TBB has a global task scheduler (that's one of the reason TBB is not linked statically but dyanmically instead). This allows control over all running threads, enabling us to use nested parallelism and the scheduler doing all the task allocation itself. That is, nested parallel execution such as in parallel_for(seq, [](const auto& rng){ parallel_sort(rng); }); is no problem at all, as the scheduler still claims control over the global environment. Therefore, use `parallel_sort` Range overload where possible. References: - https://www.threadingbuildingblocks.org/docs/help/hh_goto.htm#reference/algorithms.htm - https://www.threadingbuildingblocks.org/docs/help/hh_goto.htm#reference/algorithms/parallel_sort_func.htm - https://www.threadingbuildingblocks.org/docs/help/hh_goto.htm#reference/task_scheduler.htm - https://www.threadingbuildingblocks.org/docs/help/hh_goto.htm#reference/task_scheduler/task_scheduler_init_cls.htm - https://www.threadingbuildingblocks.org/docs/help/hh_goto.htm#tbb_userguide/Initializing_and_Terminating_the_Library.htm
255 lines
11 KiB
C++
255 lines
11 KiB
C++
/*
|
|
|
|
Copyright (c) 2015, Project OSRM contributors
|
|
All rights reserved.
|
|
|
|
Redistribution and use in source and binary forms, with or without modification,
|
|
are permitted provided that the following conditions are met:
|
|
|
|
Redistributions of source code must retain the above copyright notice, this list
|
|
of conditions and the following disclaimer.
|
|
Redistributions in binary form must reproduce the above copyright notice, this
|
|
list of conditions and the following disclaimer in the documentation and/or
|
|
other materials provided with the distribution.
|
|
|
|
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
|
|
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
|
|
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
|
|
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
|
|
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
|
|
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
|
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
|
|
ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
|
|
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
|
|
*/
|
|
|
|
#ifndef DIRECT_SHORTEST_PATH_HPP
|
|
#define DIRECT_SHORTEST_PATH_HPP
|
|
|
|
#include <boost/assert.hpp>
|
|
|
|
#include <tbb/parallel_sort.h>
|
|
|
|
#include "routing_base.hpp"
|
|
#include "../data_structures/search_engine_data.hpp"
|
|
#include "../util/integer_range.hpp"
|
|
#include "../util/timing_util.hpp"
|
|
#include "../typedefs.h"
|
|
|
|
#include <vector>
|
|
#include <algorithm>
|
|
#include <utility>
|
|
|
|
/// This is a striped down version of the general shortest path algorithm.
|
|
/// The general algorithm always computes two queries for each leg. This is only
|
|
/// necessary in case of vias, where the directions of the start node is constrainted
|
|
/// by the previous route.
|
|
/// This variation is only an optimazation for graphs with slow queries, for example
|
|
/// not fully contracted graphs.
|
|
template <class DataFacadeT>
|
|
class DirectShortestPathRouting final
|
|
: public BasicRoutingInterface<DataFacadeT, DirectShortestPathRouting<DataFacadeT>>
|
|
{
|
|
using super = BasicRoutingInterface<DataFacadeT, DirectShortestPathRouting<DataFacadeT>>;
|
|
using QueryHeap = SearchEngineData::QueryHeap;
|
|
SearchEngineData &engine_working_data;
|
|
|
|
public:
|
|
DirectShortestPathRouting(DataFacadeT *facade, SearchEngineData &engine_working_data)
|
|
: super(facade), engine_working_data(engine_working_data)
|
|
{
|
|
}
|
|
|
|
~DirectShortestPathRouting() {}
|
|
|
|
void operator()(const std::vector<PhantomNodes> &phantom_nodes_vector,
|
|
const std::vector<bool> &uturn_indicators,
|
|
InternalRouteResult &raw_route_data) const
|
|
{
|
|
engine_working_data.InitializeOrClearFirstThreadLocalStorage(
|
|
super::facade->GetNumberOfNodes());
|
|
engine_working_data.InitializeOrClearSecondThreadLocalStorage(
|
|
super::facade->GetNumberOfNodes());
|
|
|
|
QueryHeap &forward_heap = *(engine_working_data.forward_heap_1);
|
|
QueryHeap &reverse_heap = *(engine_working_data.reverse_heap_1);
|
|
|
|
QueryHeap &forward_core_heap = *(engine_working_data.forward_heap_2);
|
|
QueryHeap &reverse_core_heap = *(engine_working_data.reverse_heap_2);
|
|
|
|
// Get distance to next pair of target nodes.
