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authorRuss Cox <rsc@golang.org>2014-09-08 00:08:51 -0400
committerRuss Cox <rsc@golang.org>2014-09-08 00:08:51 -0400
commitc007ce824d9a4fccb148f9204e04c23ed2984b71 (patch)
tree7dcac257114ef5c446be5b7b68c27dea230b7c09 /src/runtime/gc_test.go
parent220a6de47eced55956eb8af8d643d4f5b67fd634 (diff)
downloadgo-c007ce824d9a4fccb148f9204e04c23ed2984b71.tar.gz
go-c007ce824d9a4fccb148f9204e04c23ed2984b71.zip
build: move package sources from src/pkg to src
Preparation was in CL 134570043. This CL contains only the effect of 'hg mv src/pkg/* src'. For more about the move, see golang.org/s/go14nopkg.
Diffstat (limited to 'src/runtime/gc_test.go')
-rw-r--r--src/runtime/gc_test.go292
1 files changed, 292 insertions, 0 deletions
diff --git a/src/runtime/gc_test.go b/src/runtime/gc_test.go
new file mode 100644
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+++ b/src/runtime/gc_test.go
@@ -0,0 +1,292 @@
+// 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 runtime_test
+
+import (
+ "os"
+ "runtime"
+ "runtime/debug"
+ "testing"
+ "time"
+ "unsafe"
+)
+
+func TestGcSys(t *testing.T) {
+ if os.Getenv("GOGC") == "off" {
+ t.Skip("skipping test; GOGC=off in environment")
+ }
+ data := struct{ Short bool }{testing.Short()}
+ got := executeTest(t, testGCSysSource, &data)
+ want := "OK\n"
+ if got != want {
+ t.Fatalf("expected %q, but got %q", want, got)
+ }
+}
+
+const testGCSysSource = `
+package main
+
+import (
+ "fmt"
+ "runtime"
+)
+
+func main() {
+ runtime.GOMAXPROCS(1)
+ memstats := new(runtime.MemStats)
+ runtime.GC()
+ runtime.ReadMemStats(memstats)
+ sys := memstats.Sys
+
+ runtime.MemProfileRate = 0 // disable profiler
+
+ itercount := 1000000
+{{if .Short}}
+ itercount = 100000
+{{end}}
+ for i := 0; i < itercount; i++ {
+ workthegc()
+ }
+
+ // Should only be using a few MB.
+ // We allocated 100 MB or (if not short) 1 GB.
+ runtime.ReadMemStats(memstats)
+ if sys > memstats.Sys {
+ sys = 0
+ } else {
+ sys = memstats.Sys - sys
+ }
+ if sys > 16<<20 {
+ fmt.Printf("using too much memory: %d bytes\n", sys)
+ return
+ }
+ fmt.Printf("OK\n")
+}
+
+func workthegc() []byte {
+ return make([]byte, 1029)
+}
+`
+
+func TestGcDeepNesting(t *testing.T) {
+ type T [2][2][2][2][2][2][2][2][2][2]*int
+ a := new(T)
+
+ // Prevent the compiler from applying escape analysis.
+ // This makes sure new(T) is allocated on heap, not on the stack.
+ t.Logf("%p", a)
+
+ a[0][0][0][0][0][0][0][0][0][0] = new(int)
+ *a[0][0][0][0][0][0][0][0][0][0] = 13
+ runtime.GC()
+ if *a[0][0][0][0][0][0][0][0][0][0] != 13 {
+ t.Fail()
+ }
+}
+
+func TestGcHashmapIndirection(t *testing.T) {
+ defer debug.SetGCPercent(debug.SetGCPercent(1))
+ runtime.GC()
+ type T struct {
+ a [256]int
+ }
+ m := make(map[T]T)
+ for i := 0; i < 2000; i++ {
+ var a T
+ a.a[0] = i
+ m[a] = T{}
+ }
+}
+
+func TestGcArraySlice(t *testing.T) {
+ type X struct {
+ buf [1]byte
+ nextbuf []byte
+ next *X
+ }
+ var head *X
+ for i := 0; i < 10; i++ {
+ p := &X{}
+ p.buf[0] = 42
+ p.next = head
+ if head != nil {
+ p.nextbuf = head.buf[:]
+ }
+ head = p
+ runtime.GC()
+ }
+ for p := head; p != nil; p = p.next {
+ if p.buf[0] != 42 {
+ t.Fatal("corrupted heap")
+ }
+ }
+}
+
+func TestGcRescan(t *testing.T) {
+ type X struct {
+ c chan error
+ nextx *X
+ }
+ type Y struct {
+ X
+ nexty *Y
+ p *int
+ }
+ var head *Y
+ for i := 0; i < 10; i++ {
+ p := &Y{}
+ p.c = make(chan error)
+ if head != nil {
+ p.nextx = &head.X
+ }
+ p.nexty = head
+ p.p = new(int)
+ *p.p = 42
+ head = p
+ runtime.GC()
+ }
+ for p := head; p != nil; p = p.nexty {
+ if *p.p != 42 {
+ t.Fatal("corrupted heap")
+ }
+ }
+}
+
+func TestGcLastTime(t *testing.T) {
+ ms := new(runtime.MemStats)
+ t0 := time.Now().UnixNano()
+ runtime.GC()
+ t1 := time.Now().UnixNano()
+ runtime.ReadMemStats(ms)
+ last := int64(ms.LastGC)
+ if t0 > last || last > t1 {
+ t.Fatalf("bad last GC time: got %v, want [%v, %v]", last, t0, t1)
+ }
+ pause := ms.PauseNs[(ms.NumGC+255)%256]
+ // Due to timer granularity, pause can actually be 0 on windows
+ // or on virtualized environments.
