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Adds a shared/exclusive lock around queries and CheckAndReloadFacade.

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Without this, it's possible for CheckAndReloadFacade to start working
while a query is still in progress, leading to undefined behaviour.
This commit is contained in:
Daniel Patterson 2016-01-15 00:57:36 -08:00 committed by Patrick Niklaus
parent 25c8711aad
commit 23b2154d98
2 changed files with 71 additions and 42 deletions
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11
library/osrm_impl.cpp
View File

@ -109,7 +109,16 @@ int OSRM::OSRM_impl::RunQuery(const RouteParameters &route_parameters, osrm::jso
}
increase_concurrent_query_count();
auto return_code = plugin_iterator->second->HandleRequest(route_parameters, json_result);
BasePlugin::Status return_code;
if (barrier) {
// 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{
(static_cast<SharedDataFacade<QueryEdge::EdgeData> *>(query_data_facade))->data_mutex};
return_code = plugin_iterator->second->HandleRequest(route_parameters, json_result);
} else {
return_code = plugin_iterator->second->HandleRequest(route_parameters, json_result);
}
decrease_concurrent_query_count();
return static_cast<int>(return_code);
}

26
server/data_structures/shared_datafacade.hpp
View File

@ -239,6 +239,8 @@ template <class EdgeDataT> class SharedDataFacade final : public BaseDataFacade<
public:
virtual ~SharedDataFacade() {}
boost::shared_mutex data_mutex;
SharedDataFacade()
{
if (!SharedMemory::RegionExists(CURRENT_REGIONS))
@ -258,6 +260,14 @@ template <class EdgeDataT> class SharedDataFacade final : public BaseDataFacade<
void CheckAndReloadFacade()
{
if (CURRENT_LAYOUT != data_timestamp_ptr->layout ||
CURRENT_DATA != data_timestamp_ptr->data ||
CURRENT_TIMESTAMP != data_timestamp_ptr->timestamp)
{
// Get exclusive lock
SimpleLogger().Write(logDEBUG) << "Updates available, getting exclusive lock";
boost::unique_lock<boost::shared_mutex> lock(data_mutex);
if (CURRENT_LAYOUT != data_timestamp_ptr->layout ||
CURRENT_DATA != data_timestamp_ptr->data)
{
@ -268,11 +278,19 @@ template <class EdgeDataT> class SharedDataFacade final : public BaseDataFacade<
CURRENT_LAYOUT = data_timestamp_ptr->layout;
CURRENT_DATA = data_timestamp_ptr->data;
CURRENT_TIMESTAMP = 0; // Force trigger a reload
SimpleLogger().Write(logDEBUG) << "Current layout was different to new layout, swapping";
}
else
{
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;
SimpleLogger().Write(logDEBUG) << "Performing data reload";
m_layout_memory.reset(SharedMemoryFactory::Get(CURRENT_LAYOUT));
data_layout = (SharedDataLayout *) (m_layout_memory->Ptr());
@ -283,9 +301,9 @@ template <class EdgeDataT> class SharedDataFacade final : public BaseDataFacade<
const char *file_index_ptr =
data_layout->GetBlockPtr<char>(shared_memory, SharedDataLayout::FILE_INDEX_PATH);
file_index_path = boost::filesystem::path(file_index_ptr);
if (!boost::filesystem::exists(file_index_path))
{
SimpleLogger().Write(logDEBUG) << "Leaf file name " << file_index_path.string();
if (!boost::filesystem::exists(file_index_path)) {
SimpleLogger().Write(logDEBUG) << "Leaf file name "
<< file_index_path.string();
throw osrm::exception("Could not load leaf index file. "
"Is any data loaded into shared memory?");
}
@ -310,6 +328,8 @@ template <class EdgeDataT> class SharedDataFacade final : public BaseDataFacade<
}
}
}
SimpleLogger().Write(logDEBUG) << "Releasing exclusive lock";
}
}
// search graph access