From: Daniel Sommermann <dcsommer@fb.com>
Date: Mon, 30 Sep 2013 21:02:07 +0000 (-0700)
Subject: Add a comment about takeOwnership()
X-Git-Tag: v0.22.0~858
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=524d0e74dbcd615e3704be2a119cd63f6c69d3fd;p=folly.git

Add a comment about takeOwnership()

Summary:
It is dangerous to pass memory into an IOBuf since usually in C++
programs, memory is allocated using `new`, while IOBuf by default frees
memory that it has taken ownership of with `free()`. For now, add a
comment warning about this (address sanitizer will warn you about this
when it happens in a live process).

Test Plan: NA

Reviewed By: tudorb@fb.com

FB internal diff: D990056

@override-unit-failures
---

diff --git a/folly/io/IOBuf.h b/folly/io/IOBuf.h
index 3473d05e..7d96e02f 100644
--- a/folly/io/IOBuf.h
+++ b/folly/io/IOBuf.h
@@ -238,7 +238,9 @@ class IOBuf {
    * buffer as the first argument, and the supplied userData value as the
    * second argument.  The free function must never throw exceptions.
    *
-   * If no FreeFunction is specified, the buffer will be freed using free().
+   * If no FreeFunction is specified, the buffer will be freed using free()
+   * which will result in undefined behavior if the memory was allocated
+   * using 'new'.
    *
    * The IOBuf data pointer will initially point to the start of the buffer,
    *