1 files changed, 77 insertions, 0 deletions
diff --git a/src/pkg/runtime/pprof/pprof_test.go b/src/pkg/runtime/pprof/pprof_test.go
new file mode 100644
index 000000000..a060917a2
--- /dev/null
+++ b/src/pkg/runtime/pprof/pprof_test.go
@@ -0,0 +1,77 @@
+// Copyright 2011 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package pprof_test
+
+import (
+	"bytes"
+	"hash/crc32"
+	"runtime"
+	. "runtime/pprof"
+	"strings"
+	"testing"
+	"unsafe"
+)
+
+func TestCPUProfile(t *testing.T) {
+	switch runtime.GOOS {
+	case "darwin":
+		// see Apple Bug Report #9177434 (copied into change description)
+		return
+	case "plan9":
+		// unimplemented
+		return
+	case "windows":
+		// unimplemented
+		return
+	}
+
+	buf := make([]byte, 100000)
+	var prof bytes.Buffer
+	if err := StartCPUProfile(&prof); err != nil {
+		t.Fatal(err)
+	}
+	// This loop takes about a quarter second on a 2 GHz laptop.
+	// We only need to get one 100 Hz clock tick, so we've got
+	// a 25x safety buffer.
+	for i := 0; i < 1000; i++ {
+		crc32.ChecksumIEEE(buf)
+	}
+	StopCPUProfile()
+
+	// Convert []byte to []uintptr.
+	bytes := prof.Bytes()
+	val := *(*[]uintptr)(unsafe.Pointer(&bytes))
+	val = val[:len(bytes)/unsafe.Sizeof(uintptr(0))]
+
+	if len(val) < 10 {
+		t.Fatalf("profile too short: %#x", val)
+	}
+	if val[0] != 0 || val[1] != 3 || val[2] != 0 || val[3] != 1e6/100 || val[4] != 0 {
+		t.Fatalf("unexpected header %#x", val[:5])
+	}
+
+	// Check that profile is well formed and contains ChecksumIEEE.
+	found := false
+	val = val[5:]
+	for len(val) > 0 {
+		if len(val) < 2 || val[0] < 1 || val[1] < 1 || uintptr(len(val)) < 2+val[1] {
+			t.Fatalf("malformed profile.  leftover: %#x", val)
+		}
+		for _, pc := range val[2 : 2+val[1]] {
+			f := runtime.FuncForPC(pc)
+			if f == nil {
+				continue
+			}
+			if strings.Contains(f.Name(), "ChecksumIEEE") {
+				found = true
+			}
+		}
+		val = val[2+val[1]:]
+	}
+
+	if !found {
+		t.Fatal("did not find ChecksumIEEE in the profile")
+	}
+}