[core] Make the BackgroundScheduler a singleton

- Do not carry it over everywhere as parameter, it is a shared
  instance anyway and the lifecycle is pretty much the app lifecycle
  from the moment we instantiate a map.
- Rename to BackgroundScheduler because it is a Scheduler that will
  do tasks in the background, we don't make assumptions if it is a
  thread pool or a single thread.
- Most importantly, remove the dependency from `core` on `platform`.

84 files changed, 218 insertions, 375 deletions

diff --git a/benchmark/api/query.benchmark.cpp b/benchmark/api/query.benchmark.cpp
index 9b7c2d7273..7f08da73d0 100644
--- a/benchmark/api/query.benchmark.cpp
+++ b/benchmark/api/query.benchmark.cpp
@@ -3,7 +3,6 @@
 #include <mbgl/map/map.hpp>
 #include <mbgl/map/map_options.hpp>
 #include <mbgl/gl/headless_frontend.hpp>
-#include <mbgl/util/default_thread_pool.hpp>
 #include <mbgl/renderer/renderer.hpp>
 #include <mbgl/style/style.hpp>
 #include <mbgl/style/image.hpp>
@@ -30,9 +29,8 @@ public:
     }
 
     util::RunLoop loop;
-    ThreadPool threadPool{ 4 };
-    HeadlessFrontend frontend { { 1000, 1000 }, 1, threadPool };
-    Map map { frontend, MapObserver::nullObserver(), threadPool,
+    HeadlessFrontend frontend { { 1000, 1000 }, 1 };
+    Map map { frontend, MapObserver::nullObserver(),
               MapOptions().withMapMode(MapMode::Static).withSize(frontend.getSize()),
               ResourceOptions().withCachePath("benchmark/fixtures/api/cache.db").withAssetPath(".").withAccessToken("foobar") };
     ScreenBox box{{ 0, 0 }, { 1000, 1000 }};
diff --git a/benchmark/api/render.benchmark.cpp b/benchmark/api/render.benchmark.cpp
index 3cff0d9056..f9d3911f0b 100644
--- a/benchmark/api/render.benchmark.cpp
+++ b/benchmark/api/render.benchmark.cpp
@@ -4,7 +4,6 @@
 #include <mbgl/map/map_observer.hpp>
 #include <mbgl/map/map_options.hpp>
 #include <mbgl/gl/headless_frontend.hpp>
-#include <mbgl/util/default_thread_pool.hpp>
 #include <mbgl/renderer/renderer.hpp>
 #include <mbgl/style/style.hpp>
 #include <mbgl/style/image.hpp>
@@ -29,7 +28,6 @@ public:
     }
 
     util::RunLoop loop;
-    ThreadPool threadPool { 4 };
 };
 
 static void prepare(Map& map, optional<std::string> json = {}) {
@@ -44,8 +42,8 @@ static void prepare(Map& map, optional<std::string> json = {}) {
 
 static void API_renderStill_reuse_map(::benchmark::State& state) {
     RenderBenchmark bench;
-    HeadlessFrontend frontend { size, pixelRatio, bench.threadPool };
-    Map map { frontend, MapObserver::nullObserver(), bench.threadPool,
+    HeadlessFrontend frontend { size, pixelRatio };
+    Map map { frontend, MapObserver::nullObserver(),
               MapOptions().withMapMode(MapMode::Static).withSize(size).withPixelRatio(pixelRatio),
               ResourceOptions().withCachePath(cachePath).withAccessToken("foobar") };
     prepare(map);
@@ -57,8 +55,8 @@ static void API_renderStill_reuse_map(::benchmark::State& state) {
 
 static void API_renderStill_reuse_map_formatted_labels(::benchmark::State& state) {
     RenderBenchmark bench;
-    HeadlessFrontend frontend { size, pixelRatio, bench.threadPool };
-    Map map { frontend, MapObserver::nullObserver(), bench.threadPool,
+    HeadlessFrontend frontend { size, pixelRatio };
+    Map map { frontend, MapObserver::nullObserver(),
               MapOptions().withMapMode(MapMode::Static).withSize(size).withPixelRatio(pixelRatio),
               ResourceOptions().withCachePath(cachePath).withAccessToken("foobar") };
     prepare(map, util::read_file("benchmark/fixtures/api/style_formatted_labels.json"));
@@ -70,8 +68,8 @@ static void API_renderStill_reuse_map_formatted_labels(::benchmark::State& state
 
 static void API_renderStill_reuse_map_switch_styles(::benchmark::State& state) {
     RenderBenchmark bench;
-    HeadlessFrontend frontend { size, pixelRatio, bench.threadPool };
-    Map map { frontend, MapObserver::nullObserver(), bench.threadPool,
+    HeadlessFrontend frontend { size, pixelRatio };
+    Map map { frontend, MapObserver::nullObserver(),
               MapOptions().withMapMode(MapMode::Static).withSize(size).withPixelRatio(pixelRatio),
               ResourceOptions().withCachePath(cachePath).withAccessToken("foobar") };
 
@@ -87,8 +85,8 @@ static void API_renderStill_recreate_map(::benchmark::State& state) {
     RenderBenchmark bench;
 
     while (state.KeepRunning()) {
-        HeadlessFrontend frontend { size, pixelRatio, bench.threadPool };
-        Map map { frontend, MapObserver::nullObserver(), bench.threadPool,
+        HeadlessFrontend frontend { size, pixelRatio };
+        Map map { frontend, MapObserver::nullObserver(),
                   MapOptions().withMapMode(MapMode::Static).withSize(size).withPixelRatio(pixelRatio),
                   ResourceOptions().withCachePath(cachePath).withAccessToken("foobar") };
         prepare(map);
diff --git a/bin/render.cpp b/bin/render.cpp
index a805953693..48402ffce6 100644
--- a/bin/render.cpp
+++ b/bin/render.cpp
@@ -5,7 +5,6 @@
 #include <mbgl/util/default_styles.hpp>
 
 #include <mbgl/gl/headless_frontend.hpp>
-#include <mbgl/util/default_thread_pool.hpp>
 #include <mbgl/style/style.hpp>
 
 #include <args.hxx>
@@ -76,9 +75,8 @@ int main(int argc, char *argv[]) {
 
     util::RunLoop loop;
 
-    ThreadPool threadPool(4);
-    HeadlessFrontend frontend({ width, height }, pixelRatio, threadPool);
-    Map map(frontend, MapObserver::nullObserver(), threadPool,
+    HeadlessFrontend frontend({ width, height }, pixelRatio);
+    Map map(frontend, MapObserver::nullObserver(),
             MapOptions().withMapMode(MapMode::Static).withSize(frontend.getSize()).withPixelRatio(pixelRatio),
             ResourceOptions().withCachePath(cache_file).withAssetPath(asset_root).withAccessToken(std::string(token)));
 
diff --git a/include/mbgl/actor/actor.hpp b/include/mbgl/actor/actor.hpp
index 0052fad242..97964ae531 100644
--- a/include/mbgl/actor/actor.hpp
+++ b/include/mbgl/actor/actor.hpp
@@ -55,6 +55,10 @@ public:
     Actor(Scheduler& scheduler, Args&&... args)
         : target(scheduler, parent, std::forward<Args>(args)...) {}
 
+    template <class... Args>
+    Actor(std::shared_ptr<Scheduler> scheduler, Args&&... args)
+        : retainer(std::move(scheduler)), target(*retainer, parent, std::forward<Args>(args)...) {}
+
     Actor(const Actor&) = delete;
 
     ActorRef<std::decay_t<Object>> self() {
@@ -62,6 +66,7 @@ public:
     }
 
 private:
+    std::shared_ptr<Scheduler> retainer;
     AspiringActor<Object> parent;
     EstablishedActor<Object> target;
 };
diff --git a/include/mbgl/actor/scheduler.hpp b/include/mbgl/actor/scheduler.hpp
index 75ead29f0a..6470ab1245 100644
--- a/include/mbgl/actor/scheduler.hpp
+++ b/include/mbgl/actor/scheduler.hpp
@@ -41,6 +41,11 @@ public:
     // Set/Get the current Scheduler for this thread
     static Scheduler* GetCurrent();
     static void SetCurrent(Scheduler*);
+
+    // Get the scheduler for asynchronous tasks. This method
+    // will lazily initialize a shared worker pool when ran
+    // from the first time.
+    static std::shared_ptr<Scheduler> GetBackground();
 };
 
