summaryrefslogtreecommitdiffstats
path: root/test/finprofiled.go
diff options
context:
space:
mode:
Diffstat (limited to 'test/finprofiled.go')
-rw-r--r--test/finprofiled.go74
1 files changed, 74 insertions, 0 deletions
diff --git a/test/finprofiled.go b/test/finprofiled.go
new file mode 100644
index 0000000..ca7e3c8
--- /dev/null
+++ b/test/finprofiled.go
@@ -0,0 +1,74 @@
+// run
+
+// Copyright 2015 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.
+
+// Test that tiny allocations with finalizers are correctly profiled.
+// Previously profile special records could have been processed prematurely
+// (while the object is still live).
+
+package main
+
+import (
+ "runtime"
+ "time"
+ "unsafe"
+)
+
+func main() {
+ runtime.MemProfileRate = 1
+ // Allocate 1M 4-byte objects and set a finalizer for every third object.
+ // Assuming that tiny block size is 16, some objects get finalizers setup
+ // only for middle bytes. The finalizer resurrects that object.
+ // As the result, all allocated memory must stay alive.
+ const (
+ N = 1 << 20
+ tinyBlockSize = 16 // runtime._TinySize
+ )
+ hold := make([]*int32, 0, N)
+ for i := 0; i < N; i++ {
+ x := new(int32)
+ if i%3 == 0 {
+ runtime.SetFinalizer(x, func(p *int32) {
+ hold = append(hold, p)
+ })
+ }
+ }
+ // Finalize as much as possible.
+ // Note: the sleep only increases probability of bug detection,
+ // it cannot lead to false failure.
+ for i := 0; i < 5; i++ {
+ runtime.GC()
+ time.Sleep(10 * time.Millisecond)
+ }
+ // Read memory profile.
+ var prof []runtime.MemProfileRecord
+ for {
+ if n, ok := runtime.MemProfile(prof, false); ok {
+ prof = prof[:n]
+ break
+ } else {
+ prof = make([]runtime.MemProfileRecord, n+10)
+ }
+ }
+ // See how much memory in tiny objects is profiled.
+ var totalBytes int64
+ for _, p := range prof {
+ bytes := p.AllocBytes - p.FreeBytes
+ nobj := p.AllocObjects - p.FreeObjects
+ size := bytes / nobj
+ if size == tinyBlockSize {
+ totalBytes += bytes
+ }
+ }
+ // 2*tinyBlockSize slack is for any boundary effects.
+ if want := N*int64(unsafe.Sizeof(int32(0))) - 2*tinyBlockSize; totalBytes < want {
+ println("got", totalBytes, "want >=", want)
+ panic("some of the tiny objects are not profiled")
+ }
+ // Just to keep hold alive.
+ if len(hold) != 0 && hold[0] == nil {
+ panic("bad")
+ }
+}