Method: Autobuild::RakeTaskParallelism#resolve_cycle

Defined in:

lib/autobuild/parallel.rb

#resolve_cycle(all_tasks, tasks, reverse_dependencies) ⇒ Object

# File 'lib/autobuild/parallel.rb', line 226

def resolve_cycle(all_tasks, tasks, reverse_dependencies)
    cycle = tasks.dup
    chain = []
    next_task = tasks.first
    loop do
        task = next_task
        chain << task
        tasks.delete(next_task)
        next_task = task.prerequisite_tasks.find do |dep_task|
            if chain.include?(dep_task)
                reject = chain.take_while { |t| t != dep_task }
                return chain[reject.size..-1]
            elsif tasks.include?(dep_task)
                true
            end
        end
        unless next_task
            Autobuild.fatal "parallel processing stopped prematurely, "\
                "but no cycle is present in the remaining tasks"
            Autobuild.fatal "remaining tasks: #{cycle.map(&:name).join(', ')}"
            Autobuild.fatal "known dependencies at initialization time that "\
                "could block the processing of the remaining tasks"
            reverse_dependencies.each do |parent_task, parents|
                if cycle.include?(parent_task)
                    parents.each do |p|
                        Autobuild.fatal "  #{p}: #{parent_task}"
                    end
                end
            end
            Autobuild.fatal "known dependencies right now that could block "\
                "the processing of the remaining tasks"
            all_tasks.each do |p|
                (cycle & p.prerequisite_tasks).each do |t|
                    Autobuild.fatal "  #{p}: #{t}"
                end
            end
            raise "failed to resolve cycle in #{cycle.map(&:name).join(', ')}"
        end
    end
    chain
end