From: Fred Drake <fdrake@acm.org>
Date: Fri, 10 Aug 2001 17:37:33 +0000 (+0000)
Subject: Added a warning about reference cycles and memory consumption to the
X-Git-Tag: v2.2a3~676
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=d635e3c468d312ce83f6cacc1989dfdc735dbc05;p=thirdparty%2FPython%2Fcpython.git

Added a warning about reference cycles and memory consumption to the
section on functions which return stack frames.

This closes SF bug #449258.
---

diff --git a/Doc/lib/libinspect.tex b/Doc/lib/libinspect.tex
index 6101ad87e0c2..e5ec9ca6204f 100644
--- a/Doc/lib/libinspect.tex
+++ b/Doc/lib/libinspect.tex
@@ -264,6 +264,16 @@ line within that list.
 The optional \var{context} argument specifies the number of lines of
 context to return, which are centered around the current line.
 
+\strong{Warning:}  Keeping references to frame objects, as found in
+the first element of the frame records these functions return, can
+cause your program to create reference cycles.  Once a reference cycle
+has been created, the lifespan of all objects which can be accessed
+from the objects which form the cycle can become much longer even if
+Python's optional cycle detector is enabled.  If such cycles must be
+created, it is important to ensure they are explicitly broken to avoid
+the delayed destruction of objects and increased memory consumption
+which occurs.
+
 \begin{funcdesc}{getouterframes}{frame\optional{, context}}
   Get a list of frame records for a frame and all higher (calling)
   frames.