Reapply r79779: "Removed gclient_utils.Popen() and use subprocess2's version instead."

It should be fine now that I've fixed python2.5 compatilibity issues in subprocess2.py.

R=dpranke@chromium.org
BUG=
TEST=

Review URL: http://codereview.chromium.org/6759074

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@80216 0039d316-1c4b-4281-b951-d872f2087c98

gclient_utils.py

@@ -17,13 +17,10 @@ import time
 import xml.dom.minidom
 import xml.parsers.expat
 
+import subprocess2
 
-def hack_subprocess():
-  """subprocess functions may throw exceptions when used in multiple threads.
-
-  See http://bugs.python.org/issue1731717 for more information.
-  """
-  subprocess._cleanup = lambda: None
+# Keep an alias for now.
+Popen = subprocess2.Popen
 
 
 class Error(Exception):
@@ -55,32 +52,6 @@ class CheckCallError(OSError, Error):
     return out
 
 
-def Popen(args, **kwargs):
-  """Calls subprocess.Popen() with hacks to work around certain behaviors.
-
-  Ensure English outpout for svn and make it work reliably on Windows.
-  """
-  logging.debug(u'%s, cwd=%s' % (u' '.join(args), kwargs.get('cwd', '')))
-  if not 'env' in kwargs:
-    # It's easier to parse the stdout if it is always in English.
-    kwargs['env'] = os.environ.copy()
-    kwargs['env']['LANGUAGE'] = 'en'
-  if not 'shell' in kwargs:
-    # *Sigh*:  Windows needs shell=True, or else it won't search %PATH% for the
-    # executable, but shell=True makes subprocess on Linux fail when it's called
-    # with a list because it only tries to execute the first item in the list.
-    kwargs['shell'] = (sys.platform=='win32')
-  try:
-    return subprocess.Popen(args, **kwargs)
-  except OSError, e:
-    if e.errno == errno.EAGAIN and sys.platform == 'cygwin':
-      raise Error(
-          'Visit '
-          'http://code.google.com/p/chromium/wiki/CygwinDllRemappingFailure to '
-          'learn how to fix this error; you need to rebase your cygwin dlls')
-    raise
-
-
 def CheckCall(command, print_error=True, **kwargs):
   """Similar subprocess.check_call() but redirects stdout and
   returns (stdout, stderr).
@@ -566,7 +537,6 @@ class ExecutionQueue(object):
   def __init__(self, jobs, progress):
     """jobs specifies the number of concurrent tasks to allow. progress is a
     Progress instance."""
-    hack_subprocess()
     # Set when a thread is done or a new item is enqueued.
     self.ready_cond = threading.Condition()
     # Maximum number of concurrent tasks.

subprocess2.py

@@ -8,6 +8,7 @@ In theory you shouldn't need anything else in subprocess, or this module failed.
 """
 
 from __future__ import with_statement
+import errno
 import logging
 import os
 import subprocess
@@ -124,7 +125,7 @@ def get_english_env(env):
 
 
 def Popen(args, **kwargs):
-  """Wraps subprocess.Popen().
+  """Wraps subprocess.Popen() with various workarounds.
 
   Returns a subprocess.Popen object.
 
@@ -134,7 +135,8 @@ def Popen(args, **kwargs):
     shell parameter to a value.
   - Adds support for VOID to not buffer when not needed.
 
-  Note: Popen() can throw OSError when cwd or args[0] doesn't exist.
+  Note: Popen() can throw OSError when cwd or args[0] doesn't exist. Translate
+  exceptions generated by cygwin when it fails trying to emulate fork().
   """
   # Make sure we hack subprocess if necessary.
   hack_subprocess()
@@ -160,7 +162,20 @@ def Popen(args, **kwargs):
     kwargs['stdout'] = open(os.devnull, 'w')
   if kwargs.get('stderr') in (VOID, os.devnull):
     kwargs['stderr'] = open(os.devnull, 'w')
-  return subprocess.Popen(args, **kwargs)
+  try:
+    return subprocess.Popen(args, **kwargs)
+  except OSError, e:
+    if e.errno == errno.EAGAIN and sys.platform == 'cygwin':
+      # Convert fork() emulation failure into a CalledProcessError().
+      raise CalledProcessError(
+          e.errno,
+          args,
+          kwargs.get('cwd'),
+          'Visit '
+          'http://code.google.com/p/chromium/wiki/CygwinDllRemappingFailure to '
+          'learn how to fix this error; you need to rebase your cygwin dlls',
+          None)
+    raise
 
 
 def call(args, timeout=None, **kwargs):

tests/gclient_utils_test.py

@@ -33,8 +33,8 @@ class GclientUtilsUnittest(GclientUtilBase):
         'ParseXML', 'Popen',
         'PrintableObject', 'RemoveDirectory', 'SoftClone', 'SplitUrlRevision',
         'SyntaxErrorToError', 'WorkItem',
-        'errno', 'hack_subprocess', 'logging', 'os', 'Queue', 're', 'rmtree',
-        'stat', 'subprocess', 'sys','threading', 'time', 'xml',
+        'errno', 'logging', 'os', 'Queue', 're', 'rmtree',
+        'stat', 'subprocess', 'subprocess2', 'sys','threading', 'time', 'xml',
     ]
     # If this test fails, you should add the relevant test.
     self.compareMembers(gclient_utils, members)