FutureValue

A threadsafe future implementation that blocks caller until a value is set.

Usage

Create a future value object

future = FutureValue.new

Create a future value object with value

If the value is known at instantiation time, can pass the value. This is more efficient and will prevent blocking.

future = FutureValue.new(10)

Set a value

future.value = 10

A RuntimeError will be raised if value is already set.

future.value = 10 unless future.has_value?

Get a value (non-blocking)

until future.has_value?
  sleep 1
end
value = future.value

Get a value (blocking)

value = future.value

Example

require 'future_value'

f = FutureValue.new

t = Thread.new do
  sleep 2
  f.value = 4
end

if f.has_value?
  puts "yes"
else
  puts "no"
end

3.times do |i|
  Thread.new do
    puts "Thread #{i} got #{f.value}"
  end
end

puts f.value

puts f.has_value?

Contributing

1. Fork it ( https://github.com/DougEverly/future_value/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request