/*
    Copyright 2005-2010 Intel Corporation.  All Rights Reserved.

    This file is part of Threading Building Blocks.

    Threading Building Blocks is free software; you can redistribute it
    and/or modify it under the terms of the GNU General Public License
    version 2 as published by the Free Software Foundation.

    Threading Building Blocks 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 General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with Threading Building Blocks; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    As a special exception, you may use this file as part of a free software
    library without restriction.  Specifically, if other files instantiate
    templates or use macros or inline functions from this file, or you compile
    this file and link it with other files to produce an executable, this
    file does not by itself cause the resulting executable to be covered by
    the GNU General Public License.  This exception does not however
    invalidate any other reasons why the executable file might be covered by
    the GNU General Public License.
*/

#include "tbb/parallel_do.h"
#include "tbb/task_scheduler_init.h"
#include "tbb/atomic.h"
#include "harness.h"
#include "harness_cpu.h"

#if defined(_MSC_VER) && defined(_Wp64)
    // Workaround for overzealous compiler warnings in /Wp64 mode
    #pragma warning (disable: 4267)
#endif /* _MSC_VER && _Wp64 */

#define N_DEPTHS     20

static tbb::atomic<int> g_values_counter;

class value_t {
    size_t x;
    value_t& operator= ( const value_t& );
public:
    value_t ( size_t xx ) : x(xx) { ++g_values_counter; }
    value_t ( const value_t& v ) : x(v.value()) { ++g_values_counter; }
    ~value_t () { --g_values_counter; }
    size_t value() const volatile { return x; }
};

#include "harness_iterator.h"

static size_t g_tasks_expected = 0;
static tbb::atomic<size_t> g_tasks_observed;

size_t FindNumOfTasks ( size_t max_depth ) {
    if( max_depth == 0 )
        return 1;
    return  max_depth * FindNumOfTasks( max_depth - 1 ) + 1;
}

//! Simplest form of the parallel_do functor object.
class FakeTaskGeneratorBody {
public:
    //! The simplest form of the function call operator
    /** It does not allow adding new tasks during its execution. **/
    void operator() ( value_t depth ) const {
        g_tasks_observed += FindNumOfTasks(depth.value());
    }
};

/** Work item is passed by reference here. **/
class FakeTaskGeneratorBody_RefVersion {
public:
    void operator() ( value_t& depth ) const {
        g_tasks_observed += FindNumOfTasks(depth.value());
    }
};

/** Work item is passed by reference to const here. **/
class FakeTaskGeneratorBody_ConstRefVersion {
public:
    void operator() ( const value_t& depth ) const {
        g_tasks_observed += FindNumOfTasks(depth.value());
    }
};

/** Work item is passed by reference to volatile here. **/
class FakeTaskGeneratorBody_VolatileRefVersion {
public:
    void operator() ( volatile value_t& depth, tbb::parallel_do_feeder<value_t>& ) const {
        g_tasks_observed += FindNumOfTasks(depth.value());
    }
};

void do_work ( const value_t& depth, tbb::parallel_do_feeder<value_t>& feeder ) {
    ++g_tasks_observed;
    size_t  d=depth.value();
    --d;
    for( size_t i = 0; i < depth.value(); ++i)
        feeder.add(value_t(d));
}

//! Standard form of the parallel_do functor object.
/** Allows adding new work items on the fly. **/
class TaskGeneratorBody
{
public:
    //! This form of the function call operator can be used when the body needs to add more work during the processing
    void operator() ( value_t depth, tbb::parallel_do_feeder<value_t>& feeder ) const {
        do_work(depth, feeder);
    }
private:
    // Assert that parallel_do does not ever access body constructors
    TaskGeneratorBody () {}
    TaskGeneratorBody ( const TaskGeneratorBody& );
    // TestBody() needs access to the default constructor
    template<class Body, class Iterator> friend void TestBody( size_t );
}; // class TaskGeneratorBody

/** Work item is passed by reference here. **/
class TaskGeneratorBody_RefVersion
{
public:
    void operator() ( value_t& depth, tbb::parallel_do_feeder<value_t>& feeder ) const {
        do_work(depth, feeder);
    }
}; // class TaskGeneratorBody

/** Work item is passed as const here. Compilers must ignore the const qualifier. **/
class TaskGeneratorBody_ConstVersion
{
public:
    void operator() ( const value_t depth, tbb::parallel_do_feeder<value_t>& feeder ) const {
        do_work(depth, feeder);
    }
}; // class TaskGeneratorBody

