Make SharedDataFacade immutable

This commit is contained in:
Patrick Niklaus 2016-10-07 01:51:34 +02:00 committed by Patrick Niklaus
parent 9af00b1925
commit ceaf362326
4 changed files with 183 additions and 109 deletions

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@ -0,0 +1,84 @@
#include "engine/datafacade/shared_datafacade.hpp"
#include "storage/shared_datatype.hpp"
#include "storage/shared_memory.hpp"
#include <boost/thread/shared_mutex.hpp>
#include <boost/thread/lock_types.hpp>
#include <memory>
namespace osrm
{
namespace engine
{
// 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.
//
// TODO: This also needs a shared memory reader lock with other clients and
// possibly osrm-datastore since updating the CURRENT_REGIONS data is not atomic.
// Currently we enfore this by waiting that all queries have finished before
// osrm-datastore writes to this section.
class DataWatchdog
{
public:
DataWatchdog()
: shared_regions(storage::makeSharedMemory(
storage::CURRENT_REGIONS, sizeof(storage::SharedDataTimestamp), false, false)),
current_timestamp {storage::LAYOUT_NONE, storage::DATA_NONE, 0}
{
}
// Tries to connect to the shared memory containing the regions table
static bool TryConnect()
{
return storage::SharedMemory::RegionExists(storage::CURRENT_REGIONS);
}
// Check if it might be worth to try to aquire a exclusive lock
bool HasNewRegion() const
{
const boost::shared_lock<boost::shared_mutex> lock(current_timestamp_mutex);
const auto shared_timestamp =
static_cast<const storage::SharedDataTimestamp *>(shared_regions->Ptr());
return shared_timestamp->layout != current_timestamp.layout ||
shared_timestamp->data != current_timestamp.data ||
shared_timestamp->timestamp != current_timestamp.timestamp;
}
// Note this can still return an emptry pointer if this function got overtaken by another thread
std::shared_ptr<datafacade::SharedDataFacade> MaybeLoadNewRegion()
{
const boost::lock_guard<boost::shared_mutex> lock(current_timestamp_mutex);
const auto shared_timestamp =
static_cast<const storage::SharedDataTimestamp *>(shared_regions->Ptr());
if (shared_timestamp->timestamp == current_timestamp.timestamp)
{
BOOST_ASSERT(shared_timestamp->layout == current_timestamp.layout);
BOOST_ASSERT(shared_timestamp->data == current_timestamp.data);
return std::shared_ptr<datafacade::SharedDataFacade>();
}
current_timestamp = *shared_timestamp;
return std::make_shared<datafacade::SharedDataFacade>(
current_timestamp.layout, current_timestamp.data, current_timestamp.timestamp);
}
private:
// shared memory table containing pointers to all shared regions
std::unique_ptr<storage::SharedMemory> shared_regions;
// mutexes should be mutable even on const objects: This enables
// marking functions as logical const and thread-safe.
