example/kill_child.rb in frontkick-0.5.1 vs example/kill_child.rb in frontkick-0.5.2

@@ -1,51 +1,77 @@
 require 'frontkick'
 
-puts "kill -TERM #{Process.pid} or Hit Ctrl-C in 10 seconds"
+class SignalHandler
+  def self.register
+    @pids ||= []
+    @main_threads ||= []
 
-result = Frontkick.exec(["sleep 10"]) do |wait_thr|
-  pid = wait_thr.pid
-  signal_pipe_r, signal_pipe_w = IO.pipe
+    if @signal_pipe_r.nil? and @signal_pipe_w.nil?
+      @signal_pipe_r, @signal_pipe_w = IO.pipe
+    end
 
-  # You know, there are many things `can't be called from trap context`
-  trap :INT do
-    signal_pipe_w.puts 'INT'
+    # For example, loogger `can't be called from trap context`
+    trap :INT do
+      @signal_pipe_w.puts 'INT'
+    end
+    trap :TERM do
+      @signal_pipe_w.puts 'TERM'
+    end
+
+    # Create a new thread to handle signals
+    # This example kills child (and self)
+    @signal_handler_thr ||= Thread.new do
+      begin
+        while readable_io = IO.select([@signal_pipe_r])
+          signal = readable_io.first[0].gets.strip
+          puts "#{signal} signal received"
+          @pids.each_with_index do |pid, idx|
+            main_thread = @main_threads[idx]
+            begin
+              puts "kill -#{signal} #{pid}"
+              Process.kill(signal, pid) rescue nil
+            rescue => e
+              main_thread.raise e
+            end
+          end
+          # case signal
+          # when 'INT'
+          #   Kernel.exit(130)
+          # when 'TERM'
+          #   Kernel.exit(148)
+          # end
+        end
+      rescue Exception => e
+        Thread.main.raise e
+      end
+    end
   end
-  trap :TERM do
-    signal_pipe_w.puts 'TERM'
+
+  def self.push(pid)
+    @pids << pid
+    @main_threads << Thread.current
   end
 
-  # Create a new thread to handle signals
-  # This example kills child and self
-  signal_handler_thr = Thread.new do
-    readable_io = IO.select([signal_pipe_r])
-    signal = readable_io.first[0].gets.strip
-    case signal
-    when 'INT'
-      puts "kill -INT #{pid}"
-      Process.kill('INT', pid) rescue nil
-      pid, status = Process.waitpid2(pid) rescue nil
-      Kernel.exit(130)
-    when 'TERM'
-      puts "kill -TERM #{pid}"
-      Process.kill('TERM', pid) rescue nil
-      pid, status = Process.waitpid2(pid) rescue nil
-      Kernel.exit(148)
-    end
+  def self.pop(pid)
+    @pids -= [pid]
+    @main_threads -= [Thread.current]
   end
+end
 
-  begin
-    # Wait child to finish (for normal situation)
-    wait_thr.join
+SignalHandler.register
 
-    # Send NOOP to finish signal_handler_thr (for normal situation)
-    signal_pipe_w.puts 'NOOP'
-    signal_handler_thr.join
+puts "## Frontkick started"
+puts "kill -TERM #{Process.pid} or Hit Ctrl-C in 10 seconds"
+result = Frontkick.exec(["sleep 10"]) do |wait_thr|
+  begin
+    SignalHandler.push(wait_thr.pid)
+    puts wait_thr.value # wait child to finish (for normal situation)
   ensure
-    signal_pipe_r.close rescue nil
-    signal_pipe_w.close rescue nil
+    SignalHandler.pop(wait_thr.pid)
   end
 end
 
-# should come here if child process finished normally,
-# but not come here if signals are received (Kernel.exit)
+puts "## Fronkick finished"
+puts "kill -TERM #{Process.pid} or Hit Ctrl-C in 5 seconds"
+sleep 5
+
 puts result.inspect