From 1d8edc07227311c83c75cf168173d5f7f941350c Mon Sep 17 00:00:00 2001
From: Arvid Norberg <arvid@libtorrent.org>
Date: Mon, 24 Mar 2008 04:38:43 +0000
Subject: [PATCH] fixed race condition in dht

---
 include/libtorrent/kademlia/dht_tracker.hpp |  7 +++++++
 src/kademlia/dht_tracker.cpp                | 15 ++++++++++++---
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/include/libtorrent/kademlia/dht_tracker.hpp b/include/libtorrent/kademlia/dht_tracker.hpp
index db01b7b64..0d0064af5 100644
--- a/include/libtorrent/kademlia/dht_tracker.hpp
+++ b/include/libtorrent/kademlia/dht_tracker.hpp
@@ -45,6 +45,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #include <boost/filesystem/operations.hpp>
 #include <boost/intrusive_ptr.hpp>
 #include <boost/detail/atomic_count.hpp>
+#include <boost/thread/mutex.hpp>
 
 #include "libtorrent/kademlia/node.hpp"
 #include "libtorrent/kademlia/node_id.hpp"
@@ -117,6 +118,12 @@ namespace libtorrent { namespace dht
 		dht_settings const& m_settings;
 		int m_refresh_bucket;
 
+		// The mutex is used to abort the dht node
+		// it's only used to set m_abort to true
+		typedef boost::mutex mutex_t;
+		mutable mutex_t m_mutex;
+		bool m_abort;
+
 		// used to resolve hostnames for nodes
 		udp::resolver m_host_resolver;
 
diff --git a/src/kademlia/dht_tracker.cpp b/src/kademlia/dht_tracker.cpp
index 4336823b6..bc638d045 100644
--- a/src/kademlia/dht_tracker.cpp
+++ b/src/kademlia/dht_tracker.cpp
@@ -155,6 +155,7 @@ namespace libtorrent { namespace dht
 		, m_refresh_timer(sock.get_io_service())
 		, m_settings(settings)
 		, m_refresh_bucket(160)
+		, m_abort(false)
 		, m_host_resolver(sock.get_io_service())
 		, m_refs(0)
 	{
@@ -212,6 +213,8 @@ namespace libtorrent { namespace dht
 
 	void dht_tracker::stop()
 	{
+		mutex_t::scoped_lock l(m_mutex);
+		m_abort = true;
 		m_timer.cancel();
 		m_connection_timer.cancel();
 		m_refresh_timer.cancel();
@@ -228,7 +231,9 @@ namespace libtorrent { namespace dht
 	void dht_tracker::connection_timeout(asio::error_code const& e)
 		try
 	{
-		if (e) return;
+		mutex_t::scoped_lock l(m_mutex);
+		if (e || m_abort) return;
+
 		time_duration d = m_dht.connection_timeout();
 		m_connection_timer.expires_from_now(d);
 		m_connection_timer.async_wait(bind(&dht_tracker::connection_timeout, self(), _1));
@@ -245,7 +250,9 @@ namespace libtorrent { namespace dht
 	void dht_tracker::refresh_timeout(asio::error_code const& e)
 		try
 	{
-		if (e) return;
+		mutex_t::scoped_lock l(m_mutex);
+		if (e || m_abort) return;
+
 		time_duration d = m_dht.refresh_timeout();
 		m_refresh_timer.expires_from_now(d);
 		m_refresh_timer.async_wait(
@@ -259,7 +266,9 @@ namespace libtorrent { namespace dht
 	void dht_tracker::tick(asio::error_code const& e)
 		try
 	{
-		if (e) return;
+		mutex_t::scoped_lock l(m_mutex);
+		if (e || m_abort) return;
+
 		m_timer.expires_from_now(minutes(tick_period));
 		m_timer.async_wait(bind(&dht_tracker::tick, self(), _1));