From b1df8043fd8e5ce004b67cb06240cebd5e7bae21 Mon Sep 17 00:00:00 2001
From: Jeromy <why@ipfs.io>
Date: Fri, 13 May 2016 09:28:52 -0700
Subject: [PATCH] refactor locking order structure

---
 limiter.go      | 59 +++++++++++++++++++++++++++++--------------------
 limiter_test.go |  4 ++++
 2 files changed, 39 insertions(+), 24 deletions(-)

diff --git a/limiter.go b/limiter.go
index 7835fe5..94ce05b 100644
--- a/limiter.go
+++ b/limiter.go
@@ -66,6 +66,20 @@ func (dl *dialLimiter) finishedDial(dj *dialJob) {
 	dl.rllock.Lock()
 	defer dl.rllock.Unlock()
 
+	if addrutil.IsFDCostlyTransport(dj.addr) {
+		dl.fdConsuming--
+		if len(dl.waitingOnFd) > 0 {
+			next := dl.waitingOnFd[0]
+			dl.waitingOnFd = dl.waitingOnFd[1:]
+			if len(dl.waitingOnFd) == 0 {
+				dl.waitingOnFd = nil // clear out memory
+			}
+			dl.fdConsuming++
+
+			go dl.executeDial(next)
+		}
+	}
+
 	// release tokens in reverse order than we take them
 	dl.activePerPeer[dj.peer]--
 	if dl.activePerPeer[dj.peer] == 0 {
@@ -87,17 +101,6 @@ func (dl *dialLimiter) finishedDial(dj *dialJob) {
 		go dl.executeDial(next)
 	}
 
-	if addrutil.IsFDCostlyTransport(dj.addr) {
-		dl.fdConsuming--
-		if len(dl.waitingOnFd) > 0 {
-			next := dl.waitingOnFd[0]
-			dl.waitingOnFd = dl.waitingOnFd[1:]
-			dl.fdConsuming++
-
-			// now, attempt to take the 'per peer limit' token
-			dl.schedulePerPeerDial(next)
-		}
-	}
 }
 
 // AddDialJob tries to take the needed tokens for starting the given dial job.
@@ -107,6 +110,13 @@ func (dl *dialLimiter) AddDialJob(dj *dialJob) {
 	dl.rllock.Lock()
 	defer dl.rllock.Unlock()
 
+	if dl.activePerPeer[dj.peer] >= dl.perPeerLimit {
+		wlist := dl.waitingOnPeerLimit[dj.peer]
+		dl.waitingOnPeerLimit[dj.peer] = append(wlist, dj)
+		return
+	}
+	dl.activePerPeer[dj.peer]++
+
 	if addrutil.IsFDCostlyTransport(dj.addr) {
 		if dl.fdConsuming >= dl.fdLimit {
 			dl.waitingOnFd = append(dl.waitingOnFd, dj)
@@ -117,7 +127,20 @@ func (dl *dialLimiter) AddDialJob(dj *dialJob) {
 		dl.fdConsuming++
 	}
 
-	dl.schedulePerPeerDial(dj)
+	// take second needed token and start dial!
+	go dl.executeDial(dj)
+}
+
+func (dl *dialLimiter) schedulePerPeerDial(j *dialJob) {
+	if dl.activePerPeer[j.peer] >= dl.perPeerLimit {
+		wlist := dl.waitingOnPeerLimit[j.peer]
+		dl.waitingOnPeerLimit[j.peer] = append(wlist, j)
+		return
+	}
+
+	// take second needed token and start dial!
+	dl.activePerPeer[j.peer]++
+	go dl.executeDial(j)
 }
 
 // executeDial calls the dialFunc, and reports the result through the response
@@ -135,15 +158,3 @@ func (dl *dialLimiter) executeDial(j *dialJob) {
 	case <-j.ctx.Done():
 	}
 }
-
-func (dl *dialLimiter) schedulePerPeerDial(j *dialJob) {
-	if dl.activePerPeer[j.peer] >= dl.perPeerLimit {
-		wlist := dl.waitingOnPeerLimit[j.peer]
-		dl.waitingOnPeerLimit[j.peer] = append(wlist, j)
-		return
-	}
-
-	// take second needed token and start dial!
-	dl.activePerPeer[j.peer]++
-	go dl.executeDial(j)
-}
diff --git a/limiter_test.go b/limiter_test.go
index 28733c5..fb1be19 100644
--- a/limiter_test.go
+++ b/limiter_test.go
@@ -3,6 +3,7 @@ package swarm
 import (
 	"fmt"
 	"math/rand"
+	"runtime"
 	"strconv"
 	"testing"
 	"time"
@@ -262,6 +263,7 @@ func TestTokenRedistribution(t *testing.T) {
 
 func TestStressLimiter(t *testing.T) {
 	df := func(ctx context.Context, p peer.ID, a ma.Multiaddr) (conn.Conn, error) {
+		fmt.Println("dial for peer: ", string(p))
 		if tcpPortOver(a, 1000) {
 			return conn.Conn(nil), nil
 		} else {
@@ -305,6 +307,8 @@ func TestStressLimiter(t *testing.T) {
 		}(peer.ID(fmt.Sprintf("testpeer%d", i)))
 	}
 
+	time.Sleep(time.Millisecond * 1000)
+	fmt.Println("NUM GOROS: ", runtime.NumGoroutine())
 	for i := 0; i < 20; i++ {
 		select {
 		case <-success:
-- 
GitLab