better handling of child PIDs and reaping of processes

TwP · Mar 19, 2017 · 69c224d · 69c224d
1 parent f625ab1
commit 69c224d
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Showing 2 changed files with 5 additions and 3 deletions.
diff --git a/lib/servolux/child.rb b/lib/servolux/child.rb
@@ -149,7 +149,7 @@ def stop
   #   the child process is not running.
   #
   def wait( flags = 0 )
-    return if @io.nil?
+    return if @pid.nil?
     _, @status = Process.wait2(@pid, flags) unless @status
     exitstatus
   end
@@ -160,7 +160,7 @@ def wait( flags = 0 )
   # @return [Boolean]
   #
   def alive?
-    return if @io.nil?
+    return if @pid.nil?
     wait(Process::WNOHANG|Process::WUNTRACED)
     Process.kill(0, @pid)
     true

diff --git a/lib/servolux/piper.rb b/lib/servolux/piper.rb
@@ -69,7 +69,9 @@ def self.daemon( nochdir = false, noclose = false )
     piper.parent {
       pid = piper.gets
       raise ::Servolux::Error, 'Could not get the child PID.' if pid.nil?
-      piper.instance_variable_set(:@child_pid, pid)
+
+      piper.wait                                     # reap the child process
+      piper.instance_variable_set(:@child_pid, pid)  # adopt the grandchild
     }
     piper.child {
       Process.setsid                     # Become session leader.