/*
    Copyright 2005-2012 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/concurrent_queue.h"
#include "tbb/atomic.h"
#include "tbb/tick_count.h"

#include "../test/harness_assert.h"
#include "../test/harness.h"

static tbb::atomic<long> FooConstructed;
static tbb::atomic<long> FooDestroyed;

class Foo {
    enum state_t{
        LIVE=0x1234,
        DEAD=0xDEAD
    };
    state_t state;
public:
    int thread_id;
    int serial;
    Foo() : state(LIVE) {
        ++FooConstructed;
    }
    Foo( const Foo& item ) : state(LIVE) {
        ASSERT( item.state==LIVE, NULL );
        ++FooConstructed;
        thread_id = item.thread_id;
        serial = item.serial;
    }
    ~Foo() {
        ASSERT( state==LIVE, NULL );
        ++FooDestroyed;
        state=DEAD;
        thread_id=0xDEAD;
        serial=0xDEAD;
    }
    void operator=( Foo& item ) {
        ASSERT( item.state==LIVE, NULL );
        ASSERT( state==LIVE, NULL );
        thread_id = item.thread_id;
        serial = item.serial;
    }
    bool is_const() {return false;}
    bool is_const() const {return true;}
};

const size_t MAXTHREAD = 256;

static int Sum[MAXTHREAD];

//! Count of various pop operations
/** [0] = pop_if_present that failed
    [1] = pop_if_present that succeeded
    [2] = pop */
static tbb::atomic<long> PopKind[3];

const int M = 10000;

struct Body: NoAssign {
    tbb::concurrent_queue<Foo>* queue;
    const int nthread;
    Body( int nthread_ ) : nthread(nthread_) {}
    void operator()( long thread_id ) const {
        long pop_kind[3] = {0,0,0};
        int serial[MAXTHREAD+1];
        memset( serial, 0, nthread*sizeof(unsigned) );
        ASSERT( thread_id<nthread, NULL );

        long sum = 0;
        for( long j=0; j<M; ++j ) {
            Foo f;
            f.thread_id = 0xDEAD;
            f.serial = 0xDEAD;
            bool prepopped = false;
            if( j&1 ) {
                prepopped = queue->pop_if_present(f);
                ++pop_kind[prepopped];
            }
            Foo g;
            g.thread_id = thread_id;
            g.serial = j+1;
            queue->push( g );
            if( !prepopped ) {
                queue->pop(f);
                ++pop_kind[2];
            }
            ASSERT( f.thread_id<=nthread, NULL );
            ASSERT( f.thread_id==nthread || serial[f.thread_id]<f.serial, "partial order violation" );
            serial[f.thread_id] = f.serial;
            sum += f.serial-1;
        }
        Sum[thread_id] = sum;
        for( int k=0; k<3; ++k )
            PopKind[k] += pop_kind[k];
    }
};

void TestPushPop( int prefill, ptrdiff_t capacity, int nthread ) {
    ASSERT( nthread>0, "nthread must be positive" );
    if( prefill+1>=capacity )
        return;
    bool success = false;
    for( int k=0; k<3; ++k )
        PopKind[k] = 0;
    for( int trial=0; !success; ++trial ) {
        FooConstructed = 0;
        FooDestroyed = 0;
        Body body(nthread);
        tbb::concurrent_queue<Foo> queue;
        queue.set_capacity( capacity );
        body.queue = &queue;
        for( int i=0; i<prefill; ++i ) {
            Foo f;
            f.thread_id = nthread;
            f.serial = 1+i;
            queue.push(f);
            ASSERT( queue.size()==i+1, NULL );
            ASSERT( !queue.empty(), NULL );
        }
        tbb::tick_count t0 = tbb::tick_count::now();
        NativeParallelFor( nthread, body );
        tbb::tick_count t1 = tbb::tick_count::now();
        double timing = (t1-t0).seconds();
        if( Verbose )
            printf("prefill=%d capacity=%d time = %g = %g nsec/operation\n", prefill, int(capacity), timing, timing/(2*M*nthread)*1.E9);
        int sum = 0;
        for( int k=0; k<nthread; ++k )
            sum += Sum[k];
        int expected = nthread*((M-1)*M/2) + ((prefill-1)*prefill)/2;
        for( int i=prefill; --i>=0; ) {
            ASSERT( !queue.empty(), NULL );
            Foo f;
            queue.pop(f);
            ASSERT( queue.size()==i, NULL );
            sum += f.serial-1;
        }
        ASSERT( queue.empty(), NULL );
        ASSERT( queue.size()==0, NULL );
        if( sum!=expected )
            printf("sum=%d expected=%d\n",sum,expected);
        ASSERT( FooConstructed==FooDestroyed, NULL );

