The C function used by uuid.uuid4 is broken on

OSX 10.6 in that after os.fork() the parent and
child generate the same sequence of UUIDs.

This patch falls back to the the Python implementation
on OSX 10.6 or later.

Fixes issue #8621.

diff --git a/Lib/test/test_uuid.py b/Lib/test/test_uuid.py
index cc21baef5dbc5f964f1286406159547f1f46bf04..d10195651c9ad65bfebc5c3a13cdff77587c10e2 100644 (file)
--- a/Lib/test/test_uuid.py
+++ b/Lib/test/test_uuid.py
@@ -446,6 +446,34 @@ class TestUUID(TestCase):
             equal(u, uuid.UUID(v))
             equal(str(u), v)
 
+    def testIssue8621(self):
+        import os
+        import sys
+        if os.name != 'posix':
+            return
+
+        # On at least some versions of OSX uuid.uuid4 generates
+        # the same sequence of UUIDs in the parent and any
+        # children started using fork.
+        fds = os.pipe()
+        pid = os.fork()
+        if pid == 0:
+            os.close(fds[0])
+            value = uuid.uuid4()
+            os.write(fds[1], value.hex)
+            sys.exit(0)
+
+        else:
+            os.close(fds[1])
+            parent_value = uuid.uuid4().hex
+            os.waitpid(pid, 0)
+            child_value = os.read(fds[0], 100)
+
+            self.assertNotEqual(parent_value, child_value)
+
+
+
+
 
 def test_main():
     test_support.run_unittest(TestUUID)

diff --git a/Lib/uuid.py b/Lib/uuid.py
index 6aaa2b475113039ddd9b63057deb40c736fa9d93..d915fb2640b95fa92b898628db2decfe9964f6b6 100644 (file)
--- a/Lib/uuid.py
+++ b/Lib/uuid.py
@@ -406,6 +406,19 @@ try:
         if hasattr(lib, 'uuid_generate_time'):
             _uuid_generate_time = lib.uuid_generate_time
 
+    # The uuid_generate_* functions are broken on MacOS X 10.6, as noted
+    # in issue #8621 the function generates the same sequence of values
+    # in the parent process and all children created using fork (unless
+    # those children use exec as well).
+    #
+    # Assume that the uuid_generate functions are broken from 10.6 onward,
+    # the test can be adjusted when a later version is fixed.
+    import sys
+    if sys.platform == 'darwin':
+        import os
+        if int(os.uname()[2].split('.')[0]) >= 10:
+            _uuid_generate_random = _uuid_generate_time = None
+
     # On Windows prior to 2000, UuidCreate gives a UUID containing the
     # hardware address.  On Windows 2000 and later, UuidCreate makes a
     # random UUID and UuidCreateSequential gives a UUID containing the

diff --git a/Misc/NEWS b/Misc/NEWS
index f672f4aabc361f4ac68baf14b4dd696b7b76c498..52fd2760c006313412d8b977241d3e84cb8409f6 100644 (file)
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -39,6 +39,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #8621: uuid.uuid4() returned the same sequence of values in the
+  parent and any children created using ``os.fork`` on MacOS X 10.6.
+
 - Issue #8313: traceback.format_exception_only() encodes unicode message to
   ASCII with backslashreplace error handler if str(value) failed