|
|
BOOST_ASSERT_MSG(1 == phantom_nodes_vector.size(),
|
|
"Direct Shortest Path Query only accepts a single source and target pair. Multiple ones have been specified.");
|
|
|
|
const auto& phantom_node_pair = phantom_nodes_vector.front();
|
|
|
|
forward_heap.Clear();
|
|
reverse_heap.Clear();
|
|
int distance = INVALID_EDGE_WEIGHT;
|
|
NodeID middle = SPECIAL_NODEID;
|
|
|
|
const EdgeWeight min_edge_offset =
|
|
std::min(-phantom_node_pair.source_phantom.GetForwardWeightPlusOffset(),
|
|
-phantom_node_pair.source_phantom.GetReverseWeightPlusOffset());
|
|
|
|
// insert new starting nodes into forward heap, adjusted by previous distances.
|
|
if (phantom_node_pair.source_phantom.forward_node_id != SPECIAL_NODEID)
|
|
{
|
|
forward_heap.Insert(
|
|
phantom_node_pair.source_phantom.forward_node_id,
|
|
-phantom_node_pair.source_phantom.GetForwardWeightPlusOffset(),
|
|
phantom_node_pair.source_phantom.forward_node_id);
|
|
}
|
|
if ( phantom_node_pair.source_phantom.reverse_node_id != SPECIAL_NODEID)
|
|
{
|
|
forward_heap.Insert(
|
|
phantom_node_pair.source_phantom.reverse_node_id,
|
|
-phantom_node_pair.source_phantom.GetReverseWeightPlusOffset(),
|
|
phantom_node_pair.source_phantom.reverse_node_id);
|
|
}
|
|
|
|
// insert new backward nodes into backward heap, unadjusted.
|
|
if (phantom_node_pair.target_phantom.forward_node_id != SPECIAL_NODEID)
|
|
{
|
|
reverse_heap.Insert(phantom_node_pair.target_phantom.forward_node_id,
|
|
phantom_node_pair.target_phantom.GetForwardWeightPlusOffset(),
|
|
phantom_node_pair.target_phantom.forward_node_id);
|
|
}
|
|
|
|
if (phantom_node_pair.target_phantom.reverse_node_id != SPECIAL_NODEID)
|
|
{
|
|
reverse_heap.Insert(phantom_node_pair.target_phantom.reverse_node_id,
|
|
phantom_node_pair.target_phantom.GetReverseWeightPlusOffset(),
|
|
phantom_node_pair.target_phantom.reverse_node_id);
|
|
}
|
|
|
|
std::vector<std::pair<NodeID, EdgeWeight>> forward_entry_points;
|
|
std::vector<std::pair<NodeID, EdgeWeight>> reverse_entry_points;
|
|
|
|
// run two-Target Dijkstra routing step.
|
|
while (0 < (forward_heap.Size() + reverse_heap.Size()) )
|
|
{
|
|
if (!forward_heap.Empty())
|
|
{
|
|
if (super::facade->IsCoreNode(forward_heap.Min()))
|
|
{
|
|
const NodeID node = forward_heap.DeleteMin();
|
|
const int key = forward_heap.GetKey(node);
|
|
forward_entry_points.emplace_back(node, key);
|
|
}
|
|
else
|
|
{
|
|
super::RoutingStep(forward_heap, reverse_heap, &middle, &distance,
|
|
min_edge_offset, true);
|
|
}
|
|
}
|
|
if (!reverse_heap.Empty())
|
|
{
|
|
if (super::facade->IsCoreNode(reverse_heap.Min()))
|
|
{
|
|
const NodeID node = reverse_heap.DeleteMin();
|
|
const int key = reverse_heap.GetKey(node);
|
|
reverse_entry_points.emplace_back(node, key);
|
|
}
|
|
else
|
|
{
|
|
super::RoutingStep(reverse_heap, forward_heap, &middle, &distance,
|
|
min_edge_offset, false);
|
|
}
|
|
}
|
|
}
|
|
|
|
// TODO check if unordered_set might be faster
|
|
// sort by id and increasing by distance
|
|
auto entry_point_comparator = [](const std::pair<NodeID, EdgeWeight>& lhs, const std::pair<NodeID, EdgeWeight>& rhs)
