Fix crash when switching radar sites while loading data from the old site

- Use thread pools owned by radar product manager, unless called statically (#51)

scwx-qt/source/scwx/qt/manager/radar_product_manager.cpp

@@ -19,7 +19,9 @@
 #   pragma warning(push, 0)
 #endif
 
+#include <boost/asio/post.hpp>
 #include <boost/asio/steady_timer.hpp>
+#include <boost/asio/thread_pool.hpp>
 #include <boost/container_hash/hash.hpp>
 #include <boost/range/irange.hpp>
 #include <boost/timer/timer.hpp>
@@ -91,7 +93,7 @@ public:
        group_ {group},
        product_ {product},
        refreshEnabled_ {false},
-       refreshTimer_ {scwx::util::io_context()},
+       refreshTimer_ {threadPool_},
        refreshTimerMutex_ {},
        provider_ {nullptr}
    {
@@ -106,6 +108,8 @@ public:
 
    void Disable();
 
+   boost::asio::thread_pool threadPool_ {1u};
+
    const std::string                             radarId_;
    const common::RadarProductGroup               group_;
    const std::string                             product_;
@@ -179,6 +183,8 @@ public:
 
    RadarProductManager* self_;
 
+   boost::asio::thread_pool threadPool_ {4u};
+
    std::shared_ptr<ProviderManager>
    GetLevel3ProviderManager(const std::string& product);
 
@@ -199,6 +205,10 @@ public:
    void UpdateRecentRecords(RadarProductRecordList& recentList,
                             std::shared_ptr<types::RadarProductRecord> record);
 
+   void LoadNexradFileAsync(CreateNexradFileFunction                    load,
+                            std::shared_ptr<request::NexradFileRequest> request,
+                            std::mutex&                                 mutex,
+                            std::chrono::system_clock::time_point       time);
    void LoadProviderData(std::chrono::system_clock::time_point time,
                          std::shared_ptr<ProviderManager>      providerManager,
                          RadarProductRecordMap&                recordMap,
@@ -523,7 +533,8 @@ void RadarProductManager::EnableRefresh(common::RadarProductGroup group,
          p->GetLevel3ProviderManager(product);
 
       // Only enable refresh on available products
-      scwx::util::async(
+      boost::asio::post(
+         p->threadPool_,
          [=, this]()
          {
             providerManager->provider_->RequestAvailableProducts();
@@ -614,7 +625,8 @@ void RadarProductManagerImpl::RefreshData(
       providerManager->refreshTimer_.cancel();
    }
 
-   scwx::util::async(
+   boost::asio::post(
+      threadPool_,
       [=, this]()
       {
          auto [newObjects, totalObjects] =
@@ -774,9 +786,8 @@ void RadarProductManagerImpl::LoadProviderData(
                   providerManager->name(),
                   scwx::util::TimeString(time));
 
-   RadarProductManagerImpl::LoadNexradFile(
+   LoadNexradFileAsync(
-      [=, &recordMap, &recordMutex, &loadDataMutex]()
+      [=, &recordMap, &recordMutex]() -> std::shared_ptr<wsr88d::NexradFile>
-         -> std::shared_ptr<wsr88d::NexradFile>
       {
          std::shared_ptr<types::RadarProductRecord> existingRecord = nullptr;
          std::shared_ptr<wsr88d::NexradFile>        nexradFile     = nullptr;
@@ -874,11 +885,15 @@ void RadarProductManager::LoadData(
 {
    logger_->debug("LoadData()");
 
+   scwx::util::async(
+      [=, &is]()
+      {
          RadarProductManagerImpl::LoadNexradFile(
             [=, &is]() -> std::shared_ptr<wsr88d::NexradFile>
             { return wsr88d::NexradFileFactory::Create(is); },
             request,
             fileLoadMutex_);
+      });
 }
 
 void RadarProductManager::LoadFile(
@@ -915,11 +930,15 @@ void RadarProductManager::LoadFile(
                           }
                        });
 
+      scwx::util::async(
+         [=]()
+         {
             RadarProductManagerImpl::LoadNexradFile(
                [=]() -> std::shared_ptr<wsr88d::NexradFile>
                { return wsr88d::NexradFileFactory::Create(filename); },
                request,
                fileLoadMutex_);
+         });
    }
    else if (request != nullptr)
    {
@@ -928,15 +947,23 @@ void RadarProductManager::LoadFile(
    }
 }
 
+void RadarProductManagerImpl::LoadNexradFileAsync(
+   CreateNexradFileFunction                    load,
+   std::shared_ptr<request::NexradFileRequest> request,
+   std::mutex&                                 mutex,
+   std::chrono::system_clock::time_point       time)
+{
+   boost::asio::post(threadPool_,
+                     [=, &mutex]()
+                     { LoadNexradFile(load, request, mutex, time); });
+}
+
 void RadarProductManagerImpl::LoadNexradFile(
    CreateNexradFileFunction                    load,
    std::shared_ptr<request::NexradFileRequest> request,
    std::mutex&                                 mutex,
    std::chrono::system_clock::time_point       time)
 {
-   scwx::util::async(
-      [=, &mutex]()
-      {
    std::unique_lock lock {mutex};
 
    std::shared_ptr<wsr88d::NexradFile> nexradFile = load();
@@ -972,7 +999,6 @@ void RadarProductManagerImpl::LoadNexradFile(
       request->set_radar_product_record(record);
       Q_EMIT request->RequestComplete(request);
    }
-      });
 }
 
 void RadarProductManagerImpl::PopulateLevel2ProductTimes(
@@ -1349,7 +1375,8 @@ void RadarProductManager::UpdateAvailableProducts()
 
    logger_->debug("UpdateAvailableProducts()");
 
-   scwx::util::async(
+   boost::asio::post(
+      p->threadPool_,
       [this]()
       {
          auto level3ProviderManager =