From: Eric Snow Date: Mon, 31 Jul 2023 23:11:15 +0000 (-0600) Subject: gh-105766: Document that Custom Allocators Must Be Thread-Safe (gh-107519) X-Git-Tag: v3.13.0a1~1117 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=db361a340af3970c279908c8746a6b9ed45f47b8;p=thirdparty%2FPython%2Fcpython.git gh-105766: Document that Custom Allocators Must Be Thread-Safe (gh-107519) --- diff --git a/Doc/c-api/memory.rst b/Doc/c-api/memory.rst index 8968b26b6432..1df8c2b911ca 100644 --- a/Doc/c-api/memory.rst +++ b/Doc/c-api/memory.rst @@ -476,6 +476,10 @@ Customize Memory Allocators thread-safe: the :term:`GIL ` is not held when the allocator is called. + For the remaining domains, the allocator must also be thread-safe: + the allocator may be called in different interpreters that do not + share a ``GIL``. + If the new allocator is not a hook (does not call the previous allocator), the :c:func:`PyMem_SetupDebugHooks` function must be called to reinstall the debug hooks on top on the new allocator. @@ -500,6 +504,8 @@ Customize Memory Allocators **must** wrap the existing allocator. Substituting the current allocator for some other arbitrary one is **not supported**. + .. versionchanged:: 3.12 + All allocators must be thread-safe. .. c:function:: void PyMem_SetupDebugHooks(void) diff --git a/Doc/whatsnew/3.12.rst b/Doc/whatsnew/3.12.rst index 0ac4a3df8fef..a5cb325cedb2 100644 --- a/Doc/whatsnew/3.12.rst +++ b/Doc/whatsnew/3.12.rst @@ -1880,6 +1880,13 @@ Porting to Python 3.12 * :c:func:`PyUnstable_Long_IsCompact` * :c:func:`PyUnstable_Long_CompactValue` +* Custom allocators, set via :c:func:`PyMem_SetAllocator`, are now + required to be thread-safe, regardless of memory domain. Allocators + that don't have their own state, including "hooks", are not affected. + If your custom allocator is not already thread-safe and you need + guidance then please create a new GitHub issue + and CC ``@ericsnowcurrently``. + Deprecated ----------