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issue with borrowed reference · pythoncapi/pythoncapi@ba41931 · GitHub

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issue with borrowed reference
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‎doc/bad_api.rst‎

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@@ -15,6 +15,15 @@ See also :ref:`Remove functions <remove-funcs>`.
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Borrowed references
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===================
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A borrowed reference is a pointer which doesn't "hold" a reference. If the
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object is destroyed, the borrowed reference becomes a dangling pointer: pointer
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pointing to freed memory which might be reused by a new object.
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Borrowed references can lead to bugs and crashes when misused. The
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:ref:`Specialized list for small integers <specialized-list>` optimization is
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incompatible with borrowed references, since the runtime cannot guess when the
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temporary object should be destroyed.
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CPython 3.7 has many functions and macros which return or use borrowed
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references. For example, ``PyTuple_GetItem()`` returns a borrowed reference,
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whereas ``PyTuple_SetItem()`` stores a borrowed reference (store an item into a

‎doc/optimization_ideas.rst‎

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@@ -110,6 +110,8 @@ PyPy experimented Software Transactional Memory (STM) but the project has
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been abandoned, `PyPy STM <http://doc.pypy.org/en/latest/stm.html>`_.
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.. _specialized-list:
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Specialized list for small integers
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===================================
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