Merge #11043: Use std::unique_ptr (C++11) where possible

a357293 Use MakeUnique<Db>(...) (practicalswift)
3e09b39 Use MakeUnique<T>(...) instead of std::unique_ptr<T>(new T(...)) (practicalswift)
8617989 Add MakeUnique (substitute for C++14 std::make_unique) (practicalswift)
d223bc9 Use unique_ptr for pcoinscatcher/pcoinsdbview/pcoinsTip/pblocktree (practicalswift)
b45c597 Use unique_ptr for pdbCopy (Db) and fix potential memory leak (practicalswift)
29ab96d Use unique_ptr for dbenv (DbEnv) (practicalswift)
f72cbf9 Use unique_ptr for pfilter (CBloomFilter) (practicalswift)
8ccf1bb Use unique_ptr for sem{Addnode,Outbound} (CSemaphore) (practicalswift)
73db063 Use unique_ptr for upnp_thread (boost::thread) (practicalswift)
0024531 Use unique_ptr for dbw (CDBWrapper) (practicalswift)
fa6d122 Use unique_ptr:s for {fee,short,long}Stats (TxConfirmStats) (practicalswift)
5a6f768 Use unique_ptr for httpRPCTimerInterface (HTTPRPCTimerInterface) (practicalswift)
860e912 Use unique_ptr for pwalletMain (CWallet) (practicalswift)

Pull request description:

  Use `std::unique_ptr` (C++11) where possible.

  Rationale:
  1. Avoid resource leaks (specifically: forgetting to `delete` an object created using `new`)
  2. Avoid undefined behaviour (specifically: double `delete`:s)

  **Note to reviewers:** Please let me know if I've missed any obvious `std::unique_ptr` candidates. Hopefully this PR should cover all the trivial cases.

Tree-SHA512: 9fbeb47b800ab8ff4e0be9f2a22ab63c23d5c613a0c6716d9183db8d22ddbbce592fb8384a8b7874bf7375c8161efb13ca2197ad6f24b75967148037f0f7b20c

1 files changed, 8 insertions, 16 deletions

diff --git a/src/net.cpp b/src/net.cpp
index d5bd4c162b..0f9de81d7f 100644
--- a/src/net.cpp
+++ b/src/net.cpp
@@ -1534,22 +1534,20 @@ void ThreadMapPort()
 
 void MapPort(bool fUseUPnP)
 {
-    static boost::thread* upnp_thread = nullptr;
+    static std::unique_ptr<boost::thread> upnp_thread;
 
     if (fUseUPnP)
     {
         if (upnp_thread) {
             upnp_thread->interrupt();
             upnp_thread->join();
-            delete upnp_thread;
         }
-        upnp_thread = new boost::thread(boost::bind(&TraceThread<void (*)()>, "upnp", &ThreadMapPort));
+        upnp_thread.reset(new boost::thread(boost::bind(&TraceThread<void (*)()>, "upnp", &ThreadMapPort)));
     }
     else if (upnp_thread) {
         upnp_thread->interrupt();
         upnp_thread->join();
-        delete upnp_thread;
-        upnp_thread = nullptr;
+        upnp_thread.reset();
     }
 }
 
@@ -2224,8 +2222,6 @@ CConnman::CConnman(uint64_t nSeed0In, uint64_t nSeed1In) : nSeed0(nSeed0In), nSe
     nLastNodeId = 0;
     nSendBufferMaxSize = 0;
     nReceiveFloodSize = 0;
-    semOutbound = nullptr;
-    semAddnode = nullptr;
     flagInterruptMsgProc = false;
     SetTryNewOutboundPeer(false);
 
@@ -2331,11 +2327,11 @@ bool CConnman::Start(CScheduler& scheduler, const Options& connOptions)
 
     if (semOutbound == nullptr) {
         // initialize semaphore
-        semOutbound = new CSemaphore(std::min((nMaxOutbound + nMaxFeeler), nMaxConnections));
+        semOutbound = MakeUnique<CSemaphore>(std::min((nMaxOutbound + nMaxFeeler), nMaxConnections));
     }
     if (semAddnode == nullptr) {
         // initialize semaphore
-        semAddnode = new CSemaphore(nMaxAddnode);
+        semAddnode = MakeUnique<CSemaphore>(nMaxAddnode);
     }
 
     //
@@ -2458,10 +2454,8 @@ void CConnman::Stop()
     vNodes.clear();
     vNodesDisconnected.clear();
     vhListenSocket.clear();
-    delete semOutbound;
-    semOutbound = nullptr;
-    delete semAddnode;
-    semAddnode = nullptr;
+    semOutbound.reset();
+    semAddnode.reset();
 }
 
 void CConnman::DeleteNode(CNode* pnode)
@@ -2747,7 +2741,7 @@ CNode::CNode(NodeId idIn, ServiceFlags nLocalServicesIn, int nMyStartingHeightIn
     nNextInvSend = 0;
     fRelayTxes = false;
     fSentAddr = false;
-    pfilter = new CBloomFilter();
+    pfilter = MakeUnique<CBloomFilter>();
     timeLastMempoolReq = 0;
     nLastBlockTime = 0;
     nLastTXTime = 0;
@@ -2777,8 +2771,6 @@ CNode::CNode(NodeId idIn, ServiceFlags nLocalServicesIn, int nMyStartingHeightIn
 CNode::~CNode()
 {
     CloseSocket(hSocket);
-
-    delete pfilter;
 }
 
 void CNode::AskFor(const CInv& inv)