|
|
{
|
|
return lhs.first < rhs.first || (lhs.first == rhs.first && lhs.second < rhs.second);
|
|
};
|
|
tbb::parallel_sort(forward_entry_points, entry_point_comparator);
|
|
tbb::parallel_sort(reverse_entry_points, entry_point_comparator);
|
|
|
|
NodeID last_id = SPECIAL_NODEID;
|
|
for (const auto p : forward_entry_points)
|
|
{
|
|
if (p.first == last_id)
|
|
{
|
|
continue;
|
|
}
|
|
forward_core_heap.Insert(p.first, p.second, p.first);
|
|
last_id = p.first;
|
|
}
|
|
last_id = SPECIAL_NODEID;
|
|
for (const auto p : reverse_entry_points)
|
|
{
|
|
if (p.first == last_id)
|
|
{
|
|
continue;
|
|
}
|
|
reverse_core_heap.Insert(p.first, p.second, p.first);
|
|
last_id = p.first;
|
|
}
|
|
|
|
// run two-target Dijkstra routing step on core with termination criterion
|
|
while (0 < (forward_core_heap.Size() + reverse_core_heap.Size()) &&
|
|
distance > (forward_core_heap.MinKey() + reverse_core_heap.MinKey()))
|
|
{
|
|
if (!forward_core_heap.Empty())
|
|
{
|
|
super::RoutingStep(forward_core_heap, reverse_core_heap, &middle, &distance,
|
|
min_edge_offset, true);
|
|
}
|
|
if (!reverse_core_heap.Empty())
|
|
{
|
|
super::RoutingStep(reverse_core_heap, forward_core_heap, &middle, &distance,
|
|
min_edge_offset, false);
|
|
}
|
|
}
|
|
|
|
// No path found for both target nodes?
|
|
if (INVALID_EDGE_WEIGHT == distance)
|
|
{
|
|
raw_route_data.shortest_path_length = INVALID_EDGE_WEIGHT;
|
|
raw_route_data.alternative_path_length = INVALID_EDGE_WEIGHT;
|
|
return;
|
|
}
|
|
|
|
// Was a paths over one of the forward/reverse nodes not found?
|
|
BOOST_ASSERT_MSG((SPECIAL_NODEID == middle || INVALID_EDGE_WEIGHT != distance),
|
|
"no path found");
|
|
|
|
std::vector<NodeID> packed_leg;
|
|
// we need to unpack sub path from core heaps
|
|
if(super::facade->IsCoreNode(middle))
|
|
{
|
|
std::vector<NodeID> packed_core_leg;
|
|
super::RetrievePackedPathFromHeap(forward_core_heap, reverse_core_heap, middle, packed_core_leg);
|
|
BOOST_ASSERT(packed_core_leg.size() > 0);
|
|
super::RetrievePackedPathFromSingleHeap(forward_heap, packed_core_leg.front(), packed_leg);
|
|
std::reverse(packed_leg.begin(), packed_leg.end());
|
|
packed_leg.insert(packed_leg.end(), packed_core_leg.begin(), packed_core_leg.end());
|
|
super::RetrievePackedPathFromSingleHeap(reverse_heap, packed_core_leg.back(), packed_leg);
|
|
}
|
|
else
|
|
{
|
|
super::RetrievePackedPathFromHeap(forward_heap, reverse_heap, middle, packed_leg);
|
|
}
|
|
|
|
|
|
BOOST_ASSERT_MSG(!packed_leg.empty(), "packed path empty");
|
|
|
|
raw_route_data.unpacked_path_segments.resize(1);
|
|
raw_route_data.source_traversed_in_reverse.push_back(
|
|
(packed_leg.front() != phantom_node_pair.source_phantom.forward_node_id));
|
|
raw_route_data.target_traversed_in_reverse.push_back(
|
|
(packed_leg.back() != phantom_node_pair.target_phantom.forward_node_id));
|
|
|
|
super::UnpackPath(packed_leg, phantom_node_pair, raw_route_data.unpacked_path_segments.front());
|
|
|
|
raw_route_data.shortest_path_length = distance;
|
|
}
|
|
};
|
|
|
|
#endif /* DIRECT_SHORTEST_PATH_HPP */
|