Codechange: Replace custom thread code with C++11 thread objects.

We assume a conforming C++11 compiler environment that has a valid <thread>-header.
Failure to run a real thread is handled gracefully.

src/linkgraph/linkgraphjob.cpp

@@ -39,7 +39,6 @@ LinkGraphJob::LinkGraphJob(const LinkGraph &orig) :
 		 * This is on purpose. */
 		link_graph(orig),
 		settings(_settings_game.linkgraph),
-		thread(NULL),
 		join_date(_date + _settings_game.linkgraph.recalc_time)
 {
 }
@@ -61,8 +60,7 @@ void LinkGraphJob::EraseFlows(NodeID from)
  */
 void LinkGraphJob::SpawnThread()
 {
-	if (!ThreadObject::New(&(LinkGraphSchedule::Run), this, &this->thread, "ottd:linkgraph")) {
-		this->thread = NULL;
+	if (!StartNewThread(&this->thread, "ottd:linkgraph", &(LinkGraphSchedule::Run), this)) {
 		/* Of course this will hang a bit.
 		 * On the other hand, if you want to play games which make this hang noticably
 		 * on a platform without threads then you'll probably get other problems first.
@@ -79,10 +77,8 @@ void LinkGraphJob::SpawnThread()
  */
 void LinkGraphJob::JoinThread()
 {
-	if (this->thread != NULL) {
-		this->thread->Join();
-		delete this->thread;
-		this->thread = NULL;
+	if (this->thread.joinable()) {
+		this->thread.join();
 	}
 }
 

src/linkgraph/linkgraphjob.h

@@ -12,7 +12,7 @@
 #ifndef LINKGRAPHJOB_H
 #define LINKGRAPHJOB_H
 
-#include "../thread/thread.h"
+#include "../thread.h"
 #include "linkgraph.h"
 #include <list>
 
@@ -59,7 +59,7 @@ private:
 protected:
 	const LinkGraph link_graph;       ///< Link graph to by analyzed. Is copied when job is started and mustn't be modified later.
 	const LinkGraphSettings settings; ///< Copy of _settings_game.linkgraph at spawn time.
-	ThreadObject *thread;             ///< Thread the job is running in or NULL if it's running in the main thread.
+	std::thread thread;               ///< Thread the job is running in or a default-constructed thread if it's running in the main thread.
 	Date join_date;                   ///< Date when the job is to be joined.
 	NodeAnnotationVector nodes;       ///< Extra node data necessary for link graph calculation.
 	EdgeAnnotationMatrix edges;       ///< Extra edge data necessary for link graph calculation.
@@ -266,7 +266,7 @@ public:
 	 * Bare constructor, only for save/load. link_graph, join_date and actually
 	 * settings have to be brutally const-casted in order to populate them.
 	 */
-	LinkGraphJob() : settings(_settings_game.linkgraph), thread(NULL),
+	LinkGraphJob() : settings(_settings_game.linkgraph),
 			join_date(INVALID_DATE) {}
 
 	LinkGraphJob(const LinkGraph &orig);

src/linkgraph/linkgraphschedule.cpp

@@ -69,13 +69,11 @@ void LinkGraphSchedule::JoinNext()
 }
 
 /**
- * Run all handlers for the given Job. This method is tailored to
- * ThreadObject::New.
- * @param j Pointer to a link graph job.
+ * Run all handlers for the given Job.
+ * @param job Pointer to a link graph job.
  */
-/* static */ void LinkGraphSchedule::Run(void *j)
+/* static */ void LinkGraphSchedule::Run(LinkGraphJob *job)
 {
-	LinkGraphJob *job = (LinkGraphJob *)j;
 	for (uint i = 0; i < lengthof(instance.handlers); ++i) {
 		instance.handlers[i]->Run(*job);
 	}

src/linkgraph/linkgraphschedule.h

@@ -53,7 +53,7 @@ public:
 	static const uint SPAWN_JOIN_TICK = 21; ///< Tick when jobs are spawned or joined every day.
 	static LinkGraphSchedule instance;
 
-	static void Run(void *j);
+	static void Run(LinkGraphJob *job);
 	static void Clear();
 
 	void SpawnNext();