feat(metrics): calculate the real pending tx (#983)

* calculate the real pending tx

* update

* move realPendingTx to miner

* update

* calculate the real pending tx by statsWithMinBaseFee

* update

* fix lint

* address comments

* add metrics to StatsWithMinBaseFee

* change read_lock to write_lock

core/tx_pool.go

@@ -124,13 +124,16 @@ var (
 	dropBetweenReorgHistogram = metrics.NewRegisteredHistogram("txpool/dropbetweenreorg", nil, metrics.NewExpDecaySample(1028, 0.015))
 
 	pendingGauge     = metrics.NewRegisteredGauge("txpool/pending", nil)
+	realPendingGauge = metrics.NewRegisteredGauge("txpool/real_pending", nil)
 	queuedGauge      = metrics.NewRegisteredGauge("txpool/queued", nil)
+	realQueuedGauge  = metrics.NewRegisteredGauge("txpool/real_queued", nil)
 	localGauge       = metrics.NewRegisteredGauge("txpool/local", nil)
 	slotsGauge       = metrics.NewRegisteredGauge("txpool/slots", nil)
 
 	reheapTimer = metrics.NewRegisteredTimer("txpool/reheap", nil)
 
 	txLifecycleTimer         = metrics.NewRegisteredTimer("txpool/txfifecycle", nil)
+	statsWithMinBaseFeeTimer = metrics.NewRegisteredTimer("txpool/stats_min_base_fee", nil)
 )
 
 // TxStatus is the current status of a transaction as seen by the pool.
@@ -271,6 +274,7 @@ type TxPool struct {
 	reorgDoneCh              chan chan struct{}
 	reorgShutdownCh          chan struct{} // requests shutdown of scheduleReorgLoop
 	reorgPauseCh             chan bool     // requests to pause scheduleReorgLoop
+	realTxActivityShutdownCh chan struct{}
 	wg                       sync.WaitGroup // tracks loop, scheduleReorgLoop
 	initDoneCh               chan struct{}  // is closed once the pool is initialized (for tests)
 
@@ -303,6 +307,7 @@ func NewTxPool(config TxPoolConfig, chainconfig *params.ChainConfig, chain block
 		queueTxEventCh:           make(chan *types.Transaction),
 		reorgDoneCh:              make(chan chan struct{}),
 		reorgShutdownCh:          make(chan struct{}),
+		realTxActivityShutdownCh: make(chan struct{}),
 		reorgPauseCh:             make(chan bool),
 		initDoneCh:               make(chan struct{}),
 		gasPrice:                 new(big.Int).SetUint64(config.PriceLimit),
@@ -336,9 +341,27 @@ func NewTxPool(config TxPoolConfig, chainconfig *params.ChainConfig, chain block
 	pool.wg.Add(1)
 	go pool.loop()
 
+	pool.wg.Add(1)
+	go pool.periodicallyCalculateRealTxActivity()
+
 	return pool
 }
 
+func (pool *TxPool) periodicallyCalculateRealTxActivity() {
+	defer pool.wg.Done()
+	ticker := time.NewTicker(time.Second)
+	defer ticker.Stop()
+	for {
+		select {
+		case <-ticker.C:
+			pool.StatsWithMinBaseFee(pool.chain.CurrentBlock().BaseFee())
+		case <-pool.realTxActivityShutdownCh:
+			log.Info("Real tx activity calculation stopped")
+			return
+		}
+	}
+}
+
 // loop is the transaction pool's main event loop, waiting for and reacting to
 // outside blockchain events as well as for various reporting and transaction
 // eviction events.
@@ -372,6 +395,7 @@ func (pool *TxPool) loop() {
 		// System shutdown.
 		case <-pool.chainHeadSub.Err():
 			close(pool.reorgShutdownCh)
+			close(pool.realTxActivityShutdownCh)
 			return
 
 		// Handle stats reporting ticks
@@ -503,10 +527,12 @@ func (pool *TxPool) stats() (int, int) {
 // StatsWithMinBaseFee retrieves the current pool stats, namely the number of pending and the
 // number of queued (non-executable) transactions greater equal minBaseFee.
 func (pool *TxPool) StatsWithMinBaseFee(minBaseFee *big.Int) (int, int) {
-	pool.mu.RLock()
+	statsStart := time.Now()
-	defer pool.mu.RUnlock()
+	pool.mu.Lock()
-
+	pendingTxs, queuedTxs := pool.statsWithMinBaseFee(minBaseFee)
-	return pool.statsWithMinBaseFee(minBaseFee)
+	pool.mu.Unlock()
+	statsWithMinBaseFeeTimer.UpdateSince(statsStart)
+	return pendingTxs, queuedTxs
 }
 
 // statsWithMinBaseFee retrieves the current pool stats, namely the number of pending and the
@@ -521,6 +547,7 @@ func (pool *TxPool) statsWithMinBaseFee(minBaseFee *big.Int) (int, int) {
 			pending++
 		}
 	}
+	realPendingGauge.Update(int64(pending))
 
 	queued := 0
 	for _, list := range pool.queue {
@@ -531,6 +558,8 @@ func (pool *TxPool) statsWithMinBaseFee(minBaseFee *big.Int) (int, int) {
 			queued++
 		}
 	}
+	realQueuedGauge.Update(int64(queued))
+
 	return pending, queued
 }