mining: replace boost::shared_ptr with std::shared_ptr

Throughout the codebase we use std::shared_ptr, except for some
instances in the miner code, where we use boost::shared_ptr for
sharing a wallet address with the miner and rpc across threads.

This patch removes all usage of boost::shared_ptr to instead use
std::shared_ptr, to reduce exposure to multiple shared pointer
implementations.

src/primitives/block.h

@@ -12,8 +12,6 @@
 #include "serialize.h"
 #include "uint256.h"
 
-#include <boost/shared_ptr.hpp>
-
 /** Nodes collect new transactions into a block, hash them into a hash tree,
  * and scan through nonce values to make the block's hash satisfy proof-of-work
  * requirements.  When they solve the proof-of-work, they broadcast the block
@@ -25,7 +23,7 @@ class CBlockHeader : public CPureBlockHeader
 {
 public:
     // auxpow (if this is a merge-minded block)
-    boost::shared_ptr<CAuxPow> auxpow;
+    std::shared_ptr<CAuxPow> auxpow;
 
     CBlockHeader()
     {

src/rpc/mining.cpp

@@ -27,7 +27,6 @@
 #include <stdint.h>
 
 #include <boost/assign/list_of.hpp>
-#include <boost/shared_ptr.hpp>
 
 #include <univalue.h>
 
@@ -97,7 +96,7 @@ UniValue getnetworkhashps(const JSONRPCRequest& request)
     return GetNetworkHashPS(request.params.size() > 0 ? request.params[0].get_int() : 120, request.params.size() > 1 ? request.params[1].get_int() : -1);
 }
 
-UniValue generateBlocks(boost::shared_ptr<CReserveScript> coinbaseScript, int nGenerate, uint64_t nMaxTries, bool keepScript, int nMineAuxPow)
+UniValue generateBlocks(std::shared_ptr<CReserveScript> coinbaseScript, int nGenerate, uint64_t nMaxTries, bool keepScript, int nMineAuxPow)
 {
     // Dogecoin: Never mine witness tx
     const bool fMineWitnessTx = false;
@@ -198,7 +197,7 @@ UniValue generate(const JSONRPCRequest& request)
         nMineAuxPow = request.params[2].get_int();
     }
 
-    boost::shared_ptr<CReserveScript> coinbaseScript;
+    std::shared_ptr<CReserveScript> coinbaseScript;
     GetMainSignals().ScriptForMining(coinbaseScript);
 
     // If the keypool is exhausted, no script is returned at all.  Catch this.
@@ -245,7 +244,7 @@ UniValue generatetoaddress(const JSONRPCRequest& request)
     if (!address.IsValid())
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Error: Invalid address");
 
-    boost::shared_ptr<CReserveScript> coinbaseScript(new CReserveScript());
+    std::shared_ptr<CReserveScript> coinbaseScript(new CReserveScript());
     coinbaseScript->reserveScript = GetScriptForDestination(address.Get());
 
     return generateBlocks(coinbaseScript, nGenerate, nMaxTries, false, nMineAuxPow);
@@ -1164,7 +1163,7 @@ UniValue getauxblockbip22(const JSONRPCRequest& request)
             + HelpExampleRpc("getauxblock", "")
             );
 
-    boost::shared_ptr<CReserveScript> coinbaseScript;
+    std::shared_ptr<CReserveScript> coinbaseScript;
     GetMainSignals().ScriptForMining(coinbaseScript);
 
     // If the keypool is exhausted, no script is returned at all.  Catch this.

src/rpc/server.cpp

@@ -19,7 +19,6 @@
 #include <boost/bind/bind.hpp>
 #include <boost/filesystem.hpp>
 #include <boost/foreach.hpp>
-#include <boost/shared_ptr.hpp>
 #include <boost/signals2/signal.hpp>
 #include <boost/thread.hpp>
 #include <boost/algorithm/string/case_conv.hpp> // for to_upper()

src/validationinterface.h

@@ -8,7 +8,6 @@
 #define BITCOIN_VALIDATIONINTERFACE_H
 
 #include <boost/signals2/signal.hpp>
-#include <boost/shared_ptr.hpp>
 #include <memory>
 
 class CBlock;
@@ -39,7 +38,7 @@ protected:
     virtual void UpdatedTransaction(const uint256 &hash) {}
     virtual void ResendWalletTransactions(int64_t nBestBlockTime, CConnman* connman) {}
     virtual void BlockChecked(const CBlock&, const CValidationState&) {}
-    virtual void GetScriptForMining(boost::shared_ptr<CReserveScript>&) {};
+    virtual void GetScriptForMining(std::shared_ptr<CReserveScript>&) {};
     virtual void ResetRequestCount(const uint256 &hash) {};
     virtual void NewPoWValidBlock(const CBlockIndex *pindex, const std::shared_ptr<const CBlock>& block) {};
     friend void ::RegisterValidationInterface(CValidationInterface*);
@@ -70,7 +69,7 @@ struct CMainSignals {
     /** Notifies listeners of a block validation result */
     boost::signals2::signal<void (const CBlock&, const CValidationState&)> BlockChecked;
     /** Notifies listeners that a key for mining is required (coinbase) */
-    boost::signals2::signal<void (boost::shared_ptr<CReserveScript>&)> ScriptForMining;
+    boost::signals2::signal<void (std::shared_ptr<CReserveScript>&)> ScriptForMining;
     /** Notifies listeners that a block has been successfully mined */
     boost::signals2::signal<void (const uint256 &)> BlockFound;
     /**

src/wallet/wallet.cpp

@@ -3458,9 +3458,9 @@ void CWallet::UpdatedTransaction(const uint256 &hashTx)
     }
 }
 
-void CWallet::GetScriptForMining(boost::shared_ptr<CReserveScript> &script)
+void CWallet::GetScriptForMining(std::shared_ptr<CReserveScript> &script)
 {
-    boost::shared_ptr<CReserveKey> rKey(new CReserveKey(this));
+    std::shared_ptr<CReserveKey> rKey(new CReserveKey(this));
     CPubKey pubkey;
     if (!rKey->GetReservedKey(pubkey))
         return;

src/wallet/wallet.h

@@ -32,7 +32,6 @@
 #include <utility>
 #include <vector>
 
-#include <boost/shared_ptr.hpp>
 #include <boost/thread.hpp>
 
 extern CWallet* pwalletMain;
@@ -878,7 +877,7 @@ public:
 
     void UpdatedTransaction(const uint256 &hashTx) override;
 
-    void GetScriptForMining(boost::shared_ptr<CReserveScript> &script) override;
+    void GetScriptForMining(std::shared_ptr<CReserveScript> &script) override;
 
     unsigned int GetKeyPoolSize()
     {