        success = true;
        if( nthread>1 && prefill==0 ) {
            // Check that pop_if_present got sufficient exercise
            for( int k=0; k<2; ++k ) {
#if (_WIN32||_WIN64)
                // The TBB library on Windows seems to have a tough time generating
                // the desired interleavings for pop_if_present, so the code tries longer, and settles
                // for fewer desired interleavings.
                const int max_trial = 100;
                const int min_requirement = 20;
#else
                const int min_requirement = 100;
                const int max_trial = 20;
#endif /* _WIN32||_WIN64 */
                if( PopKind[k]<min_requirement ) {
                    if( trial>=max_trial ) {
                        if( Verbose )
                            printf("Warning: %d threads had only %ld pop_if_present operations %s after %d trials (expected at least %d). "
                                    "This problem may merely be unlucky scheduling. "
                                    "Investigate only if it happens repeatedly.\n",
                                    nthread, long(PopKind[k]), k==0?"failed":"succeeded", max_trial, min_requirement);
                        else
                            printf("Warning: the number of %s pop_if_present operations is less than expected for %d threads. Investigate if it happens repeatedly.\n",
                                   k==0?"failed":"succeeded", nthread );
                    } else {
                        success = false;
                    }
               }
            }
        }
    }
}

template<typename Iterator1, typename Iterator2>
void TestIteratorAux( Iterator1 i, Iterator2 j, int size ) {
    // Now test iteration
    Iterator1 old_i;
    for( int k=0; k<size; ++k ) {
        ASSERT( i!=j, NULL );
        ASSERT( !(i==j), NULL );
        Foo f;
        if( k&1 ) {
            // Test pre-increment
            f = *old_i++;
            // Test assignment
            i = old_i;
        } else {
            // Test post-increment
            f=*i++;
            if( k<size-1 ) {
                // Test "->"
                ASSERT( k+2==i->serial, NULL );
            }
            // Test assignment
            old_i = i;
        }
        ASSERT( k+1==f.serial, NULL );
    }
    ASSERT( !(i!=j), NULL );
    ASSERT( i==j, NULL );
}

template<typename Iterator1, typename Iterator2>
void TestIteratorAssignment( Iterator2 j ) {
    Iterator1 i(j);
    ASSERT( i==j, NULL );
    ASSERT( !(i!=j), NULL );
    Iterator1 k;
    k = j;
    ASSERT( k==j, NULL );
    ASSERT( !(k!=j), NULL );
}