mutable boost::shared_mutex current_timestamp_mutex;
storage::SharedDataTimestamp current_timestamp;
};
}
}

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@ -16,6 +16,7 @@
#include "util/guidance/turn_lanes.hpp"
#include "engine/geospatial_query.hpp"
#include "util/packed_vector.hpp"
#include "util/range_table.hpp"
#include "util/rectangle.hpp"
#include "util/simple_logger.hpp"
@ -63,11 +64,10 @@ class SharedDataFacade final : public BaseDataFacade
storage::SharedDataLayout *data_layout;
char *shared_memory;
storage::SharedDataTimestamp *data_timestamp_ptr;
storage::SharedDataType CURRENT_LAYOUT;
storage::SharedDataType CURRENT_DATA;
unsigned CURRENT_TIMESTAMP;
storage::SharedDataType layout_region;
storage::SharedDataType data_region;
unsigned shared_timestamp;
unsigned m_check_sum;
std::unique_ptr<QueryGraph> m_query_graph;
@ -142,6 +142,17 @@ class SharedDataFacade final : public BaseDataFacade
{
BOOST_ASSERT_MSG(!m_coordinate_list.empty(), "coordinates must be loaded before r-tree");
const auto file_index_ptr = data_layout->GetBlockPtr<char>(
shared_memory, storage::SharedDataLayout::FILE_INDEX_PATH);
file_index_path = boost::filesystem::path(file_index_ptr);
if (!boost::filesystem::exists(file_index_path))
{
util::SimpleLogger().Write(logDEBUG) << "Leaf file name "
<< file_index_path.string();
throw util::exception("Could not load leaf index file. "
"Is any data loaded into shared memory?");
}
auto tree_ptr = data_layout->GetBlockPtr<RTreeNode>(
shared_memory, storage::SharedDataLayout::R_SEARCH_TREE);
m_static_rtree.reset(
@ -176,6 +187,11 @@ class SharedDataFacade final : public BaseDataFacade
coordinate_list_ptr,
data_layout->num_entries[storage::SharedDataLayout::COORDINATE_LIST]);
for (unsigned i = 0; i < m_coordinate_list.size(); ++i)
{
BOOST_ASSERT(GetCoordinateOfNode(i).IsValid());
}
auto osmnodeid_list_ptr = data_layout->GetBlockPtr<std::uint64_t>(
shared_memory, storage::SharedDataLayout::OSM_NODE_ID_LIST);
m_osmnodeid_list.reset(
@ -366,102 +382,32 @@ class SharedDataFacade final : public BaseDataFacade
public:
virtual ~SharedDataFacade() {}
boost::shared_mutex data_mutex;
SharedDataFacade()
SharedDataFacade(storage::SharedDataType layout_region_, storage::SharedDataType data_region_, unsigned shared_timestamp_)
: layout_region(layout_region_), data_region(data_region_), shared_timestamp(shared_timestamp_)
{
if (!storage::SharedMemory::RegionExists(storage::CURRENT_REGIONS))
{
throw util::exception(
"No shared memory blocks found, have you forgotten to run osrm-datastore?");
}
data_timestamp_ptr = static_cast<storage::SharedDataTimestamp *>(
storage::makeSharedMemory(
storage::CURRENT_REGIONS, sizeof(storage::SharedDataTimestamp), false, false)
->Ptr());
CURRENT_LAYOUT = storage::LAYOUT_NONE;
CURRENT_DATA = storage::DATA_NONE;
CURRENT_TIMESTAMP = 0;
util::SimpleLogger().Write(logDEBUG) << "Loading new data with shared timestamp " << shared_timestamp;
// load data
CheckAndReloadFacade();
}
BOOST_ASSERT(storage::SharedMemory::RegionExists(layout_region));
m_layout_memory.reset(storage::makeSharedMemory(layout_region));
void CheckAndReloadFacade()
{
if (CURRENT_LAYOUT != data_timestamp_ptr->layout ||
CURRENT_DATA != data_timestamp_ptr->data ||
CURRENT_TIMESTAMP != data_timestamp_ptr->timestamp)
{
// Get exclusive lock
util::SimpleLogger().Write(logDEBUG) << "Updates available, getting exclusive lock";
const boost::lock_guard<boost::shared_mutex> lock(data_mutex);
data_layout = static_cast<storage::SharedDataLayout *>(m_layout_memory->Ptr());
if (CURRENT_LAYOUT != data_timestamp_ptr->layout ||
CURRENT_DATA != data_timestamp_ptr->data)
{
// release the previous shared memory segments
storage::SharedMemory::Remove(CURRENT_LAYOUT);
storage::SharedMemory::Remove(CURRENT_DATA);
BOOST_ASSERT(storage::SharedMemory::RegionExists(data_region));
m_large_memory.reset(storage::makeSharedMemory(data_region));
shared_memory = (char *)(m_large_memory->Ptr());
CURRENT_LAYOUT = data_timestamp_ptr->layout;
CURRENT_DATA = data_timestamp_ptr->data;
CURRENT_TIMESTAMP = 0; // Force trigger a reload
util::SimpleLogger().Write(logDEBUG)