 } // namespace mbgl
diff --git a/include/mbgl/map/map.hpp b/include/mbgl/map/map.hpp
index 2fdd72dcb8..b1d4b14e4f 100644
--- a/include/mbgl/map/map.hpp
+++ b/include/mbgl/map/map.hpp
@@ -22,7 +22,6 @@
 
 namespace mbgl {
 
-class Scheduler;
 class RendererFrontend;
 
 namespace style {
@@ -34,7 +33,6 @@ class Map : private util::noncopyable {
 public:
     explicit Map(RendererFrontend&,
                  MapObserver&,
-                 Scheduler&,
                  const MapOptions&,
                  const ResourceOptions&);
     ~Map();
diff --git a/include/mbgl/renderer/renderer.hpp b/include/mbgl/renderer/renderer.hpp
index 50483fcf4b..787f9dceee 100644
--- a/include/mbgl/renderer/renderer.hpp
+++ b/include/mbgl/renderer/renderer.hpp
@@ -14,7 +14,6 @@ namespace mbgl {
 
 class RendererObserver;
 class RenderedQueryOptions;
-class Scheduler;
 class SourceQueryOptions;
 class UpdateParameters;
 
@@ -24,7 +23,7 @@ class RendererBackend;
 
 class Renderer {
 public:
-    Renderer(gfx::RendererBackend&, float pixelRatio_, Scheduler&,
+    Renderer(gfx::RendererBackend&, float pixelRatio_,
              const optional<std::string> programCacheDir = {},
              const optional<std::string> localFontFamily = {});
     ~Renderer();
diff --git a/include/mbgl/style/style.hpp b/include/mbgl/style/style.hpp
index d6fdbd8f2c..4a6a542b88 100644
--- a/include/mbgl/style/style.hpp
+++ b/include/mbgl/style/style.hpp
@@ -11,7 +11,6 @@
 namespace mbgl {
 
 class FileSource;
-class Scheduler;
 
 namespace style {
 
@@ -22,7 +21,7 @@ class Layer;
 
 class Style {
 public:
-    Style(Scheduler&, FileSource&, float pixelRatio);
+    Style(FileSource&, float pixelRatio);
     ~Style();
 
     void loadJSON(const std::string&);
diff --git a/platform/android/core-files.json b/platform/android/core-files.json
index 20dcc12c7d..ba56695bdd 100644
--- a/platform/android/core-files.json
+++ b/platform/android/core-files.json
@@ -89,9 +89,7 @@
         "platform/default/src/mbgl/gl/headless_frontend.cpp",
         "platform/default/src/mbgl/map/map_snapshotter.cpp",
         "platform/default/src/mbgl/text/bidi.cpp",
-        "platform/default/src/mbgl/util/default_thread_pool.cpp",
         "platform/default/src/mbgl/util/png_writer.cpp",
-        "platform/default/src/mbgl/util/shared_thread_pool.cpp",
         "platform/default/src/mbgl/util/thread_local.cpp",
         "platform/default/src/mbgl/util/utf.cpp",
         "platform/linux/src/headless_backend_egl.cpp"
@@ -101,9 +99,7 @@
         "mbgl/gl/headless_backend.hpp": "platform/default/include/mbgl/gl/headless_backend.hpp",
         "mbgl/gl/headless_frontend.hpp": "platform/default/include/mbgl/gl/headless_frontend.hpp",
         "mbgl/map/map_snapshotter.hpp": "platform/default/include/mbgl/map/map_snapshotter.hpp",
-        "mbgl/text/unaccent.hpp": "platform/default/include/mbgl/text/unaccent.hpp",
-        "mbgl/util/default_thread_pool.hpp": "platform/default/include/mbgl/util/default_thread_pool.hpp",
-        "mbgl/util/shared_thread_pool.hpp": "platform/default/include/mbgl/util/shared_thread_pool.hpp"
+        "mbgl/text/unaccent.hpp": "platform/default/include/mbgl/text/unaccent.hpp"
     },
     "private_headers": {
         "android_renderer_backend.hpp": "platform/android/src/android_renderer_backend.hpp",
diff --git a/platform/android/src/map_renderer.cpp b/platform/android/src/map_renderer.cpp
index 64c00585f8..92444c404d 100644
--- a/platform/android/src/map_renderer.cpp
+++ b/platform/android/src/map_renderer.cpp
@@ -2,7 +2,6 @@
 
 #include <mbgl/renderer/renderer.hpp>
 #include <mbgl/gfx/backend_scope.hpp>
-#include <mbgl/util/shared_thread_pool.hpp>
 #include <mbgl/util/run_loop.hpp>
 
 #include <string>
@@ -23,7 +22,6 @@ MapRenderer::MapRenderer(jni::JNIEnv& _env,
         , pixelRatio(pixelRatio_)
         , programCacheDir(jni::Make<std::string>(_env, programCacheDir_))
         , localIdeographFontFamily(localIdeographFontFamily_ ? jni::Make<std::string>(_env, localIdeographFontFamily_) : optional<std::string>{})
-        , threadPool(sharedThreadPool())
         , mailbox(std::make_shared<Mailbox>(*this)) {
 }
 
@@ -175,7 +173,7 @@ void MapRenderer::onSurfaceCreated(JNIEnv&) {
 
     // Create the new backend and renderer
     backend = std::make_unique<AndroidRendererBackend>();
-    renderer = std::make_unique<Renderer>(*backend, pixelRatio, *threadPool, programCacheDir, localIdeographFontFamily);
+    renderer = std::make_unique<Renderer>(*backend, pixelRatio, programCacheDir, localIdeographFontFamily);
     rendererRef = std::make_unique<ActorRef<Renderer>>(*renderer, mailbox);
 
     // Set the observer on the new Renderer implementation
diff --git a/platform/android/src/native_map_view.cpp b/platform/android/src/native_map_view.cpp
index 8f1ec9c576..ae53bcc802 100755
--- a/platform/android/src/native_map_view.cpp
+++ b/platform/android/src/native_map_view.cpp
@@ -21,7 +21,6 @@
 #include <mbgl/util/exception.hpp>
 #include <mbgl/util/geo.hpp>
 #include <mbgl/util/image.hpp>
-#include <mbgl/util/shared_thread_pool.hpp>
 #include <mbgl/util/logging.hpp>
 #include <mbgl/util/platform.hpp>
 #include <mbgl/util/projection.hpp>
@@ -66,8 +65,7 @@ NativeMapView::NativeMapView(jni::JNIEnv& _env,
                              jni::jboolean _crossSourceCollisions)
     : javaPeer(_env, _obj)
     , mapRenderer(MapRenderer::getNativePeer(_env, jMapRenderer))
-    , pixelRatio(_pixelRatio)
-    , threadPool(sharedThreadPool()) {
+    , pixelRatio(_pixelRatio) {
 
     // Get a reference to the JavaVM for callbacks
     if (_env.GetJavaVM(&vm) < 0) {
@@ -89,7 +87,7 @@ NativeMapView::NativeMapView(jni::JNIEnv& _env,
 
     // Create the core map
     map = std::make_unique<mbgl::Map>(
-        *rendererFrontend, *this, *threadPool, options,
+        *rendererFrontend, *this, options,
         mbgl::android::FileSource::getSharedResourceOptions(_env, jFileSource));
 }
 
diff --git a/platform/android/src/native_map_view.hpp b/platform/android/src/native_map_view.hpp
index c9ba6089c3..9e6ad73dd7 100755
--- a/platform/android/src/native_map_view.hpp
+++ b/platform/android/src/native_map_view.hpp
@@ -4,7 +4,6 @@
 #include <mbgl/map/camera.hpp>
 #include <mbgl/map/map.hpp>
 #include <mbgl/util/noncopyable.hpp>
-#include <mbgl/util/default_thread_pool.hpp>
 #include <mbgl/util/run_loop.hpp>
 #include <mbgl/storage/network_status.hpp>
 
@@ -258,7 +257,6 @@ private:
     int height = 64;
 
     // Ensure these are initialised last
-    std::shared_ptr<mbgl::ThreadPool> threadPool;
     std::unique_ptr<mbgl::Map> map;
     mbgl::EdgeInsets insets;
 };
diff --git a/platform/android/src/snapshotter/map_snapshotter.cpp b/platform/android/src/snapshotter/map_snapshotter.cpp
index 47a2781cb5..2eca6595e1 100644
--- a/platform/android/src/snapshotter/map_snapshotter.cpp
+++ b/platform/android/src/snapshotter/map_snapshotter.cpp
@@ -2,7 +2,6 @@
 
