From 922abb002ed2e05b6f928d4b9e989eb36b7a97de Mon Sep 17 00:00:00 2001
From: Thorsten de Buhr <thorsten.deBuhr@arm.com>
Date: Thu, 31 Aug 2023 14:55:58 +0200
Subject: [PATCH] Test with semaphore and moved wg.Add(1)

---
 cmd/installer/root.go | 33 +++++++++++++++++++--------------
 1 file changed, 19 insertions(+), 14 deletions(-)

diff --git a/cmd/installer/root.go b/cmd/installer/root.go
index 3400794..7c7875d 100644
--- a/cmd/installer/root.go
+++ b/cmd/installer/root.go
@@ -4,6 +4,7 @@
 package installer
 
 import (
+	"context"
 	"fmt"
 	"net/url"
 	"os"
@@ -20,6 +21,7 @@ import (
 	"github.com/open-cmsis-pack/cpackget/cmd/xml"
 	log "github.com/sirupsen/logrus"
 	"golang.org/x/mod/semver"
+	"golang.org/x/sync/semaphore"
 )
 
 const KeilDefaultPackRoot = "https://www.keil.com/pack/"
@@ -308,22 +310,24 @@ func DownloadPDSCFiles(skipInstalledPdscFiles bool, concurrency int, timeout int
 		log.Infof("[J%d:F\"%s\"]", numPdsc, Installation.PublicIndex)
 	}
 
+	ctx := context.TODO()
 	maxWorkers := runtime.GOMAXPROCS(0)
 	if maxWorkers > concurrency {
 		maxWorkers = concurrency
 	}
-	cnt := int(0)
+	sem := semaphore.NewWeighted(int64(maxWorkers))
+
 	for _, pdscTag := range pdscTags {
+		if err := sem.Acquire(ctx, 1); err != nil {
+			log.Errorf("Failed to acquire semaphore: %v", err)
+			break
+		}
+
 		wg.Add(1)
 		go func(pdscTag xml.PdscTag) {
+			defer sem.Release(1)
 			massDownloadPdscFiles(pdscTag, skipInstalledPdscFiles, &wg, timeout)
 		}(pdscTag)
-
-		cnt++
-		if cnt > maxWorkers {
-			cnt = 0
-			wg.Wait()
-		}
 	}
 	wg.Wait()
 
@@ -338,10 +342,12 @@ func UpdateInstalledPDSCFiles(pidxXML *xml.PidxXML, concurrency int, timeout int
 		return err
 	}
 
+	ctx := context.TODO()
 	maxWorkers := runtime.GOMAXPROCS(0)
 	if maxWorkers > concurrency {
 		maxWorkers = concurrency
 	}
+	sem := semaphore.NewWeighted(int64(maxWorkers))
 
 	for _, pdscFile := range pdscFiles {
 		log.Debugf("Checking if \"%s\" needs updating", pdscFile)
@@ -368,23 +374,22 @@ func UpdateInstalledPDSCFiles(pidxXML *xml.PidxXML, concurrency int, timeout int
 			continue
 		}
 
-		cnt := int(0)
 		versionInIndex := tags[0].Version
 		latestVersion := pdscXML.LatestVersion()
 		if versionInIndex != latestVersion {
 			log.Infof("%s::%s can be upgraded from \"%s\" to \"%s\"", pdscXML.Vendor, pdscXML.Name, latestVersion, versionInIndex)
 
+			if err := sem.Acquire(ctx, 1); err != nil {
+				log.Errorf("Failed to acquire semaphore: %v", err)
+				break
+			}
 			wg.Add(1)
+
 			pdscTag := tags[0]
 			go func(pdscTag xml.PdscTag) {
+				defer sem.Release(1)
 				massDownloadPdscFiles(pdscTag, false, &wg, timeout)
 			}(pdscTag)
-
-			cnt++
-			if cnt > maxWorkers {
-				cnt = 0
-				wg.Wait()
-			}
 		}
 	}