Redesign stoppable objects

src/ripple/app/misc/SHAMapStoreImp.cpp

@@ -359,7 +359,6 @@ SHAMapStoreImp::run()
             rendezvous_.notify_all();
             if (stop_)
             {
-                stopped();
                 return;
             }
             cond_.wait(lock);
@@ -759,22 +758,16 @@ SHAMapStoreImp::health()
 void
 SHAMapStoreImp::onStop()
 {
-    // This is really a check for `if (thread_)`.
-    if (deleteInterval_)
+    if (thread_.joinable())
     {
         {
             std::lock_guard lock(mutex_);
             stop_ = true;
+            cond_.notify_one();
         }
-        cond_.notify_one();
-        // stopped() will be called by the thread_ running run(),
-        // when it reaches the check for stop_.
-    }
-    else
-    {
-        // There is no thread running run(), so we must call stopped().
-        stopped();
+        thread_.join();
     }
+    stopped();
 }
 
 boost::optional<LedgerIndex>

src/ripple/app/misc/SHAMapStoreImp.h

@@ -135,12 +135,6 @@ class SHAMapStoreImp : public Stoppable, public SHAMapStore
         NodeStore::Scheduler& scheduler,
         beast::Journal journal);
 
-    ~SHAMapStoreImp()
-    {
-        if (thread_.joinable())
-            thread_.join();
-    }
-
     std::uint32_t
     clampFetchDepth(std::uint32_t fetch_depth) const override
     {
@@ -248,20 +242,15 @@ class SHAMapStoreImp : public Stoppable, public SHAMapStore
     Health
     health();
 
-    //
-    // Stoppable
-    //
     void
     onStart() override
     {
         if (deleteInterval_)
             thread_ = std::thread(&SHAMapStoreImp::run, this);
     }
 
-    // Called when the application begins shutdown
     void
     onStop() override;
-    // Called when all child Stoppable objects have stoped
 };
 
 }  // namespace ripple