Stop blocking ruby during long-running operations

test/test_helpers.rb

@@ -0,0 +1,27 @@
+require 'lxc'
+require 'test/unit/assertions'
+
+module TestHelpers
+  def assert_long_running_function_does_not_block_ruby(&block)
+    r, w = IO.pipe
+    begin
+      # Write something after a very short period, but only if Ruby isn't blocked!
+      t = Thread.new do
+        sleep(0.001)
+        # Sleep twice so that if the function is blocking and we wake up just
+        # after block.call(c) somehow, we will go back to sleep briefly and
+        # allow B to be written
+        sleep(0.001)
+        w.write('A')
+      end
+      # Call the function and see if Ruby gets blocked
+      block.call
+      w.write('B')
+      chars = r.read(2)
+      assert(chars == 'AB', "Expected thread to write before block finished, but it did not. Expected 'AB', got '#{chars}'")
+    ensure
+      r.close
+      w.close
+    end
+  end
+end

test/test_lxc_create_asynchronous.rb

@@ -0,0 +1,25 @@
+$:.unshift File.expand_path(File.join(File.dirname(__FILE__), 'lib'))
+
+require 'test/unit'
+require 'lxc'
+require 'test_helpers'
+
+class TestLXCCreateAsynchronous < Test::Unit::TestCase
+  include TestHelpers
+
+  def setup
+    if Process::Sys::geteuid != 0
+      raise 'This test must be ran as root'
+    end
+    @name = 'test_async_create'
+    container = LXC::Container.new(@name)
+    container.destroy if container.defined?
+  end
+
+  def test_create_allows_ruby_to_continue
+    c = LXC::Container.new(@name)
+    assert_long_running_function_does_not_block_ruby do
+      c.create('ubuntu')
+    end
+  end
+end

test/test_lxc_created.rb

@@ -6,11 +6,15 @@ require 'lxc'
 class TestLXCCreated < Test::Unit::TestCase
   def setup
     if Process::Sys::geteuid != 0
-      raise 'This test must be ran as root'
+      raise 'This test must be run as root'
     end
     @name = 'test'
     @container = LXC::Container.new(@name)
     @container.create('ubuntu') unless @container.defined?
+    # Make sure the renamed_test container does not exist, for the rename test
+    @new_name = "renamed_#{@name}"
+    new_container = LXC::Container.new(@new_name)
+    new_container.destroy if new_container.defined?
   end
 
   def test_container_defined
@@ -41,9 +45,8 @@ class TestLXCCreated < Test::Unit::TestCase
   end
 
   def test_container_rename
-    new_name = "renamed_#{@name}"
-    renamed = @container.rename(new_name)
-    assert_equal(new_name, renamed.name)
+    renamed = @container.rename(@new_name)
+    assert_equal(@new_name, renamed.name)
     rerenamed = renamed.rename(@name)
     assert_equal(@name, rerenamed.name)
   end

