From: Miss Skeleton (bot) <31488909+miss-islington@users.noreply.github.com>
Date: Sun, 25 Oct 2020 15:48:38 +0000 (-0700)
Subject: bpo-39108: Document threading issues for random.gauss() (GH-22928) (GH-22972)
X-Git-Tag: v3.9.1rc1~98
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=af891a962b62268d76ace0d4768ab0e1934a2cd1;p=thirdparty%2FPython%2Fcpython.git

bpo-39108: Document threading issues for random.gauss() (GH-22928) (GH-22972)
---

diff --git a/Doc/library/random.rst b/Doc/library/random.rst
index f9535d7d1b9a..8154dfc18ccc 100644
--- a/Doc/library/random.rst
+++ b/Doc/library/random.rst
@@ -319,6 +319,13 @@ be found in any statistics text.
    deviation.  This is slightly faster than the :func:`normalvariate` function
    defined below.
 
+   Multithreading note:  When two threads call this function
+   simultaneously, it is possible that they will receive the
+   same return value.  This can be avoided in three ways.
+   1) Have each thread use a different instance of the random
+   number generator. 2) Put locks around all calls. 3) Use the
+   slower, but thread-safe :func:`normalvariate` function instead.
+
 
 .. function:: lognormvariate(mu, sigma)