diff --git a/lib/fluent/plugin/in_exec.rb b/lib/fluent/plugin/in_exec.rb
index 295b6ce864..eeec824167 100644
--- a/lib/fluent/plugin/in_exec.rb
+++ b/lib/fluent/plugin/in_exec.rb
@@ -17,14 +17,16 @@
 require 'strptime'
 require 'yajl'
 
-require 'fluent/input'
+require 'fluent/plugin/input'
 require 'fluent/time'
 require 'fluent/timezone'
 require 'fluent/config/error'
 
-module Fluent
-  class ExecInput < Input
-    Plugin.register_input('exec', self)
+module Fluent::Plugin
+  class ExecInput < Fluent::Plugin::Input
+    Fluent::Plugin.register_input('exec', self)
+
+    helpers :child_process
 
     def initialize
       super
@@ -65,7 +67,7 @@ def configure(conf)
       end
 
       if !@tag && !@tag_key
-        raise ConfigError, "'tag' or 'tag_key' option is required on exec input"
+        raise Fleunt::ConfigError, "'tag' or 'tag_key' option is required on exec input"
       end
 
       if @time_key
@@ -90,7 +92,7 @@ def setup_parser(conf)
       case @format
       when 'tsv'
         if @keys.empty?
-          raise ConfigError, "keys option is required on exec input for tsv format"
+          raise Fluent::ConfigError, "keys option is required on exec input for tsv format"
         end
         ExecUtil::TSVParser.new(@keys, method(:on_message))
       when 'json'
@@ -106,57 +108,18 @@ def start
       super
 
       if @run_interval
-        @finished = false
-        @thread = Thread.new(&method(:run_periodic))
-      else
-        @io = IO.popen(@command, "r")
-        @pid = @io.pid
-        @thread = Thread.new(&method(:run))
-      end
-    end
-
-    def shutdown
-      if @run_interval
-        @finished = true
-        # call Thread#run which interupts sleep in order to stop run_periodic thread immediately.
-        @thread.run
-        @thread.join
-      else
-        begin
-          Process.kill(:TERM, @pid)
-        rescue #Errno::ECHILD, Errno::ESRCH, Errno::EPERM
-        end
-        if @thread.join(60)  # TODO wait time
-          return
+        child_process_execute(:exec_input, @command, interval: @run_interval, mode: [:read]) do |io|
+          run(io)
         end
-
-        begin
-          Process.kill(:KILL, @pid)
-        rescue #Errno::ECHILD, Errno::ESRCH, Errno::EPERM
+      else
+        child_process_execute(:exec_input, @command, immediate: true, mode: [:read]) do |io|
+          run(io)
         end
-        @thread.join
       end
-
-      super
     end
 
-    def run
-      @parser.call(@io)
-    end
-
-    def run_periodic
-      sleep @run_interval
-      until @finished
-        begin
-          io = IO.popen(@command, "r")
-          @parser.call(io)
-          Process.waitpid(io.pid)
-          sleep @run_interval
-        rescue
-          log.error "exec failed to run or shutdown child process", error: $!
-          log.warn_backtrace $!.backtrace
-        end
-      end
+    def run(io)
+      @parser.call(io)
     end
 
     private
@@ -174,7 +137,7 @@ def on_message(record, parsed_time = nil)
         if val = record.delete(@time_key)
           time = @time_parse_proc.call(val)
         else
-          time = Engine.now
+          time = Fluent::EventTime.now
         end
       end
 
diff --git a/test/plugin/test_in_exec.rb b/test/plugin/test_in_exec.rb
index e83a40fa53..c3f00d988d 100644
--- a/test/plugin/test_in_exec.rb
+++ b/test/plugin/test_in_exec.rb
@@ -1,17 +1,17 @@
 require_relative '../helper'
-require 'fluent/test'
+require 'fluent/test/driver/input'
 require 'fluent/plugin/in_exec'
 require 'net/http'
 
 class ExecInputTest < Test::Unit::TestCase
   def setup
     Fluent::Test.setup
-    @test_time = Fluent::EventTime.parse("2011-01-02 13:14:15")
+    @test_time = event_time("2011-01-02 13:14:15")
     @script = File.expand_path(File.join(File.dirname(__FILE__), '..', 'scripts', 'exec_script.rb'))
   end
 
   def create_driver(conf = tsv_config)
-    Fluent::Test::InputTestDriver.new(Fluent::ExecInput).configure(conf)
+    Fluent::Test::Driver::Input.new(Fluent::Plugin::ExecInput).configure(conf)
   end
 
   def tsv_config
@@ -90,7 +90,7 @@ def test_emit
       sleep 2
     end
 
-    emits = d.emits
+    emits = d.events
     assert_equal true, emits.length > 0
     assert_equal ["tag1", @test_time, {"k1"=>"ok"}], emits[0]
     assert_equal_event_time(@test_time, emits[0][1])
@@ -103,7 +103,7 @@ def test_emit_json
       sleep 2
     end
 
-    emits = d.emits
+    emits = d.events
     assert_equal true, emits.length > 0
     assert_equal ["tag1", @test_time, {"k1"=>"ok"}], emits[0]
     assert_equal_event_time(@test_time, emits[0][1])
@@ -116,7 +116,7 @@ def test_emit_msgpack
       sleep 2
     end
 
-    emits = d.emits
+    emits = d.events
     assert_equal true, emits.length > 0
     assert_equal ["tag1", @test_time, {"k1"=>"ok"}], emits[0]
     assert_equal_event_time(@test_time, emits[0][1])
@@ -129,7 +129,7 @@ def test_emit_regexp
       sleep 2
     end
 
-    emits = d.emits
+    emits = d.events
     assert_equal true, emits.length > 0
     assert_equal ["regex_tag", @test_time, {"message"=>"hello"}], emits[0]
     assert_equal_event_time(@test_time, emits[0][1])