Stoppable, make stop() require call to start()

src/beast/beast/threads/Stoppable.h

@@ -265,6 +265,7 @@ protected:
     char const* m_name;
     RootStoppable& m_root;
     Child m_child;
+    Atomic <int> m_started;
     bool volatile m_stopped;
     bool volatile m_childrenStopped;
     Children m_children;
@@ -301,6 +302,8 @@ public:
     /** Notify a root stoppable and children to stop, and block until stopped.
         Has no effect if the stoppable was already notified.
         This blocks until the stoppable and all of its children have stopped.
+        Undefined behavior results if stop() is called without a previous call
+        to start().
         Thread safety:
             Safe to call from any thread not associated with a Stoppable.
     */
@@ -316,7 +319,6 @@ public:
 
 private:
     Atomic <int> m_prepared;
-    Atomic <int> m_started;
     Atomic <int> m_calledStop;
     Atomic <int> m_calledStopAsync;
 };

src/beast/beast/threads/impl/Stoppable.cpp

@@ -46,7 +46,7 @@ Stoppable::Stoppable (char const* name, Stoppable& parent)
 Stoppable::~Stoppable ()
 {
     // Children must be stopped.
-    bassert (m_childrenStopped);
+    bassert (m_started.get() == 0 || m_childrenStopped);
 }
 
 bool Stoppable::isStopping() const
@@ -177,6 +177,9 @@ void RootStoppable::start ()
 
 void RootStoppable::stop (Journal journal)
 {
+    // Must have a prior call to start()
+    bassert (m_started.get() != 0);
+
     if (! m_calledStop.compareAndSetBool (1, 0))
     {
         journal.warning << "Stoppable::stop called again";

src/ripple_app/main/Application.cpp

@@ -157,12 +157,6 @@ public:
 
     ~ApplicationImp ()
     {
-        stop();
-        //stop ();
-
-        // Why is this needed here?
-        //m_networkOPs = nullptr;
-
         bassert (s_instance == this);
         s_instance = nullptr;
     }

src/ripple_app/main/IoServicePool.cpp

@@ -17,7 +17,6 @@
 */
 //==============================================================================
 
-
 class IoServicePool::ServiceThread : private Thread
 {
 public:
@@ -62,17 +61,9 @@ IoServicePool::IoServicePool (Stoppable& parent, String const& name, int numberO
     , m_name (name)
     , m_service (numberOfThreads)
     , m_work (boost::ref (m_service))
+    , m_threadsDesired (numberOfThreads)
 {
-    bassert (numberOfThreads > 0);
-
-    m_threads.ensureStorageAllocated (numberOfThreads);
-
-    for (int i = 0; i < numberOfThreads; ++i)
-    {
-        ++m_threadsRunning;
-        m_threads.add (new ServiceThread (m_name, *this, m_service));
-        m_threads[i]->start ();
-    }
+    bassert (m_threadsDesired > 0);
 }
 
 IoServicePool::~IoServicePool ()
@@ -90,6 +81,17 @@ IoServicePool::operator boost::asio::io_service& ()
     return m_service;
 }
 
+void IoServicePool::onStart ()
+{
+    m_threads.ensureStorageAllocated (m_threadsDesired);
+    for (int i = 0; i < m_threadsDesired; ++i)
+    {
+        m_threads.add (new ServiceThread (m_name, *this, m_service));
+        ++m_threadsRunning;
+        m_threads[i]->start ();
+    }
+}
+
 void IoServicePool::onStop ()
 {
     // VFALCO NOTE This is a hack! We should gracefully
@@ -97,6 +99,7 @@ void IoServicePool::onStop ()
     //             object using boost::optional, and let run()
     //             just return naturally.
     //
+    //m_work = boost::none;
     m_service.stop ();
 }
 

src/ripple_app/main/IoServicePool.h

@@ -31,6 +31,7 @@ public:
     boost::asio::io_service& getService ();
     operator boost::asio::io_service& ();
 
+    void onStart ();
     void onStop ();
     void onChildrenStopped ();
 
@@ -43,6 +44,7 @@ private:
     boost::asio::io_service m_service;
     boost::optional <boost::asio::io_service::work> m_work;
     OwnedArray <ServiceThread> m_threads;
+    int m_threadsDesired;
     Atomic <int> m_threadsRunning;
 };
 

src/ripple_net/basics/SNTPClient.cpp

@@ -96,8 +96,6 @@ public:
 
         mTimer.expires_from_now (boost::posix_time::seconds (NTP_QUERY_FREQUENCY));
         mTimer.async_wait (boost::bind (&SNTPClientImp::timerEntry, this, boost::asio::placeholders::error));
-
-        startThread ();
     }
 
     ~SNTPClientImp ()
@@ -107,11 +105,9 @@ public:
 
     //--------------------------------------------------------------------------
 
-    void run ()
+    void onStart ()
     {
-        m_io_service.run ();
-
-        stopped ();
+        startThread ();
     }
 
     void onStop ()
@@ -120,6 +116,13 @@ public:
         m_io_service.stop ();
     }
 
+    void run ()
+    {
+        m_io_service.run ();
+
+        stopped ();
+    }
+
     //--------------------------------------------------------------------------
 
     void init (const std::vector<std::string>& servers)