Add joinable option to SimpleThread::Options as was just done for Thread.

base/threading/simple_thread_unittest.cc

 // Copyright (c) 2012 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 <memory>
+
 #include "base/atomic_sequence_num.h"
+#include "base/memory/ptr_util.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/synchronization/waitable_event.h"
+#include "base/test/gtest_util.h"
 #include "base/threading/simple_thread.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace base {
 
 namespace {
 
 class SetIntRunner : public DelegateSimpleThread::Delegate {
  public:
   SetIntRunner(int* ptr, int val) : ptr_(ptr), val_(val) { }
   ~SetIntRunner() override {}
 
+ private:
   void Run() override { *ptr_ = val_; }
 
- private:
   int* ptr_;
   int val_;
+
+  DISALLOW_COPY_AND_ASSIGN(SetIntRunner);
+};
+
+// Signals |started_| when Run() is invoked and waits until |released_| is
+// signaled to return, signaling |done_| before doing so. Useful for tests that
+// care to control Run()'s flow.
+class ControlledRunner : public DelegateSimpleThread::Delegate {
+ public:
+  ControlledRunner()
+      : started_(WaitableEvent::ResetPolicy::MANUAL,
+                 WaitableEvent::InitialState::NOT_SIGNALED),
+        released_(WaitableEvent::ResetPolicy::MANUAL,
+                  WaitableEvent::InitialState::NOT_SIGNALED),
+        done_(WaitableEvent::ResetPolicy::MANUAL,
+              WaitableEvent::InitialState::NOT_SIGNALED) {}
+
+  ~ControlledRunner() override { ReleaseAndWaitUntilDone(); }
+
+  void WaitUntilStarted() { started_.Wait(); }
+
+  void ReleaseAndWaitUntilDone() {
+    released_.Signal();
+    done_.Wait();
+  }
+
+ private:
+  void Run() override {
+    started_.Signal();
+    released_.Wait();
+    done_.Signal();
+  }
+
+  WaitableEvent started_;
+  WaitableEvent released_;
+  WaitableEvent done_;
+
+  DISALLOW_COPY_AND_ASSIGN(ControlledRunner);
 };
 
 class WaitEventRunner : public DelegateSimpleThread::Delegate {
  public:
   explicit WaitEventRunner(WaitableEvent* event) : event_(event) { }
   ~WaitEventRunner() override {}
 
+ private:
   void Run() override {
     EXPECT_FALSE(event_->IsSignaled());
     event_->Signal();
     EXPECT_TRUE(event_->IsSignaled());
   }
- private:
+
   WaitableEvent* event_;
+
+  DISALLOW_COPY_AND_ASSIGN(WaitEventRunner);
 };
 
 class SeqRunner : public DelegateSimpleThread::Delegate {
  public:
   explicit SeqRunner(AtomicSequenceNumber* seq) : seq_(seq) { }
+
+ private:
   void Run() override { seq_->GetNext(); }
 
- private:
   AtomicSequenceNumber* seq_;
+
+  DISALLOW_COPY_AND_ASSIGN(SeqRunner);
 };
 
 // We count up on a sequence number, firing on the event when we've hit our
 // expected amount, otherwise we wait on the event.  This will ensure that we
 // have all threads outstanding until we hit our expected thread pool size.
 class VerifyPoolRunner : public DelegateSimpleThread::Delegate {
  public:
   VerifyPoolRunner(AtomicSequenceNumber* seq,
                    int total, WaitableEvent* event)
       : seq_(seq), total_(total), event_(event) { }
 
+ private:
   void Run() override {
     if (seq_->GetNext() == total_) {
       event_->Signal();
     } else {
       event_->Wait();
     }
   }
 
- private:
   AtomicSequenceNumber* seq_;
   int total_;
   WaitableEvent* event_;
+
+  DISALLOW_COPY_AND_ASSIGN(VerifyPoolRunner);
 };
 
 }  // namespace
 
 TEST(SimpleThreadTest, CreateAndJoin) {
   int stack_int = 0;
 
   SetIntRunner runner(&stack_int, 7);
   EXPECT_EQ(0, stack_int);
 
@@ skipping 45 matching lines @@
 
   EXPECT_TRUE(event.IsSignaled());
   thread.Join();
 
   // We keep the name and tid, even after the thread is gone.
   EXPECT_EQ(thread.name_prefix(), "event_waiter");
   EXPECT_EQ(thread.name(),
             std::string("event_waiter/") + IntToString(thread.tid()));
 }
 
+TEST(SimpleThreadTest, NonJoinableStartAndDieOnJoin) {
+  ControlledRunner runner;
+
+  SimpleThread::Options options;
+  options.joinable = false;
+  DelegateSimpleThread thread(&runner, "non_joinable", options);
+
+  EXPECT_FALSE(thread.HasBeenStarted());
+  thread.Start();
+  EXPECT_TRUE(thread.HasBeenStarted());
+
+  // Note: this is not quite the same as |thread.HasBeenStarted()| which
+  // represents ThreadMain() getting ready to invoke Run() whereas
+  // |runner.WaitUntilStarted()| ensures Run() was actually invoked.
+  runner.WaitUntilStarted();
+
+  EXPECT_FALSE(thread.HasBeenJoined());
+  EXPECT_DCHECK_DEATH({ thread.Join(); });
+}
+
+TEST(SimpleThreadTest, NonJoinableInactiveDelegateDestructionIsOkay) {
+  std::unique_ptr<ControlledRunner> runner(new ControlledRunner);
+
+  SimpleThread::Options options;
+  options.joinable = false;
+  std::unique_ptr<DelegateSimpleThread> thread(
+      new DelegateSimpleThread(runner.get(), "non_joinable", options));
+
+  thread->Start();
+  runner->WaitUntilStarted();
+
+  // Deleting a non-joinable SimpleThread after Run() was invoked is okay.
+  thread.reset();
+
+  runner->WaitUntilStarted();
+  runner->ReleaseAndWaitUntilDone();
+  // It should be safe to destroy a Delegate after its Run() method completed.
+  runner.reset();
+}
+
 TEST(SimpleThreadTest, ThreadPool) {
   AtomicSequenceNumber seq;
   SeqRunner runner(&seq);
   DelegateSimpleThreadPool pool("seq_runner", 10);
 
   // Add work before we're running.
   pool.AddWork(&runner, 300);
 
   EXPECT_EQ(seq.GetNext(), 0);
   pool.Start();
@@ skipping 14 matching lines @@
   VerifyPoolRunner verifier(&seq2, 9, &event);
   pool.Start();
 
   pool.AddWork(&verifier, 10);
 
   pool.JoinAll();
   EXPECT_EQ(seq2.GetNext(), 10);
 }
 
 }  // namespace base