use sync.Pool

x/move/keeper/keeper.go

@@ -45,9 +45,8 @@ type Keeper struct {
 	config moveconfig.MoveConfig
 
 	// TODO - remove after loader v2
-	moveVMs         *[]types.VMEngine
-	moveVMMutx      *sync.Mutex
-	moveVMSemaphore *semaphore.Weighted
+	vmPool     *sync.Pool
+	vmPoolSema *semaphore.Weighted
 
 	feeCollector string
 	authority    string
@@ -90,9 +89,8 @@ func NewKeeper(
 		moveConfig.ContractSimulationGasLimit = moveconfig.DefaultContractSimulationGasLimit
 	}
 
-	vmCount := 10
-	vms := make([]types.VMEngine, vmCount)
-	for i := 0; i < vmCount; i++ {
+	vmPool := new(sync.Pool)
+	vmPool.New = func() interface{} {
 		moveVM, err := vm.NewVM(vmtypes.InitiaVMConfig{
 			// TODO: check this before mainnet
 			AllowUnstable: true,
@@ -101,7 +99,7 @@ func NewKeeper(
 			panic(err)
 		}
 
-		vms[i] = &moveVM
+		return &moveVM
 	}
 
 	sb := collections.NewSchemaBuilder(storeService)
@@ -114,9 +112,8 @@ func NewKeeper(
 		msgRouter:           msgRouter,
 		grpcRouter:          grpcRouter,
 		config:              moveConfig,
-		moveVMs:             &vms,
-		moveVMMutx:          new(sync.Mutex),
-		moveVMSemaphore:     semaphore.NewWeighted(int64(vmCount)),
+		vmPool:              vmPool,
+		vmPoolSema:          semaphore.NewWeighted(int64(10)),
 		distrKeeper:         distrKeeper,
 		StakingKeeper:       stakingKeeper,
 		RewardKeeper:        rewardKeeper,

x/move/keeper/vmpool.go

@@ -6,23 +6,16 @@ import (
 	"github.com/initia-labs/initia/x/move/types"
 )
 
-func (k Keeper) acquireVM(ctx context.Context) (vm types.VMEngine) {
-	err := k.moveVMSemaphore.Acquire(ctx, 1)
+func (k Keeper) acquireVM(ctx context.Context) types.VMEngine {
+	err := k.vmPoolSema.Acquire(ctx, 1)
 	if err != nil {
 		panic(err)
 	}
 
-	k.moveVMMutx.Lock()
-	vm, *k.moveVMs = (*k.moveVMs)[0], (*k.moveVMs)[1:]
-	k.moveVMMutx.Unlock()
-
-	return
+	return k.vmPool.Get().(types.VMEngine)
 }
 
 func (k Keeper) releaseVM(vm types.VMEngine) {
-	k.moveVMMutx.Lock()
-	*k.moveVMs = append(*k.moveVMs, vm)
-	k.moveVMMutx.Unlock()
-
-	k.moveVMSemaphore.Release(1)
+	k.vmPool.Put(vm)
+	k.vmPoolSema.Release(1)
 }