 #include <mbgl/renderer/renderer.hpp>
 #include <mbgl/style/style.hpp>
-#include <mbgl/util/shared_thread_pool.hpp>
 #include <mbgl/util/logging.hpp>
 #include <mbgl/util/string.hpp>
 #include <mbgl/actor/scheduler.hpp>
@@ -27,8 +26,7 @@ MapSnapshotter::MapSnapshotter(jni::JNIEnv& _env,
                                const jni::String& _programCacheDir,
                                const jni::String& _localIdeographFontFamily)
         : javaPeer(_env, _obj)
-        , pixelRatio(_pixelRatio)
-        , threadPool(sharedThreadPool()) {
+        , pixelRatio(_pixelRatio) {
 
     // Get a reference to the JavaVM for callbacks
     if (_env.GetJavaVM(&vm) < 0) {
@@ -58,8 +56,7 @@ MapSnapshotter::MapSnapshotter(jni::JNIEnv& _env,
 
     showLogo = _showLogo;
     // Create the core snapshotter
-    snapshotter = std::make_unique<mbgl::MapSnapshotter>(threadPool,
-                                                         style,
+    snapshotter = std::make_unique<mbgl::MapSnapshotter>(style,
                                                          size,
                                                          pixelRatio,
                                                          cameraOptions,
diff --git a/platform/android/src/snapshotter/map_snapshotter.hpp b/platform/android/src/snapshotter/map_snapshotter.hpp
index e8c0885ff1..791aa61d6a 100644
--- a/platform/android/src/snapshotter/map_snapshotter.hpp
+++ b/platform/android/src/snapshotter/map_snapshotter.hpp
@@ -1,7 +1,6 @@
 #pragma once
 
 #include <mbgl/map/map_snapshotter.hpp>
-#include <mbgl/util/default_thread_pool.hpp>
 #include <mbgl/util/util.hpp>
 
 #include "../file_source.hpp"
@@ -63,7 +62,6 @@ private:
     float pixelRatio;
     bool showLogo;
 
-    std::shared_ptr<mbgl::ThreadPool> threadPool;
     std::unique_ptr<Actor<mbgl::MapSnapshotter::Callback>> snapshotCallback;
     std::unique_ptr<mbgl::MapSnapshotter> snapshotter;
 
diff --git a/platform/android/src/style/sources/geojson_source.cpp b/platform/android/src/style/sources/geojson_source.cpp
index a9307afe67..5ff4864275 100644
--- a/platform/android/src/style/sources/geojson_source.cpp
+++ b/platform/android/src/style/sources/geojson_source.cpp
@@ -17,7 +17,6 @@
 #include "../conversion/url_or_tileset.hpp"
 
 #include <string>
-#include <mbgl/util/shared_thread_pool.hpp>
 
 // GeoJSONSource uses a "coalescing" model for high frequency asynchronous data update calls,
 // which in practice means, that any update that started processing is going to finish
@@ -48,16 +47,14 @@ namespace android {
         : Source(env, std::make_unique<mbgl::style::GeoJSONSource>(
                 jni::Make<std::string>(env, sourceId),
                 convertGeoJSONOptions(env, options)))
-        , threadPool(sharedThreadPool())
-        , converter(std::make_unique<Actor<FeatureConverter>>(*threadPool)) {
+        , converter(std::make_unique<Actor<FeatureConverter>>(Scheduler::GetBackground())) {
     }
 
     GeoJSONSource::GeoJSONSource(jni::JNIEnv& env,
                                  mbgl::style::Source& coreSource,
                                  AndroidRendererFrontend& frontend)
         : Source(env, coreSource, createJavaPeer(env), frontend)
-        , threadPool(sharedThreadPool())
-        , converter(std::make_unique<Actor<FeatureConverter>>(*threadPool)) {
+        , converter(std::make_unique<Actor<FeatureConverter>>(Scheduler::GetBackground())) {
     }
 
     GeoJSONSource::~GeoJSONSource() = default;
diff --git a/platform/darwin/src/MGLMapSnapshotter.mm b/platform/darwin/src/MGLMapSnapshotter.mm
index 171f24e4d0..65bed2cf42 100644
--- a/platform/darwin/src/MGLMapSnapshotter.mm
+++ b/platform/darwin/src/MGLMapSnapshotter.mm
@@ -8,9 +8,7 @@
 #import <mbgl/map/camera.hpp>
 #import <mbgl/storage/resource_options.hpp>
 #import <mbgl/storage/default_file_source.hpp>
-#import <mbgl/util/default_thread_pool.hpp>
 #import <mbgl/util/string.hpp>
-#import <mbgl/util/shared_thread_pool.hpp>
 
 #import "MGLOfflineStorage_Private.h"
 #import "MGLGeometry_Private.h"
@@ -125,7 +123,6 @@ const CGFloat MGLSnapshotterMinimumPixelSize = 64;
 @end
 
 @implementation MGLMapSnapshotter {
-    std::shared_ptr<mbgl::ThreadPool> _mbglThreadPool;
     std::unique_ptr<mbgl::MapSnapshotter> _mbglMapSnapshotter;
     std::unique_ptr<mbgl::Actor<mbgl::MapSnapshotter::Callback>> _snapshotCallback;
 }
@@ -176,7 +173,6 @@ const CGFloat MGLSnapshotterMinimumPixelSize = 64;
 
     _mbglMapSnapshotter.reset();
     _snapshotCallback.reset();
-    _mbglThreadPool.reset();
     
     self.terminated = YES;
 }
@@ -591,8 +587,6 @@ const CGFloat MGLSnapshotterMinimumPixelSize = 64;
     _options = options;
 
     auto mbglFileSource = [[MGLOfflineStorage sharedOfflineStorage] mbglFileSource];
-
-    _mbglThreadPool = mbgl::sharedThreadPool();
     
     std::string styleURL = std::string([options.styleURL.absoluteString UTF8String]);
     std::pair<bool, std::string> style = std::make_pair(false, styleURL);
@@ -630,7 +624,7 @@ const CGFloat MGLSnapshotterMinimumPixelSize = 64;
 
     // Create the snapshotter
     _mbglMapSnapshotter = std::make_unique<mbgl::MapSnapshotter>(
-        _mbglThreadPool, style, size, pixelRatio, cameraOptions, coordinateBounds, config.cacheDir, config.localFontFamilyName, resourceOptions);
+        style, size, pixelRatio, cameraOptions, coordinateBounds, config.cacheDir, config.localFontFamilyName, resourceOptions);
 }
 
 @end
diff --git a/platform/default/include/mbgl/gl/headless_frontend.hpp b/platform/default/include/mbgl/gl/headless_frontend.hpp
index ff733f423d..1e693bdef1 100644
--- a/platform/default/include/mbgl/gl/headless_frontend.hpp
+++ b/platform/default/include/mbgl/gl/headless_frontend.hpp
@@ -10,7 +10,6 @@
 
 namespace mbgl {
 
-class Scheduler;
 class Renderer;
 class Map;
 class TransformState;
@@ -22,13 +21,11 @@ class RendererBackend;
 class HeadlessFrontend : public RendererFrontend {
 public:
     HeadlessFrontend(float pixelRatio_,
-                     Scheduler&,
                      const optional<std::string> programCacheDir = {},
                      gfx::ContextMode mode = gfx::ContextMode::Unique,
                      const optional<std::string> localFontFamily = {});
     HeadlessFrontend(Size,
                      float pixelRatio_,
-                     Scheduler&,
                      const optional<std::string> programCacheDir = {},
                      gfx::ContextMode mode = gfx::ContextMode::Unique,
                      const optional<std::string> localFontFamily = {});
diff --git a/platform/default/include/mbgl/map/map_snapshotter.hpp b/platform/default/include/mbgl/map/map_snapshotter.hpp
index ccc3ee17f7..db1ba1f267 100644
--- a/platform/default/include/mbgl/map/map_snapshotter.hpp
+++ b/platform/default/include/mbgl/map/map_snapshotter.hpp
@@ -26,8 +26,7 @@ class Style;
 
 class MapSnapshotter {
 public:
-    MapSnapshotter(std::shared_ptr<Scheduler> scheduler,
-                   const std::pair<bool, std::string> style,
+    MapSnapshotter(const std::pair<bool, std::string> style,
                    const Size&,
                    const float pixelRatio,
                    const optional<CameraOptions> cameraOptions,
diff --git a/platform/default/include/mbgl/util/shared_thread_pool.hpp b/platform/default/include/mbgl/util/shared_thread_pool.hpp
deleted file mode 100644
index 04a3cb58d5..0000000000
--- a/platform/default/include/mbgl/util/shared_thread_pool.hpp
+++ /dev/null
@@ -1,9 +0,0 @@
-#pragma once
-
-#include <mbgl/util/default_thread_pool.hpp>
-
-namespace mbgl {
-
-std::shared_ptr<ThreadPool> sharedThreadPool();
-
-} // namespace mbgl
diff --git a/platform/default/src/mbgl/gl/headless_frontend.cpp b/platform/default/src/mbgl/gl/headless_frontend.cpp
index 7e56996f63..101028b5c8 100644
--- a/platform/default/src/mbgl/gl/headless_frontend.cpp
+++ b/platform/default/src/mbgl/gl/headless_frontend.cpp
@@ -10,17 +10,15 @@
 namespace mbgl {
 
