Use Add instead of Push to correctly order timed txs in event heap

vms/platformvm/service.go

@@ -1275,7 +1275,7 @@ func (service *Service) IssueTx(_ *http.Request, args *IssueTxArgs, response *Is
 		if err := tx.initialize(service.vm); err != nil {
 			return fmt.Errorf("error initializing tx: %s", err)
 		}
-		service.vm.unissuedEvents.Push(tx)
+		service.vm.unissuedEvents.Add(tx)
 		response.TxID = tx.ID()
 	case DecisionTx:
 		if err := tx.initialize(service.vm); err != nil {

vms/platformvm/static_service.go

@@ -4,7 +4,6 @@
 package platformvm
 
 import (
-	"container/heap"
 	"errors"
 	"net/http"
 
@@ -174,8 +173,8 @@ func (*StaticService) BuildGenesis(_ *http.Request, args *BuildGenesisArgs, repl
 			return errAccountHasNoValue
 		}
 		accounts = append(accounts, newAccount(
-			account.Address, // ID
-			0,               // nonce
+			account.Address,         // ID
+			0,                       // nonce
 			uint64(account.Balance), // balance
 		))
 	}
@@ -210,7 +209,7 @@ func (*StaticService) BuildGenesis(_ *http.Request, args *BuildGenesisArgs, repl
 			return err
 		}
 
-		heap.Push(validators, tx)
+		validators.Add(tx)
 	}
 
 	// Specify the chains that exist at genesis.

vms/platformvm/static_service_test.go

@@ -111,3 +111,72 @@ func TestBuildGenesisInvalidEndtime(t *testing.T) {
 		t.Fatalf("Should have errored due to an invalid end time")
 	}
 }
+
+func TestBuildGenesisReturnsSortedValidators(t *testing.T) {
+	id := ids.NewShortID([20]byte{1})
+	account := APIAccount{
+		Address: id,
+		Balance: 123456789,
+	}
+
+	weight := json.Uint64(987654321)
+	validator1 := APIDefaultSubnetValidator{
+		APIValidator: APIValidator{
+			StartTime: 0,
+			EndTime:   20,
+			Weight:    &weight,
+			ID:        id,
+		},
+		Destination: id,
+	}
+
+	validator2 := APIDefaultSubnetValidator{
+		APIValidator: APIValidator{
+			StartTime: 3,
+			EndTime:   15,
+			Weight:    &weight,
+			ID:        id,
+		},
+		Destination: id,
+	}
+
+	validator3 := APIDefaultSubnetValidator{
+		APIValidator: APIValidator{
+			StartTime: 1,
+			EndTime:   10,
+			Weight:    &weight,
+			ID:        id,
+		},
+		Destination: id,
+	}
+
+	args := BuildGenesisArgs{
+		Accounts: []APIAccount{
+			account,
+		},
+		Validators: []APIDefaultSubnetValidator{
+			validator1,
+			validator2,
+			validator3,
+		},
+		Time: 5,
+	}
+	reply := BuildGenesisReply{}
+
+	ss := StaticService{}
+	if err := ss.BuildGenesis(nil, &args, &reply); err != nil {
+		t.Fatalf("BuildGenesis should not have errored")
+	}
+
+	genesis := &Genesis{}
+	Codec.Unmarshal(reply.Bytes.Bytes, genesis)
+	validators := genesis.Validators
+	currentValidator := validators.Remove()
+	for validators.Len() > 0 {
+		nextValidator := validators.Remove()
+		if currentValidator.EndTime().Unix() > nextValidator.EndTime().Unix() {
+			t.Fatalf("Validators returned by genesis should be a min heap sorted by end time")
+		}
+		currentValidator = nextValidator
+	}
+}

vms/platformvm/vm.go

@@ -4,7 +4,6 @@
 package platformvm
 
 import (
-	"container/heap"
 	"errors"
 	"fmt"
 	"time"
@@ -698,7 +697,7 @@ func (vm *VM) resetTimer() {
 			vm.SnowmanVM.NotifyBlockReady() // Should issue a ProposeAddValidator
 			return
 		}
-		// If the tx doesn't meet the syncrony bound, drop it
+		// If the tx doesn't meet the synchrony bound, drop it
 		vm.unissuedEvents.Remove()
 		vm.Ctx.Log.Debug("dropping tx to add validator because its start time has passed")
 	}
@@ -780,8 +779,8 @@ func (vm *VM) calculateValidators(db database.Database, timestamp time.Time, sub
 		if timestamp.Before(nextTx.StartTime()) {
 			break
 		}
-		heap.Push(current, nextTx)
-		heap.Pop(pending)
+		current.Add(nextTx)
+		pending.Remove()
 		started.Add(nextTx.Vdr().ID())
 	}
 	return current, pending, started, stopped, nil

vms/platformvm/vm_test.go

@@ -5,7 +5,6 @@ package platformvm
 
 import (
 	"bytes"
-	"container/heap"
 	"errors"
 	"testing"
 	"time"
@@ -226,7 +225,7 @@ func GenesisCurrentValidators() *EventHeap {
 			testNetworkID,                           // network ID
 			key,                                     // key paying tx fee and stake
 		)
-		heap.Push(validators, validator)
+		validators.Add(validator)
 	}
 	return validators
 }
@@ -1011,7 +1010,7 @@ func TestCreateSubnet(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	vm.unissuedEvents.Push(addValidatorTx)
+	vm.unissuedEvents.Add(addValidatorTx)
 	blk, err = vm.BuildBlock() // should add validator to the new subnet
 	if err != nil {
 		t.Fatal(err)