Fix usage of Popen.wait(). This is liable to deadlock if used with…

theano/configdefaults.py

@@ -117,19 +117,10 @@ AddConfigVar('mode',
 enum = EnumStr("g++", "")
 
 # Test whether or not g++ is present: disable C code if it is not.
-# Using the dummy file descriptor below is a workaround for a crash experienced
-# in an unusual Python 2.4.4 Windows environment with the default stdin=None.
-dummy_stdin = open(os.devnull)
 try:
-    try:
-        rc = call_subprocess_Popen(['g++', '-v'], stdout=subprocess.PIPE,
-                                   stderr=subprocess.PIPE,
-                                   stdin=dummy_stdin).wait()
-    except OSError:
+    rc = call_subprocess_Popen(['g++', '-v'])
+except OSError:
     rc = 1
-finally:
-    dummy_stdin.close()
-    del dummy_stdin
 if rc == 0:
     # Keep the default linker the same as the one for the mode FAST_RUN
     AddConfigVar('linker',

theano/gof/cmodule.py

@@ -29,7 +29,8 @@ from theano.compat.six import b, BytesIO, StringIO
 from theano.gof.utils import flatten
 from theano.configparser import config
 from theano.gof.cc import hash_from_code
-from theano.misc.windows import call_subprocess_Popen
+from theano.misc.windows import (subprocess_Popen, call_subprocess_Popen,
+                                 output_subprocess_Popen)
 
 # we will abuse the lockfile mechanism when reading and writing the registry
 from theano.gof import compilelock
@@ -1516,11 +1517,8 @@ def gcc_llvm():
         pass
         p = None
         try:
-            p = call_subprocess_Popen(['g++', '--version'],
-                                      stdout=subprocess.PIPE,
-                                      stderr=subprocess.PIPE)
-            p.wait()
-            output = p.stdout.read() + p.stderr.read()
+            p_out = output_subprocess_Popen(['g++', '--version'])
+            output = p_out[0] + p_out[1]
         except OSError:
             # Typically means g++ cannot be found.
             # So it is not an llvm compiler.
@@ -1573,7 +1571,7 @@ class GCC_compiler(object):
             GCC_compiler.march_flags = []
 
             def get_lines(cmd, parse=True):
-                p = call_subprocess_Popen(cmd,
+                p = subprocess_Popen(cmd,
                                      stdout=subprocess.PIPE,
                                      stderr=subprocess.PIPE,
                                      stdin=subprocess.PIPE,
@@ -1815,21 +1813,15 @@ class GCC_compiler(object):
                 os.write(fd, src_code)
                 os.close(fd)
                 fd = None
-                proc = call_subprocess_Popen(
-                        ['g++', path, '-o', exe_path] + flags,
-                        stdout=subprocess.PIPE,
-                        stderr=subprocess.PIPE)
-                proc.wait()
-                if proc.returncode != 0:
+                p_ret = call_subprocess_Popen(
+                    ['g++', path, '-o', exe_path] + flags)
+                if p_ret != 0:
                     compilation_ok = False
                 elif try_run:
                     # Try to execute the program
                     try:
-                        proc = call_subprocess_Popen([exe_path],
-                                stdout=subprocess.PIPE,
-                                stderr=subprocess.PIPE)
-                        proc.wait()
-                        run_ok = (proc.returncode == 0)
+                        p_ret = call_subprocess_Popen([exe_path])
+                        run_ok = (p_ret == 0)
                     finally:
                         os.remove(exe_path)
             finally:
@@ -1962,14 +1954,14 @@ class GCC_compiler(object):
             print >> sys.stderr, ' '.join(cmd)
 
         try:
-            p = call_subprocess_Popen(cmd, stderr=subprocess.PIPE)
-            compile_stderr = decode(p.communicate()[1])
+            p_out = output_subprocess_Popen(cmd)
+            compile_stderr = decode(p_out[1])
         except Exception:
             # An exception can occur e.g. if `g++` is not found.
             print_command_line_error()
             raise
 
-        status = p.returncode
+        status = p_out[2]
 
         if status:
             print '==============================='

theano/gof/compiledir.py

@@ -16,27 +16,17 @@ import numpy
 import theano
 from theano.configparser import config, AddConfigVar, ConfigParam, StrParam
 from theano.gof.utils import flatten
-from theano.misc.windows import call_subprocess_Popen
+from theano.misc.windows import output_subprocess_Popen
 
 
 _logger = logging.getLogger("theano.gof.compiledir")
 