 HeadlessFrontend::HeadlessFrontend(float pixelRatio_,
-                                   Scheduler& scheduler,
                                    const optional<std::string> programCacheDir,
                                    const gfx::ContextMode contextMode,
                                    const optional<std::string> localFontFamily)
     : HeadlessFrontend(
-          { 256, 256 }, pixelRatio_, scheduler, programCacheDir, contextMode, localFontFamily) {
+          { 256, 256 }, pixelRatio_, programCacheDir, contextMode, localFontFamily) {
 }
 
 HeadlessFrontend::HeadlessFrontend(Size size_,
                                    float pixelRatio_,
-                                   Scheduler& scheduler,
                                    const optional<std::string> programCacheDir,
                                    const gfx::ContextMode contextMode,
                                    const optional<std::string> localFontFamily)
@@ -40,7 +38,7 @@ HeadlessFrontend::HeadlessFrontend(Size size_,
             renderer->render(*updateParameters_);
         }
     }),
-    renderer(std::make_unique<Renderer>(backend, pixelRatio, scheduler, programCacheDir, localFontFamily)) {
+    renderer(std::make_unique<Renderer>(backend, pixelRatio, programCacheDir, localFontFamily)) {
 }
 
 HeadlessFrontend::~HeadlessFrontend() = default;
diff --git a/platform/default/src/mbgl/map/map_snapshotter.cpp b/platform/default/src/mbgl/map/map_snapshotter.cpp
index 6e02ac8532..7bfa2462a0 100644
--- a/platform/default/src/mbgl/map/map_snapshotter.cpp
+++ b/platform/default/src/mbgl/map/map_snapshotter.cpp
@@ -14,8 +14,7 @@ namespace mbgl {
 
 class MapSnapshotter::Impl {
 public:
-    Impl(std::shared_ptr<Scheduler>,
-         const std::pair<bool, std::string> style,
+    Impl(const std::pair<bool, std::string> style,
          const Size&,
          const float pixelRatio,
          const optional<CameraOptions> cameraOptions,
@@ -42,13 +41,11 @@ public:
     void snapshot(ActorRef<MapSnapshotter::Callback>);
 
 private:
-    std::shared_ptr<Scheduler> scheduler;
     HeadlessFrontend frontend;
     Map map;
 };
 
-MapSnapshotter::Impl::Impl(std::shared_ptr<Scheduler> scheduler_,
-                           const std::pair<bool, std::string> style,
+MapSnapshotter::Impl::Impl(const std::pair<bool, std::string> style,
                            const Size& size,
                            const float pixelRatio,
                            const optional<CameraOptions> cameraOptions,
@@ -56,12 +53,10 @@ MapSnapshotter::Impl::Impl(std::shared_ptr<Scheduler> scheduler_,
                            const optional<std::string> programCacheDir,
                            const optional<std::string> localFontFamily,
                            const ResourceOptions& resourceOptions)
-    : scheduler(std::move(scheduler_)),
-      frontend(
-          size, pixelRatio, *scheduler, programCacheDir, gfx::ContextMode::Unique, localFontFamily),
+     : frontend(
+          size, pixelRatio, programCacheDir, gfx::ContextMode::Unique, localFontFamily),
       map(frontend,
           MapObserver::nullObserver(),
-          *scheduler,
           MapOptions().withMapMode(MapMode::Static).withSize(size).withPixelRatio(pixelRatio),
           resourceOptions) {
     if (style.first) {
@@ -168,8 +163,7 @@ LatLngBounds MapSnapshotter::Impl::getRegion() const {
     return map.latLngBoundsForCamera(getCameraOptions());
 }
 
-MapSnapshotter::MapSnapshotter(std::shared_ptr<Scheduler> scheduler,
-                               const std::pair<bool, std::string> style,
+MapSnapshotter::MapSnapshotter(const std::pair<bool, std::string> style,
                                const Size& size,
                                const float pixelRatio,
                                const optional<CameraOptions> cameraOptions,
@@ -178,7 +172,7 @@ MapSnapshotter::MapSnapshotter(std::shared_ptr<Scheduler> scheduler,
                                const optional<std::string> localFontFamily,
                                const ResourceOptions& resourceOptions)
    : impl(std::make_unique<util::Thread<MapSnapshotter::Impl>>(
-       "Map Snapshotter", std::move(scheduler), style, size, pixelRatio, cameraOptions,
+       "Map Snapshotter", style, size, pixelRatio, cameraOptions,
        region, programCacheDir, localFontFamily, resourceOptions.clone())) {}
 
 MapSnapshotter::~MapSnapshotter() = default;
diff --git a/platform/default/src/mbgl/util/shared_thread_pool.cpp b/platform/default/src/mbgl/util/shared_thread_pool.cpp
deleted file mode 100644
index d7facbab94..0000000000
--- a/platform/default/src/mbgl/util/shared_thread_pool.cpp
+++ /dev/null
@@ -1,14 +0,0 @@
-#include <mbgl/util/shared_thread_pool.hpp>
-
-namespace mbgl {
-
-std::shared_ptr<ThreadPool> sharedThreadPool() {
-    static std::weak_ptr<ThreadPool> weak;
-    auto pool = weak.lock();
-    if (!pool) {
-        weak = pool = std::make_shared<ThreadPool>(4);
-    }
-    return pool;
-}
-
-} // namespace mbgl
diff --git a/platform/glfw/main.cpp b/platform/glfw/main.cpp
index 4e631ec895..04cff3962a 100644
--- a/platform/glfw/main.cpp
+++ b/platform/glfw/main.cpp
@@ -5,7 +5,6 @@
 #include <mbgl/util/default_styles.hpp>
 #include <mbgl/util/logging.hpp>
 #include <mbgl/util/platform.hpp>
-#include <mbgl/util/default_thread_pool.hpp>
 #include <mbgl/util/string.hpp>
 #include <mbgl/storage/default_file_source.hpp>
 #include <mbgl/style/style.hpp>
@@ -109,10 +108,9 @@ int main(int argc, char *argv[]) {
         mbgl::Log::Warning(mbgl::Event::Setup, "Application is offline. Press `O` to toggle online status.");
     }
 
-    mbgl::ThreadPool threadPool(4);
-    GLFWRendererFrontend rendererFrontend { std::make_unique<mbgl::Renderer>(view->getRendererBackend(), view->getPixelRatio(), threadPool), *view };
+    GLFWRendererFrontend rendererFrontend { std::make_unique<mbgl::Renderer>(view->getRendererBackend(), view->getPixelRatio()), *view };
 
-    mbgl::Map map(rendererFrontend, *view, threadPool,
+    mbgl::Map map(rendererFrontend, *view,
                   mbgl::MapOptions().withSize(view->getSize()).withPixelRatio(view->getPixelRatio()), resourceOptions);
 
     backend.setMap(&map);
@@ -199,5 +197,6 @@ int main(int argc, char *argv[]) {
                     settings.latitude, settings.longitude, settings.zoom, settings.bearing);
 
