Class: FDB::Future

Inherits:
Object
  • Object
show all
Defined in:
lib/fdbimpl.rb

Direct Known Subclasses

FutureKeyValueArray, FutureNil, LazyFuture

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(fpointer) ⇒ Future

Returns a new instance of Future.



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# File 'lib/fdbimpl.rb', line 309

def initialize(fpointer)
  @fpointer = fpointer
  ObjectSpace.define_finalizer(self, FDB::Future.finalize(@fpointer))
end

Class Method Details

.finalize(ptr) ⇒ Object 



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# File 'lib/fdbimpl.rb', line 302

def self.finalize(ptr)
  proc do
    #puts "Destroying future #{ptr}"
    FDBC.fdb_future_destroy(ptr)
  end
end

.wait_for_any(*futures) ⇒ Object 



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# File 'lib/fdbimpl.rb', line 358

def self.wait_for_any(*futures)
  if futures.empty?
    raise ArgumentError, "wait_for_any requires at least one future"
  end

  mx = Mutex.new
  cv = ConditionVariable.new

  ready_idx = -1

  futures.each_with_index do |f, i|
    f.on_ready do |f|
      mx.synchronize {
        if ready_idx < 0
          ready_idx = i
          cv.signal
        end
      }
    end
  end

  mx.synchronize {
    if ready_idx < 0
      cv.wait mx
    end
  }

  ready_idx
end

Instance Method Details

#block_until_ready ⇒ Object 



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# File 'lib/fdbimpl.rb', line 322

def block_until_ready
  FDBC.check_error FDBC.fdb_future_block_until_ready(@fpointer)
end

#callback_wrapper(f, &block) ⇒ Object 



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# File 'lib/fdbimpl.rb', line 327

def callback_wrapper(f, &block)
  begin
    yield f
  rescue Exception
    begin
      $stderr.puts "Discarding uncaught exception from user callback:"
      $stderr.puts "#{$@.first}: #{$!.message} (#{$!.class})", $@.drop(1).map{|s| "\t#{s}"}
    rescue Exception
    end
  end
end

#cancel ⇒ Object 



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# File 'lib/fdbimpl.rb', line 314

def cancel
  FDBC.fdb_future_cancel(@fpointer)
end

#on_ready(&block) ⇒ Object 



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# File 'lib/fdbimpl.rb', line 326

def on_ready(&block)
  def callback_wrapper(f, &block)
    begin
      yield f
    rescue Exception
      begin
        $stderr.puts "Discarding uncaught exception from user callback:"
        $stderr.puts "#{$@.first}: #{$!.message} (#{$!.class})", $@.drop(1).map{|s| "\t#{s}"}
      rescue Exception
      end
    end
  end

  entry = CallbackEntry.new

  FDB.cb_mutex.synchronize {
    pos = FDB.ffi_callbacks.length
    entry.index = pos
    FDB.ffi_callbacks << entry
  }

  entry.callback = FFI::Function.new(:void, [:pointer, :pointer]) do |ign1, ign2|
    FDB.cb_mutex.synchronize {
      FDB.ffi_callbacks[-1].index = entry.index
      FDB.ffi_callbacks[entry.index] = FDB.ffi_callbacks[-1]
      FDB.ffi_callbacks.pop
    }
    callback_wrapper(self, &block)
  end
  FDBC.fdb_future_set_callback(@fpointer, entry.callback, nil)
end

#ready? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/fdbimpl.rb', line 318

def ready?
  return !FDBC.fdb_future_is_ready(@fpointer).zero?
end