osrm-backend/include/engine/data_watchdog.hpp
2017-08-21 13:00:12 +02:00

114 lines
3.6 KiB
C++

#ifndef OSRM_ENGINE_DATA_WATCHDOG_HPP
#define OSRM_ENGINE_DATA_WATCHDOG_HPP
#include "engine/datafacade/contiguous_internalmem_datafacade.hpp"
#include "engine/datafacade/shared_memory_allocator.hpp"
#include "engine/datafacade_factory.hpp"
#include "storage/shared_datatype.hpp"
#include "storage/shared_memory.hpp"
#include "storage/shared_monitor.hpp"
#include <boost/interprocess/sync/named_upgradable_mutex.hpp>
#include <boost/thread/lock_types.hpp>
#include <boost/thread/locks.hpp>
#include <boost/thread/shared_mutex.hpp>
#include <memory>
#include <thread>
namespace osrm
{
namespace engine
{
namespace detail
{
// We need this wrapper type since template-template specilization of FacadeT is broken on clang
// when it is combined with an templated alias (DataFacade in this case).
// See https://godbolt.org/g/ZS6Xmt for an example.
template <typename AlgorithmT, typename FacadeT> class DataWatchdogImpl;
template <typename AlgorithmT>
class DataWatchdogImpl<AlgorithmT, datafacade::ContiguousInternalMemoryDataFacade<AlgorithmT>> final
{
using mutex_type = typename storage::SharedMonitor<storage::SharedDataTimestamp>::mutex_type;
using Facade = datafacade::ContiguousInternalMemoryDataFacade<AlgorithmT>;
public:
DataWatchdogImpl() : active(true), timestamp(0)
{
// create the initial facade before launching the watchdog thread
{
boost::interprocess::scoped_lock<mutex_type> current_region_lock(barrier.get_mutex());
facade_factory =
DataFacadeFactory<datafacade::ContiguousInternalMemoryDataFacade, AlgorithmT>(
std::make_shared<datafacade::SharedMemoryAllocator>(barrier.data().region));
timestamp = barrier.data().timestamp;
}
watcher = std::thread(&DataWatchdogImpl::Run, this);
}
~DataWatchdogImpl()
{
active = false;
barrier.notify_all();
watcher.join();
}
std::shared_ptr<const Facade> Get(const api::BaseParameters &params) const
{
return facade_factory.Get(params);
}
std::shared_ptr<const Facade> Get(const api::TileParameters &params) const
{
return facade_factory.Get(params);
}
private:
void Run()
{
while (active)
{
boost::interprocess::scoped_lock<mutex_type> current_region_lock(barrier.get_mutex());
while (active && timestamp == barrier.data().timestamp)
{
barrier.wait(current_region_lock);
}
if (timestamp != barrier.data().timestamp)
{
auto region = barrier.data().region;
facade_factory =
DataFacadeFactory<datafacade::ContiguousInternalMemoryDataFacade, AlgorithmT>(
std::make_shared<datafacade::SharedMemoryAllocator>(region));
timestamp = barrier.data().timestamp;
util::Log() << "updated facade to region " << region << " with timestamp "
<< timestamp;
}
}
util::Log() << "DataWatchdog thread stopped";
}
storage::SharedMonitor<storage::SharedDataTimestamp> barrier;
std::thread watcher;
bool active;
unsigned timestamp;
DataFacadeFactory<datafacade::ContiguousInternalMemoryDataFacade, AlgorithmT> facade_factory;
};
}
// This class monitors the shared memory region that contains the pointers to
// the data and layout regions that should be used. This region is updated
// once a new dataset arrives.
template <typename AlgorithmT, template <typename A> class FacadeT>
using DataWatchdog = detail::DataWatchdogImpl<AlgorithmT, FacadeT<AlgorithmT>>;
}
}
#endif