[New-bugs-announce] [issue18227] Use Python memory allocators in external libraries like zlib or OpenSSL

[STINNER Victor]

New submission from STINNER Victor:

With the PEP 445 and the issue #3329, Python will get an API to setup custom memory allocators. To be able to configure how memory is handled in external libraries, some libraries allow to setup a custom allocator too. New functions PyMem_RawMalloc(), PyMem_GetRawAllocators() PyMem_SetRawAllocators() can be used for that.

The safest option is to only reuse custom allocators if a library allows to setup them for a specfic function call or a specific object, and not replace the memory allocators globally. For example, the lzma library allows to set memory allocators only for one compressor object: LzmaEnc_Create(&SzAllocForLzma);

We might change the global allocators of a library if Python is not embedded, but Python *is* the application (the standard "python" program).

I don't know yet if it is safe to reuse custom memory allocators.

Windows has for example a special behaviour: each DLL (dynamic library) has its own heap, memory allocator in a DLL cannot be released from another DLL. Would this issue introduce such bug?

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components: Interpreter Core
messages: 191248
nosy: christian.heimes, haypo
priority: normal
severity: normal
status: open
title: Use Python memory allocators in external libraries like zlib or OpenSSL
versions: Python 3.4

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue18227>
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