/** Work item is passed by reference to const here. **/
class TaskGeneratorBody_ConstRefVersion
{
public:
    void operator() ( const value_t& depth, tbb::parallel_do_feeder<value_t>& feeder ) const {
        do_work(depth, feeder);
    }
}; // class TaskGeneratorBody

/** Work item is passed by reference to volatile here. **/
class TaskGeneratorBody_VolatileRefVersion
{
public:
    void operator() ( volatile value_t& depth, tbb::parallel_do_feeder<value_t>& feeder ) const {
        do_work(const_cast<value_t&>(depth), feeder);
    }
}; // class TaskGeneratorBody

/** Work item is passed by reference to volatile here. **/
class TaskGeneratorBody_ConstVolatileRefVersion
{
public:
    void operator() ( const volatile value_t& depth, tbb::parallel_do_feeder<value_t>& feeder ) const {
        do_work(const_cast<value_t&>(depth), feeder);
    }
}; // class TaskGeneratorBody


static value_t g_depths[N_DEPTHS] = {0, 1, 2, 3, 4, 0, 1, 0, 1, 2, 0, 1, 2, 3, 0, 1, 2, 0, 1, 2};

template<class Body, class Iterator>
void TestBody ( size_t depth ) {
    typedef typename std::iterator_traits<Iterator>::value_type value_type;
    value_type a_depths[N_DEPTHS] = {0, 1, 2, 3, 4, 0, 1, 0, 1, 2, 0, 1, 2, 3, 0, 1, 2, 0, 1, 2};
    Body body;
    Iterator begin(a_depths);
    Iterator end(a_depths + depth);
    g_tasks_observed = 0;
    tbb::parallel_do(begin, end, body);
    ASSERT (g_tasks_observed == g_tasks_expected, NULL);
}

template<class Iterator>
void TestIterator_RvalueOnly ( int /*nthread*/, size_t depth ) {
    g_values_counter = 0;
    TestBody<FakeTaskGeneratorBody, Iterator> (depth);
    TestBody<FakeTaskGeneratorBody_ConstRefVersion, Iterator> (depth);
    TestBody<TaskGeneratorBody, Iterator> (depth);
    TestBody<TaskGeneratorBody_ConstVersion, Iterator> (depth);
    TestBody<TaskGeneratorBody_ConstRefVersion, Iterator> (depth);
}

template<class Iterator>
void TestIterator ( int nthread, size_t depth ) {
    TestIterator_RvalueOnly<Iterator>(nthread, depth);
    TestBody<FakeTaskGeneratorBody_RefVersion, Iterator> (depth);
    TestBody<FakeTaskGeneratorBody_VolatileRefVersion, Iterator> (depth);
    TestBody<TaskGeneratorBody_RefVersion, Iterator> (depth);
    TestBody<TaskGeneratorBody_VolatileRefVersion, Iterator> (depth);
    TestBody<TaskGeneratorBody_ConstVolatileRefVersion, Iterator> (depth);
}

void Run( int nthread ) {
    for( size_t depth = 0; depth <= N_DEPTHS; ++depth ) {
        g_tasks_expected = 0;
        for ( size_t i=0; i < depth; ++i )
            g_tasks_expected += FindNumOfTasks( g_depths[i].value() );
        // Test for iterators over values convertible to work item type
        TestIterator_RvalueOnly<size_t*>(nthread, depth);
        // Test for random access iterators
        TestIterator<value_t*>(nthread, depth);
        // Test for input iterators
        TestIterator<Harness::InputIterator<value_t> >(nthread, depth);
        // Test for forward iterators
        TestIterator<Harness::ForwardIterator<value_t> >(nthread, depth);
    }
}

int TestMain () {
    if( MinThread<1 ) {
        REPORT("number of threads must be positive\n");
        exit(1);
    }
    for( int p=MinThread; p<=MaxThread; ++p ) {
        tbb::task_scheduler_init init( p );
        Run(p);
        // Test that all workers sleep when no work
        TestCPUUserTime(p);
    }
    // This check must be performed after the scheduler terminated because only in this 
    // case there is a guarantee that the workers already destroyed their last tasks. 
    ASSERT( g_values_counter == 0, "Value objects were leaked" );
    return Harness::Done;
}