// threadedtests.cpp - Tests for threaded code
//

/**
 *    Copyright (C) 2008 10gen Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
 *    as published by the Free Software Foundation.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU Affero General Public License for more details.
 *
 *    You should have received a copy of the GNU Affero General Public License
 *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "pch.h"
#include "../bson/util/atomic_int.h"
#include "../util/concurrency/mvar.h"
#include "../util/concurrency/thread_pool.h"
#include <boost/thread.hpp>
#include <boost/bind.hpp>

#include "dbtests.h"

namespace ThreadedTests {

    template <int nthreads_param=10>
    class ThreadedTest {
    public:
        virtual void setup() {} //optional
        virtual void subthread() = 0;
        virtual void validate() = 0;

        static const int nthreads = nthreads_param;

        void run() {
            setup();
            launch_subthreads(nthreads);
            validate();
        }

        virtual ~ThreadedTest() {}; // not necessary, but makes compilers happy

    private:
        void launch_subthreads(int remaining) {
            if (!remaining) return;

            boost::thread athread(boost::bind(&ThreadedTest::subthread, this));

            launch_subthreads(remaining - 1);

            athread.join();
        }
    };

    class MongoMutexTest : public ThreadedTest<135> { 
        enum { N = 100000 };
        MongoMutex *mm;
        virtual void setup() { 
            mm = new MongoMutex("MongoMutexTest");
        }
        virtual void subthread() { 
            Client::initThread("mongomutextest");
            sleepmillis(0);
            for( int i = 0; i < N; i++ ) { 
                if( i % 20000 == 0 ) 
                    log() << i << endl;
                if( i % 7 == 0 ) { 
                    mm->lock_shared();
                    mm->lock_shared();
                    mm->unlock_shared();
                    mm->unlock_shared();
                }
                else if( i % 7 == 1 ) { 
                    mm->lock_shared();
                    ASSERT( mm->atLeastReadLocked() );
                    mm->unlock_shared();
                }
                else if( i % 7 == 2 ) { 
                    mm->lock();
                    ASSERT( mm->isWriteLocked() );
                    mm->unlock();
                }
                else if( i % 7 == 3 ) { 
                    mm->lock();
                    mm->lock_shared();
                    ASSERT( mm->isWriteLocked() );
                    mm->unlock_shared();
                    mm->unlock();
                }
                else if( i % 7 == 4 ) { 
                    mm->lock();
                    mm->releaseEarly();
                    mm->unlock();
                }
                else if( i % 7 == 5 ) { 
                    if( mm->lock_try(1) ) { 
                        mm->unlock();
                    }
                }
                else if( i % 7 == 6 ) { 
                    if( mm->lock_shared_try(0) ) { 
                        mm->unlock_shared();
                    }
                }
                else { 
                    mm->lock_shared();
                    mm->unlock_shared();
                }
            }
            cc().shutdown();
        }
        virtual void validate() { 
            ASSERT( !mm->atLeastReadLocked() );
            mm->lock();
            mm->unlock();
            mm->lock_shared();
            mm->unlock_shared();
        }
    };

    // Tested with up to 30k threads
    class IsAtomicUIntAtomic : public ThreadedTest<> {
        static const int iterations = 1000000;
        AtomicUInt target;

        void subthread() {
            for(int i=0; i < iterations; i++) {
                //target.x++; // verified to fail with this version
                target++;
            }
        }
        void validate() {
            ASSERT_EQUALS(target.x , unsigned(nthreads * iterations));

            AtomicUInt u;
            ASSERT_EQUALS(0u, u);
            ASSERT_EQUALS(0u, u++);
            ASSERT_EQUALS(2u, ++u);
            ASSERT_EQUALS(2u, u--);
            ASSERT_EQUALS(0u, --u);
            ASSERT_EQUALS(0u, u);
        }
    };

    class MVarTest : public ThreadedTest<> {
        static const int iterations = 10000;
        MVar<int> target;

    public:
        MVarTest() : target(0) {}
        void subthread() {
            for(int i=0; i < iterations; i++) {
                int val = target.take();
#if BOOST_VERSION >= 103500
                //increase chances of catching failure
                boost::this_thread::yield();
#endif
                target.put(val+1);
            }
        }
        void validate() {
            ASSERT_EQUALS(target.take() , nthreads * iterations);
        }
    };

    class ThreadPoolTest {
        static const int iterations = 10000;
        static const int nThreads = 8;

        AtomicUInt counter;
        void increment(int n) {
            for (int i=0; i<n; i++) {
                counter++;
            }
        }

    public:
        void run() {
            ThreadPool tp(nThreads);

            for (int i=0; i < iterations; i++) {
                tp.schedule(&ThreadPoolTest::increment, this, 2);
            }

            tp.join();

            ASSERT(counter == (unsigned)(iterations * 2));
        }
    };

    class LockTest {
    public:
        void run() {
            // quick atomicint wrap test
            // MSGID likely assumes this semantic
            AtomicUInt counter = 0xffffffff;
            counter++;
            ASSERT( counter == 0 );

            writelocktry lk( "" , 0 );
            ASSERT( lk.got() );
        }
    };

    class All : public Suite {
    public:
        All() : Suite( "threading" ) {
        }

        void setupTests() {
            add< IsAtomicUIntAtomic >();
            add< MVarTest >();
            add< ThreadPoolTest >();
            add< LockTest >();
            add< MongoMutexTest >();
        }
    } myall;
}