     view = nullptr;
+
     return 0;
 }
diff --git a/platform/ios/core-files.json b/platform/ios/core-files.json
index c3e54a45b0..98833b0c94 100644
--- a/platform/ios/core-files.json
+++ b/platform/ios/core-files.json
@@ -14,9 +14,7 @@
         "platform/default/src/mbgl/gl/headless_frontend.cpp",
         "platform/default/src/mbgl/map/map_snapshotter.cpp",
         "platform/default/src/mbgl/text/bidi.cpp",
-        "platform/default/src/mbgl/util/default_thread_pool.cpp",
         "platform/default/src/mbgl/util/png_writer.cpp",
-        "platform/default/src/mbgl/util/shared_thread_pool.cpp",
         "platform/default/src/mbgl/util/thread_local.cpp",
         "platform/default/src/mbgl/util/utf.cpp"
     ],
@@ -26,9 +24,7 @@
         "mbgl/gl/headless_backend.hpp": "platform/default/include/mbgl/gl/headless_backend.hpp",
         "mbgl/gl/headless_frontend.hpp": "platform/default/include/mbgl/gl/headless_frontend.hpp",
         "mbgl/map/map_snapshotter.hpp": "platform/default/include/mbgl/map/map_snapshotter.hpp",
-        "mbgl/util/default_styles.hpp": "platform/default/include/mbgl/util/default_styles.hpp",
-        "mbgl/util/default_thread_pool.hpp": "platform/default/include/mbgl/util/default_thread_pool.hpp",
-        "mbgl/util/shared_thread_pool.hpp": "platform/default/include/mbgl/util/shared_thread_pool.hpp"
+        "mbgl/util/default_styles.hpp": "platform/default/include/mbgl/util/default_styles.hpp"
     },
     "private_headers": {
         "CFHandle.hpp": "platform/darwin/src/CFHandle.hpp"
diff --git a/platform/ios/src/MGLMapView.mm b/platform/ios/src/MGLMapView.mm
index a4f994a2f4..fa49a2f280 100644
--- a/platform/ios/src/MGLMapView.mm
+++ b/platform/ios/src/MGLMapView.mm
@@ -10,7 +10,6 @@
 #include <mbgl/map/mode.hpp>
 #include <mbgl/util/platform.hpp>
 #include <mbgl/storage/reachability.h>
-#include <mbgl/util/default_thread_pool.hpp>
 #include <mbgl/storage/resource_options.hpp>
 #include <mbgl/storage/network_status.hpp>
 #include <mbgl/style/style.hpp>
@@ -29,7 +28,6 @@
 #include <mbgl/util/default_styles.hpp>
 #include <mbgl/util/chrono.hpp>
 #include <mbgl/util/run_loop.hpp>
-#include <mbgl/util/shared_thread_pool.hpp>
 #include <mbgl/util/string.hpp>
 #include <mbgl/util/projection.hpp>
 
@@ -280,8 +278,6 @@ public:
     MBGLView *_mbglView;
     std::unique_ptr<MGLRenderFrontend> _rendererFrontend;
     
-    std::shared_ptr<mbgl::ThreadPool> _mbglThreadPool;
-
     BOOL _opaque;
 
     MGLAnnotationTagContextMap _annotationContextsByAnnotationTag;
@@ -476,9 +472,8 @@ public:
 
     // setup mbgl map
     MGLRendererConfiguration *config = [MGLRendererConfiguration currentConfiguration];
-    _mbglThreadPool = mbgl::sharedThreadPool();
 
-    auto renderer = std::make_unique<mbgl::Renderer>(*_mbglView, config.scaleFactor, *_mbglThreadPool, config.cacheDir, config.localFontFamilyName);
+    auto renderer = std::make_unique<mbgl::Renderer>(*_mbglView, config.scaleFactor, config.cacheDir, config.localFontFamilyName);
     BOOL enableCrossSourceCollisions = !config.perSourceCollisions;
     _rendererFrontend = std::make_unique<MGLRenderFrontend>(std::move(renderer), self, *_mbglView);
 
@@ -495,7 +490,7 @@ public:
                    .withAssetPath([NSBundle mainBundle].resourceURL.path.UTF8String);
 
     NSAssert(!_mbglMap, @"_mbglMap should be NULL");
-    _mbglMap = new mbgl::Map(*_rendererFrontend, *_mbglView, *_mbglThreadPool, mapOptions, resourceOptions);
+    _mbglMap = new mbgl::Map(*_rendererFrontend, *_mbglView, mapOptions, resourceOptions);
 
     // start paused if in IB
     if (background) {
@@ -772,7 +767,6 @@ public:
     _mbglView = nullptr;
 
     _rendererFrontend.reset();
-    _mbglThreadPool.reset();
 }
 
 - (void)dealloc
diff --git a/platform/linux/config.cmake b/platform/linux/config.cmake
index 4405e0583f..118dfe696c 100644
--- a/platform/linux/config.cmake
+++ b/platform/linux/config.cmake
@@ -72,11 +72,6 @@ macro(mbgl_platform_core)
         # Snapshotting
         PRIVATE platform/default/src/mbgl/map/map_snapshotter.cpp
         PRIVATE platform/default/include/mbgl/map/map_snapshotter.hpp
-
-        # Thread pool
-        PRIVATE platform/default/src/mbgl/util/default_thread_pool.cpp
-        PRIVATE platform/default/src/mbgl/util/default_thread_pool.cpp
-        PRIVATE platform/default/src/mbgl/util/shared_thread_pool.cpp
     )
 
     target_include_directories(mbgl-core
diff --git a/platform/macos/core-files.json b/platform/macos/core-files.json
index 9ec41f651a..abeda5796b 100644
--- a/platform/macos/core-files.json
+++ b/platform/macos/core-files.json
@@ -13,9 +13,7 @@
         "platform/default/src/mbgl/gl/headless_frontend.cpp",
         "platform/default/src/mbgl/map/map_snapshotter.cpp",
         "platform/default/src/mbgl/text/bidi.cpp",
-        "platform/default/src/mbgl/util/default_thread_pool.cpp",
         "platform/default/src/mbgl/util/png_writer.cpp",
-        "platform/default/src/mbgl/util/shared_thread_pool.cpp",
         "platform/default/src/mbgl/util/thread_local.cpp",
         "platform/default/src/mbgl/util/utf.cpp"
     ],
@@ -24,9 +22,7 @@
         "mbgl/util/image+MGLAdditions.hpp": "platform/darwin/include/mbgl/util/image+MGLAdditions.hpp",
         "mbgl/gl/headless_backend.hpp": "platform/default/include/mbgl/gl/headless_backend.hpp",
         "mbgl/gl/headless_frontend.hpp": "platform/default/include/mbgl/gl/headless_frontend.hpp",
-        "mbgl/map/map_snapshotter.hpp": "platform/default/include/mbgl/map/map_snapshotter.hpp",
-        "mbgl/util/default_thread_pool.hpp": "platform/default/include/mbgl/util/default_thread_pool.hpp",
-        "mbgl/util/shared_thread_pool.hpp": "platform/default/include/mbgl/util/shared_thread_pool.hpp"
+        "mbgl/map/map_snapshotter.hpp": "platform/default/include/mbgl/map/map_snapshotter.hpp"
     },
     "private_headers": {
         "CFHandle.hpp": "platform/darwin/src/CFHandle.hpp"
diff --git a/platform/macos/src/MGLMapView.mm b/platform/macos/src/MGLMapView.mm
index e9259cf907..77eb300aef 100644
--- a/platform/macos/src/MGLMapView.mm
+++ b/platform/macos/src/MGLMapView.mm
@@ -31,7 +31,6 @@
 #import <mbgl/annotation/annotation.hpp>
 #import <mbgl/map/camera.hpp>
 #import <mbgl/storage/reachability.h>
-#import <mbgl/util/default_thread_pool.hpp>
 #import <mbgl/style/image.hpp>
 #import <mbgl/renderer/renderer.hpp>
 #import <mbgl/gl/renderer_backend.hpp>
@@ -43,7 +42,6 @@
 #import <mbgl/util/chrono.hpp>
 #import <mbgl/util/exception.hpp>
 #import <mbgl/util/run_loop.hpp>
-#import <mbgl/util/shared_thread_pool.hpp>
 #import <mbgl/util/string.hpp>
 #import <mbgl/util/projection.hpp>
 
@@ -164,7 +162,6 @@ public:
     mbgl::Map *_mbglMap;
     MGLMapViewImpl *_mbglView;
     std::unique_ptr<MGLRenderFrontend> _rendererFrontend;
-    std::shared_ptr<mbgl::ThreadPool> _mbglThreadPool;
 
     NSPanGestureRecognizer *_panGestureRecognizer;
     NSMagnificationGestureRecognizer *_magnificationGestureRecognizer;
@@ -283,10 +280,9 @@ public:
     NSURL *legacyCacheURL = [cachesDirectoryURL URLByAppendingPathComponent:@"cache.db"];
     [[NSFileManager defaultManager] removeItemAtURL:legacyCacheURL error:NULL];
 
-    _mbglThreadPool = mbgl::sharedThreadPool();
     MGLRendererConfiguration *config = [MGLRendererConfiguration currentConfiguration];
 
