From d8f53ad9888a04fb5c50551c566b85ffd25afb90 Mon Sep 17 00:00:00 2001
From: Helge Norberg <helge.norberg@svt.se>
Date: Tue, 8 Nov 2016 19:22:08 +0100
Subject: [PATCH] [polling_filesystem_monitor] Fixed bug where unallocated
 memory could be read by polling_filesystem_monitor at server shutdown

---
 common/polling_filesystem_monitor.cpp | 46 +++++++++++++++++----------
 shell/server.cpp                      |  3 ++
 2 files changed, 33 insertions(+), 16 deletions(-)

diff --git a/common/polling_filesystem_monitor.cpp b/common/polling_filesystem_monitor.cpp
index c189218ea..74962590b 100644
--- a/common/polling_filesystem_monitor.cpp
+++ b/common/polling_filesystem_monitor.cpp
@@ -203,17 +203,19 @@ private:
 	}
 };
 
-class polling_filesystem_monitor : public filesystem_monitor
+class polling_filesystem_monitor
+		: public filesystem_monitor
+		, public spl::enable_shared_from_this<polling_filesystem_monitor>
 {
-	tbb::atomic<bool> running_;
-	std::shared_ptr<boost::asio::io_service> scheduler_;
-	directory_monitor root_monitor_;
-	boost::asio::deadline_timer timer_;
-	int scan_interval_millis_;
-	std::promise<void> initial_scan_completion_;
-	tbb::concurrent_queue<boost::filesystem::path> to_reemmit_;
-	tbb::atomic<bool> reemmit_all_;
-	executor executor_;
+	tbb::atomic<bool>								running_;
+	std::shared_ptr<boost::asio::io_service>		scheduler_;
+	directory_monitor								root_monitor_;
+	boost::asio::deadline_timer						timer_;
+	int												scan_interval_millis_;
+	std::promise<void>								initial_scan_completion_;
+	tbb::concurrent_queue<boost::filesystem::path>	to_reemmit_;
+	tbb::atomic<bool>								reemmit_all_;
+	executor										executor_;
 public:
 	polling_filesystem_monitor(
 			const boost::filesystem::path& folder_to_watch,
@@ -231,6 +233,10 @@ public:
 	{
 		running_ = true;
 		reemmit_all_ = false;
+	}
+
+	void start()
+	{
 		executor_.begin_invoke([this]
 		{
 			scan();
@@ -243,7 +249,7 @@ public:
 	{
 		running_ = false;
 		boost::system::error_code e;
-		timer_.cancel(e);
+		timer_.cancel(e); // Can still have be queued for execution by asio, therefore the task has a weak_ptr to this
 	}
 
 	std::future<void> initial_files_processed() override
@@ -266,11 +272,15 @@ private:
 		if (!running_)
 			return;
 
-		timer_.expires_from_now(
-			boost::posix_time::milliseconds(scan_interval_millis_));
-		timer_.async_wait([this](const boost::system::error_code& e)
+		std::weak_ptr<polling_filesystem_monitor> weak_self = shared_from_this();
+
+		timer_.expires_from_now(boost::posix_time::milliseconds(scan_interval_millis_));
+		timer_.async_wait([weak_self](const boost::system::error_code& e)
 		{
-			begin_scan();
+			auto strong_self = weak_self.lock();
+
+			if (strong_self)
+				strong_self->begin_scan();
 		});
 	}
 
@@ -344,7 +354,7 @@ filesystem_monitor::ptr polling_filesystem_monitor_factory::create(
 		const filesystem_monitor_handler& handler,
 		const initial_files_handler& initial_files_handler)
 {
-	return spl::make_shared<polling_filesystem_monitor>(
+	auto monitor = spl::make_shared<polling_filesystem_monitor>(
 			folder_to_watch,
 			events_of_interest_mask,
 			report_already_existing,
@@ -352,6 +362,10 @@ filesystem_monitor::ptr polling_filesystem_monitor_factory::create(
 			impl_->scheduler_,
 			handler,
 			initial_files_handler);
+
+	monitor->start();
+
+	return monitor;
 }
 
 }
diff --git a/shell/server.cpp b/shell/server.cpp
index 3d78ed36b..69fa7c083 100644
--- a/shell/server.cpp
+++ b/shell/server.cpp
@@ -109,12 +109,15 @@ std::shared_ptr<boost::asio::io_service> create_running_io_service()
 				CASPAR_LOG_CURRENT_EXCEPTION();
 			}
 		}
+
+		CASPAR_LOG(info) << "[asio] Global io_service uninitialized.";
 	});
 
 	return std::shared_ptr<boost::asio::io_service>(
 			service.get(),
 			[service, work, thread](void*) mutable
 			{
+				CASPAR_LOG(info) << "[asio] Shutting down global io_service.";
 				work.reset();
 				service->stop();
 				if (thread->get_id() != boost::this_thread::get_id())
-- 
2.39.2