interrupt.cpp

// Copyright (C) 2007, International Business Machines
// Corporation and others.  All Rights Reserved.
// This code is licensed under the terms of the Eclipse Public License (EPL).

#include <cassert>
#include <iomanip>

#include "CoinPragma.hpp"
#include "CbcModel.hpp"
#include "OsiClpSolverInterface.hpp"
#include "CbcSolver.hpp"

#include "CoinTime.hpp"

//#############################################################################

/************************************************************************

This main program shows how to take advantage of the standalone cbc in your program,
while still making major modifications.
This is very like driver4 but allows interrupts in clp for faster stopping
It would be up to user to clean up output as stopping in Clp seems to
give correct results but can think it is stopping in an odd way.
To make cleaner would need more events defined (in Cbc AND Clp)
First it reads in an integer model from an mps file
Then it initializes the integer model with cbc defaults
Then it calls CbcMain1 passing all parameters apart from first but with callBack to modify stuff
Finally it prints solution

************************************************************************/
/* Meaning of whereFrom:
   1 after initial solve by dualsimplex etc
   2 after preprocessing
   3 just before branchAndBound (so user can override)
   4 just after branchAndBound (before postprocessing)
   5 after postprocessing
*/
/* Meaning of model status is as normal
   status
      -1 before branchAndBound
      0 finished - check isProvenOptimal or isProvenInfeasible to see if solution found
      (or check value of best solution)
      1 stopped - on maxnodes, maxsols, maxtime
      2 difficulties so run was abandoned
      (5 event user programmed event occurred) 

      cbc secondary status of problem
        -1 unset (status_ will also be -1)
	0 search completed with solution
	1 linear relaxation not feasible (or worse than cutoff)
	2 stopped on gap
	3 stopped on nodes
	4 stopped on time
	5 stopped on user event
	6 stopped on solutions
	7 linear relaxation unbounded

   but initially check if status is 0 and secondary status is 1 -> infeasible
   or you can check solver status.
*/
/* Return non-zero to return quickly */
static int callBack(CbcModel *model, int whereFrom)
{
  int returnCode = 0;
  switch (whereFrom) {
  case 1:
  case 2:
    if (!model->status() && model->secondaryStatus())
      returnCode = 1;
    break;
  case 3: {
    //CbcCompareUser compare;
    //model->setNodeComparison(compare);
  } break;
  case 4:
    // If not good enough could skip postprocessing
    break;
  case 5:
    break;
  default:
    abort();
  }
  return returnCode;
}
#include "CbcEventHandler.hpp"
static int cancelAsap = 0;
/*
  0 - not yet in Cbc
  1 - in Cbc with new signal handler
  2 - ending Cbc
*/
static int statusOfCbc = 0;
#include "CoinSignal.hpp"
static CoinSighandler_t saveSignal = static_cast< CoinSighandler_t >(0);

extern "C" {
static void
#if defined(_MSC_VER)
  __cdecl
#endif // _MSC_VER
  signal_handler(int /*whichSignal*/)
{
  cancelAsap = 3;
  return;
}
}
/** This is so user can trap events and do useful stuff.  

    CbcModel model_ is available as well as anything else you care 
    to pass in
*/

class MyEventHandler3 : public CbcEventHandler {

public:
  /**@name Overrides */
  //@{
  virtual CbcAction event(CbcEvent whichEvent);
  //@}

  /**@name Constructors, destructor etc*/
  //@{
  /** Default constructor. */
  MyEventHandler3();
  /// Constructor with pointer to model (redundant as setEventHandler does)
  MyEventHandler3(CbcModel *model);
  /** Destructor */
  virtual ~MyEventHandler3();
  /** The copy constructor. */
  MyEventHandler3(const MyEventHandler3 &rhs);
  /// Assignment
  MyEventHandler3 &operator=(const MyEventHandler3 &rhs);
  /// Clone
  virtual CbcEventHandler *clone() const;
  //@}

protected:
  // data goes here
};
//-------------------------------------------------------------------
// Default Constructor
//-------------------------------------------------------------------
MyEventHandler3::MyEventHandler3()
  : CbcEventHandler()
{
}

//-------------------------------------------------------------------
// Copy constructor
//-------------------------------------------------------------------
MyEventHandler3::MyEventHandler3(const MyEventHandler3 &rhs)
  : CbcEventHandler(rhs)
{
}