<< "Current layout was different to new layout, swapping";
}
else
{
util::SimpleLogger().Write(logDEBUG)
<< "Current layout was same to new layout, not swapping";
}
if (CURRENT_TIMESTAMP != data_timestamp_ptr->timestamp)
{
CURRENT_TIMESTAMP = data_timestamp_ptr->timestamp;
util::SimpleLogger().Write(logDEBUG) << "Performing data reload";
m_layout_memory.reset(storage::makeSharedMemory(CURRENT_LAYOUT));
data_layout = static_cast<storage::SharedDataLayout *>(m_layout_memory->Ptr());
m_large_memory.reset(storage::makeSharedMemory(CURRENT_DATA));
shared_memory = (char *)(m_large_memory->Ptr());
const auto file_index_ptr = data_layout->GetBlockPtr<char>(
shared_memory, storage::SharedDataLayout::FILE_INDEX_PATH);
file_index_path = boost::filesystem::path(file_index_ptr);
if (!boost::filesystem::exists(file_index_path))
{
util::SimpleLogger().Write(logDEBUG) << "Leaf file name "
<< file_index_path.string();
throw util::exception("Could not load leaf index file. "
"Is any data loaded into shared memory?");
}
LoadGraph();
LoadChecksum();
LoadNodeAndEdgeInformation();
LoadGeometries();
LoadTimestamp();
LoadViaNodeList();
LoadNames();
LoadTurnLaneDescriptions();
LoadCoreInformation();
LoadProfileProperties();
LoadRTree();
LoadIntersectionClasses();
util::SimpleLogger().Write() << "number of geometries: "
<< m_coordinate_list.size();
for (unsigned i = 0; i < m_coordinate_list.size(); ++i)
{
BOOST_ASSERT(GetCoordinateOfNode(i).IsValid());
}
}
util::SimpleLogger().Write(logDEBUG) << "Releasing exclusive lock";
}
LoadGraph();
LoadChecksum();
LoadNodeAndEdgeInformation();
LoadGeometries();
LoadTimestamp();
LoadViaNodeList();
LoadNames();
LoadTurnLaneDescriptions();
LoadCoreInformation();
LoadProfileProperties();
LoadRTree();
LoadIntersectionClasses();
}
// search graph access

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@ -5,6 +5,7 @@
#include "util/json_container.hpp"
#include <memory>
#include <mutex>
#include <string>
#include <unordered_map>
@ -53,6 +54,8 @@ namespace datafacade
class BaseDataFacade;
}
class DataWatchdog;
class Engine final
{
public:
@ -73,6 +76,7 @@ class Engine final
private:
std::unique_ptr<storage::SharedBarriers> lock;
std::unique_ptr<DataWatchdog> watchdog;
std::unique_ptr<plugins::ViaRoutePlugin> route_plugin;
std::unique_ptr<plugins::TablePlugin> table_plugin;
@ -81,7 +85,10 @@ class Engine final
std::unique_ptr<plugins::MatchPlugin> match_plugin;
std::unique_ptr<plugins::TilePlugin> tile_plugin;
std::shared_ptr<datafacade::BaseDataFacade> query_data_facade;
// reading and setting this is protected by lock
mutable std::shared_ptr<datafacade::BaseDataFacade> query_data_facade;
// ensures that when we set facade we can do it without race conditions
mutable std::unique_ptr<std::mutex> facade_update_mutex;
};
}
}

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@ -2,6 +2,7 @@
#include "engine/api/route_parameters.hpp"
#include "engine/engine_config.hpp"
#include "engine/status.hpp"
#include "engine/data_watchdog.hpp"
#include "engine/plugins/match.hpp"
#include "engine/plugins/nearest.hpp"
@ -36,7 +37,9 @@ namespace
template <typename ParameterT, typename PluginT, typename ResultT>
osrm::engine::Status
RunQuery(const std::unique_ptr<osrm::storage::SharedBarriers> &lock,
const std::shared_ptr<osrm::engine::datafacade::BaseDataFacade> &facade,
std::mutex &facade_update_mutex,
osrm::engine::DataWatchdog& watchdog,
std::shared_ptr<osrm::engine::datafacade::BaseDataFacade> &facade,
const ParameterT &parameters,
PluginT &plugin,
ResultT &result)
@ -53,11 +56,32 @@ RunQuery(const std::unique_ptr<osrm::storage::SharedBarriers> &lock,
boost::interprocess::sharable_lock<boost::interprocess::named_sharable_mutex> query_lock(
lock->query_mutex);
auto &shared_facade = static_cast<osrm::engine::datafacade::SharedDataFacade &>(*facade);
shared_facade.CheckAndReloadFacade();
// Get a shared data lock so that other threads won't update
// things while the query is running
boost::shared_lock<boost::shared_mutex> data_lock{shared_facade.data_mutex};
{
// this lock ensures that we are never overtaken while creating a new
// facade and setting it.
