Process.detach: avoid singleton class creation

* process.c (Init_process): subclass Thread as Process::Waiter
  (rb_detach_process): use Process::Waiter instead of singleton class

* test/ruby/test_process.rb (test_process_detach): new test

* inits.c (rb_call_inits): call Init_Thread before Init_process to
  ensure Process::Waiter may be a subclass of Thread

Thanks to headius for reporting [Bug #10231]
Thanks to nobu for review of my initial patch.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47561 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,14 @@
+Sat Sep 13 04:40:04 2014  Eric Wong  <e@80x24.org>
+
+	* process.c (Init_process): subclass Thread as Process::Waiter
+	  (rb_detach_process): use Process::Waiter instead of singleton class
+	  Thanks to headius and nobu. [Bug #10231]
+
+	* test/ruby/test_process.rb (test_process_detach): new test
+
+	* inits.c (rb_call_inits): call Init_Thread before Init_process to
+	  ensure Process::Waiter may be a subclass of Thread
+
 Fri Sep 12 18:14:28 2014  Eric Wong  <e@80x24.org>
 
 	* vm.c (env_alloc): inline to avoid extra zeroing

inits.c

@@ -46,7 +46,6 @@ rb_call_inits(void)
     CALL(Time);
     CALL(Random);
     CALL(signal);
-    CALL(process);
     CALL(load);
     CALL(Proc);
     CALL(Binding);
@@ -56,6 +55,7 @@ rb_call_inits(void)
     CALL(VM);
     CALL(ISeq);
     CALL(Thread);
+    CALL(process);
     CALL(Cont);
     CALL(Rational);
     CALL(Complex);

process.c

@@ -1007,6 +1007,8 @@ proc_waitall(void)
     return result;
 }
 
+static VALUE rb_cWaiter;
+
 static inline ID
 id_pid(void)
 {
@@ -1038,7 +1040,7 @@ rb_detach_process(rb_pid_t pid)
 {
     VALUE watcher = rb_thread_create(detach_process_watcher, (void*)(VALUE)pid);
     rb_thread_local_aset(watcher, id_pid(), PIDT2NUM(pid));
-    rb_define_singleton_method(watcher, "pid", detach_process_pid, 0);
+    RBASIC_SET_CLASS(watcher, rb_cWaiter);
     return watcher;
 }
 
@@ -7516,6 +7518,11 @@ Init_process(void)
     rb_define_module_function(rb_mProcess, "waitall", proc_waitall, 0);
     rb_define_module_function(rb_mProcess, "detach", proc_detach, 1);
 
+    rb_cWaiter = rb_define_class_under(rb_mProcess, "Waiter", rb_cThread);
+    rb_undef_alloc_func(rb_cWaiter);
+    rb_undef_method(CLASS_OF(rb_cWaiter), "new");
+    rb_define_method(rb_cWaiter, "pid", detach_process_pid, 0);
+
     rb_cProcessStatus = rb_define_class_under(rb_mProcess, "Status", rb_cObject);
     rb_undef_method(CLASS_OF(rb_cProcessStatus), "new");
 

test/ruby/test_process.rb

@@ -1965,4 +1965,12 @@ EOS
       runner.close
     end
   end if defined?(fork)
+
+  def test_process_detach
+    pid = fork {}
+    th = Process.detach(pid)
+    assert_equal pid, th.pid
+    status = th.value
+    assert status.success?, status.inspect
+  end if defined?(fork)
 end