From: Fred Drake Date: Tue, 23 Apr 2002 21:21:20 +0000 (+0000) Subject: Add text about circular references caused by storing frames in local X-Git-Tag: v2.3c1~5810 X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=99d17006c12d2e768a7b8e1c706adf6b4e152140;p=python Add text about circular references caused by storing frames in local variables. This closes SF bug #543148. --- diff --git a/Doc/lib/libinspect.tex b/Doc/lib/libinspect.tex index 186fd586b3..a1293f0e96 100644 --- a/Doc/lib/libinspect.tex +++ b/Doc/lib/libinspect.tex @@ -321,3 +321,19 @@ which occurs.} Return a list of frame records for the stack below the current exception. \end{funcdesc} + +Stackframes stored directly or indirectly in local variables can +easily cause reference cycles. Though the cycle detector will catch +these, destruction of the frames (and local variables) can be made +deterministic by removing the cycle in a \keyword{finally} clause. +This is also important if the cycle detector was disabled when Python +was compiled or using \function{gc.disable()}. For example: + +\begin{verbatim} +def handle_stackframe_without_leak(): + frame = inspect.currentframe() + try: + # do something with the frame + finally: + del frame +\end{verbatim}