New upstream version 3.1.2upstream/3.1.2upstream

1 files changed, 36 insertions, 24 deletions

diff --git a/src/engine/SCons/Platform/win32.py b/src/engine/SCons/Platform/win32.py
index 3eff40f..b386afa 100644
--- a/src/engine/SCons/Platform/win32.py
+++ b/src/engine/SCons/Platform/win32.py
@@ -30,7 +30,7 @@ selection method.
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #
 
-__revision__ = "src/engine/SCons/Platform/win32.py 72ae09dc35ac2626f8ff711d8c4b30b6138e08e3 2019-08-08 14:50:06 bdeegan"
+__revision__ = "src/engine/SCons/Platform/win32.py bee7caf9defd6e108fc2998a2520ddb36a967691 2019-12-17 02:07:09 bdeegan"
 
 import os
 import os.path
@@ -51,10 +51,6 @@ try:
     import msvcrt
     import win32api
     import win32con
-
-    msvcrt.get_osfhandle
-    win32api.SetHandleInformation
-    win32con.HANDLE_FLAG_INHERIT
 except ImportError:
     parallel_msg = \
         "you do not seem to have the pywin32 extensions installed;\n" + \
@@ -66,28 +62,44 @@ except AttributeError:
 else:
     parallel_msg = None
 
-    _builtin_open = open
+    if sys.version_info.major == 2:
+        import __builtin__
+
+        _builtin_file = __builtin__.file
+        _builtin_open = __builtin__.open
+
+        def _scons_fixup_mode(mode):
+            """Adjust 'mode' to mark handle as non-inheritable.
+
+            SCons is multithreaded, so allowing handles to be inherited by
+            children opens us up to races, where (e.g.) processes spawned by
+            the Taskmaster may inherit and retain references to files opened
+            by other threads. This may lead to sharing violations and,
+            ultimately, build failures.
+
+            By including 'N' as part of fopen's 'mode' parameter, all file
+            handles returned from these functions are atomically marked as
+            non-inheritable.
+            """
+            if not mode:
+                # Python's default is 'r'.
+                # https://docs.python.org/2/library/functions.html#open
+                mode = 'rN'
+            elif 'N' not in mode:
+                mode += 'N'
+            return mode
 
-    def _scons_open(*args, **kw):
-        fp = _builtin_open(*args, **kw)
-        win32api.SetHandleInformation(msvcrt.get_osfhandle(fp.fileno()),
-                                      win32con.HANDLE_FLAG_INHERIT,
-                                      0)
-        return fp
+        class _scons_file(_builtin_file):
+            def __init__(self, name, mode=None, *args, **kwargs):
+                _builtin_file.__init__(self, name, _scons_fixup_mode(mode),
+                                       *args, **kwargs)
 
-    open = _scons_open
+        def _scons_open(name, mode=None, *args, **kwargs):
+            return _builtin_open(name, _scons_fixup_mode(mode),
+                                 *args, **kwargs)
 
-    if sys.version_info.major == 2:
-        _builtin_file = file
-        class _scons_file(_builtin_file):
-            def __init__(self, *args, **kw):
-                _builtin_file.__init__(self, *args, **kw)
-                win32api.SetHandleInformation(msvcrt.get_osfhandle(self.fileno()),
-                 win32con.HANDLE_FLAG_INHERIT, 0)
-        file = _scons_file
-    else:
-        # No longer needed for python 3.4 and above. Files are opened non sharable
-        pass
+        __builtin__.file = _scons_file
+        __builtin__.open = _scons_open