Take values rather than references in thread target object constructors

6 files changed, 24 insertions, 18 deletions

diff --git a/platform/android/src/snapshotter/map_snapshotter.cpp b/platform/android/src/snapshotter/map_snapshotter.cpp
index 155fdf81fb..c5fd7e21d7 100644
--- a/platform/android/src/snapshotter/map_snapshotter.cpp
+++ b/platform/android/src/snapshotter/map_snapshotter.cpp
@@ -36,7 +36,7 @@ MapSnapshotter::MapSnapshotter(jni::JNIEnv& _env,
     }
 
     jFileSource = FileSource::getNativePeer(_env, _jFileSource);
-    auto& fileSource = mbgl::android::FileSource::getDefaultFileSource(_env, _jFileSource);
+    fileSource = std::shared_ptr<mbgl::FileSource>(&mbgl::android::FileSource::getDefaultFileSource(_env, _jFileSource));
     auto size = mbgl::Size { static_cast<uint32_t>(width), static_cast<uint32_t>(height) };
 
     optional<mbgl::CameraOptions> cameraOptions;
@@ -59,7 +59,7 @@ MapSnapshotter::MapSnapshotter(jni::JNIEnv& _env,
     showLogo = _showLogo;
     // Create the core snapshotter
     snapshotter = std::make_unique<mbgl::MapSnapshotter>(fileSource,
-                                                         *threadPool,
+                                                         threadPool,
                                                          style,
                                                          size,
                                                          pixelRatio,
@@ -173,4 +173,4 @@ void MapSnapshotter::registerNative(jni::JNIEnv& env) {
 }
 
 } // namespace android
-} // namespace mbgl
\ No newline at end of file
+} // namespace mbgl
diff --git a/platform/android/src/snapshotter/map_snapshotter.hpp b/platform/android/src/snapshotter/map_snapshotter.hpp
index 3be2cb4f6c..47c7fd912a 100644
--- a/platform/android/src/snapshotter/map_snapshotter.hpp
+++ b/platform/android/src/snapshotter/map_snapshotter.hpp
@@ -70,10 +70,11 @@ private:
     std::unique_ptr<mbgl::MapSnapshotter> snapshotter;
 
     FileSource *jFileSource;
+    std::shared_ptr<mbgl::FileSource> fileSource;
     void activateFilesource(JNIEnv&);
     void deactivateFilesource(JNIEnv&);
     bool activatedFilesource = false;
 };
 
 } // namespace android
-} // namespace mbgl
\ No newline at end of file
+} // namespace mbgl
diff --git a/platform/darwin/src/MGLMapSnapshotter.mm b/platform/darwin/src/MGLMapSnapshotter.mm
index 2a2bef8fb8..1d52360d88 100644
--- a/platform/darwin/src/MGLMapSnapshotter.mm
+++ b/platform/darwin/src/MGLMapSnapshotter.mm
@@ -86,6 +86,7 @@ const CGFloat MGLSnapshotterMinimumPixelSize = 64;
 
 @implementation MGLMapSnapshotter {
     std::shared_ptr<mbgl::ThreadPool> _mbglThreadPool;
+    std::shared_ptr<mbgl::FileSource> _mbglFileSource;
     std::unique_ptr<mbgl::MapSnapshotter> _mbglMapSnapshotter;
     std::unique_ptr<mbgl::Actor<mbgl::MapSnapshotter::Callback>> _snapshotCallback;
 }
@@ -438,7 +439,7 @@ const CGFloat MGLSnapshotterMinimumPixelSize = 64;
 - (void)setOptions:(MGLMapSnapshotOptions *)options
 {
     _options = options;
-    mbgl::DefaultFileSource *mbglFileSource = [MGLOfflineStorage sharedOfflineStorage].mbglFileSource;
+    _mbglFileSource = std::shared_ptr<mbgl::FileSource>([MGLOfflineStorage sharedOfflineStorage].mbglFileSource);
     _mbglThreadPool = mbgl::sharedThreadPool();
     
     std::string styleURL = std::string([options.styleURL.absoluteString UTF8String]);
@@ -469,7 +470,7 @@ const CGFloat MGLSnapshotterMinimumPixelSize = 64;
     }
     
     // Create the snapshotter
-    _mbglMapSnapshotter = std::make_unique<mbgl::MapSnapshotter>(*mbglFileSource, *_mbglThreadPool, style, size, pixelRatio, cameraOptions, coordinateBounds);
+    _mbglMapSnapshotter = std::make_unique<mbgl::MapSnapshotter>(_mbglFileSource, _mbglThreadPool, style, size, pixelRatio, cameraOptions, coordinateBounds);
 }
 
