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path: root/src/pkg/runtime/race/testdata/select_test.go
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-rw-r--r--src/pkg/runtime/race/testdata/select_test.go286
1 files changed, 286 insertions, 0 deletions
diff --git a/src/pkg/runtime/race/testdata/select_test.go b/src/pkg/runtime/race/testdata/select_test.go
new file mode 100644
index 000000000..4a3a23647
--- /dev/null
+++ b/src/pkg/runtime/race/testdata/select_test.go
@@ -0,0 +1,286 @@
+// Copyright 2012 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 race_test
+
+import (
+ "runtime"
+ "testing"
+)
+
+func TestNoRaceSelect1(t *testing.T) {
+ var x int
+ compl := make(chan bool)
+ c := make(chan bool)
+ c1 := make(chan bool)
+
+ go func() {
+ x = 1
+ // At least two channels are needed because
+ // otherwise the compiler optimizes select out.
+ // See comment in runtime/chan.c:^selectgo.
+ select {
+ case c <- true:
+ case c1 <- true:
+ }
+ compl <- true
+ }()
+ select {
+ case <-c:
+ case c1 <- true:
+ }
+ x = 2
+ <-compl
+}
+
+func TestNoRaceSelect2(t *testing.T) {
+ var x int
+ compl := make(chan bool)
+ c := make(chan bool)
+ c1 := make(chan bool)
+ go func() {
+ select {
+ case <-c:
+ case <-c1:
+ }
+ x = 1
+ compl <- true
+ }()
+ x = 2
+ close(c)
+ runtime.Gosched()
+ <-compl
+}
+
+func TestNoRaceSelect3(t *testing.T) {
+ var x int
+ compl := make(chan bool)
+ c := make(chan bool, 10)
+ c1 := make(chan bool)
+ go func() {
+ x = 1
+ select {
+ case c <- true:
+ case <-c1:
+ }
+ compl <- true
+ }()
+ <-c
+ x = 2
+ <-compl
+}
+
+func TestNoRaceSelect4(t *testing.T) {
+ type Task struct {
+ f func()
+ done chan bool
+ }
+
+ queue := make(chan Task)
+ dummy := make(chan bool)
+
+ go func() {
+ for {
+ select {
+ case t := <-queue:
+ t.f()
+ t.done <- true
+ }
+ }
+ }()
+
+ doit := func(f func()) {
+ done := make(chan bool, 1)
+ select {
+ case queue <- Task{f, done}:
+ case <-dummy:
+ }
+ select {
+ case <-done:
+ case <-dummy:
+ }
+ }
+
+ var x int
+ doit(func() {
+ x = 1
+ })
+ _ = x
+}
+
+func TestNoRaceSelect5(t *testing.T) {
+ test := func(sel, needSched bool) {
+ var x int
+ ch := make(chan bool)
+ c1 := make(chan bool)
+
+ done := make(chan bool, 2)
+ go func() {
+ if needSched {
+ runtime.Gosched()
+ }
+ // println(1)
+ x = 1
+ if sel {
+ select {
+ case ch <- true:
+ case <-c1:
+ }
+ } else {
+ ch <- true
+ }
+ done <- true
+ }()
+
+ go func() {
+ // println(2)
+ if sel {
+ select {
+ case <-ch:
+ case <-c1:
+ }
+ } else {
+ <-ch
+ }
+ x = 1
+ done <- true
+ }()
+ <-done
+ <-done
+ }
+
+ test(true, true)
+ test(true, false)
+ test(false, true)
+ test(false, false)
+}
+
+func TestRaceSelect1(t *testing.T) {
+ var x int
+ compl := make(chan bool, 2)
+ c := make(chan bool)
+ c1 := make(chan bool)
+
+ go func() {
+ <-c
+ <-c
+ }()
+ f := func() {
+ select {
+ case c <- true:
+ case c1 <- true:
+ }
+ x = 1
+ compl <- true
+ }
+ go f()
+ go f()
+ <-compl
+ <-compl
+}
+
+func TestRaceSelect2(t *testing.T) {
+ var x int
+ compl := make(chan bool)
+ c := make(chan bool)
+ c1 := make(chan bool)
+ go func() {
+ x = 1
+ select {
+ case <-c:
+ case <-c1:
+ }
+ compl <- true
+ }()
+ close(c)
+ x = 2
+ <-compl
+}
+
+func TestRaceSelect3(t *testing.T) {
+ var x int
+ compl := make(chan bool)
+ c := make(chan bool)
+ c1 := make(chan bool)
+ go func() {
+ x = 1
+ select {
+ case c <- true:
+ case c1 <- true:
+ }
+ compl <- true
+ }()
+ x = 2
+ select {
+ case <-c:
+ }
+ <-compl
+}
+
+func TestRaceSelect4(t *testing.T) {
+ done := make(chan bool, 1)
+ var x int
+ go func() {
+ select {
+ default:
+ x = 2
+ }
+ done <- true
+ }()
+ _ = x
+ <-done
+}
+
+// The idea behind this test:
+// there are two variables, access to one
+// of them is synchronized, access to the other
+// is not.
+// Select must (unconditionaly) choose the non-synchronized variable
+// thus causing exactly one race.
+// Currently this test doesn't look like it accomplishes
+// this goal.
+func TestRaceSelect5(t *testing.T) {
+ done := make(chan bool, 1)
+ c1 := make(chan bool, 1)
+ c2 := make(chan bool)
+ var x, y int
+ go func() {
+ select {
+ case c1 <- true:
+ x = 1
+ case c2 <- true:
+ y = 1
+ }
+ done <- true
+ }()
+ _ = x
+ _ = y
+ <-done
+}
+
+// select statements may introduce
+// flakiness: whether this test contains
+// a race depends on the scheduling
+// (some may argue that the code contains
+// this race by definition)
+/*
+func TestFlakyDefault(t *testing.T) {
+ var x int
+ c := make(chan bool, 1)
+ done := make(chan bool, 1)
+ go func() {
+ select {
+ case <-c:
+ x = 2
+ default:
+ x = 3
+ }
+ done <- true
+ }()
+ x = 1
+ c <- true
+ _ = x
+ <-done
+}
+*/