From: Ben Darnell <ben@bendarnell.com>
Date: Wed, 12 Jun 2013 03:32:40 +0000 (-0400)
Subject: Set CLOEXEC on subprocess pipe endpoints so they are not inherited by the child.
X-Git-Tag: v3.1.0~6
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3cf90980bc1f534229e3c63d241dcfedd38c8c4d;p=thirdparty%2Ftornado.git

Set CLOEXEC on subprocess pipe endpoints so they are not inherited by the child.

This is what the subprocess module does when it creates pipes, and is
necessary so that a close of the writing side of the stdin pipe will
be recognized by the child process.
---

diff --git a/tornado/process.py b/tornado/process.py
index 438db66d2..5f05b1828 100644
--- a/tornado/process.py
+++ b/tornado/process.py
@@ -33,6 +33,7 @@ from binascii import hexlify
 from tornado import ioloop
 from tornado.iostream import PipeIOStream
 from tornado.log import gen_log
+from tornado.platform.auto import set_close_exec
 from tornado import stack_context
 
 try:
@@ -69,6 +70,13 @@ def _reseed_random():
     random.seed(seed)
 
 
+def _pipe_cloexec():
+    r, w = os.pipe()
+    set_close_exec(r)
+    set_close_exec(w)
+    return r, w
+
+
 _task_id = None
 
 
@@ -184,17 +192,17 @@ class Subprocess(object):
         self.io_loop = kwargs.pop('io_loop', None)
         to_close = []
         if kwargs.get('stdin') is Subprocess.STREAM:
-            in_r, in_w = os.pipe()
+            in_r, in_w = _pipe_cloexec()
             kwargs['stdin'] = in_r
             to_close.append(in_r)
             self.stdin = PipeIOStream(in_w, io_loop=self.io_loop)
         if kwargs.get('stdout') is Subprocess.STREAM:
-            out_r, out_w = os.pipe()
+            out_r, out_w = _pipe_cloexec()
             kwargs['stdout'] = out_w
             to_close.append(out_w)
             self.stdout = PipeIOStream(out_r, io_loop=self.io_loop)
         if kwargs.get('stderr') is Subprocess.STREAM:
-            err_r, err_w = os.pipe()
+            err_r, err_w = _pipe_cloexec()
             kwargs['stderr'] = err_w
             to_close.append(err_w)
             self.stderr = PipeIOStream(err_r, io_loop=self.io_loop)
diff --git a/tornado/test/process_test.py b/tornado/test/process_test.py
index 588488b95..5299a12a4 100644
--- a/tornado/test/process_test.py
+++ b/tornado/test/process_test.py
@@ -154,6 +154,20 @@ class SubprocessTest(AsyncTestCase):
         data = self.wait()
         self.assertEqual(data, b"")
 
+    def test_close_stdin(self):
+        # Close the parent's stdin handle and see that the child recognizes it.
+        subproc = Subprocess([sys.executable, '-u', '-i'],
+                             stdin=Subprocess.STREAM,
+                             stdout=Subprocess.STREAM, stderr=subprocess.STDOUT,
+                             io_loop=self.io_loop)
+        self.addCleanup(lambda: os.kill(subproc.pid, signal.SIGTERM))
+        subproc.stdout.read_until(b'>>> ', self.stop)
+        self.wait()
+        subproc.stdin.close()
+        subproc.stdout.read_until_close(self.stop)
+        data = self.wait()
+        self.assertEqual(data, b"\n")
+
     def test_stderr(self):
         subproc = Subprocess([sys.executable, '-u', '-c',
                               r"import sys; sys.stderr.write('hello\n')"],