X-Git-Url: https://git.arvados.org/arvados.git/blobdiff_plain/c63c699aa9948f6a672536ba08e664471fb0d654..3d8da9e64df7c0dd0302b7d2f4d188a9ede9099c:/lib/crunchstat/crunchstat.go

diff --git a/lib/crunchstat/crunchstat.go b/lib/crunchstat/crunchstat.go
index e0ef058835..056ef0d185 100644
--- a/lib/crunchstat/crunchstat.go
+++ b/lib/crunchstat/crunchstat.go
@@ -1,3 +1,7 @@
+// Copyright (C) The Arvados Authors. All rights reserved.
+//
+// SPDX-License-Identifier: AGPL-3.0
+
 // Package crunchstat reports resource usage (CPU, memory, disk,
 // network) for a cgroup.
 package crunchstat
@@ -40,7 +44,7 @@ type Reporter struct {
 
 	// Where cgroup accounting files live on this system, e.g.,
 	// "/sys/fs/cgroup".
-	CgroupRoot   string
+	CgroupRoot string
 
 	// Parent cgroup, e.g., "docker".
 	CgroupParent string
@@ -56,7 +60,8 @@ type Reporter struct {
 	lastDiskSample   map[string]ioSample
 	lastCPUSample    cpuSample
 
-	done chan struct{}
+	done    chan struct{} // closed when we should stop reporting
+	flushed chan struct{} // closed when we have made our last report
 }
 
 // Start starts monitoring in a new goroutine, and returns
@@ -72,6 +77,7 @@ type Reporter struct {
 // Callers should not modify public data fields after calling Start.
 func (r *Reporter) Start() {
 	r.done = make(chan struct{})
+	r.flushed = make(chan struct{})
 	go r.run()
 }
 
@@ -81,12 +87,13 @@ func (r *Reporter) Start() {
 // Nothing will be logged after Stop returns.
 func (r *Reporter) Stop() {
 	close(r.done)
+	<-r.flushed
 }
 
 func (r *Reporter) readAllOrWarn(in io.Reader) ([]byte, error) {
 	content, err := ioutil.ReadAll(in)
 	if err != nil {
-		r.Logger.Print(err)
+		r.Logger.Printf("warning: %v", err)
 	}
 	return content, err
 }
@@ -162,7 +169,7 @@ func (r *Reporter) getContainerNetStats() (io.Reader, error) {
 		statsFilename := fmt.Sprintf("/proc/%s/net/dev", taskPid)
 		stats, err := ioutil.ReadFile(statsFilename)
 		if err != nil {
-			r.Logger.Print(err)
+			r.Logger.Printf("notice: %v", err)
 			continue
 		}
 		return strings.NewReader(string(stats)), nil
@@ -312,6 +319,9 @@ func (r *Reporter) getCPUCount() int64 {
 	}
 	defer cpusetFile.Close()
 	b, err := r.readAllOrWarn(cpusetFile)
+	if err != nil {
+		return 0
+	}
 	sp := strings.Split(string(b), ",")
 	cpus := int64(0)
 	for _, v := range sp {
@@ -337,12 +347,16 @@ func (r *Reporter) doCPUStats() {
 		return
 	}
 
-	nextSample := cpuSample{true, time.Now(), 0, 0, r.getCPUCount()}
 	var userTicks, sysTicks int64
 	fmt.Sscanf(string(b), "user %d\nsystem %d", &userTicks, &sysTicks)
 	userHz := float64(C.sysconf(C._SC_CLK_TCK))
-	nextSample.user = float64(userTicks) / userHz
-	nextSample.sys = float64(sysTicks) / userHz
+	nextSample := cpuSample{
+		hasData:    true,
+		sampleTime: time.Now(),
+		user:       float64(userTicks) / userHz,
+		sys:        float64(sysTicks) / userHz,
+		cpus:       r.getCPUCount(),
+	}
 
 	delta := ""
 	if r.lastCPUSample.hasData {
@@ -356,9 +370,11 @@ func (r *Reporter) doCPUStats() {
 	r.lastCPUSample = nextSample
 }
 
-// Report stats periodically until r.done indicates someone called
-// Stop.
+// Report stats periodically until we learn (via r.done) that someone
+// called Stop.
 func (r *Reporter) run() {
+	defer close(r.flushed)
+
 	r.reportedStatFile = make(map[string]string)
 
 	if !r.waitForCIDFile() || !r.waitForCgroup() {
@@ -383,7 +399,7 @@ func (r *Reporter) run() {
 }
 
 // If CID is empty, wait for it to appear in CIDFile. Return true if
-// we get it before r.done indicates someone called Stop.
+// we get it before we learn (via r.done) that someone called Stop.
 func (r *Reporter) waitForCIDFile() bool {
 	if r.CID != "" || r.CIDFile == "" {
 		return true
@@ -400,7 +416,7 @@ func (r *Reporter) waitForCIDFile() bool {
 		select {
 		case <-ticker.C:
 		case <-r.done:
-			r.Logger.Printf("CID never appeared in %+q: %v", r.CIDFile, err)
+			r.Logger.Printf("warning: CID never appeared in %+q: %v", r.CIDFile, err)
 			return false
 		}
 	}
@@ -423,9 +439,9 @@ func (r *Reporter) waitForCgroup() bool {
 		select {
 		case <-ticker.C:
 		case <-warningTimer:
-			r.Logger.Printf("cgroup stats files have not appeared after %v (config error?) -- still waiting...", r.PollPeriod)
+			r.Logger.Printf("warning: cgroup stats files have not appeared after %v (config error?) -- still waiting...", r.PollPeriod)
 		case <-r.done:
-			r.Logger.Printf("cgroup stats files never appeared for %v", r.CID)
+			r.Logger.Printf("warning: cgroup stats files never appeared for %v", r.CID)
 			return false
 		}
 	}