[core] [node] pass thread pool impl to Map constructor

Updates mbgl::Map constructor usage everywhere

Adds NodeThreadPool implementation using AsyncQueue to call
Nan::AsyncQueueWorker from main thread

3 files changed, 8 insertions, 89 deletions

diff --git a/src/mbgl/actor/thread_pool.cpp b/src/mbgl/actor/thread_pool.cpp
deleted file mode 100644
index 2995ed26ad..0000000000
--- a/src/mbgl/actor/thread_pool.cpp
+++ /dev/null
@@ -1,55 +0,0 @@
-#include <mbgl/actor/thread_pool.hpp>
-#include <mbgl/actor/mailbox.hpp>
-
-namespace mbgl {
-
-ThreadPool::ThreadPool(std::size_t count) {
-    threads.reserve(count);
-    for (std::size_t i = 0; i < count; ++i) {
-        threads.emplace_back([this] () {
-            while (true) {
-                std::unique_lock<std::mutex> lock(mutex);
-
-                cv.wait(lock, [this] {
-                    return !queue.empty() || terminate;
-                });
-
-                if (terminate) {
-                    return;
-                }
-
-                auto mailbox = queue.front();
-                queue.pop();
-                lock.unlock();
-
-                if (auto locked = mailbox.lock()) {
-                    locked->receive();
-                }
-            }
-        });
-    }
-}
-
-ThreadPool::~ThreadPool() {
-    {
-        std::lock_guard<std::mutex> lock(mutex);
-        terminate = true;
-    }
-
-    cv.notify_all();
-
-    for (auto& thread : threads) {
-        thread.join();
-    }
-}
-
-void ThreadPool::schedule(std::weak_ptr<Mailbox> mailbox) {
-    {
-        std::lock_guard<std::mutex> lock(mutex);
-        queue.push(mailbox);
-    }
-
-    cv.notify_one();
-}
-
-} // namespace mbgl
diff --git a/src/mbgl/actor/thread_pool.hpp b/src/mbgl/actor/thread_pool.hpp
deleted file mode 100644
index a14d16d771..0000000000
--- a/src/mbgl/actor/thread_pool.hpp
+++ /dev/null
@@ -1,27 +0,0 @@
-#pragma once
-
-#include <mbgl/actor/scheduler.hpp>
-
-#include <condition_variable>
-#include <mutex>
-#include <queue>
-#include <thread>
-
-namespace mbgl {
-
-class ThreadPool : public Scheduler {
-public:
-    ThreadPool(std::size_t count);
-    ~ThreadPool() override;
-
-    void schedule(std::weak_ptr<Mailbox>) override;
-
-private:
-    std::vector<std::thread> threads;
-    std::queue<std::weak_ptr<Mailbox>> queue;
-    std::mutex mutex;
-    std::condition_variable cv;
-    bool terminate { false };
-};
-
-} // namespace mbgl
diff --git a/src/mbgl/map/map.cpp b/src/mbgl/map/map.cpp
index bf2462e2ab..d948225d8a 100644
--- a/src/mbgl/map/map.cpp
+++ b/src/mbgl/map/map.cpp
@@ -21,7 +21,7 @@
 #include <mbgl/util/async_task.hpp>
 #include <mbgl/util/mapbox.hpp>
 #include <mbgl/util/tile_coordinate.hpp>
-#include <mbgl/actor/thread_pool.hpp>
+#include <mbgl/actor/scheduler.hpp>
 #include <mbgl/platform/log.hpp>
 
 namespace mbgl {
@@ -36,7 +36,7 @@ enum class RenderState : uint8_t {
 
 class Map::Impl : public style::Observer {
 public:
-    Impl(View&, FileSource&, MapMode, GLContextMode, ConstrainMode, ViewportMode);
+    Impl(View&, FileSource&, Scheduler&, MapMode, GLContextMode, ConstrainMode, ViewportMode);
 
     void onSourceAttributionChanged(style::Source&, const std::string&) override;
     void onUpdate(Update) override;
@@ -51,6 +51,7 @@ public:
 
     View& view;
     FileSource& fileSource;
+    Scheduler& scheduler;
 
     RenderState renderState = RenderState::Never;
     Transform transform;
@@ -63,7 +64,6 @@ public:
 
     Update updateFlags = Update::Nothing;
     util::AsyncTask asyncUpdate;
-    ThreadPool workerThreadPool;
 
     std::unique_ptr<AnnotationManager> annotationManager;
     std::unique_ptr<Painter> painter;
@@ -81,20 +81,22 @@ public:
     bool loading = false;
 };
 
-Map::Map(View& view, FileSource& fileSource, MapMode mapMode, GLContextMode contextMode, ConstrainMode constrainMode, ViewportMode viewportMode)
-    : impl(std::make_unique<Impl>(view, fileSource, mapMode, contextMode, constrainMode, viewportMode)) {
+Map::Map(View& view, FileSource& fileSource, Scheduler& scheduler, MapMode mapMode, GLContextMode contextMode, ConstrainMode constrainMode, ViewportMode viewportMode)
+    : impl(std::make_unique<Impl>(view, fileSource, scheduler, mapMode, contextMode, constrainMode, viewportMode)) {
     view.initialize(this);
     update(Update::Dimensions);
 }
 
 Map::Impl::Impl(View& view_,
                 FileSource& fileSource_,
+                Scheduler& scheduler_,
                 MapMode mode_,
                 GLContextMode contextMode_,
                 ConstrainMode constrainMode_,
                 ViewportMode viewportMode_)
     : view(view_),
       fileSource(fileSource_),
+      scheduler(scheduler_),
       transform([this](MapChange change) { view.notifyMapChange(change); },
                 constrainMode_,
                 viewportMode_),
@@ -102,7 +104,6 @@ Map::Impl::Impl(View& view_,
       contextMode(contextMode_),
       pixelRatio(view.getPixelRatio()),
       asyncUpdate([this] { update(); }),
-      workerThreadPool(4),
       annotationManager(std::make_unique<AnnotationManager>(pixelRatio)) {
 }
 
@@ -230,7 +231,7 @@ void Map::Impl::update() {
     style::UpdateParameters parameters(pixelRatio,
                                        debugOptions,
                                        transform.getState(),
-                                       workerThreadPool,
+                                       scheduler,
                                        fileSource,
                                        mode,
                                        *annotationManager,