+ if pause == 0 {
+ t.Logf("last GC pause was 0")
+ } else if pause > 10e9 {
+ t.Logf("bad last GC pause: got %v, want [0, 10e9]", pause)
+ }
+}
+
+var hugeSink interface{}
+
+func TestHugeGCInfo(t *testing.T) {
+ // The test ensures that compiler can chew these huge types even on weakest machines.
+ // The types are not allocated at runtime.
+ if hugeSink != nil {
+ // 400MB on 32 bots, 4TB on 64-bits.
+ const n = (400 << 20) + (unsafe.Sizeof(uintptr(0))-4)<<40
+ hugeSink = new([n]*byte)
+ hugeSink = new([n]uintptr)
+ hugeSink = new(struct {
+ x float64
+ y [n]*byte
+ z []string
+ })
+ hugeSink = new(struct {
+ x float64
+ y [n]uintptr
+ z []string
+ })
+ }
+}
+
+func BenchmarkSetTypeNoPtr1(b *testing.B) {
+ type NoPtr1 struct {
+ p uintptr
+ }
+ var p *NoPtr1
+ for i := 0; i < b.N; i++ {
+ p = &NoPtr1{}
+ }
+ _ = p
+}
+func BenchmarkSetTypeNoPtr2(b *testing.B) {
+ type NoPtr2 struct {
+ p, q uintptr
+ }
+ var p *NoPtr2
+ for i := 0; i < b.N; i++ {
+ p = &NoPtr2{}
+ }
+ _ = p
+}
+func BenchmarkSetTypePtr1(b *testing.B) {
+ type Ptr1 struct {
+ p *byte
+ }
+ var p *Ptr1
+ for i := 0; i < b.N; i++ {
+ p = &Ptr1{}
+ }
+ _ = p
+}
+func BenchmarkSetTypePtr2(b *testing.B) {
+ type Ptr2 struct {
+ p, q *byte
+ }
+ var p *Ptr2
+ for i := 0; i < b.N; i++ {
+ p = &Ptr2{}
+ }
+ _ = p
+}
+
+func BenchmarkAllocation(b *testing.B) {
+ type T struct {
+ x, y *byte
+ }
+ ngo := runtime.GOMAXPROCS(0)
+ work := make(chan bool, b.N+ngo)
+ result := make(chan *T)
+ for i := 0; i < b.N; i++ {
+ work <- true
+ }
+ for i := 0; i < ngo; i++ {
+ work <- false
+ }
+ for i := 0; i < ngo; i++ {
+ go func() {
+ var x *T
+ for <-work {
+ for i := 0; i < 1000; i++ {
+ x = &T{}
+ }
+ }
+ result <- x
+ }()
+ }
+ for i := 0; i < ngo; i++ {
+ <-result
+ }
+}
+
+func TestPrintGC(t *testing.T) {
+ if testing.Short() {
+ t.Skip("Skipping in short mode")
+ }
+ defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(2))
+ done := make(chan bool)
+ go func() {
+ for {
+ select {
+ case <-done:
+ return
+ default:
+ runtime.GC()
+ }
+ }
+ }()
+ for i := 0; i < 1e4; i++ {
+ func() {
+ defer print("")
+ }()
+ }
+ close(done)
+}