From e557babaad421e48a6c36acec1e75fb8c93f383f Mon Sep 17 00:00:00 2001
From: Thomas Goyne <tg@realm.io>
Date: Fri, 4 Dec 2015 12:07:42 -0800
Subject: [PATCH] Fix the generic implementation of ExternalCommitHelper

---
 src/impl/generic/external_commit_helper.cpp | 3 +++
 src/impl/generic/external_commit_helper.hpp | 6 +++---
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/src/impl/generic/external_commit_helper.cpp b/src/impl/generic/external_commit_helper.cpp
index 66417642..e50e884a 100644
--- a/src/impl/generic/external_commit_helper.cpp
+++ b/src/impl/generic/external_commit_helper.cpp
@@ -32,7 +32,10 @@ ExternalCommitHelper::ExternalCommitHelper(RealmCoordinator& parent)
 , m_sg(*m_history, parent.is_in_memory() ? SharedGroup::durability_MemOnly : SharedGroup::durability_Full,
        parent.get_encryption_key().data())
 , m_thread(std::async(std::launch::async, [=] {
+    m_sg.begin_read();
     while (m_sg.wait_for_change()) {
+        m_sg.end_read();
+        m_sg.begin_read();
         m_parent.on_change();
     }
 }))
diff --git a/src/impl/generic/external_commit_helper.hpp b/src/impl/generic/external_commit_helper.hpp
index 3249430e..d056566e 100644
--- a/src/impl/generic/external_commit_helper.hpp
+++ b/src/impl/generic/external_commit_helper.hpp
@@ -40,12 +40,12 @@ public:
 private:
     RealmCoordinator& m_parent;
 
-    // The listener thread
-    std::future<void> m_thread;
-
     // A shared group used to listen for changes
     std::unique_ptr<ClientHistory> m_history;
     SharedGroup m_sg;
+
+    // The listener thread
+    std::future<void> m_thread;
 };
 
 } // namespace _impl