test/test_lxc_long_running.rb

@@ -0,0 +1,228 @@
+$:.unshift File.expand_path(File.join(File.dirname(__FILE__), 'lib'))
+
+require 'test/unit'
+require 'lxc'
+require 'test_helpers'
+
+class TestLXCLongRunning < Test::Unit::TestCase
+  include TestHelpers
+
+  def setup
+    if Process::Sys::geteuid != 0
+      raise 'This test must be run as root'
+    end
+    @name = 'test'
+    @container = LXC::Container.new(@name)
+    @container.create('ubuntu') unless @container.defined?
+    @container.start unless @container.running?
+    @container.unfreeze
+    # Destroy leftover snapshots so we don't take up the whole disk
+    @container.snapshot_list.each do |snapshot, commentfile, timestamp, snapshotfile|
+      @container.snapshot_destroy(snapshot)
+    end
+  end
+
+# TODO find a way to test unblockness for functions that don't run quite so long
+#  def test_add_device_node_allows_ruby_to_continue
+#    assert_long_running_function_does_not_block_ruby do
+#      @container.add_device_node('/dev/ttyS0')
+#    end
+#  end
+
+  def test_attach_wait_true_allows_ruby_to_continue
+    assert_long_running_function_does_not_block_ruby do
+      @container.attach(wait: true) do
+        sleep(2)
+      end
+    end
+  end
+
+  def test_clone_allows_ruby_to_continue
+    # Ensure the "cloned" VM does not exist
+    cloned_name = "#{@name}_cloned"
+    cloned_to_destroy = LXC::Container.new(cloned_name)
+    cloned_to_destroy.destroy if cloned_to_destroy.defined?
+
+    cloned = nil
+    @container.stop
+    begin
+      assert_long_running_function_does_not_block_ruby do
+        cloned = @container.clone(cloned_name)
+      end
+    ensure
+      @container.start
+    end
+    # Verify that it did something
+    assert(@container.name == @name, "original container name has changed from '#{@name}' to '#{@container.name}''")
+    assert(@container.running?, "original container is not running")
+    assert(cloned.name == cloned_name, "new container name should be '#{cloned_name}', is '#{cloned.name}'")
+    assert(cloned.init_pid != @container.init_pid, "cloned container init pid is the same as the original!  Something ain't right.")
+  end
+
+# TODO Unsure how to test this without attaching to the actual tty!  Must be a way to obtain a pipe or false tty of some sort.  Manual run reveals it works, however.
+#  def test_console_allows_ruby_to_continue
+#    assert_long_running_function_does_not_block_ruby do
+#      @container.console
+#    end
+#  end
+
+  def test_destroy_allows_ruby_to_continue
+    container = LXC::Container.new("test_destroy")
+    container.create('ubuntu') if !container.defined?
+    assert_long_running_function_does_not_block_ruby do
+      container.destroy
+    end
+    assert(!container.defined?, "Destroy did not destroy the container!")
+  end
+
+# TODO find a way to test unblockness for functions that don't run quite so long
+#  def test_freeze_allows_ruby_to_continue
+#    begin
+#      assert_long_running_function_does_not_block_ruby do
+#        @container.freeze
+#      end
+#    ensure
+#      @container.unfreeze
+#    end
+#  end
+
+# TODO find a way to test unblockness for functions that don't run quite so long
+#  def test_load_config_allows_ruby_to_continue
+#    File.open('/tmp/blah', 'w') do |file|
+#      file.write("\n\n\n\n")
+#    end
+#    begin
+#      container = LXC::Container.new('blahdeblah')
+#      assert_long_running_function_does_not_block_ruby do
+#        container.load_config('/tmp/blah')
+#      end
+#    ensure
+#      File.delete('/tmp/blah')
+#    end
+#  end
+
+# TODO find a way to test unblockness for functions that don't run quite so long
+#  def test_reboot_allows_ruby_to_continue
+#    assert_long_running_function_does_not_block_ruby do
+#      @container.reboot
+#    end
+#  end
+
+# TODO find a way to test unblockness for functions that don't run quite so long
+#  def test_remove_device_node_allows_ruby_to_continue
+#    assert_long_running_function_does_not_block_ruby do
+#      @container.remove_device_node('/dev/ttyS0')
+#    end
+#  end
+
+# TODO find a way to test unblockness for functions that don't run quite so long
+#  def test_save_config_allows_ruby_to_continue
+#    File.unlink('/tmp/blah') if File.exist?('/tmp/blah')
+#    assert_long_running_function_does_not_block_ruby do
+#      @container.save_config('/tmp/blah')
+#    end
+#    assert(File.exist?('/tmp/blah'), "save_config did not save /tmp/blah!")
+#  end
+
+  def test_shutdown_allows_ruby_to_continue
+    begin
+      assert_long_running_function_does_not_block_ruby do
+        @container.shutdown
+      end
+    ensure
+      @container.start if !@container.running?
+    end
+  end
+
+  def test_snapshot_allows_ruby_to_continue
+    @container.stop
+    begin
+      assert_long_running_function_does_not_block_ruby do
+        @container.snapshot
+      end
+    ensure
+      @container.start
+    end
+  end
+
+  def test_snapshot_destroy_allows_ruby_to_continue
+    @container.stop
+    begin
+      snapshot = @container.snapshot
+      assert_long_running_function_does_not_block_ruby do
+        @container.snapshot_destroy(snapshot)
+      end
+    ensure
+      @container.start
+    end
+  end
+
+# TODO find a way to test unblockness for functions that don't run quite so long
+#  def test_snapshot_list_allows_ruby_to_continue
+#    @container.stop
+#    begin
+#      snapshot = @container.snapshot
+#      assert_long_running_function_does_not_block_ruby do
+#        assert(@container.snapshot_list > 0, "Snapshot list was empty!"
+#      end
+#    ensure
+#      @container.start
+#    end
+#  end
+
+  def test_snapshot_restore_allows_ruby_to_continue
+    @container.stop
+    begin
+      snapshot = @container.snapshot
+      assert_long_running_function_does_not_block_ruby do
+        @container.snapshot_restore(snapshot)
+      end
+    ensure
+      @container.start
+    end
+  end
+
+  def test_start_allows_ruby_to_continue
+    @container.stop
+    assert_long_running_function_does_not_block_ruby do
+      @container.start
+    end
+    assert(@container.running?, "Start did not start container! State = #{@container.state}")
+  end
+
+# TODO find a way to test unblockness for functions that don't run quite so long
+#  def test_stop_allows_ruby_to_continue
+#    begin
+#      assert_long_running_function_does_not_block_ruby do
+#        @container.stop
+#      end
+#      assert(!@container.running?, "Stop did not stop container! State = #{@container.state}")
+#    ensure
+#      @container.start if !@container.running?
+#    end
+#  end
+
+# TODO find a way to test unblockness for functions that don't run quite so long
+#  def test_unfreeze_allows_ruby_to_continue
+#    @container.freeze
+#    assert_long_running_function_does_not_block_ruby do
+#      @container.unfreeze
+#    end
+#  end
+
+  def test_wait_allows_ruby_to_continue
+    t = Thread.new do
+      sleep(0.5)
+      @container.stop
+    end
+    begin
+      assert_long_running_function_does_not_block_ruby do
+        @container.wait(:stopped, 2)
+      end
+      assert(@container.state == :stopped, "Container never stopped! State is now #{@container.state.inspect}")
+    ensure
+      t.join
+      @container.start if !@container.running?
+    end
+  end
+end