rt: Detach pthreads before exiting

Joinable pthreads need to be either joined or detached and we no
longer join with the scheduler threads.

src/rt/rust_task_thread.cpp

@@ -319,6 +319,7 @@ rust_task_thread::create_task(rust_task *spawner, const char *name,
 
 void rust_task_thread::run() {
     this->start_main_loop();
+    detach();
     sched->release_task_thread();
 }
 

src/rt/sync/rust_thread.cpp

@@ -4,6 +4,9 @@
 rust_thread::rust_thread() : thread(0) {
 }
 
+rust_thread::~rust_thread() {
+}
+
 #if defined(__WIN32__)
 static DWORD WINAPI
 #elif defined(__GNUC__)
@@ -41,3 +44,12 @@ rust_thread::join() {
 #endif
    thread = 0;
 }
+
+void
+rust_thread::detach() {
+#if !defined(__WIN32__)
+    // Don't leak pthread resources.
+    // http://crosstantine.blogspot.com/2010/01/pthreadcreate-memory-leak.html
+    pthread_detach(thread);
+#endif
+}

src/rt/sync/rust_thread.h

@@ -12,6 +12,8 @@ public:
     pthread_t thread;
 #endif
     rust_thread();
+    virtual ~rust_thread();
+
     void start();
 
     virtual void run() {
@@ -19,8 +21,7 @@ public:
     }
 
     void join();
-
+    void detach();
-    virtual ~rust_thread() {}   // quiet the compiler
 };
 
 #endif /* RUST_THREAD_H */