From: Martin Quinson <martin.quinson@loria.fr>
Date: Wed, 26 Apr 2017 11:56:10 +0000 (+0200)
Subject: comment++ on that code that I barely understand but exhibits bugs
X-Git-Tag: v3.16~309
X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/commitdiff_plain/6e3289e56fd7ab16327569a2f961006bd985c2f4?ds=inline

comment++ on that code that I barely understand but exhibits bugs
---

diff --git a/src/simix/ActorImpl.hpp b/src/simix/ActorImpl.hpp
index f2a18a6240..3e0f707c0a 100644
--- a/src/simix/ActorImpl.hpp
+++ b/src/simix/ActorImpl.hpp
@@ -79,6 +79,8 @@ public:
   {
     // inspired from http://www.boost.org/doc/libs/1_55_0/doc/html/atomic/usage_examples.html
     if (process->refcount_.fetch_sub(1, std::memory_order_release) == 1) {
+      // Make sure that any changes done on other threads before their acquire are commited before our delete
+      // http://stackoverflow.com/questions/27751025/why-is-an-acquire-barrier-needed-before-deleting-the-data-in-an-atomically-refer
       std::atomic_thread_fence(std::memory_order_acquire);
       delete process;
     }