Remove dkgRndSleepTime from consensus params and make sleeping it non-random

src/chainparams.cpp

@@ -118,7 +118,6 @@ static Consensus::LLMQParams llmq10_60 = {
         .dkgPhaseBlocks = 2,
         .dkgMiningWindowStart = 10, // dkgPhaseBlocks * 5 = after finalization
         .dkgMiningWindowEnd = 18,
-        .dkgRndSleepTime = 0,
         .dkgBadVotesThreshold = 8,
 
         .neighborConnections = 2,
@@ -137,7 +136,6 @@ static Consensus::LLMQParams llmq50_60 = {
         .dkgPhaseBlocks = 2,
         .dkgMiningWindowStart = 10, // dkgPhaseBlocks * 5 = after finalization
         .dkgMiningWindowEnd = 18,
-        .dkgRndSleepTime = 1 * 60 * 1000,
         .dkgBadVotesThreshold = 40,
 
         .neighborConnections = 2,
@@ -156,7 +154,6 @@ static Consensus::LLMQParams llmq400_60 = {
         .dkgPhaseBlocks = 4,
         .dkgMiningWindowStart = 20, // dkgPhaseBlocks * 5 = after finalization
         .dkgMiningWindowEnd = 28,
-        .dkgRndSleepTime = 2 * 60 * 1000,
         .dkgBadVotesThreshold = 300,
 
         .neighborConnections = 4,
@@ -176,7 +173,6 @@ static Consensus::LLMQParams llmq400_85 = {
         .dkgPhaseBlocks = 4,
         .dkgMiningWindowStart = 20, // dkgPhaseBlocks * 5 = after finalization
         .dkgMiningWindowEnd = 48, // give it a larger mining window to make sure it is mined
-        .dkgRndSleepTime = 2 * 60 * 1000,
         .dkgBadVotesThreshold = 300,
 
         .neighborConnections = 4,

src/consensus/params.h

@@ -98,10 +98,6 @@ struct LLMQParams {
     // session failed.
     int dkgMiningWindowEnd;
 
-    // Each member will sleep for a random time between 0 and dkgRndSleepTime milliseconds. The purpose of this is to
-    // avoid overloading the network due to all members sending out expensive-to-verify DKG messages at once
-    int dkgRndSleepTime;
-
     // In the complaint phase, members will vote on other members being bad (missing valid contribution). If at least
     // dkgBadVotesThreshold have voted for another member to be bad, it will considered to be bad by all other members
     // as well. This serves as a protection against late-comers who send their contribution on the bring of

src/llmq/quorums_dkgsession.h

@@ -293,6 +293,8 @@ public:
 
     bool Init(int _height, const uint256& _quorumHash, const std::vector<CDeterministicMNCPtr>& mns, const uint256& _myProTxHash);
 
+    size_t GetMyMemberIndex() const { return myIdx; }
+
     /**
      * The following sets of methods are for the first 4 phases handled in the session. The flow of message calls
      * is identical for all phases:

src/llmq/quorums_dkgsessionhandler.cpp

@@ -236,13 +236,27 @@ void CDKGSessionHandler::WaitForNewQuorum(const uint256& oldQuorumHash)
     }
 }
 
