Class: Libuv::Reactor

Inherits:
Object show all
Extended by:
Accessors, ClassMethods
Includes:
Assertions, Resource
Defined in:
lib/libuv/reactor.rb

Defined Under Namespace

Modules: ClassMethods

Constant Summary collapse

CRITICAL = 
::Mutex.new

Constants included from Accessors

Accessors::Functions

Constants included from Assertions

Assertions::MSG_NO_PROC

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Accessors

reactor

Methods included from ClassMethods

create, current, default, new

Methods included from Resource

#check_result, #check_result!, #resolve, #to_ptr

Methods included from Assertions

#assert_block, #assert_boolean, #assert_type

Constructor Details

#initialize(pointer) ⇒ Reactor

Initialize a reactor using an FFI::Pointer to a libuv reactor



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# File 'lib/libuv/reactor.rb', line 56

def initialize(pointer) # :notnew:
    @pointer = pointer
    @reactor = self
    @run_count = 0
    @ref_count = 0

    # Create an async call for scheduling work from other threads
    @run_queue = Queue.new
    @process_queue = @reactor.async method(:process_queue_cb)
    @process_queue.unref

    # Create a next tick timer
    @next_tick = @reactor.timer method(:next_tick_cb)
    @next_tick.unref

    # Create an async call for ending the reactor
    @stop_reactor = @reactor.async method(:stop_cb)
    @stop_reactor.unref

    # Libuv can prevent the application shutting down once the main thread has ended
    # The addition of a prepare function prevents this from happening.
    @reactor_prep = Libuv::Prepare.new(@reactor, method(:noop))
    @reactor_prep.unref
    @reactor_prep.start

    # LibUV ingnores program interrupt by default.
    # We provide normal behaviour and allow this to be overriden
    @on_signal = []
    sig_callback = method(:signal_cb)
    self.signal(:INT, sig_callback).unref
    self.signal(:HUP, sig_callback).unref
    self.signal(:TERM, sig_callback).unref

    # Notify of errors
    @throw_on_exit = nil
    @reactor_notify_default = @reactor_notify = proc { |error|
        @throw_on_exit = error
    }
end

Instance Attribute Details

#run_count ⇒ Object (readonly)

Returns the value of attribute run_count.



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# File 'lib/libuv/reactor.rb', line 96

def run_count
  @run_count
end

Instance Method Details

#all(*promises) ⇒ ::Libuv::Q::Promise

Combines multiple promises into a single promise that is resolved when all of the input promises are resolved. (thread safe)

Parameters:

  • a number of promises that will be combined into a single promise

Returns:

  • Returns a single promise that will be resolved with an array of values, each value corresponding to the promise at the same index in the promises array. If any of the promises is resolved with a rejection, this resulting promise will be resolved with the same rejection.



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# File 'lib/libuv/reactor.rb', line 245

def all(*promises)
    Q.all(@reactor, *promises)
end

#any(*promises) ⇒ ::Libuv::Q::Promise

Combines multiple promises into a single promise that is resolved when any of the input promises are resolved.

Parameters:

  • a number of promises that will be combined into a single promise

Returns:

  • Returns a single promise



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# File 'lib/libuv/reactor.rb', line 255

def any(*promises)
    Q.any(@reactor, *promises)
end

#async(callback = nil, &block) ⇒ ::Libuv::Async

Get a new Async handle

Returns:



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# File 'lib/libuv/reactor.rb', line 379

def async(callback = nil, &block)
    callback ||= block
    handle = Async.new(@reactor)
    handle.progress callback if callback
    handle
end

#check(callback = nil, &blk) ⇒ ::Libuv::Check

Get a new Check handle

Returns:



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# File 'lib/libuv/reactor.rb', line 364

def check(callback = nil, &blk)
    Check.new(@reactor, callback || blk)
end

#defer ⇒ ::Libuv::Q::Deferred

Creates a deferred result object for where the result of an operation may only be returned at some point in the future or is being processed on a different thread (thread safe)

Returns:



