From 0fb55060d25080d0b570545fc5f6052a14b9ea2d Mon Sep 17 00:00:00 2001
From: Gunnar Beutner <gunnar@beutner.name>
Date: Fri, 20 Feb 2015 15:23:06 +0100
Subject: [PATCH] Fix another potential deadlock in SocketEvents::WakeUpThread

refs #8484
---
 lib/base/socketevents.cpp | 20 ++++++++++++--------
 lib/base/socketevents.hpp |  2 +-
 2 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/lib/base/socketevents.cpp b/lib/base/socketevents.cpp
index aa1cc6ee6..fdf49ee65 100644
--- a/lib/base/socketevents.cpp
+++ b/lib/base/socketevents.cpp
@@ -149,17 +149,21 @@ void SocketEvents::ThreadProc(void)
 	}
 }
 
-void SocketEvents::WakeUpThread(void)
+void SocketEvents::WakeUpThread(bool wait)
 {
-	if (boost::this_thread::get_id() != l_SocketIOThread.get_id()) {
-		boost::mutex::scoped_lock lock(l_SocketIOMutex);
+	if (wait) {
+		if (boost::this_thread::get_id() != l_SocketIOThread.get_id()) {
+			boost::mutex::scoped_lock lock(l_SocketIOMutex);
 
-		l_SocketIOFDChanged = true;
+			l_SocketIOFDChanged = true;
 
+			(void) send(l_SocketIOEventFDs[1], "T", 1, 0);
+
+			while (l_SocketIOFDChanged)
+				l_SocketIOCV.wait(lock);
+		}
+	} else {
 		(void) send(l_SocketIOEventFDs[1], "T", 1, 0);
-
-		while (l_SocketIOFDChanged)
-			l_SocketIOCV.wait(lock);
 	}
 }
 
@@ -209,7 +213,7 @@ void SocketEvents::Unregister(void)
 		m_FD = INVALID_SOCKET;
 	}
 
-	WakeUpThread();
+	WakeUpThread(true);
 }
 
 void SocketEvents::ChangeEvents(int events)
diff --git a/lib/base/socketevents.hpp b/lib/base/socketevents.hpp
index 645de789b..2523d6543 100644
--- a/lib/base/socketevents.hpp
+++ b/lib/base/socketevents.hpp
@@ -51,7 +51,7 @@ private:
 	static void InitializeThread(void);
 	static void ThreadProc(void);
 
-	static void WakeUpThread(void);
+	static void WakeUpThread(bool wait = false);
 
 	int GetPollEvents(void) const;