From 26fb816da7078d687f7540e2e0a2d525801592f7 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Sun, 22 Nov 2009 21:40:35 +0000
Subject: [PATCH] Prevent crashing if the Resolver jams

---
 source/netvis.cpp   |  1 +
 source/resolver.cpp | 30 ++++++++++++++++++++++++------
 source/resolver.h   |  2 ++
 3 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/source/netvis.cpp b/source/netvis.cpp
index 3aff9cd..dce0837 100644
--- a/source/netvis.cpp
+++ b/source/netvis.cpp
@@ -141,6 +141,7 @@ void NetVis::tick()
 		}
 		else if(i->second->get_activity()<del_limit)
 		{
+			resolver->cancel(i->second);
 			delete i->second;
 			disabled_hosts.erase(i++);
 		}
diff --git a/source/resolver.cpp b/source/resolver.cpp
index d8dc41d..702ce96 100644
--- a/source/resolver.cpp
+++ b/source/resolver.cpp
@@ -34,6 +34,24 @@ void Resolver::push(Host *h)
 	in_queue.push_back(h);
 }
 
+void Resolver::cancel(Host *h)
+{
+	MutexLock l_(mutex);
+
+	if(h==current)
+	{
+		current=0;
+		return;
+	}
+
+	for(list<Host *>::iterator i=in_queue.begin(); i!=in_queue.end(); ++i)
+		if(*i==h)
+		{
+			in_queue.erase(i);
+			break;
+		}
+}
+
 void Resolver::tick()
 {
 	MutexLock l_(mutex);
@@ -49,24 +67,24 @@ void Resolver::main()
 	{
 		while(!done)
 		{
-			Host *host;
+			sockaddr_in addr;
+			addr.sin_family = AF_INET;
 			{
 				MutexLock l_(mutex);
 				if(in_queue.empty())
 					break;
-				host = in_queue.front();
+				current = in_queue.front();
 				in_queue.erase(in_queue.begin());
+				addr.sin_addr.s_addr = htonl(current->get_address());
 			}
 			
-			sockaddr_in addr;
-			addr.sin_family = AF_INET;
-			addr.sin_addr.s_addr = htonl(host->get_address());
 			char buf[128];
 			int err = getnameinfo(reinterpret_cast<sockaddr *>(&addr), sizeof(addr), buf, sizeof(buf), 0, 0, NI_NOFQDN|NI_NAMEREQD);
 			if(err==0)
 			{
 				MutexLock l_(mutex);
-				out_queue.push_back(Result(host, buf));
+				if(current)
+					out_queue.push_back(Result(current, buf));
 			}
 		}
 
diff --git a/source/resolver.h b/source/resolver.h
index fb9dd10..4b6e498 100644
--- a/source/resolver.h
+++ b/source/resolver.h
@@ -27,6 +27,7 @@ private:
 
 	std::list<Host *> in_queue;
 	std::list<Result> out_queue;
+	Host *current;
 	Msp::Mutex mutex;
 	bool done;
 
@@ -35,6 +36,7 @@ public:
 	~Resolver();
 
 	void push(Host *);
+	void cancel(Host *);
 	void tick();
 private:
 	void main();
-- 
2.43.0