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# File 'lib/libuv/reactor.rb', line 233

def defer
    Q.defer(@reactor)
end

#file(path, flags = 0, mode: 0, **opts, &blk) ⇒ ::Libuv::File

Opens a file and returns an object that can be used to manipulate it

Parameters:

  • the path to the file or folder for watching

  • (defaults to: 0)

    see ruby File::Constants

  • (defaults to: 0)

Returns:



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# File 'lib/libuv/reactor.rb', line 446

def file(path, flags = 0, mode: 0, **opts, &blk)
    assert_type(String, path, "path must be a String")
    assert_type(Integer, flags, "flags must be an Integer")
    assert_type(Integer, mode, "mode must be an Integer")
    File.new(@reactor, path, flags, mode: mode, **opts, &blk)
end

#filesystem ⇒ ::Libuv::Filesystem

Returns an object for manipulating the filesystem

Returns:



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# File 'lib/libuv/reactor.rb', line 456

def filesystem
    Filesystem.new(@reactor)
end

#finally(*promises) ⇒ ::Libuv::Q::Promise

Combines multiple promises into a single promise that is resolved when all of the input promises are resolved or rejected.

Parameters:

  • a number of promises that will be combined into a single promise

Returns:

  • Returns a single promise that will be resolved with an array of values, each [result, wasResolved] value pair corresponding to a at the same index in the promises array.



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# File 'lib/libuv/reactor.rb', line 266

def finally(*promises)
    Q.finally(@reactor, *promises)
end

#fs_event(path) ⇒ ::Libuv::FSEvent

Get a new FSEvent instance

Parameters:

  • the path to the file or folder for watching

Returns:

Raises:

  • if path is not a string



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# File 'lib/libuv/reactor.rb', line 435

def fs_event(path)
    assert_type(String, path)
    FSEvent.new(@reactor, path)
end

#handle ⇒ Object 



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# File 'lib/libuv/reactor.rb', line 155

def handle; @pointer; end

#idle(callback = nil, &block) ⇒ ::Libuv::Idle

Get a new Idle handle

Parameters:

  • (defaults to: nil)

    the callback to be called on idle trigger

Returns:



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# File 'lib/libuv/reactor.rb', line 372

def idle(callback = nil, &block)
    Idle.new(@reactor, callback || block)
end

#inspect ⇒ Object

Overwrite as errors in jRuby can literally hang VM when inspecting as many many classes will reference this class



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# File 'lib/libuv/reactor.rb', line 150

def inspect
    "#<#{self.class}:0x#{self.__id__.to_s(16)} NT=#{@run_queue.length}>"
end

#log(error, msg = nil, trace = nil) ⇒ Object

Notifies the reactor there was an event that should be logged

Parameters:

  • the error

  • (defaults to: nil)

    optional context on the error

  • (defaults to: nil)

    optional additional trace of caller if async



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# File 'lib/libuv/reactor.rb', line 506

def log(error, msg = nil, trace = nil)
    @reactor_notify.call(error, msg, trace)
end

#lookup(hostname, hint = :IPv4, port = 9, wait: true, &block) ⇒ ::Libuv::Dns

Lookup a hostname

Parameters:

  • the domain name to lookup

  • (defaults to: 9)

    the service being connected too

  • the callback to be called on success

Returns:



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# File 'lib/libuv/reactor.rb', line 420

def lookup(hostname, hint = :IPv4, port = 9, wait: true, &block)
    dns = Dns.new(@reactor, hostname, port, hint, wait: wait)    # Work is a promise object
    if block_given? || !wait
        dns.then block
        dns
    else
        dns.results
    end
end

#lookup_error(err) ⇒ ::Libuv::Error

Lookup an error code and return is as an error object

Parameters:

  • The error code to look up.

