Merged revisions 66703,66708 via svnmerge from

svn+ssh://pythondev@svn.python.org/python/trunk

........
  r66703 | gregory.p.smith | 2008-09-30 15:41:13 -0500 (Tue, 30 Sep 2008) | 6 lines

  Works around issue3863: freebsd4/5/6 and os2emx are known to have OS bugs when
  calling fork() from a child thread.  This disables that unit test (with a note
  printed to stderr) on those platforms.

  A caveat about buggy platforms is added to the os.fork documentation.
........
  r66708 | andrew.macintyre | 2008-09-30 22:25:25 -0500 (Tue, 30 Sep 2008) | 9 lines

  fix for issue 3862: test_array fails FreeBSD 7 amd64

  FreeBSD 7's underlying malloc() is behaves differently to earlier versions
  and seriously overcommits available memory on amd64.  This may affect
  other 64bit platforms in some circumstances, so the scale of the
  problematic test is wound back.

  Patch by Mark Dickinson, reviewed by Martin von Loewis.
........

3 files changed, 15 insertions, 4 deletions

diff --git a/Doc/library/os.rst b/Doc/library/os.rst
index 82a5b98..81a3f35 100644
--- a/Doc/library/os.rst
+++ b/Doc/library/os.rst
@@ -1389,6 +1389,10 @@ written in Python, such as a mail server's external command delivery program.
 
    Fork a child process.  Return ``0`` in the child and the child's process id in the
    parent.  If an error occurs :exc:`OSError` is raised.
+
+   Note that some platforms including FreeBSD <= 6.3, Cygwin and OS/2 EMX have
+   known issues when using fork() from a thread.
+
    Availability: Unix.
 
 
diff --git a/Lib/test/test_array.py b/Lib/test/test_array.py
index 5b6b9f2..ff9026a 100755
--- a/Lib/test/test_array.py
+++ b/Lib/test/test_array.py
@@ -964,20 +964,21 @@ class DoubleTest(FPTest):
     minitemsize = 8
 
     def test_alloc_overflow(self):
+        from sys import maxsize
         a = array.array('d', [-1]*65536)
         try:
-            a *= 65536
+            a *= maxsize//65536 + 1
         except MemoryError:
             pass
         else:
-            self.fail("a *= 2**16 didn't raise MemoryError")
+            self.fail("Array of size > maxsize created - MemoryError expected")
         b = array.array('d', [ 2.71828183, 3.14159265, -1])
         try:
-            b * 1431655766
+            b * (maxsize//3 + 1)
         except MemoryError:
             pass
         else:
-            self.fail("a * 1431655766 didn't raise MemoryError")
+            self.fail("Array of size > maxsize created - MemoryError expected")
 
 tests.append(DoubleTest)
 
diff --git a/Lib/test/test_threading.py b/Lib/test/test_threading.py
index a7f2322..f26e7bb 100644
--- a/Lib/test/test_threading.py
+++ b/Lib/test/test_threading.py
@@ -397,6 +397,12 @@ class ThreadJoinOnShutdown(unittest.TestCase):
         import os
         if not hasattr(os, 'fork'):
             return
+        # Skip platforms with known problems forking from a worker thread.
+        # See http://bugs.python.org/issue3863.
+        if sys.platform in ('freebsd4', 'freebsd5', 'freebsd6', 'os2emx'):
+            print >>sys.stderr, ('Skipping test_3_join_in_forked_from_thread'
+                                 ' due to known OS bugs on'), sys.platform
+            return
         script = """if 1:
             main_thread = threading.current_thread()
             def worker():