Add initial support of lightweight thread.

Author: take-cheeze

mrbgem.rake

@@ -4,6 +4,7 @@ MRuby::Gem::Specification.new('mruby-uv') do |spec|
   spec.summary = 'libuv mruby binding'
   spec.add_dependency 'mruby-time',    core: 'mruby-time'
   spec.add_dependency 'mruby-sprintf', core: 'mruby-sprintf'
+  spec.add_dependency 'mruby-fiber',   core: 'mruby-fiber'
 
   def self.run_command(env, command)
     fail "#{command} failed" unless system(env, command)

mrblib/yarn.rb

@@ -0,0 +1,95 @@
+module UV
+  def self.sleep sec
+    current_yarn.sleep sec
+  end
+
+  def self.current_yarn
+    ret = UV.current_loop.current_yarn
+    raise "yarn not running" if ret.nil?
+    ret
+  end
+
+  class Loop
+    attr_reader :current_yarn
+
+    def current_yarn=(y)
+      raise "cannot double run yarn" if current_yarn
+      raise "not yarn" unless y.kind_of? UV::Yarn
+
+      @current_yarn = y
+    end
+
+    def clear_current_yarn
+      @current_yarn = nil
+    end
+  end
+
+  class Yarn
+    def initialize(loop = UV.current_loop, &blk)
+      @fiber = Fiber.new(&blk)
+      @loop = loop
+    end
+
+    attr_reader :loop, :error
+
+    def ended?; @fiber.nil? end
+    def result
+      raise "not ended" unless ended?
+      @result
+    end
+
+    def check_error
+      raise @error if @error
+    end
+
+    def timer
+      @timer ||= UV::Timer.new
+      # raise 'timer already used' if @timer.active?
+      @timer
+    end
+
+    def to_proc
+      @proc ||= Proc.new{|*args, &blk| self.resume(*args, &blk) }
+    end
+
+    def start(*args)
+      raise "already started" if @started
+      @started = true
+
+      resume(*args)
+    end
+
+    def sleep sec
+      timer.start(sec * 1000.0, 0) do
+        self.resume
+      end
+      Fiber.yield(timer, self)
+    end
+
+    def resume(*args)
+      raise "cannot resume unstarted yarn" unless @started
+      raise "cannot run ended yarn" if ended?
+
+      @loop.current_yarn = self
+
+      prev_loop = UV.current_loop
+      @loop.make_current
+
+      *ret = @fiber.resume(*args)
+
+      if @fiber.alive?
+        raise "invalid yield" if !ret.first.kind_of?(UV::Req) && !ret.first.kind_of?(UV::Timer)
+      else
+        @fiber = nil
+        @result = ret
+      end
+
+    rescue => e
+      @error = e
+
+    ensure
+      @loop.clear_current_yarn
+      prev_loop.make_current if prev_loop
+    end
+  end
+end

test/yarn.rb

@@ -0,0 +1,12 @@
+assert "Yarn" do
+  y = UV::Yarn.new do
+    t = UV.current_loop.now
+    UV.sleep 0.1
+    assert_true (UV.current_loop.now - t) >= 100
+    UV.sleep 0.1
+    assert_true (UV.current_loop.now - t) >= 200
+  end
+
+  y.start
+  y.loop.run
+end