Returns:



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# File 'lib/libuv/reactor.rb', line 296

def lookup_error(err)
    name = ::Libuv::Ext.err_name(err)

    if name
        msg  = ::Libuv::Ext.strerror(err)
        ::Libuv::Error.const_get(name.to_sym).new("#{msg}, #{name}:#{err}")
    else
        # We want a back-trace in this case
        raise "error lookup failed for code #{err}"
    end
rescue Exception => e
    @reactor.log e, 'performing error lookup'
    e
end

#next_tick(callback = nil, &block) ⇒ Object

Queue some work to be processed in the next iteration of the event reactor (thread safe)

Parameters:

  • (defaults to: nil)

    the callback to be called on the reactor thread

Raises:

  • if block is not given



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# File 'lib/libuv/reactor.rb', line 482

def next_tick(callback = nil, &block)
    callback ||= block
    assert_block(callback)

    @run_queue << callback
    if reactor_thread?
        # Create a next tick timer
        if not @next_tick_scheduled
            @next_tick.start(0)
            @next_tick_scheduled = true
            @next_tick.ref
        end
    else
        @process_queue.call
    end

    self
end

#notifier(callback = nil, &blk) ⇒ ::Libuv::Q::Promise

Provides a promise notifier for receiving un-handled exceptions

Returns:



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# File 'lib/libuv/reactor.rb', line 224

def notifier(callback = nil, &blk)
    @reactor_notify = callback || blk || @reactor_notify_default
    self
end

#now ⇒ Fixnum

Get current time in milliseconds

Returns:



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# File 'lib/libuv/reactor.rb', line 288

def now
    ::Libuv::Ext.now(@pointer)
end

#on_program_interrupt(callback = nil, &block) ⇒ Object

Allows user defined behaviour when sig int is received



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# File 'lib/libuv/reactor.rb', line 398

def on_program_interrupt(callback = nil, &block)
    @on_signal << (callback || block)
    self
end

#pipe(ipc = false) ⇒ ::Libuv::Pipe

Get a new Pipe instance

Parameters:

  • (defaults to: false)

    indicate if a handle will be used for ipc, useful for sharing tcp socket between processes

Returns:



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# File 'lib/libuv/reactor.rb', line 342

def pipe(ipc = false)
    Pipe.new(@reactor, ipc)
end

#prepare(callback = nil, &blk) ⇒ ::Libuv::Prepare

Get a new Prepare handle

Returns:



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# File 'lib/libuv/reactor.rb', line 357

def prepare(callback = nil, &blk)
    Prepare.new(@reactor, callback || blk)
end

#reactor_running? ⇒ Boolean Also known as: running?

Tells you whether the Libuv reactor reactor is currently running.

Returns:



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# File 'lib/libuv/reactor.rb', line 525

def reactor_running?
    @reactor_running
end

#reactor_thread? ⇒ Boolean

True if the calling thread is the same thread as the reactor.

Returns:



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# File 'lib/libuv/reactor.rb', line 518

def reactor_thread?
    self == Thread.current.thread_variable_get(:reactor)
end

#ref ⇒ Object

Prevents the reactor loop from stopping



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# File 'lib/libuv/reactor.rb', line 205

def ref
    if reactor_thread? && reactor_running?
        @process_queue.ref if @ref_count == 0
        @ref_count += 1
    end
end

#reject(reason) ⇒ Object

Creates a promise that is resolved as rejected with the specified reason. This api should be used to forward rejection in a chain of promises. If you are dealing with the last promise in a promise chain, you don't need to worry about it.



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# File 'lib/libuv/reactor.rb', line 273

def reject(reason)
    Q.reject(@reactor, reason)
end

#run(run_type = :UV_RUN_DEFAULT) {|promise| ... } ⇒ Object

Run the actual event reactor. This method will block until the reactor is stopped.

Parameters:

  • (defaults to: :UV_RUN_DEFAULT)

Yield Parameters:

  • promise (::Libuv::Q::Promise) —

    Yields a promise that can be used for logging unhandled exceptions on the reactor.



