chore: wait in the precommit step without re-scheduling

consensus/state.go

@@ -293,7 +293,7 @@
 // GetRoundState returns a shallow copy of the internal consensus state.
 func (cs *State) GetRoundState() *cstypes.RoundState {
 	cs.rsMtx.RLock()
 	rs := cs.rs // copy
 	cs.rsMtx.RUnlock()
 	return &rs
 }
@@ -302,7 +302,7 @@
 func (cs *State) GetRoundStateJSON() ([]byte, error) {
 	cs.rsMtx.RLock()
 	defer cs.rsMtx.RUnlock()
 	return cmtjson.Marshal(cs.rs)
 }
 
 // GetRoundStateSimpleJSON returns a json of RoundStateSimple
@@ -939,7 +939,7 @@
 			}
 		}
 
 		rs := cs.rs
 		var mi msgInfo
 
 		select {
@@ -983,7 +983,7 @@
 
 			// if the timeout is relevant to the rs
 			// go to the next step
 			cs.handleTimeout(ti, rs)
 
 		case <-cs.Quit():
 			onExit(cs)
@@ -1084,7 +1084,7 @@
 	}
 }
 
 func (cs *State) handleTimeout(ti timeoutInfo, rs cstypes.RoundState) {
 	cs.Logger.Trace("received tock", "timeout", ti.Duration, "height", ti.Height, "round", ti.Round, "step", ti.Step)
 
 	// timeouts must be for current height, round, step
@@ -1622,9 +1622,23 @@
 		return
 	}
 
-	if ready, waitTime := cs.isReadyToPrecommit(); !ready {
-		logger.Debug("rescheduling precommit", "delay(ms)", waitTime.Milliseconds())
-		cs.scheduleTimeout(waitTime, height, round, cstypes.RoundStepPrevoteWait)
+	if !cs.rs.StartedPrecommitSleep.Load() {
+		cs.rs.StartedPrecommitSleep.Store(true)
+		waitTime := cs.precommitDelay()
+		logger.Debug("delaying precommit", "delay", waitTime)
+		cs.unlockAll()
+		t := time.NewTimer(waitTime)
+		select {
+		case <-cs.Quit():
+			cs.lockAll()
+			return
+		case <-t.C:
+		}
+		cs.lockAll()
+		cs.rs.StartedPrecommitSleep.Store(false)
+	} else {
+		logger.Debug("already entered precommit sleep")
+		// if any other routine tries to enter precommit, we just return
 		return
 	}
 
@@ -2105,20 +2119,20 @@
 // KMSSigningDelay is a constant representing a delay used primarily to adjust for KMS signing latencies.
 const KMSSigningDelay = 200 * time.Millisecond
 
-// isReadyToPrecommit calculates if the process has waited at least a certain number of seconds
+// precommitDelay calculates if the process has waited at least a certain number of seconds
 // from their start time before they can vote
 // If the application's DelayedPrecommitTimeout is set to 0, no precommit wait is done.
-func (cs *State) isReadyToPrecommit() (bool, time.Duration) {
+func (cs *State) precommitDelay() time.Duration {
 	if cs.state.Timeouts.DelayedPrecommitTimeout == 0 {
 		// setting 0 as a special case not to reschedule the pre-commit
-		return true, 0
+		return 0
 	}
 	precommitVoteTime := cs.rs.StartTime.Add(cs.state.Timeouts.DelayedPrecommitTimeout)
 	waitTime := time.Until(precommitVoteTime)
 	if _, ok := cs.privValidator.(*privval.SignerClient); ok {
 		waitTime = waitTime - KMSSigningDelay
 	}
-	return waitTime <= 0, waitTime
+	return waitTime
 }
 
 //-----------------------------------------------------------------------------

consensus/types/round_state.go

@@ -3,6 +3,7 @@ package types
 import (
 	"encoding/json"
 	"fmt"
+	"sync/atomic"
 	"time"
 
 	"github.com/cometbft/cometbft/libs/bytes"
@@ -65,10 +66,11 @@ func (rs RoundStepType) String() string {
 // NOTE: Not thread safe. Should only be manipulated by functions downstream
 // of the cs.receiveRoutine
 type RoundState struct {
-	Height    int64         `json:"height"` // Height we are working on
-	Round     int32         `json:"round"`
-	Step      RoundStepType `json:"step"`
-	StartTime time.Time     `json:"start_time"`
+	Height                int64         `json:"height"` // Height we are working on
+	Round                 int32         `json:"round"`
+	Step                  RoundStepType `json:"step"`
+	StartTime             time.Time     `json:"start_time"`
+	StartedPrecommitSleep atomic.Bool
 
 	// Subjective time when +2/3 precommits for Block at Round were found
 	CommitTime         time.Time           `json:"commit_time"`