Version 26 / New masternode consensus system

- Consensus system selects 1/10 of the oldest masternodes by payment, then selects payee by score from those. This fixes various race conditions when blocks are close together or inconsistant historical winner lists.
- Ask for up to 2 cycles of history
- Keep up to 5 cycles of history locally

configure.ac

@@ -3,7 +3,7 @@ AC_PREREQ([2.60])
 define(_CLIENT_VERSION_MAJOR, 0)
 define(_CLIENT_VERSION_MINOR, 12)
 define(_CLIENT_VERSION_REVISION, 0)
-define(_CLIENT_VERSION_BUILD, 25)
+define(_CLIENT_VERSION_BUILD, 26)
 define(_CLIENT_VERSION_IS_RELEASE, true)
 define(_COPYRIGHT_YEAR, 2015)
 AC_INIT([Dash Core],[_CLIENT_VERSION_MAJOR._CLIENT_VERSION_MINOR._CLIENT_VERSION_REVISION],[info@dashpay.io],[dash])

src/clientversion.h

@@ -17,7 +17,7 @@
 #define CLIENT_VERSION_MAJOR 0
 #define CLIENT_VERSION_MINOR 12
 #define CLIENT_VERSION_REVISION 0
-#define CLIENT_VERSION_BUILD 25
+#define CLIENT_VERSION_BUILD 26
 
 //! Set to true for release, false for prerelease or test build
 #define CLIENT_VERSION_IS_RELEASE true

src/instantx.h

@@ -27,7 +27,7 @@ class CConsensusVote;
 class CTransaction;
 class CTransactionLock;
 
-static const int MIN_INSTANTX_PROTO_VERSION = 70093;
+static const int MIN_INSTANTX_PROTO_VERSION = 70094;
 
 extern map<uint256, CTransaction> mapTxLockReq;
 extern map<uint256, CTransaction> mapTxLockReqRejected;

src/masternode-payments.cpp

@@ -365,7 +365,7 @@ void CMasternodePayments::ProcessMessageMasternodePayments(CNode* pfrom, std::st
            return;
         }
 
-        int nFirstBlock = (masternodeSync.IsSynced() ? (chainActive.Tip()->nHeight - (mnodeman.CountEnabled()*1.1)) : chainActive.Tip()->nHeight - 10);
+        int nFirstBlock = chainActive.Tip()->nHeight - (mnodeman.CountEnabled()*2);
         if(winner.nBlockHeight < nFirstBlock || winner.nBlockHeight > chainActive.Tip()->nHeight+20){
             LogPrintf("mnw - winner out of range - FirstBlock %d Height %d bestHeight %d\n", nFirstBlock, winner.nBlockHeight, chainActive.Tip()->nHeight);
             return;
@@ -427,6 +427,8 @@ bool CMasternodePayments::GetBlockPayee(int nBlockHeight, CScript& payee)
     return false;
 }
 
+// Is this masternode scheduled to get paid soon? 
+// -- Only look ahead up to 7 blocks to allow for propagation
 bool CMasternodePayments::IsScheduled(CMasternode& mn, int nNotBlockHeight)
 {
     CBlockIndex* pindexPrev = chainActive.Tip();
@@ -436,7 +438,7 @@ bool CMasternodePayments::IsScheduled(CMasternode& mn, int nNotBlockHeight)
     mnpayee = GetScriptForDestination(mn.pubkey.GetID());
 
     CScript payee;
-    for(int64_t h = pindexPrev->nHeight-1; h <= pindexPrev->nHeight+11; h++){
+    for(int64_t h = pindexPrev->nHeight; h <= pindexPrev->nHeight+7; h++){
         if(h == nNotBlockHeight) continue;
         if(mapMasternodeBlocks.count(h)){
             if(mapMasternodeBlocks[h].GetPayee(payee)){
@@ -564,7 +566,8 @@ void CMasternodePayments::CleanPaymentList()
 
     if(chainActive.Tip() == NULL) return;
 
-    int nLimit = std::max(((int)mnodeman.size())*2, 1000);
+    //keep up to five cycles for historical sake
+    int nLimit = std::max(((int)mnodeman.size())*5, 1000);
 
     std::map<uint256, CMasternodePaymentWinner>::iterator it = mapMasternodePayeeVotes.begin();
     while(it != mapMasternodePayeeVotes.end()) {
@@ -742,7 +745,7 @@ void CMasternodePayments::Sync(CNode* node, int nCountNeeded)
 
     if(chainActive.Tip() == NULL) return;
 
-    int nCount = (mnodeman.CountEnabled()*1.1);
+    int nCount = (mnodeman.CountEnabled()*2);
     if(nCountNeeded > nCount) nCountNeeded = nCount;
 
     std::map<uint256, CMasternodePaymentWinner>::iterator it = mapMasternodePayeeVotes.begin();

src/masternode-sync.cpp

@@ -174,7 +174,7 @@ void CMasternodeSync::Process()
                     CBlockIndex* pindexPrev = chainActive.Tip();
                     if(pindexPrev == NULL) return;
 
-                    int nMnCount = mnodeman.CountEnabled()*1.1;
+                    int nMnCount = mnodeman.CountEnabled()*2;
                     int nCountNeeded = (pindexPrev->nHeight - masternodePayments.GetNewestBlock());
                     int nHaveBlocks = (pindexPrev->nHeight - masternodePayments.GetOldestBlock());
                     if(nHaveBlocks < nMnCount || nCountNeeded > nMnCount) { 

src/masternode.cpp

@@ -241,7 +241,7 @@ int64_t CMasternode::GetLastPaid() {
 
     const CBlockIndex *BlockReading = chainActive.Tip();
 