-    auto renderer = std::make_unique<mbgl::Renderer>(*_mbglView, config.scaleFactor, *_mbglThreadPool, config.cacheDir, config.localFontFamilyName);
+    auto renderer = std::make_unique<mbgl::Renderer>(*_mbglView, config.scaleFactor, config.cacheDir, config.localFontFamilyName);
     BOOL enableCrossSourceCollisions = !config.perSourceCollisions;
     _rendererFrontend = std::make_unique<MGLRenderFrontend>(std::move(renderer), self, *_mbglView, true);
 
@@ -302,7 +298,7 @@ public:
     resourceOptions.withCachePath([[MGLOfflineStorage sharedOfflineStorage] mbglCachePath])
                    .withAssetPath([NSBundle mainBundle].resourceURL.path.UTF8String);
 
-    _mbglMap = new mbgl::Map(*_rendererFrontend, *_mbglView, *_mbglThreadPool, mapOptions, resourceOptions);
+    _mbglMap = new mbgl::Map(*_rendererFrontend, *_mbglView, mapOptions, resourceOptions);
 
     // Install the OpenGL layer. Interface Builder’s synchronous drawing means
     // we can’t display a map, so don’t even bother to have a map layer.
diff --git a/platform/node/src/node_map.cpp b/platform/node/src/node_map.cpp
index 7156a1f1bf..0a7da3a83a 100644
--- a/platform/node/src/node_map.cpp
+++ b/platform/node/src/node_map.cpp
@@ -630,8 +630,8 @@ void NodeMap::cancel() {
         reinterpret_cast<NodeMap *>(h->data)->renderFinished();
     });
 
-    frontend = std::make_unique<mbgl::HeadlessFrontend>(mbgl::Size{ 256, 256 }, pixelRatio, threadpool);
-    map = std::make_unique<mbgl::Map>(*frontend, mapObserver, threadpool,
+    frontend = std::make_unique<mbgl::HeadlessFrontend>(mbgl::Size{ 256, 256 }, pixelRatio);
+    map = std::make_unique<mbgl::Map>(*frontend, mapObserver,
                                       mbgl::MapOptions().withSize(frontend->getSize())
                                       .withPixelRatio(pixelRatio)
                                       .withMapMode(mode)
@@ -1214,8 +1214,8 @@ NodeMap::NodeMap(v8::Local<v8::Object> options)
             : true;
     }())
     , mapObserver(NodeMapObserver())
-    , frontend(std::make_unique<mbgl::HeadlessFrontend>(mbgl::Size { 256, 256 }, pixelRatio, threadpool))
-    , map(std::make_unique<mbgl::Map>(*frontend, mapObserver, threadpool,
+    , frontend(std::make_unique<mbgl::HeadlessFrontend>(mbgl::Size { 256, 256 }, pixelRatio))
+    , map(std::make_unique<mbgl::Map>(*frontend, mapObserver,
                                       mbgl::MapOptions().withSize(frontend->getSize())
                                       .withPixelRatio(pixelRatio)
                                       .withMapMode(mode)
diff --git a/platform/node/src/node_map.hpp b/platform/node/src/node_map.hpp
index 65664b34bb..d45dbec92b 100644
--- a/platform/node/src/node_map.hpp
+++ b/platform/node/src/node_map.hpp
@@ -1,7 +1,5 @@
 #pragma once
 
-#include "node_thread_pool.hpp"
-
 #include <mbgl/map/map.hpp>
 #include <mbgl/storage/file_source.hpp>
 #include <mbgl/util/image.hpp>
@@ -79,7 +77,6 @@ public:
     const float pixelRatio;
     mbgl::MapMode mode;
     bool crossSourceCollisions;
-    NodeThreadPool threadpool;
     NodeMapObserver mapObserver;
     std::unique_ptr<mbgl::HeadlessFrontend> frontend;
     std::unique_ptr<mbgl::Map> map;
diff --git a/platform/node/src/node_thread_pool.cpp b/platform/node/src/node_thread_pool.cpp
index 1f37565e8a..de403c605c 100644
--- a/platform/node/src/node_thread_pool.cpp
+++ b/platform/node/src/node_thread_pool.cpp
@@ -2,6 +2,7 @@
 #include "util/async_queue.hpp"
 
 #include <mbgl/actor/mailbox.hpp>
+#include <mbgl/platform/background_scheduler.hpp>
 
 namespace node_mbgl {
 
@@ -35,3 +36,14 @@ void NodeThreadPool::Worker::WorkComplete() {
 }
 
 } // namespace node_mbgl
+
+namespace mbgl {
+namespace platform {
+
+Scheduler& GetBackgroundScheduler() {
+    static node_mbgl::NodeThreadPool pool;
+    return pool;
+}
+
+} // namespace platform
+} // namespace mbgl
diff --git a/platform/qt/qt.cmake b/platform/qt/qt.cmake
index 911af25bc4..fb572b807b 100644
--- a/platform/qt/qt.cmake
+++ b/platform/qt/qt.cmake
@@ -17,12 +17,6 @@ set(MBGL_QT_CORE_FILES
     PRIVATE platform/default/include/mbgl/gl/headless_backend.hpp
     PRIVATE platform/qt/src/headless_backend_qt.cpp
 
-    # Thread pool
-    PRIVATE platform/default/src/mbgl/util/shared_thread_pool.cpp
-    PRIVATE platform/default/include/mbgl/util/shared_thread_pool.hpp
-    PRIVATE platform/default/src/mbgl/util/default_thread_pool.cpp
-    PRIVATE platform/default/include/mbgl/util/default_thread_pool.hpp
-
     # Thread
     PRIVATE platform/qt/src/thread_local.cpp
 
diff --git a/platform/qt/src/qmapboxgl.cpp b/platform/qt/src/qmapboxgl.cpp
index e54733aba7..329bf23085 100644
--- a/platform/qt/src/qmapboxgl.cpp
+++ b/platform/qt/src/qmapboxgl.cpp
@@ -43,7 +43,6 @@
 #include <mbgl/util/projection.hpp>
 #include <mbgl/util/rapidjson.hpp>
 #include <mbgl/util/run_loop.hpp>
-#include <mbgl/util/shared_thread_pool.hpp>
 #include <mbgl/util/traits.hpp>
 #include <mbgl/actor/scheduler.hpp>
 
@@ -1724,7 +1723,6 @@ mbgl::ResourceOptions resourceOptionsFromQMapboxGLSettings(const QMapboxGLSettin
 
 QMapboxGLPrivate::QMapboxGLPrivate(QMapboxGL *q, const QMapboxGLSettings &settings, const QSize &size, qreal pixelRatio_)
     : QObject(q)
-    , m_threadPool(mbgl::sharedThreadPool())
     , m_mode(settings.contextMode())
     , m_pixelRatio(pixelRatio_)
     , m_localFontFamily(settings.localFontFamily())
@@ -1741,7 +1739,7 @@ QMapboxGLPrivate::QMapboxGLPrivate(QMapboxGL *q, const QMapboxGLSettings &settin
     auto resourceOptions = resourceOptionsFromQMapboxGLSettings(settings);
 
     // Setup the Map object.
-    mapObj = std::make_unique<mbgl::Map>(*this, *m_mapObserver, *m_threadPool,
+    mapObj = std::make_unique<mbgl::Map>(*this, *m_mapObserver,
                                          mapOptionsFromQMapboxGLSettings(settings, size, m_pixelRatio),
                                          resourceOptions);
 
@@ -1799,7 +1797,6 @@ void QMapboxGLPrivate::createRenderer()
 
     m_mapRenderer = std::make_unique<QMapboxGLMapRenderer>(
         m_pixelRatio,
-        *m_threadPool,
         m_mode,
         m_localFontFamily
     );
diff --git a/platform/qt/src/qmapboxgl_map_renderer.cpp b/platform/qt/src/qmapboxgl_map_renderer.cpp
index d72b5d0f2c..eba50af6bf 100644
--- a/platform/qt/src/qmapboxgl_map_renderer.cpp
+++ b/platform/qt/src/qmapboxgl_map_renderer.cpp
@@ -26,9 +26,9 @@ static auto *getScheduler() {
     return scheduler.localData().get();
 };
 