// Constructor with pointer to model
MyEventHandler3::MyEventHandler3(CbcModel *model)
  : CbcEventHandler(model)
{
}

//-------------------------------------------------------------------
// Destructor
//-------------------------------------------------------------------
MyEventHandler3::~MyEventHandler3()
{
}

//----------------------------------------------------------------
// Assignment operator
//-------------------------------------------------------------------
MyEventHandler3 &
MyEventHandler3::operator=(const MyEventHandler3 &rhs)
{
  if (this != &rhs) {
    CbcEventHandler::operator=(rhs);
  }
  return *this;
}
//-------------------------------------------------------------------
// Clone
//-------------------------------------------------------------------
CbcEventHandler *MyEventHandler3::clone() const
{
  return new MyEventHandler3(*this);
}

CbcEventHandler::CbcAction
MyEventHandler3::event(CbcEvent whichEvent)
{
  if (!statusOfCbc) {
    // override signal handler
    // register signal handler
    saveSignal = signal(SIGINT, signal_handler);
    statusOfCbc = 1;
  }
  if ((cancelAsap & 2) != 0) {
    printf("Cbc got cancel\n");
    // switch off Clp cancel
    cancelAsap &= 2;
    return stop;
  }
  // If in sub tree carry on
  if (!model_->parentModel()) {
    if (whichEvent == endSearch && statusOfCbc == 1) {
      // switch off cancel
      cancelAsap = 0;
      // restore signal handler
      signal(SIGINT, saveSignal);
      statusOfCbc = 2;
    }
    if (whichEvent == solution || whichEvent == heuristicSolution) {
#ifdef STOP_EARLY
      return stop; // say finished
#else
#ifdef WANT_SOLUTION
      // If preprocessing was done solution will be to processed model
      int numberColumns = model_->getNumCols();
      const double *bestSolution = model_->bestSolution();
      assert(bestSolution);
      printf("value of solution is %g\n", model_->getObjValue());
      for (int i = 0; i < numberColumns; i++) {
        if (fabs(bestSolution[i]) > 1.0e-8)
          printf("%d %g\n", i, bestSolution[i]);
      }
#endif
      return noAction; // carry on
#endif
    } else {
      return noAction; // carry on
    }
  } else {
    return noAction; // carry on
  }
}
/** This is so user can trap events and do useful stuff.  

    ClpSimplex model_ is available as well as anything else you care 
    to pass in
*/

class MyEventHandler4 : public ClpEventHandler {

public:
  /**@name Overrides */
  //@{
  virtual int event(Event whichEvent);
  //@}

  /**@name Constructors, destructor etc*/
  //@{
  /** Default constructor. */
  MyEventHandler4();
  /// Constructor with pointer to model (redundant as setEventHandler does)
  MyEventHandler4(ClpSimplex *model);
  /** Destructor */
  virtual ~MyEventHandler4();
  /** The copy constructor. */
  MyEventHandler4(const MyEventHandler4 &rhs);
  /// Assignment
  MyEventHandler4 &operator=(const MyEventHandler4 &rhs);
  /// Clone
  virtual ClpEventHandler *clone() const;
  //@}

protected:
  // data goes here
};
//-------------------------------------------------------------------
// Default Constructor
//-------------------------------------------------------------------
MyEventHandler4::MyEventHandler4()
  : ClpEventHandler()
{
}

//-------------------------------------------------------------------
// Copy constructor
//-------------------------------------------------------------------
MyEventHandler4::MyEventHandler4(const MyEventHandler4 &rhs)
  : ClpEventHandler(rhs)
{
}

// Constructor with pointer to model
MyEventHandler4::MyEventHandler4(ClpSimplex *model)
  : ClpEventHandler(model)
{
}

//-------------------------------------------------------------------
// Destructor
//-------------------------------------------------------------------
MyEventHandler4::~MyEventHandler4()
{
}

