From 87bbdd3085bc8f42407db5a709dd79288c35f5c2 Mon Sep 17 00:00:00 2001 From: Tim Peters Date: Sat, 6 Apr 2002 09:14:33 +0000 Subject: [PATCH] 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. --- Doc/api/memory.tex | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/Doc/api/memory.tex b/Doc/api/memory.tex index 2f4525906c4..3da6860ac98 100644 --- a/Doc/api/memory.tex +++ b/Doc/api/memory.tex @@ -26,7 +26,7 @@ the private 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 -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 Python objects and other internal buffers is performed on demand by 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}} -The following function sets, modeled after the ANSI C standard, are -available for allocating and releasing memory from the Python heap: +The following function sets, modeled after the ANSI C standard, +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} Allocates \var{n} bytes and returns a pointer of type \ctype{void*} 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. \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. 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 - \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 is non-\NULL. Unless \var{p} is \NULL, it must have been 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 \cfunction{PyMem_Realloc()}. Otherwise, or if \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} The following type-oriented macros are provided for convenience. Note