81 lines
2.6 KiB
C++
81 lines
2.6 KiB
C++
/*****************************************************************************
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*
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* This file is part of Mapnik (c++ mapping toolkit)
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*
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* Copyright (C) 2012 Artem Pavlenko, Jean-Francois Doyon
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*
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*****************************************************************************/
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#ifndef MAPNIK_THREADS_HPP
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#define MAPNIK_THREADS_HPP
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#include <boost/thread.hpp>
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#include <boost/python.hpp>
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namespace mapnik {
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class python_thread
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{
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/* Docs:
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http://docs.python.org/c-api/init.html#thread-state-and-the-global-interpreter-lock
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*/
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public:
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static void unblock()
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{
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#ifdef MAPNIK_DEBUG
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if (state.get())
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{
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std::cerr << "ERROR: Python threads are already unblocked. "
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"Unblocking again will loose the current state and "
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"might crash later. Aborting!\n";
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abort(); //This is a serious error and can't be handled in any other sane way
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}
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#endif
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PyThreadState *_save = 0; //Name defined by python
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Py_UNBLOCK_THREADS;
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state.reset(_save);
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#ifdef MAPNIK_DEBUG
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if (!_save) {
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thread_support = false;
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}
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#endif
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}
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static void block()
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{
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#ifdef MAPNIK_DEBUG
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if (thread_support && !state.get())
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{
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std::cerr << "ERROR: Trying to restore python thread state, "
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"but no state is saved. Can't continue and also "
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"can't raise an exception because the python "
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"interpreter might be non-function. Aborting!\n";
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abort();
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}
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#endif
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PyThreadState *_save = state.release(); //Name defined by python
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Py_BLOCK_THREADS;
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}
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private:
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static boost::thread_specific_ptr<PyThreadState> state;
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#ifdef MAPNIK_DEBUG
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static bool thread_support;
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#endif
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};
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} //namespace
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#endif // MAPNIK_THREADS_HPP
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