[core] Use an actor model for tile worker concurrency

6 files changed, 31 insertions, 74 deletions

diff --git a/src/mbgl/style/source_impl.cpp b/src/mbgl/style/source_impl.cpp
index e124cde583..58ae3d9f91 100644
--- a/src/mbgl/style/source_impl.cpp
+++ b/src/mbgl/style/source_impl.cpp
@@ -5,6 +5,7 @@
 #include <mbgl/renderer/painter.hpp>
 #include <mbgl/style/update_parameters.hpp>
 #include <mbgl/style/query_parameters.hpp>
+#include <mbgl/text/placement_config.hpp>
 #include <mbgl/platform/log.hpp>
 #include <mbgl/math/clamp.hpp>
 #include <mbgl/util/tile_cover.hpp>
@@ -77,7 +78,7 @@ const std::map<UnwrappedTileID, RenderTile>& Source::Impl::getRenderTiles() cons
     return renderTiles;
 }
 
-void Source::Impl::loadTiles(const UpdateParameters& parameters) {
+void Source::Impl::updateTiles(const UpdateParameters& parameters) {
     if (!loaded) {
         return;
     }
@@ -161,28 +162,17 @@ void Source::Impl::loadTiles(const UpdateParameters& parameters) {
             ++retainIt;
         }
     }
-}
 
-bool Source::Impl::parseTiles(const UpdateParameters& parameters) {
-    bool allTilesUpdated = true;
-    const PlacementConfig newConfig{ parameters.transformState.getAngle(),
-                                     parameters.transformState.getPitch(),
-                                     parameters.debugOptions & MapDebugOptions::Collision };
+    const PlacementConfig config { parameters.transformState.getAngle(),
+                                   parameters.transformState.getPitch(),
+                                   parameters.debugOptions & MapDebugOptions::Collision };
+
     for (auto& pair : tiles) {
-        auto tile = pair.second.get();
-        if (parameters.shouldReparsePartialTiles && tile->isIncomplete()) {
-            if (!tile->parsePending()) {
-                allTilesUpdated = false;
-            }
-        } else {
-            tile->redoPlacement(newConfig);
-        }
+        pair.second->setPlacementConfig(config);
     }
-
-    return allTilesUpdated;
 }
 
-void Source::Impl::reload() {
+void Source::Impl::reloadTiles() {
     cache.clear();
 
     for (auto& pair : tiles) {
@@ -258,18 +248,14 @@ void Source::Impl::setObserver(SourceObserver* observer_) {
     observer = observer_;
 }
 
-void Source::Impl::onTileLoaded(Tile& tile, TileLoadState loadState) {
-    observer->onTileLoaded(base, tile.id, loadState);
+void Source::Impl::onTileChanged(Tile& tile) {
+    observer->onTileChanged(base, tile.id);
 }
 
 void Source::Impl::onTileError(Tile& tile, std::exception_ptr error) {
     observer->onTileError(base, tile.id, error);
 }
 
-void Source::Impl::onTileUpdated(Tile& tile) {
-    observer->onTileUpdated(base, tile.id);
-}
-
 void Source::Impl::dumpDebugLogs() const {
     Log::Info(Event::General, "Source::id: %s", base.getID().c_str());
     Log::Info(Event::General, "Source::loaded: %d", loaded);
diff --git a/src/mbgl/style/source_impl.hpp b/src/mbgl/style/source_impl.hpp
index 5a54f4781a..0de3760fc3 100644
--- a/src/mbgl/style/source_impl.hpp
+++ b/src/mbgl/style/source_impl.hpp
@@ -43,16 +43,14 @@ public:
     virtual void loadDescription(FileSource&) = 0;
     bool isLoaded() const;
 
-    // Request or parse all the tiles relevant for the "TransformState". This method
-    // will return true if all the tiles were scheduled for updating of false if
-    // they were not. shouldReparsePartialTiles must be set to "true" if there is
-    // new data available that a tile in the "partial" state might be interested at.
-    void loadTiles(const UpdateParameters&);
-    bool parseTiles(const UpdateParameters&);
+    // Called when the camera has changed or icons or glyphs are loaded. May load new
+    // tiles, unload obsolete tiles, and trigger further parsing of incomplete tiles or
+    // re-placement of existing complete tiles.
+    void updateTiles(const UpdateParameters&);
 