//! Test the iterators for concurrent_queue
void TestIterator() {
    tbb::concurrent_queue<Foo> queue;
    tbb::concurrent_queue<Foo>& const_queue = queue;
    for( int j=0; j<500; ++j ) {
        TestIteratorAux(       queue.begin(),       queue.end(), j );
        TestIteratorAux( const_queue.begin(), const_queue.end(), j );
        TestIteratorAux( const_queue.begin(),       queue.end(), j );
        TestIteratorAux(       queue.begin(), const_queue.end(), j );
        Foo f;
        f.serial = j+1;
        queue.push(f);
    }
    TestIteratorAssignment<tbb::concurrent_queue<Foo>::const_iterator>( const_queue.begin() );
    TestIteratorAssignment<tbb::concurrent_queue<Foo>::const_iterator>(       queue.begin() );
    TestIteratorAssignment<tbb::concurrent_queue<Foo>::      iterator>(       queue.begin() );
}

void TestConcurrentQueueType() {
    AssertSameType( tbb::concurrent_queue<Foo>::value_type(), Foo() );
    Foo f;
    const Foo g;
    tbb::concurrent_queue<Foo>::reference r = f;
    ASSERT( &r==&f, NULL );
    ASSERT( !r.is_const(), NULL );
    tbb::concurrent_queue<Foo>::const_reference cr = g;
    ASSERT( &cr==&g, NULL );
    ASSERT( cr.is_const(), NULL );
}

template<typename T>
void TestEmptyQueue() {
    const tbb::concurrent_queue<T> queue;
    ASSERT( queue.size()==0, NULL );
    ASSERT( queue.capacity()>0, NULL );
    ASSERT( size_t(queue.capacity())>=size_t(-1)/(sizeof(void*)+sizeof(T)), NULL );
}

void TestFullQueue() {
    for( int n=0; n<10; ++n ) {
        FooConstructed = 0;
        FooDestroyed = 0;
        tbb::concurrent_queue<Foo> queue;
        queue.set_capacity(n);
        for( int i=0; i<=n; ++i ) {
            Foo f;
            f.serial = i;
            bool result = queue.push_if_not_full( f );
            ASSERT( result==(i<n), NULL );
        }
        for( int i=0; i<=n; ++i ) {
            Foo f;
            bool result = queue.pop_if_present( f );
            ASSERT( result==(i<n), NULL );
            ASSERT( !result || f.serial==i, NULL );
        }
        ASSERT( FooConstructed==FooDestroyed, NULL );
    }
}

template<typename T>
struct TestNegativeQueueBody: NoAssign {
    tbb::concurrent_queue<T>& queue;
    const int nthread;
    TestNegativeQueueBody( tbb::concurrent_queue<T>& q, int n ) : queue(q), nthread(n) {}
    void operator()( int k ) const {
        if( k==0 ) {
            int number_of_pops = nthread-1;
            // Wait for all pops to pend.
            while( queue.size()>-number_of_pops ) {
                __TBB_Yield();
            }
            for( int i=0; ; ++i ) {
                ASSERT( queue.size()==i-number_of_pops, NULL );
                ASSERT( queue.empty()==(queue.size()<=0), NULL );
                if( i==number_of_pops ) break;
                // Satisfy another pop
                queue.push( T() );
            }
        } else {
            // Pop item from queue
            T item;
            queue.pop(item);
        }
    }
};

//! Test a queue with a negative size.
template<typename T>
void TestNegativeQueue( int nthread ) {
    tbb::concurrent_queue<T> queue;
    NativeParallelFor( nthread, TestNegativeQueueBody<T>(queue,nthread) );
}

int TestMain () {
    TestEmptyQueue<char>();
    TestEmptyQueue<Foo>();
    TestFullQueue();
    TestConcurrentQueueType();
    TestIterator();

    // Test concurrent operations
    for( int nthread=MinThread; nthread<=MaxThread; ++nthread ) {
        TestNegativeQueue<Foo>(nthread);
        for( int prefill=0; prefill<64; prefill+=(1+prefill/3) ) {
            TestPushPop(prefill,ptrdiff_t(-1),nthread);
            TestPushPop(prefill,ptrdiff_t(1),nthread);
            TestPushPop(prefill,ptrdiff_t(2),nthread);
            TestPushPop(prefill,ptrdiff_t(10),nthread);
            TestPushPop(prefill,ptrdiff_t(100),nthread);
        }
    }
    return Harness::Done;
}
