From e74f1092c7844190ac67b7fdcf4fe821f8278b81 Mon Sep 17 00:00:00 2001
From: sippeangelo <holmberg.simon@gmail.com>
Date: Fri, 2 Oct 2015 18:12:00 +0200
Subject: [PATCH] Fixed crash when events were (un)subscribed while events were
 processing

---
 include/Core/EventBroker.h    |  8 +++++
 src/game/Core/EventBroker.cpp | 67 ++++++++++++++++++++++++++---------
 src/tests/EventFixture.h      |  2 +-
 3 files changed, 59 insertions(+), 18 deletions(-)

diff --git a/include/Core/EventBroker.h b/include/Core/EventBroker.h
index cb5e39c..ce2a5a4 100644
--- a/include/Core/EventBroker.h
+++ b/include/Core/EventBroker.h
@@ -24,6 +24,7 @@
 #include <map>
 #include <unordered_map>
 #include <list>
+#include <tuple>
 
 #define EVENT_SUBSCRIBE_MEMBER(relay, handler) \
 	relay = decltype(relay)(std::bind(handler, this, std::placeholders::_1)); \
@@ -123,16 +124,23 @@ public:
 	void Unsubscribe(BaseEventRelay &relay);
 
 private:
+	bool m_IsProcessing = false;
+
 	typedef std::string ContextTypeName_t; // typeid(ContextType).name()
 	typedef std::string EventTypeName_t; // typeid(EventType).name()
 
 	typedef std::unordered_multimap<EventTypeName_t, BaseEventRelay*> EventRelays_t;
 	typedef std::unordered_map<ContextTypeName_t, EventRelays_t> ContextRelays_t;
 	ContextRelays_t m_ContextRelays;
+	std::vector<BaseEventRelay*> m_RelaysToSubscribe;
+	std::vector<BaseEventRelay*> m_RelaysToUnsubscribe;
 
 	typedef std::list<std::pair<EventTypeName_t, std::shared_ptr<Event>>> EventQueue_t;
 	std::shared_ptr<EventQueue_t> m_EventQueueRead;
 	std::shared_ptr<EventQueue_t> m_EventQueueWrite;
+
+	void subscribeImmediate(BaseEventRelay& relay);
+	void unsubscribeImmediate(BaseEventRelay& relay);
 };
 
 template <typename EventType>
diff --git a/src/game/Core/EventBroker.cpp b/src/game/Core/EventBroker.cpp
index c8015c1..ce91fd9 100644
--- a/src/game/Core/EventBroker.cpp
+++ b/src/game/Core/EventBroker.cpp
@@ -29,32 +29,26 @@ dd::BaseEventRelay::~BaseEventRelay()
 
 void dd::EventBroker::Unsubscribe(BaseEventRelay &relay) // ?
 {
-	auto contextIt = m_ContextRelays.find(relay.m_ContextTypeName);
-	if (contextIt == m_ContextRelays.end())
-		return;
-
-	auto eventRelays = contextIt->second;
-
-	auto itpair = eventRelays.equal_range(relay.m_EventTypeName);
-	for (auto it = itpair.first; it != itpair.second; ++it)
-	{
-		if (it->second == &relay)
-		{
-			relay.m_Broker = nullptr;
-			eventRelays.erase(it);
-			break;
-		}
+	if (m_IsProcessing) {
+		m_RelaysToUnsubscribe.push_back(&relay);
+	} else {
+		unsubscribeImmediate(relay);
 	}
 }
 
 void dd::EventBroker::Subscribe(BaseEventRelay &relay)
 {
-	relay.m_Broker = this;
-	m_ContextRelays[relay.m_ContextTypeName].insert(std::make_pair(relay.m_EventTypeName, &relay));
+	if (m_IsProcessing) {
+		m_RelaysToSubscribe.push_back(&relay);
+	} else {
+		subscribeImmediate(relay);
+	}
 }
 
 int dd::EventBroker::Process(std::string contextTypeName)
 {
+	m_IsProcessing = true;
+
 	auto it = m_ContextRelays.find(contextTypeName);
 	if (it == m_ContextRelays.end())
 		return 0;
@@ -77,6 +71,20 @@ int dd::EventBroker::Process(std::string contextTypeName)
 		}
 	}
 
+	m_IsProcessing = false;
+
+	// Process pending subscriptions
+	for (auto& r : m_RelaysToSubscribe) {
+		subscribeImmediate(*r);
+	}
+	m_RelaysToSubscribe.clear();
+
+	// Process pending unsubscriptions
+	for (auto& r : m_RelaysToUnsubscribe) {
+		unsubscribeImmediate(*r);
+	}
+	m_RelaysToUnsubscribe.clear();
+
 	return eventsProcessed;
 }
 
@@ -84,4 +92,29 @@ void dd::EventBroker::Swap()
 {
 	std::swap(m_EventQueueRead, m_EventQueueWrite);
 	m_EventQueueWrite->clear();
+
+}
+
+void dd::EventBroker::subscribeImmediate(dd::BaseEventRelay& relay)
+{
+	relay.m_Broker = this;
+	m_ContextRelays[relay.m_ContextTypeName].insert(std::make_pair(relay.m_EventTypeName, &relay));
+}
+
+void dd::EventBroker::unsubscribeImmediate(dd::BaseEventRelay& relay)
+{
+	auto contextIt = m_ContextRelays.find(relay.m_ContextTypeName);
+	if (contextIt == m_ContextRelays.end()) {
+		return;
+	}
+
+	auto eventRelays = contextIt->second;
+	auto itpair = eventRelays.equal_range(relay.m_EventTypeName);
+	for (auto it = itpair.first; it != itpair.second; ++it) {
+		if (it->second == &relay) {
+			relay.m_Broker = nullptr;
+			eventRelays.erase(it);
+			break;
+		}
+	}
 }
diff --git a/src/tests/EventFixture.h b/src/tests/EventFixture.h
index 1548a08..4f78080 100644
--- a/src/tests/EventFixture.h
+++ b/src/tests/EventFixture.h
@@ -10,7 +10,7 @@ struct EventFixture
 	EventFixture()
 	{
 		this->EventBroker = new dd::EventBroker();
-		m_EEventType = decltype(m_EEventType)(std::bind(&OnEvent, this, std::placeholders::_1));
+		m_EEventType = decltype(m_EEventType)(std::bind(&EventFixture::OnEvent, this, std::placeholders::_1));
 		this->EventBroker->Subscribe(m_EEventType);
 		Run();
 		Check();