-QMapboxGLMapRenderer::QMapboxGLMapRenderer(qreal pixelRatio, mbgl::ThreadPool &tp, QMapboxGLSettings::GLContextMode mode, const QString &localFontFamily)
+QMapboxGLMapRenderer::QMapboxGLMapRenderer(qreal pixelRatio, QMapboxGLSettings::GLContextMode mode, const QString &localFontFamily)
     : m_backend(static_cast<mbgl::gfx::ContextMode>(mode)),
-      m_renderer(std::make_unique<mbgl::Renderer>(m_backend, pixelRatio, tp, mbgl::optional<std::string> {},
+      m_renderer(std::make_unique<mbgl::Renderer>(m_backend, pixelRatio, mbgl::optional<std::string> {},
                  localFontFamily.isEmpty() ? mbgl::nullopt : mbgl::optional<std::string> { localFontFamily.toStdString() }))
     , m_forceScheduler(needsToForceScheduler())
 {
diff --git a/platform/qt/src/qmapboxgl_map_renderer.hpp b/platform/qt/src/qmapboxgl_map_renderer.hpp
index 7db0da99fa..2769b2b874 100644
--- a/platform/qt/src/qmapboxgl_map_renderer.hpp
+++ b/platform/qt/src/qmapboxgl_map_renderer.hpp
@@ -5,7 +5,6 @@
 
 #include <mbgl/renderer/renderer.hpp>
 #include <mbgl/renderer/renderer_observer.hpp>
-#include <mbgl/util/shared_thread_pool.hpp>
 #include <mbgl/util/util.hpp>
 
 #include <QtGlobal>
@@ -25,7 +24,7 @@ class QMapboxGLMapRenderer : public QObject
     Q_OBJECT
 
 public:
-    QMapboxGLMapRenderer(qreal pixelRatio, mbgl::ThreadPool &, QMapboxGLSettings::GLContextMode, const QString &localFontFamily);
+    QMapboxGLMapRenderer(qreal pixelRatio, QMapboxGLSettings::GLContextMode, const QString &localFontFamily);
     virtual ~QMapboxGLMapRenderer();
 
     void render();
diff --git a/platform/qt/src/qmapboxgl_p.hpp b/platform/qt/src/qmapboxgl_p.hpp
index 6a5b5ce04f..7f7040d7ac 100644
--- a/platform/qt/src/qmapboxgl_p.hpp
+++ b/platform/qt/src/qmapboxgl_p.hpp
@@ -8,7 +8,6 @@
 #include <mbgl/map/map.hpp>
 #include <mbgl/renderer/renderer_frontend.hpp>
 #include <mbgl/storage/resource_transform.hpp>
-#include <mbgl/util/default_thread_pool.hpp>
 #include <mbgl/util/geo.hpp>
 
 #include <QObject>
@@ -56,7 +55,6 @@ private:
     std::shared_ptr<mbgl::UpdateParameters> m_updateParameters;
 
     std::unique_ptr<QMapboxGLMapObserver> m_mapObserver;
-    std::shared_ptr<mbgl::ThreadPool> m_threadPool;
     std::unique_ptr<QMapboxGLMapRenderer> m_mapRenderer;
     std::unique_ptr<mbgl::Actor<mbgl::ResourceTransform>> m_resourceTransform;
 
diff --git a/platform/qt/src/qmapboxgl_renderer_backend.hpp b/platform/qt/src/qmapboxgl_renderer_backend.hpp
index aba8003323..f821eda969 100644
--- a/platform/qt/src/qmapboxgl_renderer_backend.hpp
+++ b/platform/qt/src/qmapboxgl_renderer_backend.hpp
@@ -4,7 +4,6 @@
 
 #include <mbgl/gfx/renderable.hpp>
 #include <mbgl/gl/renderer_backend.hpp>
-#include <mbgl/util/shared_thread_pool.hpp>
 
 class QMapboxGLRendererBackend final : public mbgl::gl::RendererBackend,
                                        public mbgl::gfx::Renderable {
diff --git a/src/core-files.json b/src/core-files.json
index c0412dd3a8..d721935268 100644
--- a/src/core-files.json
+++ b/src/core-files.json
@@ -302,6 +302,7 @@
         "src/mbgl/util/rapidjson.cpp",
         "src/mbgl/util/stopwatch.cpp",
         "src/mbgl/util/string.cpp",
+        "src/mbgl/util/thread_pool.cpp",
         "src/mbgl/util/tile_cover.cpp",
         "src/mbgl/util/tile_cover_impl.cpp",
         "src/mbgl/util/tiny_sdf.cpp",
@@ -762,6 +763,7 @@
         "mbgl/util/std.hpp": "src/mbgl/util/std.hpp",
         "mbgl/util/stopwatch.hpp": "src/mbgl/util/stopwatch.hpp",
         "mbgl/util/thread_local.hpp": "src/mbgl/util/thread_local.hpp",
+        "mbgl/util/thread_pool.hpp": "src/mbgl/util/thread_pool.hpp",
         "mbgl/util/tile_coordinate.hpp": "src/mbgl/util/tile_coordinate.hpp",
         "mbgl/util/tile_cover.hpp": "src/mbgl/util/tile_cover.hpp",
         "mbgl/util/tile_cover_impl.hpp": "src/mbgl/util/tile_cover_impl.hpp",
diff --git a/src/mbgl/actor/scheduler.cpp b/src/mbgl/actor/scheduler.cpp
index d7cdb2737b..cb0c7728ec 100644
--- a/src/mbgl/actor/scheduler.cpp
+++ b/src/mbgl/actor/scheduler.cpp
@@ -1,8 +1,11 @@
 #include <mbgl/actor/scheduler.hpp>
 #include <mbgl/util/thread_local.hpp>
+#include <mbgl/util/thread_pool.hpp>
 
 namespace mbgl {
-    
+
+util::ThreadLocal<Scheduler> g_currentScheduler;
+
 static auto& current() {
     static util::ThreadLocal<Scheduler> scheduler;
     return scheduler;
@@ -16,4 +19,19 @@ Scheduler* Scheduler::GetCurrent() {
     return current().get();
 }
 
+// static
+std::shared_ptr<Scheduler> Scheduler::GetBackground() {
+    static std::weak_ptr<Scheduler> weak;
+    static std::mutex mtx;
+
+    std::lock_guard<std::mutex> lock(mtx);
+    std::shared_ptr<Scheduler> scheduler = weak.lock();
+
+    if (!scheduler) {
+        weak = scheduler = std::make_shared<ThreadPool>(4);
+    }
+
+    return scheduler;
+}
+
 } //namespace mbgl
diff --git a/src/mbgl/map/map.cpp b/src/mbgl/map/map.cpp
index c31bb8ca34..c35f33305c 100644
--- a/src/mbgl/map/map.cpp
+++ b/src/mbgl/map/map.cpp
@@ -17,7 +17,6 @@
 #include <mbgl/util/exception.hpp>
 #include <mbgl/util/mapbox.hpp>
 #include <mbgl/util/tile_coordinate.hpp>
-#include <mbgl/actor/scheduler.hpp>
 #include <mbgl/util/logging.hpp>
 #include <mbgl/math/log2.hpp>
 
@@ -29,10 +28,9 @@ using namespace style;
 
 Map::Map(RendererFrontend& frontend,
          MapObserver& observer,
-         Scheduler& scheduler,
          const MapOptions& mapOptions,
          const ResourceOptions& resourceOptions)
-    : impl(std::make_unique<Impl>(frontend, observer, scheduler,
+    : impl(std::make_unique<Impl>(frontend, observer,
                                   FileSource::getSharedFileSource(resourceOptions),
                                   mapOptions)) {}
 
diff --git a/src/mbgl/map/map_impl.cpp b/src/mbgl/map/map_impl.cpp
index 1ec7255822..fa15461ff2 100644
--- a/src/mbgl/map/map_impl.cpp
+++ b/src/mbgl/map/map_impl.cpp
@@ -9,18 +9,16 @@ namespace mbgl {
 
 Map::Impl::Impl(RendererFrontend& frontend_,
                 MapObserver& observer_,
-                Scheduler& scheduler_,
                 std::shared_ptr<FileSource> fileSource_,
                 const MapOptions& mapOptions)
         : observer(observer_),
           rendererFrontend(frontend_),
-          scheduler(scheduler_),
           transform(observer, mapOptions.constrainMode(), mapOptions.viewportMode()),
           mode(mapOptions.mapMode()),
           pixelRatio(mapOptions.pixelRatio()),
           crossSourceCollisions(mapOptions.crossSourceCollisions()),
           fileSource(std::move(fileSource_)),
-          style(std::make_unique<style::Style>(scheduler, *fileSource, pixelRatio)),
+          style(std::make_unique<style::Style>(*fileSource, pixelRatio)),
           annotationManager(*style) {
     transform.setNorthOrientation(mapOptions.northOrientation());
     style->impl->setObserver(this);
diff --git a/src/mbgl/map/map_impl.hpp b/src/mbgl/map/map_impl.hpp
index f233f78275..84b43c8343 100644
--- a/src/mbgl/map/map_impl.hpp
+++ b/src/mbgl/map/map_impl.hpp
@@ -1,7 +1,5 @@
 #pragma once
 
