Fixed member use after destruction in BarrierClosure.

base/barrier_closure_unittest.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/barrier_closure.h"
 
 #include "base/bind.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace {
 
 void Increment(int* count) { (*count)++; }
 
 TEST(BarrierClosureTest, RunImmediatelyForZeroClosures) {
   int count = 0;
-  base::Closure doneClosure(base::Bind(&Increment, base::Unretained(&count)));
+  base::Closure done_closure(base::Bind(&Increment, base::Unretained(&count)));
 
-  base::Closure barrierClosure = base::BarrierClosure(0, doneClosure);
+  base::Closure barrier_closure = base::BarrierClosure(0, done_closure);
   EXPECT_EQ(1, count);
 }
 
 TEST(BarrierClosureTest, RunAfterNumClosures) {
   int count = 0;
-  base::Closure doneClosure(base::Bind(&Increment, base::Unretained(&count)));
+  base::Closure done_closure(base::Bind(&Increment, base::Unretained(&count)));
 
-  base::Closure barrierClosure = base::BarrierClosure(2, doneClosure);
+  base::Closure barrier_closure = base::BarrierClosure(2, done_closure);
   EXPECT_EQ(0, count);
 
-  barrierClosure.Run();
+  barrier_closure.Run();
   EXPECT_EQ(0, count);
 
-  barrierClosure.Run();
+  barrier_closure.Run();
   EXPECT_EQ(1, count);
 }
 
+class DestructionIndicator {
+ public:
+  // Sets |*destructed| to true in destructor.
+  DestructionIndicator(bool* destructed) : destructed_(destructed) {
+    *destructed_ = false;
+  }
+
+  ~DestructionIndicator() { *destructed_ = true; }
+
+  void DoNothing() {}
+
+ private:
+  bool* destructed_;
+};
+
+TEST(BarrierClosureTest, ReleasesDoneClosureWhenDone) {
+  bool done_destructed = false;
+  base::Closure barrier_closure = base::BarrierClosure(
+      1, base::Bind(&DestructionIndicator::DoNothing,
+                    base::Owned(new DestructionIndicator(&done_destructed))));
+  EXPECT_FALSE(done_destructed);
+  barrier_closure.Run();
+  EXPECT_TRUE(done_destructed);
+}
+
+void ResetBarrierClosure(base::Closure* closure) {
+  *closure = base::Closure();
+}
+
+// Tests a case when |done_closure| resets a |barrier_closure|.
+// |barrier_closure| is a Closure holding the |done_closure|. |done_closure|
+// holds a pointer back to the |barrier_closure|. When |barrier_closure| is
+// Run() it calls ResetBarrierClosure() which erases the |barrier_closure| while
+// still inside of its Run(). The Run() implementation (in base::BarrierClosure)
+// must not try use itself after executing ResetBarrierClosure() or this test
+// would crash inside Run().
+TEST(BarrierClosureTest, KeepingClosureAliveUntilDone) {
+  base::Closure barrier_closure;
+  base::Closure done_closure =
+      base::Bind(ResetBarrierClosure, &barrier_closure);
+  barrier_closure = base::BarrierClosure(1, done_closure);
+  barrier_closure.Run();
+}
+
 }  // namespace