Add helper KeepRefUntilDone

webrtc/base/callback_unittest.cc

 /*
  *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #include "webrtc/base/bind.h"
 #include "webrtc/base/callback.h"
 #include "webrtc/base/gunit.h"
+#include "webrtc/base/keep_ref_until_done.h"
+#include "webrtc/base/refcount.h"
 
 namespace rtc {
 
 namespace {
 
 void f() {}
 int g() { return 42; }
 int h(int x) { return x * x; }
 void i(int& x) { x *= x; }  // NOLINT: Testing refs
 
 struct BindTester {
   int a() { return 24; }
   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) {
   Callback0<void> cb;
   EXPECT_TRUE(cb.empty());
   cb();  // Executing an empty callback should not crash.
   cb = Callback0<void>(&f);
   EXPECT_FALSE(cb.empty());
   cb();
 }
@@ skipping 32 matching lines @@
   EXPECT_EQ(24, cb1());
   EXPECT_EQ(24, cb1());
   cb1 = Bind(&BindTester::b, &t, 10);
   EXPECT_EQ(100, cb1());
   EXPECT_EQ(100, cb1());
   cb1 = Bind(&BindTester::b, &t, 5);
   EXPECT_EQ(25, cb1());
   EXPECT_EQ(25, cb1());
 }
 
+TEST(KeepRefUntilDoneTest, simple) {
+  RefCountedBindTester t;
+  EXPECT_EQ(0, t.RefCount());
+  {
+    Callback0<void> cb = KeepRefUntilDone(&t);
+    EXPECT_EQ(1, t.RefCount());
+    cb();
+    EXPECT_EQ(1, t.RefCount());
+    cb();
+    EXPECT_EQ(1, t.RefCount());
+  }
+  EXPECT_EQ(0, t.RefCount());
+}
+
+TEST(KeepRefUntilDoneTest, copy) {
+  RefCountedBindTester t;
+  EXPECT_EQ(0, t.RefCount());
+  Callback0<void> cb2;
+  {
+    Callback0<void> cb = KeepRefUntilDone(&t);
+    EXPECT_EQ(1, t.RefCount());
+    cb2 = cb;
+  }
+  EXPECT_EQ(1, t.RefCount());
+  cb2 = Callback0<void>();
+  EXPECT_EQ(0, t.RefCount());
+}
+
+TEST(KeepRefUntilDoneTest, scopedref) {
+  RefCountedBindTester t;
+  EXPECT_EQ(0, t.RefCount());
+  {
+    scoped_refptr<RefCountedBindTester> t_scoped_ref(&t);
+    Callback0<void> cb = KeepRefUntilDone(t_scoped_ref);
+    t_scoped_ref = nullptr;
+    EXPECT_EQ(1, t.RefCount());
+    cb();
+    EXPECT_EQ(1, t.RefCount());
+  }
+  EXPECT_EQ(0, t.RefCount());
+}
+
 }  // namespace rtc