// This is important since we need to ensure there is always exactly
// one facade per shared memory region.
// TODO: Remove this once the SharedDataFacade doesn't own the shared memory
// segment anymore.
std::lock_guard<std::mutex> update_lock(facade_update_mutex);
if (watchdog.HasNewRegion())
{
auto new_facade = watchdog.MaybeLoadNewRegion();
// for now the external locking will ensure that loading the new region
// will ways work. In the future we might allow being overtaken
// by other threads and they will also try to update.
if (new_facade)
{
// TODO remove once we allow for more then one SharedMemoryFacade at the same time
// at this point no other query is allowed to reference this facade!
// the old facade will die exactly here
BOOST_ASSERT(facade.use_count() == 1);
facade = std::move(new_facade);
}
}
}
osrm::engine::Status status = plugin.HandleRequest(facade, parameters, result);
@ -77,7 +101,20 @@ Engine::Engine(const EngineConfig &config)
{
if (config.use_shared_memory)
{
query_data_facade = std::make_shared<datafacade::SharedDataFacade>();
if (!DataWatchdog::TryConnect())
{
throw util::exception(
"No shared memory blocks found, have you forgotten to run osrm-datastore?");
}
facade_update_mutex = std::make_unique<std::mutex>();
watchdog = std::make_unique<DataWatchdog>();
// this will always either return a value or throw an exception
// in the initial run
query_data_facade = watchdog->MaybeLoadNewRegion();
BOOST_ASSERT(query_data_facade);
BOOST_ASSERT(watchdog);
BOOST_ASSERT(lock);
}
else
{
@ -106,32 +143,32 @@ Engine &Engine::operator=(Engine &&) noexcept = default;
Status Engine::Route(const api::RouteParameters &params, util::json::Object &result) const
{
return RunQuery(lock, query_data_facade, params, *route_plugin, result);
return RunQuery(lock, *facade_update_mutex, *watchdog, query_data_facade, params, *route_plugin, result);
}
Status Engine::Table(const api::TableParameters &params, util::json::Object &result) const
{
return RunQuery(lock, query_data_facade, params, *table_plugin, result);
return RunQuery(lock, *facade_update_mutex, *watchdog, query_data_facade, params, *table_plugin, result);
}
Status Engine::Nearest(const api::NearestParameters &params, util::json::Object &result) const
{
return RunQuery(lock, query_data_facade, params, *nearest_plugin, result);
return RunQuery(lock, *facade_update_mutex, *watchdog, query_data_facade, params, *nearest_plugin, result);
}
Status Engine::Trip(const api::TripParameters &params, util::json::Object &result) const
{
return RunQuery(lock, query_data_facade, params, *trip_plugin, result);
return RunQuery(lock, *facade_update_mutex, *watchdog, query_data_facade, params, *trip_plugin, result);
}
Status Engine::Match(const api::MatchParameters &params, util::json::Object &result) const
{
return RunQuery(lock, query_data_facade, params, *match_plugin, result);
return RunQuery(lock, *facade_update_mutex, *watchdog, query_data_facade, params, *match_plugin, result);
}
Status Engine::Tile(const api::TileParameters &params, std::string &result) const
{
return RunQuery(lock, query_data_facade, params, *tile_plugin, result);
return RunQuery(lock, *facade_update_mutex, *watchdog, query_data_facade, params, *tile_plugin, result);
}
} // engine ns