Checking in vendor folder for ease of using go get.

vendor/git.apache.org/thrift.git/lib/cpp/test/RWMutexStarveTest.cpp

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+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+#include <iostream>
+#include <unistd.h>
+
+#include <boost/shared_ptr.hpp>
+#include <boost/test/unit_test.hpp>
+
+#include "thrift/concurrency/Mutex.h"
+#include "thrift/concurrency/PosixThreadFactory.h"
+
+using boost::shared_ptr;
+using boost::unit_test::test_suite;
+using boost::unit_test::framework::master_test_suite;
+
+using namespace apache::thrift::concurrency;
+using namespace std;
+
+class Locker : public Runnable {
+protected:
+  Locker(boost::shared_ptr<ReadWriteMutex> rwlock, bool writer)
+    : rwlock_(rwlock), writer_(writer), started_(false), gotLock_(false), signaled_(false) {}
+
+public:
+  virtual void run() {
+    started_ = true;
+    if (writer_) {
+      rwlock_->acquireWrite();
+    } else {
+      rwlock_->acquireRead();
+    }
+    gotLock_ = true;
+    while (!signaled_) {
+      usleep(5000);
+    }
+    rwlock_->release();
+  }
+
+  bool started() const { return started_; }
+  bool gotLock() const { return gotLock_; }
+  void signal() { signaled_ = true; }
+
+protected:
+  boost::shared_ptr<ReadWriteMutex> rwlock_;
+  bool writer_;
+  volatile bool started_;
+  volatile bool gotLock_;
+  volatile bool signaled_;
+};
+
+class Reader : public Locker {
+public:
+  Reader(boost::shared_ptr<ReadWriteMutex> rwlock) : Locker(rwlock, false) {}
+};
+
+class Writer : public Locker {
+public:
+  Writer(boost::shared_ptr<ReadWriteMutex> rwlock) : Locker(rwlock, true) {}
+};
+
+void test_starve(PosixThreadFactory::POLICY policy) {
+  // the man pages for pthread_wrlock_rdlock suggest that any OS guarantee about
+  // writer starvation may be influenced by the scheduling policy, so let's try
+  // all 3 policies to see if any of them work.
+  PosixThreadFactory factory(policy);
+  factory.setDetached(false);
+
+  boost::shared_ptr<ReadWriteMutex> rwlock(new NoStarveReadWriteMutex());
+
+  boost::shared_ptr<Reader> reader1(new Reader(rwlock));
+  boost::shared_ptr<Reader> reader2(new Reader(rwlock));
+  boost::shared_ptr<Writer> writer(new Writer(rwlock));
+
+  boost::shared_ptr<Thread> treader1 = factory.newThread(reader1);
+  boost::shared_ptr<Thread> treader2 = factory.newThread(reader2);
+  boost::shared_ptr<Thread> twriter = factory.newThread(writer);
+
+  // launch a reader and make sure he has the lock
+  treader1->start();
+  while (!reader1->gotLock()) {
+    usleep(2000);
+  }
+
+  // launch a writer and make sure he's blocked on the lock
+  twriter->start();
+  while (!writer->started()) {
+    usleep(2000);
+  }
+  // tricky part... we can never be 100% sure that the writer is actually
+  // blocked on the lock, but we can pretty reasonably sure because we know
+  // he just executed the line immediately before getting the lock, and
+  // we'll wait a full second for him to get on it.
+  sleep(1);
+
+  // launch a second reader... if the RWMutex guarantees that writers won't
+  // starve, this reader should not be able to acquire the lock until the writer
+  // has acquired and released it.
+  treader2->start();
+  while (!reader2->started()) {
+    usleep(2000);
+  }
+  // again... can't be 100% sure the reader is waiting on (or has) the lock
+  // but we can be close.
+  sleep(1);
+
+  // tell reader 1 to let go of the lock
+  reader1->signal();
+
+  // wait for someone to get the lock
+  while (!reader2->gotLock() && !writer->gotLock()) {
+    usleep(2000);
+  }
+
+  // the test succeeded if the WRITER got the lock.
+  bool success = writer->gotLock();
+
+  // tell everyone we're done and wait for them to finish
+  reader2->signal();
+  writer->signal();
+  treader1->join();
+  treader2->join();
+  twriter->join();
+
+  // make sure it worked.
+  BOOST_CHECK_MESSAGE(success, "writer is starving");
+}
+
+BOOST_AUTO_TEST_SUITE(RWMutexStarveTest)
+
+BOOST_AUTO_TEST_CASE(test_starve_other) {
+  test_starve(PosixThreadFactory::OTHER);
+}
+
+BOOST_AUTO_TEST_CASE(test_starve_rr) {
+  test_starve(PosixThreadFactory::ROUND_ROBIN);
+}
+
+BOOST_AUTO_TEST_CASE(test_starve_fifo) {
+  test_starve(PosixThreadFactory::FIFO);
+}
+
+BOOST_AUTO_TEST_SUITE_END()