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# File 'lib/libuv/reactor.rb', line 162

def run(run_type = :UV_RUN_DEFAULT)
    if not @reactor_running
        begin
            @reactor_running = true
            raise 'only one reactor allowed per-thread' if Thread.current.thread_variable_get(:reactor)

            Thread.current.thread_variable_set(:reactor, @reactor)
            @throw_on_exit = nil

            if block_given?
                update_time
                ::Fiber.new {
                    begin
                        yield @reactor
                    rescue Exception => e
                        log(e, 'in reactor run block')
                    end
                }.resume
            end
            @run_count += 1
            ::Libuv::Ext.run(@pointer, run_type)  # This is blocking
        ensure
            Thread.current.thread_variable_set(:reactor, nil)
            @reactor_running = false
            @run_queue.clear
        end

        # Raise the last unhandled error to occur on the reactor thread
        raise @throw_on_exit if @throw_on_exit

    elsif block_given?
        if reactor_thread?
            update_time
            yield @reactor
        else
            raise 'reactor already running on another thread'
        end
    end

    @reactor
end

#schedule(callback = nil, &block) ⇒ Object

Schedule some work to be processed on the event reactor as soon as possible (thread safe)

Parameters:

  • (defaults to: nil)

    the callback to be called on the reactor thread

Raises:

  • if block is not given



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# File 'lib/libuv/reactor.rb', line 464

def schedule(callback = nil, &block)
    callback ||= block
    assert_block(callback)

    if reactor_thread?
        callback.call
    else
        @run_queue << callback
        @process_queue.call
    end

    self
end

#signal(signum = nil, callback = nil, &block) ⇒ ::Libuv::Signal

Get a new signal handler

Returns:



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# File 'lib/libuv/reactor.rb', line 389

def signal(signum = nil, callback = nil, &block)
    callback ||= block
    handle = Signal.new(@reactor)
    handle.progress callback if callback
    handle.start(signum) if signum
    handle
end

#stop ⇒ Object

Closes handles opened by the reactor class and completes the current reactor iteration (thread safe)



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# File 'lib/libuv/reactor.rb', line 511

def stop
    @stop_reactor.call
end

#tcp(callback = nil, &blk) ⇒ ::Libuv::TCP

Get a new TCP instance

Returns:



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# File 'lib/libuv/reactor.rb', line 314

def tcp(callback = nil, &blk)
    callback ||= blk
    TCP.new(@reactor, progress: callback)
end

#timer(callback = nil, &blk) ⇒ ::Libuv::Timer

Get a new timer instance

Parameters:

  • (defaults to: nil)

    the callback to be called on timer trigger

Returns:



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# File 'lib/libuv/reactor.rb', line 350

def timer(callback = nil, &blk)
    Timer.new(@reactor, callback || blk)
end

#tty(fileno, readable = false) ⇒ ::Libuv::TTY

Get a new TTY instance

Parameters:

  • Integer file descriptor of a tty device

  • (defaults to: false)

    Boolean indicating if TTY is readable

Returns:



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# File 'lib/libuv/reactor.rb', line 332

def tty(fileno, readable = false)
    assert_type(Integer, fileno, "io#fileno must return an integer file descriptor, #{fileno.inspect} given")

    TTY.new(@reactor, fileno, readable)
end

#udp(callback = nil, &blk) ⇒ ::Libuv::UDP

Get a new UDP instance

Returns:



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# File 'lib/libuv/reactor.rb', line 322

def udp(callback = nil, &blk)
    callback ||= blk
    UDP.new(@reactor, progress: callback)
end

#unref ⇒ Object

Allows the reactor loop to stop



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# File 'lib/libuv/reactor.rb', line 213

def unref
    if reactor_thread? && reactor_running? && @ref_count > 0
        @ref_count -= 1
        @process_queue.unref if @ref_count == 0
    end
end

#update_time ⇒ Object

forces reactor time update, useful for getting more granular times

Returns:

  • nil



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# File 'lib/libuv/reactor.rb', line 280

def update_time
    ::Libuv::Ext.update_time(@pointer)
    self
end

#work(callback = nil, &block) ⇒ ::Libuv::Work

Queue some work for processing in the libuv thread pool

Parameters:

  • (defaults to: nil)

    the callback to be called in the thread pool

Returns:

Raises:

  • if block is not given



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# File 'lib/libuv/reactor.rb', line 408

def work(callback = nil, &block)
    callback ||= block
    assert_block(callback)
    Work.new(@reactor, callback)    # Work is a promise object
end