http: correctly cleanup ws engine

if sender thread was started, one have to call join it - even when
thread function was normally returned

net/http/src/THttpLongPollEngine.cxx

@@ -35,13 +35,6 @@ THttpLongPollEngine::THttpLongPollEngine(bool raw) : THttpWSEngine(), fRaw(raw)
 {
 }
 
-//////////////////////////////////////////////////////////////////////////
-/// destructor
-
-THttpLongPollEngine::~THttpLongPollEngine()
-{
-}
-
 //////////////////////////////////////////////////////////////////////////
 /// returns ID of the engine, created from this pointer
 

net/http/src/THttpLongPollEngine.h

@@ -36,7 +36,7 @@ protected:
 
 public:
    THttpLongPollEngine(bool raw = false);
-   virtual ~THttpLongPollEngine();
+   virtual ~THttpLongPollEngine() = default;
 
    UInt_t GetId() const override;
 

net/http/src/THttpWSEngine.h

@@ -32,7 +32,7 @@ private:
    bool fDisabled{false};   ///<!  true shortly before cleanup, set under locked fMutex from WSHandler
 
    std::thread fSendThrd;    ///<! dedicated thread for all send operations
-   bool fHasSendThrd{false}; ///<! if any special thread was started
+   bool fHasSendThrd{false}; ///<! if thread was started one have to call join method for it
    std::mutex fCondMutex;    ///<! mutex used to access condition
    std::condition_variable fCond; ///<! condition used to sync with sending thread
 
@@ -52,7 +52,7 @@ protected:
    virtual Bool_t CanSendDirectly() { return kTRUE; }
 
 public:
-   virtual ~THttpWSEngine() {}
+   virtual ~THttpWSEngine() = default;
 
    virtual UInt_t GetId() const = 0;
 

net/http/src/THttpWSHandler.cxx

@@ -84,7 +84,8 @@ THttpWSHandler::~THttpWSHandler()
 
    {
       std::lock_guard<std::mutex> grd(fMutex);
-      clr = std::move(fEngines);
+      for (auto &eng : fEngines)
+         clr.emplace_back(std::move(eng));
    }
 
    for (auto &eng : clr) {
@@ -301,7 +302,6 @@ Int_t THttpWSHandler::RunSendingThrd(std::shared_ptr<THttpWSEngine> engine)
          std::unique_lock<std::mutex> lk(engine->fCondMutex);
          engine->fCond.wait(lk);
       }
-      engine->fHasSendThrd = false; // if thread exit - mark this
    });
 
    engine->fSendThrd.swap(thrd);