runtime/pprof: emit count profiles with debug=0 as proto profiles

count profiles with debug=1 retain their previous format.
Also add a test check for the proto profiles since all runtime/pprof
tests only look at the debug=1 profiles.

Change-Id: Ibe805585b597e5d3570807115940a1dc4535c03f
Reviewed-on: https://go-review.googlesource.com/33148
Run-TryBot: Michael Matloob <matloob@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

src/go/build/deps_test.go

@@ -175,7 +175,7 @@ var pkgDeps = map[string][]string{
 	"regexp/syntax":                     {"L2"},
 	"runtime/debug":                     {"L2", "fmt", "io/ioutil", "os", "time"},
 	"runtime/pprof/internal/protopprof": {"L2", "fmt", "internal/pprof/profile", "os", "time"},
-	"runtime/pprof":                     {"L2", "fmt", "os", "runtime/pprof/internal/protopprof", "text/tabwriter", "time"},
+	"runtime/pprof":                     {"L2", "fmt", "internal/pprof/profile", "os", "runtime/pprof/internal/protopprof", "text/tabwriter", "time"},
 	"runtime/trace":                     {"L0"},
 	"text/tabwriter":                    {"L2"},
 

src/runtime/pprof/pprof.go

@@ -73,6 +73,7 @@ import (
 	"bufio"
 	"bytes"
 	"fmt"
+	"internal/pprof/profile"
 	"io"
 	"runtime"
 	"runtime/pprof/internal/protopprof"
@@ -340,17 +341,8 @@ type countProfile interface {
 }
 
 // printCountProfile prints a countProfile at the specified debug level.
+// The profile will be in compressed proto format unless debug is nonzero.
 func printCountProfile(w io.Writer, debug int, name string, p countProfile) error {
-	b := bufio.NewWriter(w)
-	var tw *tabwriter.Writer
-	w = b
-	if debug > 0 {
-		tw = tabwriter.NewWriter(w, 1, 8, 1, '\t', 0)
-		w = tw
-	}
-
-	fmt.Fprintf(w, "%s profile: total %d\n", name, p.Len())
-
 	// Build count of each stack.
 	var buf bytes.Buffer
 	key := func(stk []uintptr) string {
@@ -376,17 +368,37 @@ func printCountProfile(w io.Writer, debug int, name string, p countProfile) erro
 
 	sort.Sort(&keysByCount{keys, count})
 
-	for _, k := range keys {
-		fmt.Fprintf(w, "%d %s\n", count[k], k)
 	if debug > 0 {
-			printStackRecord(w, p.Stack(index[k]), false)
+		// Print debug profile in legacy format
+		tw := tabwriter.NewWriter(w, 1, 8, 1, '\t', 0)
+		fmt.Fprintf(tw, "%s profile: total %d\n", name, p.Len())
+		for _, k := range keys {
+			fmt.Fprintf(tw, "%d %s\n", count[k], k)
+			printStackRecord(tw, p.Stack(index[k]), false)
 		}
+		return tw.Flush()
 	}
 
-	if tw != nil {
-		tw.Flush()
+	// Output profile in protobuf form.
+	prof := &profile.Profile{
+		PeriodType: &profile.ValueType{Type: name, Unit: "count"},
+		Period:     1,
+		Sample:     make([]*profile.Sample, 0, len(keys)),
+		SampleType: []*profile.ValueType{{Type: name, Unit: "count"}},
 	}
-	return b.Flush()
+	for _, k := range keys {
+		stk := p.Stack(index[k])
+		c := count[k]
+		locs := make([]*profile.Location, len(stk))
+		for i, addr := range stk {
+			locs[i] = &profile.Location{Address: uint64(addr) - 1}
+		}
+		prof.Sample = append(prof.Sample, &profile.Sample{
+			Location: locs,
+			Value:    []int64{int64(c)},
+		})
+	}
+	return prof.Write(w)
 }
 
 // keysByCount sorts keys with higher counts first, breaking ties by key string order.

src/runtime/pprof/pprof_test.go

@@ -679,13 +679,31 @@ func TestGoroutineCounts(t *testing.T) {
 	time.Sleep(10 * time.Millisecond) // let goroutines block on channel
 
 	var w bytes.Buffer
-	Lookup("goroutine").WriteTo(&w, 1)
+	goroutineProf := Lookup("goroutine")
+
+	// Check debug profile
+	goroutineProf.WriteTo(&w, 1)
 	prof := w.String()
 
 	if !containsInOrder(prof, "\n50 @ ", "\n40 @", "\n10 @", "\n1 @") {
 		t.Errorf("expected sorted goroutine counts:\n%s", prof)
 	}
 
+	// Check proto profile
+	w.Reset()
+	goroutineProf.WriteTo(&w, 0)
+	p, err := profile.Parse(&w)
+	if err != nil {
+		t.Errorf("error parsing protobuf profile: %v", err)
+	}
+	if err := p.CheckValid(); err != nil {
+		t.Errorf("protobuf profile is invalid: %v", err)
+	}
+	if !containsCounts(p, []int64{50, 40, 10, 1}) {
+		t.Errorf("expected count profile to contain goroutines with counts %v, got %v",
+			[]int64{50, 40, 10, 1}, p)
+	}
+
 	close(c)
 
 	time.Sleep(10 * time.Millisecond) // let goroutines exit
@@ -701,3 +719,23 @@ func containsInOrder(s string, all ...string) bool {
 	}
 	return true
 }
+
+func containsCounts(prof *profile.Profile, counts []int64) bool {
+	m := make(map[int64]int)
+	for _, c := range counts {
+		m[c]++
+	}
+	for _, s := range prof.Sample {
+		// The count is the single value in the sample
+		if len(s.Value) != 1 {
+			return false
+		}
+		m[s.Value[0]]--
+	}
+	for _, n := range m {
+		if n > 0 {
+			return false
+		}
+	}
+	return true
+}