Make hypervisor getVisors concurrent.

go.mod

@@ -3,7 +3,7 @@ module github.com/SkycoinProject/skywire-mainnet
 go 1.13
 
 require (
-	github.com/SkycoinProject/dmsg v0.0.0-20200226145926-514fc8d015a1
+	github.com/SkycoinProject/dmsg v0.0.0-20200227084433-7605a550f502
 	github.com/SkycoinProject/skycoin v0.27.0
 	github.com/SkycoinProject/yamux v0.0.0-20191213015001-a36efeefbf6a
 	github.com/armon/go-socks5 v0.0.0-20160902184237-e75332964ef5

go.sum

@@ -3,6 +3,8 @@ github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03
 github.com/OneOfOne/xxhash v1.2.2/go.mod h1:HSdplMjZKSmBqAxg5vPj2TmRDmfkzw+cTzAElWljhcU=
 github.com/SkycoinProject/dmsg v0.0.0-20200226145926-514fc8d015a1 h1:51rz38hyi2RKpNr/CEJgsVwjy22yt8gEess2WlzibmA=
 github.com/SkycoinProject/dmsg v0.0.0-20200226145926-514fc8d015a1/go.mod h1:eCoemDDyfyfNTFrapYKNEItwtRIj54UGpu4Ffcznuds=
+github.com/SkycoinProject/dmsg v0.0.0-20200227084433-7605a550f502 h1:fxCUIQ5EXmo0LpryqsqREysixAqtjSO6m60nDbe12iQ=
+github.com/SkycoinProject/dmsg v0.0.0-20200227084433-7605a550f502/go.mod h1:eCoemDDyfyfNTFrapYKNEItwtRIj54UGpu4Ffcznuds=
 github.com/SkycoinProject/skycoin v0.26.0 h1:8/ZRZb2VM2DM4YTIitRJMZ3Yo/3H1FFmbCMx5o6ekmA=
 github.com/SkycoinProject/skycoin v0.26.0/go.mod h1:xqPLOKh5B6GBZlGA7B5IJfQmCy7mwimD9NlqxR3gMXo=
 github.com/SkycoinProject/skycoin v0.27.0 h1:N3IHxj8ossHOcsxLYOYugT+OaELLncYHJHxbbYLPPmY=

pkg/hypervisor/hypervisor.go

@@ -251,23 +251,33 @@ type summaryResp struct {
 // provides summary of all visors.
 func (m *Hypervisor) getVisors() http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
-		var summaries []summaryResp
-
 		m.mu.RLock()
-		for pk, c := range m.visors {
-			summary, err := c.RPC.Summary()
-			if err != nil {
-				log.Errorf("failed to obtain summary from Hypervisor with pk %s. Error: %v", pk, err)
+		wg := new(sync.WaitGroup)
+		wg.Add(len(m.visors))
+		summaries, i := make([]summaryResp, len(m.visors)), 0
 
-				summary = &visor.Summary{PubKey: pk}
-			}
-
-			summaries = append(summaries, summaryResp{
-				TCPAddr: c.Addr.String(),
-				Online:  err == nil,
-				Summary: summary,
-			})
+		for pk, c := range m.visors {
+			go func(pk cipher.PubKey, c VisorConn, i int) {
+				log := log.WithField("visor_addr", c.Addr)
+				log.WithField("func", "c.RPC.Summary()").Debug("Calling RPC.")
+
+				summary, err := c.RPC.Summary()
+				if err != nil {
+					log.WithError(err).
+						Warn("Failed to obtain visor summary.")
+					summary = &visor.Summary{PubKey: pk}
+				}
+				summaries[i] = summaryResp{
+					TCPAddr: c.Addr.String(),
+					Online:  err == nil,
+					Summary: summary,
+				}
+				wg.Done()
+			}(pk, c, i)
+			i++
 		}
+
+		wg.Wait()
 		m.mu.RUnlock()
 
 		httputil.WriteJSON(w, r, http.StatusOK, summaries)

vendor/modules.txt

@@ -1,4 +1,4 @@
-# github.com/SkycoinProject/dmsg v0.0.0-20200226145926-514fc8d015a1
+# github.com/SkycoinProject/dmsg v0.0.0-20200227084433-7605a550f502
 github.com/SkycoinProject/dmsg
 github.com/SkycoinProject/dmsg/cipher
 github.com/SkycoinProject/dmsg/disc