-# Using the dummy file descriptors below is a workaround for a crash
-# experienced in an unusual Python 2.4.4 Windows environment with the default
-# None values.
-dummy_err = open(os.devnull, 'w')
-p = None
 try:
-    p = call_subprocess_Popen(['g++', '-dumpversion'],
-                              stdout=subprocess.PIPE,
-                              stderr=dummy_err.fileno())
-    p.wait()
-    gcc_version_str = p.stdout.readline().strip().decode()
+    p_out = output_subprocess_Popen(['g++', '-dumpversion'])
+    gcc_version_str = p_out[0].strip().decode()
 except OSError:
     # Typically means gcc cannot be found.
     gcc_version_str = 'GCC_NOT_FOUND'
-del p
-del dummy_err
 
 
 def local_bitwidth():

theano/misc/windows.py

@@ -2,7 +2,7 @@ import os
 import subprocess
 
 
-def call_subprocess_Popen(command, **params):
+def subprocess_Popen(command, **params):
     """
     Utility function to work around windows behavior that open windows
     """
@@ -36,3 +36,30 @@ def call_subprocess_Popen(command, **params):
         if stdin is not None:
             del stdin
     return proc
+
+def call_subprocess_Popen(command, **params):
+    if 'stdout' in params or 'stderr' in params:
+        raise TypeError("don't use stderr or stdout with call_subprocess_Popen")
+    null = open(os.devnull, 'wb')
+    # stdin to devnull is a workaround for a crash in a weird Windows
+    # environement where sys.stdin was None
+    params.setdefault('stdin', null)
+    params['stdout'] = null
+    params['stderr'] = null
+    p = subprocess_Popen(command, **params)
+    p.wait()
+    return p.returncode
+
+def output_subprocess_Popen(command, **params):
+    if 'stdout' in params or 'stderr' in params:
+        raise TypeError("don't use stderr or stdout with output_subprocess_Popen")
+    # stdin to devnull is a workaround for a crash in a weird Windows
+    # environement where sys.stdin was None
+    if not hasattr(params, 'stdin'):
+        null = open(os.devnull, 'wb')
+        params['stdin'] = null
+    params['stdout'] = subprocess.PIPE
+    params['stderr'] = subprocess.PIPE
+    p = subprocess_Popen(command, **params)
+    out = p.communicate()
+    return out + (p.returncode,)

theano/sandbox/cuda/nvcc_compiler.py

@@ -16,7 +16,7 @@ from theano.gof.cmodule import (std_libs, std_lib_dirs,
                                 std_include_dirs, dlimport,
                                 get_lib_extension)
 from theano.gof.python25 import any
-from theano.misc.windows import call_subprocess_Popen
+from theano.misc.windows import output_subprocess_Popen
 
 _logger = logging.getLogger("theano.sandbox.cuda.nvcc_compiler")
 _logger.setLevel(logging.WARN)
@@ -98,12 +98,8 @@ nvcc_version = None
 def is_nvcc_available():
     """Return True iff the nvcc compiler is found."""
     def set_version():
-        p = call_subprocess_Popen([nvcc_path, '--version'],
-                                  stdout=subprocess.PIPE,
-                                  stderr=subprocess.PIPE)
-        p.wait()
-
-        ver_line = decode(p.stdout.readlines()[-1])
+        p_out = output_subprocess_Popen([nvcc_path, '--version'])
+        ver_line = decode(p_out[0].split('\n')[-1])
         build, version = ver_line.split(',')[1].strip().split()
 
         assert build == 'release'

theano/tests/run_tests_in_batch.py

@@ -62,7 +62,7 @@ import sys
 import time
 
 import theano
-from theano.misc.windows import call_subprocess_Popen
+from theano.misc.windows import output_subprocess_Popen
 
 
 def main(stdout=None, stderr=None, argv=None, theano_nose=None,
@@ -271,19 +271,17 @@ def run(stdout, stderr, argv, theano_nose, batch_size, time_profile,
                     time.ctime(), test_id, data["ids"][test_id]))
                 f_rawlog.flush()
 
-                proc = call_subprocess_Popen(
+                p_out = output_subprocess_Popen(
                     ([python, theano_nose, '-v', '--with-id']
                      + [str(test_id)] + argv +
-                     ['--disabdocstring']),
+                     ['--disabdocstring']))
                     # the previous option calls a custom Nosetests plugin
                     # precluding automatic sustitution of doc. string for
                     # test name in display
                     # (see class 'DisabDocString' in file theano-nose)
-                    stderr=subprocess.PIPE,
-                    stdout=dummy_out.fileno())
 
                 # recovering and processing data from pipe
-                err = proc.stderr.read()
+                err = p_out[1]
                 # print the raw log
                 f_rawlog.write(err)
                 f_rawlog.flush()