Class: NIO::Selector
- Inherits:
-
Object
- Object
- NIO::Selector
- Defined in:
- lib/nio/selector.rb,
ext/nio4r/selector.c
Overview
Selectors monitor IO objects for events of interest
Instance Method Summary collapse
-
#close ⇒ Object
Close this selector and free its resources.
-
#closed? ⇒ Boolean
Is this selector closed?.
-
#deregister(io) ⇒ Object
Deregister the given IO object from the selector.
-
#initialize ⇒ Object
constructor
Methods.
-
#register(io, interest) ⇒ Object
Register interest in an IO object with the selector for the given types of events.
-
#registered?(io) ⇒ Boolean
Is the given IO object registered with the selector?.
-
#select(timeout = nil) ⇒ Object
Select which monitors are ready.
-
#select_each(timeout = nil, &block) ⇒ Object
Select for ready monitors, successively yielding each one in a block.
-
#wakeup ⇒ Object
Wake up a thread that’s in the middle of selecting on this selector, if any such thread exists.
Constructor Details
#initialize ⇒ Object
Methods
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# File 'lib/nio/selector.rb', line 5 def initialize @selectables = {} @lock = Mutex.new # Other threads can wake up a selector @wakeup, @waker = IO.pipe @closed = false end |
Instance Method Details
#close ⇒ Object
Close this selector and free its resources
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# File 'lib/nio/selector.rb', line 131 def close @lock.synchronize do return if @closed @wakeup.close rescue nil @waker.close rescue nil @closed = true end end |
#closed? ⇒ Boolean
Is this selector closed?
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# File 'lib/nio/selector.rb', line 142 def closed?; @closed end |
#deregister(io) ⇒ Object
Deregister the given IO object from the selector
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# File 'lib/nio/selector.rb', line 31 def deregister(io) @lock.synchronize do monitor = @selectables.delete io monitor.close(false) if monitor and not monitor.closed? monitor end end |
#register(io, interest) ⇒ Object
Register interest in an IO object with the selector for the given types of events. Valid event types for interest are:
-
:r - is the IO readable?
-
:w - is the IO writeable?
-
:rw - is the IO either readable or writeable?
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# File 'lib/nio/selector.rb', line 19 def register(io, interest) @lock.synchronize do raise ArgumentError, "this IO is already registered with the selector" if @selectables[io] monitor = Monitor.new(io, interest, self) @selectables[io] = monitor monitor end end |
#registered?(io) ⇒ Boolean
Is the given IO object registered with the selector?
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# File 'lib/nio/selector.rb', line 40 def registered?(io) @lock.synchronize { @selectables.has_key? io } end |
#select(timeout = nil) ⇒ Object
Select which monitors are ready
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# File 'lib/nio/selector.rb', line 45 def select(timeout = nil) @lock.synchronize do readers, writers = [@wakeup], [] @selectables.each do |io, monitor| readers << io if monitor.interests == :r || monitor.interests == :rw writers << io if monitor.interests == :w || monitor.interests == :rw end ready_readers, ready_writers = Kernel.select readers, writers, [], timeout return unless ready_readers # timeout or wakeup if block_given? result = 0 else result = [] end ready_readers.each do |io| if io == @wakeup # Clear all wakeup signals we've received by reading them # Wakeups should have level triggered behavior begin @wakeup.read_nonblock(1024) # Loop until we've drained all incoming events redo rescue Errno::EWOULDBLOCK end return else monitor = @selectables[io] monitor.readiness = :r if block_given? yield monitor result += 1 else result << monitor end end end ready_readwriters = ready_readers & ready_writers ready_writers = ready_writers - ready_readwriters [[ready_writers, :w], [ready_readwriters, :rw]].each do |ios, readiness| ios.each do |io| monitor = @selectables[io] monitor.readiness = readiness if block_given? yield monitor result += 1 else result << monitor end end end result end end |
#select_each(timeout = nil, &block) ⇒ Object
Select for ready monitors, successively yielding each one in a block
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# File 'lib/nio/selector.rb', line 111 def select_each(timeout = nil, &block) selected = select(timeout) return unless selected selected.each(&block) selected.size end |
#wakeup ⇒ Object
Wake up a thread that’s in the middle of selecting on this selector, if any such thread exists.
Invoking this method more than once between two successive select calls has the same effect as invoking it just once. In other words, it provides level-triggered behavior.
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# File 'lib/nio/selector.rb', line 124 def wakeup # Send the selector a signal in the form of writing data to a pipe @waker << "\0" nil end |