/**********************************************************************
 *
 * GEOS - Geometry Engine Open Source
 * http://geos.osgeo.org
 *
 * Copyright (C) 2012 Sandro Santilli <strk@keybit.net>
 *
 * This is free software; you can redistribute and/or modify it under
 * the terms of the GNU Lesser General Public Licence as published
 * by the Free Software Foundation. 
 * See the COPYING file for more information.
 *
 **********************************************************************/

#include <geos/util/Interrupt.h>
#include <geos/util/GEOSException.h> // for inheritance

namespace {
  /* Could these be portably stored in thread-specific space ? */
  bool requested = false;

  geos::util::Interrupt::Callback *callback = 0;
}

namespace geos {
namespace util { // geos::util

class GEOS_DLL InterruptedException: public GEOSException {
public:
    InterruptedException() :
        GEOSException("InterruptedException", "Interrupted!") {}
};

void Interrupt::request() { requested = true; }

void Interrupt::cancel() { requested = false; }

bool Interrupt::check() { return requested; }

Interrupt::Callback* Interrupt::registerCallback(Interrupt::Callback *cb) {
    Callback* prev = callback;
    callback = cb;
    return prev;
  }

void Interrupt::process() {
    if ( callback ) (*callback)();
    if ( requested ) {
        requested = false;
        interrupt();
    }
}


void
Interrupt::interrupt() {
  requested = false;
  throw InterruptedException();
}


} // namespace geos::util
} // namespace geos