/*
    Copyright 2005-2011 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 "job_automaton.h"
#define HARNESS_NO_PARSE_COMMAND_LINE 1
#include "harness.h"
#include "harness_barrier.h"

class State {
    Harness::SpinBarrier barrier;
    rml::internal::job_automaton ja;
    rml::job job;
    tbb::atomic<int> job_created;
    tbb::atomic<int> job_destroyed;
    tbb::atomic<bool> job_received;
public:
    State() : barrier(2) {
        job_created = 0;
        job_destroyed = 0;
        job_received = false;
    }
    void exercise( bool is_owner );
    ~State() {
        ASSERT( job_created==job_destroyed, "accounting error" );
        ASSERT( job_destroyed<=1, "destroyed job twice" );
    }
};

int DelayMask;
const int N = 14; 
tbb::atomic<int> Coverage[N];

//! Mark kth interval as covered and insert delay if kth bit of DelayMask is set.
/** An interval is the code between two operations on the job_automaton that we are testing. */
void Cover( int k ) {
    ASSERT( k<N, NULL );
    ++Coverage[k];
    if( DelayMask>>k&1 ) {
        // Introduce delay (and possibly a thread context switch)
        __TBB_Yield();
    }
}

void State::exercise( bool is_owner ) {
    barrier.wait();
    if( is_owner ) {
        Cover(0);
        if( ja.try_acquire() ) {
            Cover(1);
            ++job_created; 
            ja.set_and_release(job);
            Cover(2);
            if( ja.try_acquire() ) {
                Cover(3);
                ja.release();
                Cover(4);
                if( ja.try_acquire() ) {
                    Cover(5);
                    ja.release();
                }
            }
            Cover(6);
        } else {
            Cover(7);
        }
        if( DelayMask&1<<N ) {
            while( !job_received ) 
                __TBB_Yield();
        }
    } else {
        // Using extra bit of DelayMask for choosing whether to run wait_for_job or not.
        if( DelayMask&1<<N ) {
            rml::job* j= &ja.wait_for_job(); 
            if( j!=&job ) REPORT("%p\n",j);
            ASSERT( j==&job, NULL );
            job_received = true;
        }
        Cover(8);
    }   
    rml::job* j;
    if( ja.try_plug(j) ) {
        ASSERT( j==&job || !j, NULL );
        if( j ) {
            Cover(9+is_owner);
            ++job_destroyed;
        } else {
            __TBB_ASSERT( !is_owner, "owner failed to create job but plugged self" );
            Cover(11);
        } 
    } else {
        Cover(12+is_owner);
    }
}

class Loop: NoAssign {
    State& s;
public:
    Loop(State& s_) : s(s_) {}
    void operator()( int i ) const {s.exercise(i==0);}
};

/** Return true if coverage is acceptable.
    If report==true, issue message if it is unacceptable. */
bool CheckCoverage( bool report ) {
    bool okay = true;
    for( int i=0; i<N; ++i ) {
        const int min_coverage = 4; 
        if( Coverage[i]<min_coverage ) {
            okay = false;
            if( report )
                REPORT("Warning: Coverage[%d]=%d is less than acceptable minimum of %d\n", i, int(Coverage[i]),min_coverage);
        }
    }
    return okay;
}

int TestMain () {
    for( DelayMask=0; DelayMask<8<<N; ++DelayMask ) {
        State s;
        NativeParallelFor( 2, Loop(s) );
        if( CheckCoverage(false) ) { 
            // Reached acceptable code coverage level
            break;
        }
    }
    CheckCoverage(true);
    return Harness::Done;
}