     // Request that all loaded tiles re-run the layout operation on the existing source
     // data with fresh style information.
-    void reload();
+    void reloadTiles();
 
     void startRender(algorithm::ClipIDGenerator&,
                      const mat4& projMatrix,
@@ -88,9 +86,8 @@ protected:
 
 private:
     // TileObserver implementation.
-    void onTileLoaded(Tile&, TileLoadState) override;
+    void onTileChanged(Tile&) override;
     void onTileError(Tile&, std::exception_ptr) override;
-    void onTileUpdated(Tile&) override;
 
     virtual uint16_t getTileSize() const = 0;
     virtual Range<uint8_t> getZoomRange() = 0;
diff --git a/src/mbgl/style/source_observer.hpp b/src/mbgl/style/source_observer.hpp
index 6e0b226c3b..26b25b78da 100644
--- a/src/mbgl/style/source_observer.hpp
+++ b/src/mbgl/style/source_observer.hpp
@@ -19,9 +19,8 @@ public:
     virtual void onSourceLoaded(Source&) {}
     virtual void onSourceError(Source&, std::exception_ptr) {}
 
-    virtual void onTileLoaded(Source&, const OverscaledTileID&, TileLoadState) {}
+    virtual void onTileChanged(Source&, const OverscaledTileID&) {}
     virtual void onTileError(Source&, const OverscaledTileID&, std::exception_ptr) {}
-    virtual void onTileUpdated(Source&, const OverscaledTileID&) {}
 };
 
 } // namespace style
diff --git a/src/mbgl/style/style.cpp b/src/mbgl/style/style.cpp
index 34790683bc..a00c5e4efc 100644
--- a/src/mbgl/style/style.cpp
+++ b/src/mbgl/style/style.cpp
@@ -43,8 +43,7 @@ Style::Style(FileSource& fileSource_, float pixelRatio)
       spriteStore(std::make_unique<SpriteStore>(pixelRatio)),
       spriteAtlas(std::make_unique<SpriteAtlas>(1024, 1024, pixelRatio, *spriteStore)),
       lineAtlas(std::make_unique<LineAtlas>(256, 512)),
-      observer(&nullObserver),
-      workers(4) {
+      observer(&nullObserver) {
     glyphStore->setObserver(this);
     spriteStore->setObserver(this);
 }
@@ -215,19 +214,8 @@ double Style::getDefaultPitch() const {
 }
 
 void Style::updateTiles(const UpdateParameters& parameters) {
-    bool allTilesUpdated = true;
-
     for (const auto& source : sources) {
-        source->baseImpl->loadTiles(parameters);
-        if (!source->baseImpl->parseTiles(parameters)) {
-            allTilesUpdated = false;
-        }
-    }
-
-    // We can only stop updating "partial" tiles when all of them
-    // were notified of the arrival of the new resources.
-    if (allTilesUpdated) {
-        shouldReparsePartialTiles = false;
+        source->baseImpl->updateTiles(parameters);
     }
 }
 
@@ -235,7 +223,7 @@ void Style::relayout() {
     for (const auto& sourceID : updateBatch.sourceIDs) {
         Source* source = getSource(sourceID);
         if (!source) continue;
-        source->baseImpl->reload();
+        source->baseImpl->reloadTiles();
     }
     updateBatch.sourceIDs.clear();
 }
@@ -447,7 +435,6 @@ void Style::setObserver(style::Observer* observer_) {
 }
 
 void Style::onGlyphsLoaded(const FontStack& fontStack, const GlyphRange& glyphRange) {
-    shouldReparsePartialTiles = true;
     observer->onGlyphsLoaded(fontStack, glyphRange);
     observer->onUpdate(Update::Repaint);
 }
@@ -473,12 +460,8 @@ void Style::onSourceError(Source& source, std::exception_ptr error) {
     observer->onResourceError(error);
 }
 
