mempool: chan bool -> chan struct{}

mempool/mempool.go

@@ -78,7 +78,7 @@ type Mempool struct {
 	recheckCursor        *clist.CElement // next expected response
 	recheckEnd           *clist.CElement // re-checking stops here
 	notifiedTxsAvailable bool
-	txsAvailable         chan bool // fires once for each height, when the mempool is not empty
+	txsAvailable         chan struct{} // fires once for each height, when the mempool is not empty
 
 	// Keep a cache of already-seen txs.
 	// This reduces the pressure on the proxyApp.
@@ -130,7 +130,7 @@ func NewMempool(
 // ensuring it will trigger once every height when transactions are available.
 // NOTE: not thread safe - should only be called once, on startup
 func (mem *Mempool) EnableTxsAvailable() {
-	mem.txsAvailable = make(chan bool, 1)
+	mem.txsAvailable = make(chan struct{}, 1)
 }
 
 // SetLogger sets the Logger.
@@ -348,7 +348,7 @@ func (mem *Mempool) resCbRecheck(req *abci.Request, res *abci.Response) {
 // TxsAvailable returns a channel which fires once for every height,
 // and only when transactions are available in the mempool.
 // NOTE: the returned channel may be nil if EnableTxsAvailable was not called.
-func (mem *Mempool) TxsAvailable() <-chan bool {
+func (mem *Mempool) TxsAvailable() <-chan struct{} {
 	return mem.txsAvailable
 }
 
@@ -360,7 +360,7 @@ func (mem *Mempool) notifyTxsAvailable() {
 		// channel cap is 1, so this will send once
 		mem.notifiedTxsAvailable = true
 		select {
-		case mem.txsAvailable <- true:
+		case mem.txsAvailable <- struct{}{}:
 		default:
 		}
 	}

mempool/mempool_test.go

@@ -38,7 +38,7 @@ func newMempoolWithApp(cc proxy.ClientCreator) *Mempool {
 	return mempool
 }
 
-func ensureNoFire(t *testing.T, ch <-chan bool, timeoutMS int) {
+func ensureNoFire(t *testing.T, ch <-chan struct{}, timeoutMS int) {
 	timer := time.NewTimer(time.Duration(timeoutMS) * time.Millisecond)
 	select {
 	case <-ch:
@@ -47,7 +47,7 @@ func ensureNoFire(t *testing.T, ch <-chan bool, timeoutMS int) {
 	}
 }
 
-func ensureFire(t *testing.T, ch <-chan bool, timeoutMS int) {
+func ensureFire(t *testing.T, ch <-chan struct{}, timeoutMS int) {
 	timer := time.NewTimer(time.Duration(timeoutMS) * time.Millisecond)
 	select {
 	case <-ch:

state/services.go

@@ -27,7 +27,7 @@ type Mempool interface {
 	Flush()
 	FlushAppConn() error
 
-	TxsAvailable() <-chan bool
+	TxsAvailable() <-chan struct{}
 	EnableTxsAvailable()
 }
 
@@ -43,7 +43,7 @@ func (m MockMempool) Reap(n int) types.Txs                               { retur
 func (m MockMempool) Update(height int64, txs types.Txs) error           { return nil }
 func (m MockMempool) Flush()                                             {}
 func (m MockMempool) FlushAppConn() error                                { return nil }
-func (m MockMempool) TxsAvailable() <-chan bool                          { return make(chan bool) }
+func (m MockMempool) TxsAvailable() <-chan struct{}                      { return make(chan struct{}) }
 func (m MockMempool) EnableTxsAvailable()                                {}
 
 //------------------------------------------------------