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Minor clarification about what's actually promised for PyMem_Malloc(0). 

I probably didn't do a correct thing for the LaTeX spelling of the
integer 1.
This commit is contained in:
Tim Peters 2002-04-06 09:14:33 +00:00
parent 303d05d317
commit 87bbdd3085
1 changed files with 8 additions and 6 deletions
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14
Doc/api/memory.tex
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@ -26,7 +26,7 @@ the private heap.
It is important to understand that the management of the Python heap It is important to understand that the management of the Python heap
is performed by the interpreter itself and that the user has no is performed by the interpreter itself and that the user has no
control on it, even if she regularly manipulates object pointers to control over it, even if she regularly manipulates object pointers to
memory blocks inside that heap. The allocation of heap space for memory blocks inside that heap. The allocation of heap space for
Python objects and other internal buffers is performed on demand by Python objects and other internal buffers is performed on demand by
the Python memory manager through the Python/C API functions listed in the Python memory manager through the Python/C API functions listed in
@ -79,14 +79,16 @@ the I/O buffer escapes completely the Python memory manager.
\section{Memory Interface \label{memoryInterface}} \section{Memory Interface \label{memoryInterface}}
The following function sets, modeled after the ANSI C standard, are The following function sets, modeled after the ANSI C standard,
available for allocating and releasing memory from the Python heap: but specifying behavior when requesting zero bytes,
are available for allocating and releasing memory from the Python heap:
\begin{cfuncdesc}{void*}{PyMem_Malloc}{size_t n} \begin{cfuncdesc}{void*}{PyMem_Malloc}{size_t n}
Allocates \var{n} bytes and returns a pointer of type \ctype{void*} Allocates \var{n} bytes and returns a pointer of type \ctype{void*}
to the allocated memory, or \NULL{} if the request fails. to the allocated memory, or \NULL{} if the request fails.
Requesting zero bytes returns a non-\NULL{} pointer. Requesting zero bytes returns a distinct non-\NULL{} pointer if
possible, as if \cfunction{PyMem_Malloc(1)} had been called instead.
The memory will not have been initialized in any way. The memory will not have been initialized in any way.
\end{cfuncdesc} \end{cfuncdesc}
@ -94,7 +96,7 @@ available for allocating and releasing memory from the Python heap:
Resizes the memory block pointed to by \var{p} to \var{n} bytes. Resizes the memory block pointed to by \var{p} to \var{n} bytes.
The contents will be unchanged to the minimum of the old and the new The contents will be unchanged to the minimum of the old and the new
sizes. If \var{p} is \NULL, the call is equivalent to sizes. If \var{p} is \NULL, the call is equivalent to
\cfunction{PyMem_Malloc(\var{n})}; if \var{n} is equal to zero, the \cfunction{PyMem_Malloc(\var{n})}; else if \var{n} is equal to zero, the
memory block is resized but is not freed, and the returned pointer memory block is resized but is not freed, and the returned pointer
is non-\NULL. Unless \var{p} is \NULL, it must have been is non-\NULL. Unless \var{p} is \NULL, it must have been
returned by a previous call to \cfunction{PyMem_Malloc()} or returned by a previous call to \cfunction{PyMem_Malloc()} or
@ -106,7 +108,7 @@ available for allocating and releasing memory from the Python heap:
returned by a previous call to \cfunction{PyMem_Malloc()} or returned by a previous call to \cfunction{PyMem_Malloc()} or
\cfunction{PyMem_Realloc()}. Otherwise, or if \cfunction{PyMem_Realloc()}. Otherwise, or if
\cfunction{PyMem_Free(p)} has been called before, undefined \cfunction{PyMem_Free(p)} has been called before, undefined
behaviour occurs. If \var{p} is \NULL, no operation is performed. behavior occurs. If \var{p} is \NULL, no operation is performed.
\end{cfuncdesc} \end{cfuncdesc}
The following type-oriented macros are provided for convenience. Note The following type-oriented macros are provided for convenience. Note