//----------------------------------------------------------------
// Assignment operator
//-------------------------------------------------------------------
MyEventHandler4 &
MyEventHandler4::operator=(const MyEventHandler4 &rhs)
{
  if (this != &rhs) {
    ClpEventHandler::operator=(rhs);
  }
  return *this;
}
//-------------------------------------------------------------------
// Clone
//-------------------------------------------------------------------
ClpEventHandler *MyEventHandler4::clone() const
{
  return new MyEventHandler4(*this);
}

int MyEventHandler4::event(Event whichEvent)
{
  if ((cancelAsap & 1) != 0) {
    printf("Clp got cancel\n");
    return 5;
  } else {
    return -1;
  }
}

int main(int argc, const char *argv[])
{

  OsiClpSolverInterface solver1;
  //#define USE_OSI_NAMES
#ifdef USE_OSI_NAMES
  // Say we are keeping names (a bit slower this way)
  solver1.setIntParam(OsiNameDiscipline, 1);
#endif
  // Read in model using argv[1]
  // and assert that it is a clean model
  std::string mpsFileName;
#if defined(SAMPLEDIR)
  mpsFileName = SAMPLEDIR "/p0033.mps";
#else
  if (argc < 2) {
    fprintf(stderr, "Do not know where to find sample MPS files.\n");
    exit(1);
  }
#endif
  if (argc >= 2)
    mpsFileName = argv[1];
  int numMpsReadErrors = solver1.readMps(mpsFileName.c_str(), "");
  if (numMpsReadErrors != 0) {
    printf("%d errors reading MPS file\n", numMpsReadErrors);
    return numMpsReadErrors;
  }
  // Tell solver to return fast if presolve or initial solve infeasible
  solver1.getModelPtr()->setMoreSpecialOptions(3);
  // allow Clp to handle interrupts
  MyEventHandler4 clpEventHandler;
  solver1.getModelPtr()->passInEventHandler(&clpEventHandler);

  /* Two ways of doing this depending on whether NEW_STYLE_SOLVER defined.
     So we need pointer to model.  Old way could use modelA. rather than model->
   */
  // Messy code below copied from CbcSolver.cpp
#if NEW_STYLE_SOLVER == 0
  // Pass to Cbc initialize defaults
  CbcModel modelA(solver1);
  CbcSolverUsefulData solverData;
  CbcModel *model = &modelA;
  CbcMain0(modelA,solverData);
  // Event handler
  MyEventHandler3 eventHandler;
  model->passInEventHandler(&eventHandler);
  /* Now go into code for standalone solver
     Could copy arguments and add -quit at end to be safe
     but this will do
  */
  if (argc > 2) {
    CbcMain1(argc - 1, argv + 1, modelA, callBack,solverData);
  } else {
    const char *argv2[] = { "driver4", "-solve", "-quit" };
    CbcMain1(3, argv2, modelA, callBack,solverData);
  }
#else
  CbcSolver control(solver1);
  // initialize
  control.fillValuesInSolver();
  // Event handler
  MyEventHandler3 eventHandler;
  CbcModel *model = control.model();
  model->passInEventHandler(&eventHandler);
  control.solve(argc - 1, argv + 1, 1);
#endif
  // Solver was cloned so get current copy
  OsiSolverInterface *solver = model->solver();
  // Print solution if finished (could get from model->bestSolution() as well

  if (model->bestSolution()) {

    const double *solution = solver->getColSolution();

    int iColumn;
    int numberColumns = solver->getNumCols();
    std::cout << std::setiosflags(std::ios::fixed | std::ios::showpoint) << std::setw(14);

    std::cout << "--------------------------------------" << std::endl;
#ifdef USE_OSI_NAMES

    for (iColumn = 0; iColumn < numberColumns; iColumn++) {
      double value = solution[iColumn];
      if (fabs(value) > 1.0e-7 && solver->isInteger(iColumn))
        std::cout << std::setw(6) << iColumn << " " << std::setw(8) << setiosflags(std::ios::left) << solver->getColName(iColumn)
                  << resetiosflags(std::ios::adjustfield) << std::setw(14) << " " << value << std::endl;
    }
#else
    // names may not be in current solver - use original

    for (iColumn = 0; iColumn < numberColumns; iColumn++) {
      double value = solution[iColumn];
      if (fabs(value) > 1.0e-7 && solver->isInteger(iColumn))
        std::cout << std::setw(6) << iColumn << " " << std::setw(8) << setiosflags(std::ios::left) << solver1.getModelPtr()->columnName(iColumn)
                  << resetiosflags(std::ios::adjustfield) << std::setw(14) << " " << value << std::endl;
    }
#endif
    std::cout << "--------------------------------------" << std::endl;

    std::cout << std::resetiosflags(std::ios::fixed | std::ios::showpoint | std::ios::scientific);
  } else {
    std::cout << " No solution!" << std::endl;
  }
  return 0;
}