method are not
# matured and can be changed in a future.
#
# obj = ['test']
# Ractor.shareable?(obj) #=> false
# Ractor.make_shareable(obj) #=> ["test"]
# Ractor.shareable?(obj) #=> true
# obj.frozen? #=> true
# obj[0].frozen? #=> true
#
# # Copy vs non-copy versions:
# obj1 = ['test']
# obj1s = Ractor.make_shareable(obj1)
# obj1.frozen? #=> true
# obj1s.object_id == obj1.object_id #=> true
# obj2 = ['test']
# obj2s = Ractor.make_shareable(obj2, copy: true)
# obj2.frozen? #=> false
# obj2s.frozen? #=> true
# obj2s.object_id == obj1.object_id #=> false
# obj2s[0].object_id == obj2[0].object_id #=> false
#
# See also the "Shareable and unshareable objects" section in the Ractor class docs.
def self.make_shareable obj, copy: false
if copy
__builtin_cexpr! %q{