-void Style::onTileLoaded(Source& source, const OverscaledTileID& tileID, TileLoadState loadState) {
-    if (loadState == TileLoadState::First) {
-        shouldReparsePartialTiles = true;
-    }
-
-    observer->onTileLoaded(source, tileID, loadState);
+void Style::onTileChanged(Source& source, const OverscaledTileID& tileID) {
+    observer->onTileChanged(source, tileID);
     observer->onUpdate(Update::Repaint);
 }
 
@@ -490,12 +473,7 @@ void Style::onTileError(Source& source, const OverscaledTileID& tileID, std::exc
     observer->onResourceError(error);
 }
 
-void Style::onTileUpdated(Source&, const OverscaledTileID&) {
-    observer->onUpdate(Update::Repaint);
-}
-
 void Style::onSpriteLoaded() {
-    shouldReparsePartialTiles = true;
     observer->onSpriteLoaded();
     observer->onUpdate(Update::Repaint);
 }
diff --git a/src/mbgl/style/style.hpp b/src/mbgl/style/style.hpp
index 8027313ab9..3e678ec060 100644
--- a/src/mbgl/style/style.hpp
+++ b/src/mbgl/style/style.hpp
@@ -12,25 +12,28 @@
 
 #include <mbgl/util/noncopyable.hpp>
 #include <mbgl/util/chrono.hpp>
-#include <mbgl/util/worker.hpp>
 #include <mbgl/util/optional.hpp>
 #include <mbgl/util/feature.hpp>
 #include <mbgl/util/geo.hpp>
 
 #include <cstdint>
+#include <memory>
 #include <string>
 #include <vector>
 
 namespace mbgl {
 
 class FileSource;
+class GlyphStore;
 class GlyphAtlas;
+class SpriteStore;
 class SpriteAtlas;
 class LineAtlas;
 class RenderData;
 
 namespace style {
 
+class Layer;
 class UpdateParameters;
 class QueryParameters;
 
@@ -134,9 +137,8 @@ private:
     // SourceObserver implementation.
     void onSourceLoaded(Source&) override;
     void onSourceError(Source&, std::exception_ptr) override;
-    void onTileLoaded(Source&, const OverscaledTileID&, TileLoadState) override;
+    void onTileChanged(Source&, const OverscaledTileID&) override;
     void onTileError(Source&, const OverscaledTileID&, std::exception_ptr) override;
-    void onTileUpdated(Source&, const OverscaledTileID&) override;
 
     // LayerObserver implementation.
     void onLayerFilterChanged(Layer&) override;
@@ -154,9 +156,7 @@ private:
     bool hasPendingTransitions = false;
 
 public:
-    bool shouldReparsePartialTiles = false;
     bool loaded = false;
-    Worker workers;
 };
 
 } // namespace style
diff --git a/src/mbgl/style/update_parameters.hpp b/src/mbgl/style/update_parameters.hpp
index 306cddf706..900f4b5183 100644
--- a/src/mbgl/style/update_parameters.hpp
+++ b/src/mbgl/style/update_parameters.hpp
@@ -5,7 +5,7 @@
 namespace mbgl {
 
 class TransformState;
-class Worker;
+class Scheduler;
 class FileSource;
 class AnnotationManager;
 
@@ -18,18 +18,16 @@ public:
     UpdateParameters(float pixelRatio_,
                           MapDebugOptions debugOptions_,
                           const TransformState& transformState_,
-                          Worker& worker_,
+                          Scheduler& workerScheduler_,
                           FileSource& fileSource_,
-                          bool shouldReparsePartialTiles_,
                           const MapMode mode_,
                           AnnotationManager& annotationManager_,
                           Style& style_)
         : pixelRatio(pixelRatio_),
           debugOptions(debugOptions_),
           transformState(transformState_),
-          worker(worker_),
+          workerScheduler(workerScheduler_),
           fileSource(fileSource_),
-          shouldReparsePartialTiles(shouldReparsePartialTiles_),
           mode(mode_),
           annotationManager(annotationManager_),
           style(style_) {}
@@ -37,9 +35,8 @@ public:
     float pixelRatio;
     MapDebugOptions debugOptions;
     const TransformState& transformState;
-    Worker& worker;
+    Scheduler& workerScheduler;
     FileSource& fileSource;
-    bool shouldReparsePartialTiles;
     const MapMode mode;
     AnnotationManager& annotationManager;