-void CDKGSessionHandler::RandomSleep(QuorumPhase curPhase,
+// Sleep some time to not fully overload the whole network
+void CDKGSessionHandler::SleepBeforePhase(QuorumPhase curPhase,
                                           uint256& expectedQuorumHash,
                                           double randomSleepFactor,
                                           const WhileWaitFunc& runWhileWaiting)
 {
-    // Randomly sleep some time to not fully overload the whole network
+    // expected time for a full phase
-    int64_t endTime = GetTimeMillis() + GetRandInt((int)(params.dkgRndSleepTime * randomSleepFactor));
+    double phaseTime = params.dkgPhaseBlocks * Params().GetConsensus().nPowTargetSpacing * 1000;
+    // expected time per member
+    phaseTime = phaseTime / params.size;
+    // Don't expect perfect block times and thus reduce the phase time to be on the secure side (caller chooses factor)
+    phaseTime *= randomSleepFactor;
+
+    if (Params().MineBlocksOnDemand()) {
+        // on regtest, blocks can be mined on demand without any significant time passing between these. We shouldn't
+        // wait before phases in this case
+        phaseTime = 0;
+    }
+
+    int64_t sleepTime = (int64_t)(phaseTime * curSession->GetMyMemberIndex());
+    int64_t endTime = GetTimeMillis() + sleepTime;
     while (GetTimeMillis() < endTime) {
         if (stopRequested || ShutdownRequested()) {
             throw AbortPhaseException();
@@ -264,7 +278,7 @@ void CDKGSessionHandler::HandlePhase(QuorumPhase curPhase,
                                      const StartPhaseFunc& startPhaseFunc,
                                      const WhileWaitFunc& runWhileWaiting)
 {
-    RandomSleep(curPhase, expectedQuorumHash, randomSleepFactor, runWhileWaiting);
+    SleepBeforePhase(curPhase, expectedQuorumHash, randomSleepFactor, runWhileWaiting);
     startPhaseFunc();
     WaitForNextPhase(curPhase, nextPhase, expectedQuorumHash, runWhileWaiting);
 }
@@ -501,7 +515,7 @@ void CDKGSessionHandler::HandleDKGRound()
     auto fContributeWait = [this] {
         return ProcessPendingMessageBatch<CDKGContribution>(*curSession, pendingContributions, 8);
     };
-    HandlePhase(QuorumPhase_Contribute, QuorumPhase_Complain, curQuorumHash, 1, fContributeStart, fContributeWait);
+    HandlePhase(QuorumPhase_Contribute, QuorumPhase_Complain, curQuorumHash, 0.5, fContributeStart, fContributeWait);
 
     // Complain
     auto fComplainStart = [this]() {
@@ -510,7 +524,7 @@ void CDKGSessionHandler::HandleDKGRound()
     auto fComplainWait = [this] {
         return ProcessPendingMessageBatch<CDKGComplaint>(*curSession, pendingComplaints, 8);
     };
-    HandlePhase(QuorumPhase_Complain, QuorumPhase_Justify, curQuorumHash, 0, fComplainStart, fComplainWait);
+    HandlePhase(QuorumPhase_Complain, QuorumPhase_Justify, curQuorumHash, 0.1, fComplainStart, fComplainWait);
 
     // Justify
     auto fJustifyStart = [this]() {
@@ -519,7 +533,7 @@ void CDKGSessionHandler::HandleDKGRound()
     auto fJustifyWait = [this] {
         return ProcessPendingMessageBatch<CDKGJustification>(*curSession, pendingJustifications, 8);
     };
-    HandlePhase(QuorumPhase_Justify, QuorumPhase_Commit, curQuorumHash, 0, fJustifyStart, fJustifyWait);
+    HandlePhase(QuorumPhase_Justify, QuorumPhase_Commit, curQuorumHash, 0.1, fJustifyStart, fJustifyWait);
 
     // Commit
     auto fCommitStart = [this]() {
@@ -528,7 +542,7 @@ void CDKGSessionHandler::HandleDKGRound()
     auto fCommitWait = [this] {
         return ProcessPendingMessageBatch<CDKGPrematureCommitment>(*curSession, pendingPrematureCommitments, 8);
     };
-    HandlePhase(QuorumPhase_Commit, QuorumPhase_Finalize, curQuorumHash, 1, fCommitStart, fCommitWait);
+    HandlePhase(QuorumPhase_Commit, QuorumPhase_Finalize, curQuorumHash, 0.5, fCommitStart, fCommitWait);
 
     auto finalCommitments = curSession->FinalizeCommitments();
     for (auto& fqc : finalCommitments) {

src/llmq/quorums_dkgsessionhandler.h

@@ -127,7 +127,7 @@ private:
     typedef std::function<bool()> WhileWaitFunc;
     void WaitForNextPhase(QuorumPhase curPhase, QuorumPhase nextPhase, uint256& expectedQuorumHash, const WhileWaitFunc& runWhileWaiting);
     void WaitForNewQuorum(const uint256& oldQuorumHash);
-    void RandomSleep(QuorumPhase curPhase, uint256& expectedQuorumHash, double randomSleepFactor, const WhileWaitFunc& runWhileWaiting);
+    void SleepBeforePhase(QuorumPhase curPhase, uint256& expectedQuorumHash, double randomSleepFactor, const WhileWaitFunc& runWhileWaiting);
     void HandlePhase(QuorumPhase curPhase, QuorumPhase nextPhase, uint256& expectedQuorumHash, double randomSleepFactor, const StartPhaseFunc& startPhaseFunc, const WhileWaitFunc& runWhileWaiting);
     void HandleDKGRound();
     void PhaseHandlerThread();