Add helper KeepRefUntilDone

webrtc/base/callback_unittest.cc

Index: webrtc/base/callback_unittest.cc
diff --git a/webrtc/base/callback_unittest.cc b/webrtc/base/callback_unittest.cc
index 66c939140ee2ef9e99e93416c2720819f204e105..876206ac517b0680ac6c947de9231c8fbbe89ddd 100644
--- a/webrtc/base/callback_unittest.cc
+++ b/webrtc/base/callback_unittest.cc
@@ -11,6 +11,8 @@
 #include "webrtc/base/bind.h"
 #include "webrtc/base/callback.h"
 #include "webrtc/base/gunit.h"
+#include "webrtc/base/refcount.h"
+#include "webrtc/base/release_when_done_callback.h"
 
 namespace rtc {
 
@@ -26,6 +28,21 @@ struct BindTester {
   int b(int x) const { return x * x; }
 };
 
+class RefCountedBindTester : public RefCountInterface {
+ public:
+  RefCountedBindTester() : count_(0) {}
+  int AddRef() const override {
+    return ++count_;
+  }
+  int Release() const {
+    return --count_;
+  }
+  int RefCount() const { return count_; }
+
+ private:
+  mutable int count_;
+};
+
 }  // namespace
 
 TEST(CallbackTest, VoidReturn) {
@@ -78,4 +95,32 @@ TEST(CallbackTest, WithBind) {
   EXPECT_EQ(25, cb1());
 }
 
+TEST(ReleaseWhenDoneCallbackTest, simple) {
+  RefCountedBindTester t;
+  EXPECT_EQ(0, t.RefCount());
+  {
+    Callback0<void> cb = ReleaseWhenDoneCallback(&t);
+    EXPECT_EQ(1, t.RefCount());
+    cb();
+    EXPECT_EQ(1, t.RefCount());
+    cb();
+    EXPECT_EQ(1, t.RefCount());
+  }
+  EXPECT_EQ(0, t.RefCount());
+}
+
+TEST(ReleaseWhenDoneCallbackTest, copy) {
+  RefCountedBindTester t;
+  EXPECT_EQ(0, t.RefCount());
+  Callback0<void> cb2;
+  {
+    Callback0<void> cb = ReleaseWhenDoneCallback(&t);
+    EXPECT_EQ(1, t.RefCount());
+    cb2 = cb;

[tommi, 2015/11/30 08:45:51]

add EXPECT_EQ(2, t.RefCount()); ?

[perkj_webrtc, 2015/11/30 12:54:19]

Actually no - it is still one. See callback. Each callback has |Helper| that is
ref counted itself.

[tommi, 2015/11/30 13:05:01]

Brilliant

+  }
+  EXPECT_EQ(1, t.RefCount());
+  cb2 = Callback0<void>();
+  EXPECT_EQ(0, t.RefCount());
+}
+
 }  // namespace rtc