-    int nMnCount = mnodeman.CountEnabled()*1.1;
+    int nMnCount = mnodeman.CountEnabled()*2;
     int n = 0;
     for (unsigned int i = 1; BlockReading && BlockReading->nHeight > 0; i++) {
         if(n >= nMnCount){

src/masternodeman.cpp

@@ -29,6 +29,7 @@ struct CompareValueOnly
         return t1.first < t2.first;
     }
 };
+
 struct CompareValueOnlyMN
 {
     bool operator()(const pair<int64_t, CMasternode>& t1,
@@ -384,11 +385,19 @@ CMasternode *CMasternodeMan::Find(const CPubKey &pubKeyMasternode)
     return NULL;
 }
 
+// 
+// Deterministically select the oldest/best masternode to pay on the network
+//
 CMasternode* CMasternodeMan::GetNextMasternodeInQueueForPayment(int nBlockHeight)
 {
     LOCK(cs);
 
-    CMasternode *pOldestMasternode = NULL;
+    CMasternode *pBestMasternode = NULL;
+    std::vector<pair<int64_t, CTxIn> > vecMasternodeLastPaid;
+
+    /*
+        Make a vector with all of the last paid times
+    */
 
     BOOST_FOREACH(CMasternode &mn, vMasternodes)
     {
@@ -398,18 +407,37 @@ CMasternode* CMasternodeMan::GetNextMasternodeInQueueForPayment(int nBlockHeight
         // //check protocol version
         if(mn.protocolVersion < masternodePayments.GetMinMasternodePaymentsProto()) continue;
 
-        //it's in the list -- so let's skip it
+        //it's in the list (up to 7 entries ahead of current block to allow propagation) -- so let's skip it
         if(masternodePayments.IsScheduled(mn, nBlockHeight)) continue;
 
         //make sure it has as many confirmations as there are masternodes
         if(mn.GetMasternodeInputAge() < CountEnabled()) continue;
 
-        if(pOldestMasternode == NULL || pOldestMasternode->SecondsSincePayment() < mn.SecondsSincePayment()){
+        vecMasternodeLastPaid.push_back(make_pair(mn.SecondsSincePayment(), mn.vin));
-            pOldestMasternode = &mn;
-        }
     }
 
-    return pOldestMasternode;
+    // Sort them low to high
+    sort(vecMasternodeLastPaid.rbegin(), vecMasternodeLastPaid.rend(), CompareValueOnly());
+
+    // Look at 1/10 of the oldest nodes (by last payment), calculate their scores and pay the best one
+    //  -- This doesn't look at who is being paid in the +7-10 blocks, allowing for double payments very rarely
+    //  -- 1/100 payments should be a double payment on mainnet - (1/(3000/10))*3 --(chance per block * chances before IsScheduled will fire)
+    int nTenthNetwork = mnodeman.CountEnabled()/10;
+    int nCount = 0; 
+    uint256 nHigh = 0;
+    BOOST_FOREACH (PAIRTYPE(int64_t, CTxIn)& s, vecMasternodeLastPaid){
+        CMasternode* pmn = mnodeman.Find(s.second);
+        if(!pmn) break;
+
+        uint256 n = pmn->CalculateScore(1, nBlockHeight-100);
+        if(n > nHigh){
+            nHigh = n;
+            pBestMasternode = pmn;
+        }
+        nCount++;
+        if(nCount >= nTenthNetwork) break;
+    }
+    return pBestMasternode;
 }
 
 CMasternode *CMasternodeMan::FindRandom()
@@ -682,7 +710,6 @@ void CMasternodeMan::ProcessMessage(CNode* pfrom, std::string& strCommand, CData
                     }
                 }
                 int64_t askAgain = GetTime() + MASTERNODES_DSEG_SECONDS;
-
                 mAskedUsForMasternodeList[pfrom->addr] = askAgain;
             }
         } //else, asking for a specific node which is ok

src/version.h

@@ -10,7 +10,7 @@
  * network protocol versioning
  */
 
-static const int PROTOCOL_VERSION = 70093;
+static const int PROTOCOL_VERSION = 70094;
 
 //! initial proto version, to be increased after version/verack negotiation
 static const int INIT_PROTO_VERSION = 209;
@@ -22,19 +22,19 @@ static const int GETHEADERS_VERSION = 70077;
 static const int MIN_PEER_PROTO_VERSION = 70066;
 
 //! minimum peer version accepted by DarksendPool
-static const int MIN_POOL_PEER_PROTO_VERSION = 70093;
+static const int MIN_POOL_PEER_PROTO_VERSION = 70094;
 
 //! minimum peer version for masternode budgets
-static const int MIN_BUDGET_PEER_PROTO_VERSION = 70093;
+static const int MIN_BUDGET_PEER_PROTO_VERSION = 70094;
 
 //! minimum peer version for masternode winner broadcasts
-static const int MIN_MNW_PEER_PROTO_VERSION = 70093;
+static const int MIN_MNW_PEER_PROTO_VERSION = 70094;
 
 //! minimum peer version that can receive masternode payments
 // V1 - Last protocol version before update
 // V2 - Newest protocol version
 static const int MIN_MASTERNODE_PAYMENT_PROTO_VERSION_1 = 70066;
-static const int MIN_MASTERNODE_PAYMENT_PROTO_VERSION_2 = 70093;
+static const int MIN_MASTERNODE_PAYMENT_PROTO_VERSION_2 = 70094;
 
 //! nTime field added to CAddress, starting with this version;
 //! if possible, avoid requesting addresses nodes older than this