 @end
diff --git a/platform/default/default_file_source.cpp b/platform/default/default_file_source.cpp
index cb602995a4..26b67134cb 100644
--- a/platform/default/default_file_source.cpp
+++ b/platform/default/default_file_source.cpp
@@ -18,7 +18,7 @@ namespace mbgl {
 
 class DefaultFileSource::Impl {
 public:
-    Impl(ActorRef<Impl> self, std::shared_ptr<FileSource> assetFileSource_, const std::string& cachePath, uint64_t maximumCacheSize)
+    Impl(ActorRef<Impl> self, std::shared_ptr<FileSource> assetFileSource_, std::string cachePath, uint64_t maximumCacheSize)
             : assetFileSource(assetFileSource_)
             , localFileSource(std::make_unique<LocalFileSource>()) {
         // Initialize the Database asynchronously so as to not block Actor creation.
diff --git a/platform/default/mbgl/map/map_snapshotter.cpp b/platform/default/mbgl/map/map_snapshotter.cpp
index a909e3fe9b..d7703e15b2 100644
--- a/platform/default/mbgl/map/map_snapshotter.cpp
+++ b/platform/default/mbgl/map/map_snapshotter.cpp
@@ -13,8 +13,8 @@ namespace mbgl {
 
 class MapSnapshotter::Impl {
 public:
-    Impl(FileSource&,
-         Scheduler&,
+    Impl(std::shared_ptr<FileSource>,
+         std::shared_ptr<Scheduler>,
          const std::pair<bool, std::string> style,
          const Size&,
          const float pixelRatio,
@@ -40,20 +40,24 @@ public:
     void snapshot(ActorRef<MapSnapshotter::Callback>);
 
 private:
+    std::shared_ptr<FileSource> fileSource;
+    std::shared_ptr<Scheduler> scheduler;
     HeadlessFrontend frontend;
     Map map;
 };
 
-MapSnapshotter::Impl::Impl(FileSource& fileSource,
-           Scheduler& scheduler,
+MapSnapshotter::Impl::Impl(std::shared_ptr<FileSource> fileSource_,
+           std::shared_ptr<Scheduler> scheduler_,
            const std::pair<bool, std::string> style,
            const Size& size,
            const float pixelRatio,
            const optional<CameraOptions> cameraOptions,
            const optional<LatLngBounds> region,
            const optional<std::string> programCacheDir)
-    : frontend(size, pixelRatio, fileSource, scheduler, programCacheDir)
-    , map(frontend, MapObserver::nullObserver(), size, pixelRatio, fileSource, scheduler, MapMode::Static) {
+    : fileSource(std::move(fileSource_))
+    , scheduler(std::move(scheduler_))
+    , frontend(size, pixelRatio, *fileSource, *scheduler, programCacheDir)
+    , map(frontend, MapObserver::nullObserver(), size, pixelRatio, *fileSource, *scheduler, MapMode::Static) {
 
     if (style.first) {
         map.getStyle().loadJSON(style.second);
@@ -149,15 +153,15 @@ LatLngBounds MapSnapshotter::Impl::getRegion() const {
     return map.latLngBoundsForCamera(getCameraOptions());
 }
 
-MapSnapshotter::MapSnapshotter(FileSource& fileSource,
-                               Scheduler& scheduler,
+MapSnapshotter::MapSnapshotter(std::shared_ptr<FileSource> fileSource,
+                               std::shared_ptr<Scheduler> scheduler,
                                const std::pair<bool, std::string> style,
                                const Size& size,
                                const float pixelRatio,
                                const optional<CameraOptions> cameraOptions,
                                const optional<LatLngBounds> region,
                                const optional<std::string> programCacheDir)
-   : impl(std::make_unique<util::Thread<MapSnapshotter::Impl>>("Map Snapshotter", fileSource, scheduler, style, size, pixelRatio, cameraOptions, region, programCacheDir)) {
+   : impl(std::make_unique<util::Thread<MapSnapshotter::Impl>>("Map Snapshotter", std::move(fileSource), std::move(scheduler), style, size, pixelRatio, cameraOptions, region, programCacheDir)) {
 }
 
 MapSnapshotter::~MapSnapshotter() = default;
diff --git a/platform/default/mbgl/map/map_snapshotter.hpp b/platform/default/mbgl/map/map_snapshotter.hpp
index b9e6307664..dd90d54b26 100644
--- a/platform/default/mbgl/map/map_snapshotter.hpp
+++ b/platform/default/mbgl/map/map_snapshotter.hpp
@@ -25,8 +25,8 @@ class Style;
 
 class MapSnapshotter {
 public:
-    MapSnapshotter(FileSource& fileSource,
-                   Scheduler& scheduler,
+    MapSnapshotter(std::shared_ptr<FileSource> fileSource,
+                   std::shared_ptr<Scheduler> scheduler,
                    const std::pair<bool, std::string> style,
                    const Size&,
                    const float pixelRatio,