-#include <mbgl/actor/actor.hpp>
-#include <mbgl/actor/scheduler.hpp>
 #include <mbgl/annotation/annotation_manager.hpp>
 #include <mbgl/map/map.hpp>
 #include <mbgl/map/map_observer.hpp>
@@ -30,7 +28,7 @@ struct StillImageRequest {
 
 class Map::Impl : public style::Observer, public RendererObserver {
 public:
-    Impl(RendererFrontend&, MapObserver&, Scheduler&, std::shared_ptr<FileSource>, const MapOptions&);
+    Impl(RendererFrontend&, MapObserver&, std::shared_ptr<FileSource>, const MapOptions&);
     ~Impl() final;
 
     // StyleObserver
@@ -54,7 +52,6 @@ public:
 
     MapObserver& observer;
     RendererFrontend& rendererFrontend;
-    Scheduler& scheduler;
 
     Transform transform;
 
diff --git a/src/mbgl/renderer/renderer.cpp b/src/mbgl/renderer/renderer.cpp
index 18cb0ebc07..ba213c435d 100644
--- a/src/mbgl/renderer/renderer.cpp
+++ b/src/mbgl/renderer/renderer.cpp
@@ -9,12 +9,10 @@ namespace mbgl {
 
 Renderer::Renderer(gfx::RendererBackend& backend,
                    float pixelRatio_,
-                   Scheduler& scheduler_,
                    const optional<std::string> programCacheDir_,
                    const optional<std::string> localFontFamily_)
     : impl(std::make_unique<Impl>(backend,
                                   pixelRatio_,
-                                  scheduler_,
                                   std::move(programCacheDir_),
                                   std::move(localFontFamily_))) {
 }
diff --git a/src/mbgl/renderer/renderer_impl.cpp b/src/mbgl/renderer/renderer_impl.cpp
index c756234e8d..3db9439b5c 100644
--- a/src/mbgl/renderer/renderer_impl.cpp
+++ b/src/mbgl/renderer/renderer_impl.cpp
@@ -40,11 +40,9 @@ static RendererObserver& nullObserver() {
 
 Renderer::Impl::Impl(gfx::RendererBackend& backend_,
                      float pixelRatio_,
-                     Scheduler& scheduler_,
                      const optional<std::string> programCacheDir_,
                      const optional<std::string> localFontFamily_)
     : backend(backend_)
-    , scheduler(scheduler_)
     , observer(&nullObserver())
     , pixelRatio(pixelRatio_)
     , programCacheDir(std::move(programCacheDir_))
@@ -114,7 +112,6 @@ void Renderer::Impl::render(const UpdateParameters& updateParameters) {
         updateParameters.pixelRatio,
         updateParameters.debugOptions,
         updateParameters.transformState,
-        scheduler,
         updateParameters.fileSource,
         updateParameters.mode,
         updateParameters.annotationManager,
diff --git a/src/mbgl/renderer/renderer_impl.hpp b/src/mbgl/renderer/renderer_impl.hpp
index f0d4720ce2..270ea4d517 100644
--- a/src/mbgl/renderer/renderer_impl.hpp
+++ b/src/mbgl/renderer/renderer_impl.hpp
@@ -26,7 +26,6 @@ class UpdateParameters;
 class RenderStaticData;
 class RenderedQueryOptions;
 class SourceQueryOptions;
-class Scheduler;
 class GlyphManager;
 class ImageManager;
 class LineAtlas;
@@ -42,7 +41,6 @@ class Renderer::Impl : public GlyphManagerObserver,
 public:
     Impl(gfx::RendererBackend&,
          float pixelRatio_,
-         Scheduler&,
          const optional<std::string> programCacheDir,
          const optional<std::string> localFontFamily_);
     ~Impl() final;
@@ -99,7 +97,6 @@ private:
     friend class Renderer;
 
     gfx::RendererBackend& backend;
-    Scheduler& scheduler;
 
     RendererObserver* observer;
 
diff --git a/src/mbgl/renderer/tile_parameters.hpp b/src/mbgl/renderer/tile_parameters.hpp
index 665c7490d2..cbe8dfb3ba 100644
--- a/src/mbgl/renderer/tile_parameters.hpp
+++ b/src/mbgl/renderer/tile_parameters.hpp
@@ -5,7 +5,6 @@
 namespace mbgl {
 
 class TransformState;
-class Scheduler;
 class FileSource;
 class AnnotationManager;
 class ImageManager;
@@ -16,7 +15,6 @@ public:
     const float pixelRatio;
     const MapDebugOptions debugOptions;
     const TransformState& transformState;
-    Scheduler& workerScheduler;
     FileSource& fileSource;
     const MapMode mode;
     AnnotationManager& annotationManager;
diff --git a/src/mbgl/sprite/sprite_loader.cpp b/src/mbgl/sprite/sprite_loader.cpp
index ce8fbe5894..bfb0c570d6 100644
--- a/src/mbgl/sprite/sprite_loader.cpp
+++ b/src/mbgl/sprite/sprite_loader.cpp
@@ -20,9 +20,9 @@ namespace mbgl {
 static SpriteLoaderObserver nullObserver;
 
 struct SpriteLoader::Loader {
-    Loader(Scheduler& scheduler, SpriteLoader& imageManager)
+    Loader(SpriteLoader& imageManager)
         : mailbox(std::make_shared<Mailbox>(*Scheduler::GetCurrent())),
-          worker(scheduler, ActorRef<SpriteLoader>(imageManager, mailbox)) {
+          worker(Scheduler::GetBackground(), ActorRef<SpriteLoader>(imageManager, mailbox)) {
     }
 
     std::shared_ptr<const std::string> image;
@@ -40,14 +40,14 @@ SpriteLoader::SpriteLoader(float pixelRatio_)
 
 SpriteLoader::~SpriteLoader() = default;
 
-void SpriteLoader::load(const std::string& url, Scheduler& scheduler, FileSource& fileSource) {
+void SpriteLoader::load(const std::string& url, FileSource& fileSource) {
     if (url.empty()) {
         // Treat a non-existent sprite as a successfully loaded empty sprite.
         observer->onSpriteLoaded({});
         return;
     }
 
-    loader = std::make_unique<Loader>(scheduler, *this);
+    loader = std::make_unique<Loader>(*this);
 
     loader->jsonRequest = fileSource.request(Resource::spriteJSON(url, pixelRatio), [this](Response res) {
         if (res.error) {
diff --git a/src/mbgl/sprite/sprite_loader.hpp b/src/mbgl/sprite/sprite_loader.hpp
index 0daf46be9c..0b7d37fa14 100644
--- a/src/mbgl/sprite/sprite_loader.hpp
+++ b/src/mbgl/sprite/sprite_loader.hpp
@@ -12,7 +12,6 @@
 
 namespace mbgl {
 
-class Scheduler;
 class FileSource;
 class SpriteLoaderObserver;
 
@@ -21,7 +20,7 @@ public:
     SpriteLoader(float pixelRatio);
     ~SpriteLoader();
 
-    void load(const std::string& url, Scheduler&, FileSource&);
+    void load(const std::string& url, FileSource&);
 
     void setObserver(SpriteLoaderObserver*);
 
diff --git a/src/mbgl/style/sources/custom_geometry_source.cpp b/src/mbgl/style/sources/custom_geometry_source.cpp
index 7420be9320..6e9d8d65fb 100644
--- a/src/mbgl/style/sources/custom_geometry_source.cpp
+++ b/src/mbgl/style/sources/custom_geometry_source.cpp
@@ -4,7 +4,6 @@
 #include <mbgl/actor/actor.hpp>
 #include <mbgl/actor/scheduler.hpp>
 #include <mbgl/tile/tile_id.hpp>
-#include <mbgl/util/shared_thread_pool.hpp>
 #include <tuple>
 #include <map>
 
@@ -14,8 +13,7 @@ namespace style {
 CustomGeometrySource::CustomGeometrySource(std::string id,
                                        const CustomGeometrySource::Options options)
     : Source(makeMutable<CustomGeometrySource::Impl>(std::move(id), options)),
-    threadPool(sharedThreadPool()),
-    loader(std::make_unique<Actor<CustomTileLoader>>(*threadPool, options.fetchTileFunction, options.cancelTileFunction)) {
+    loader(std::make_unique<Actor<CustomTileLoader>>(Scheduler::GetBackground(), options.fetchTileFunction, options.cancelTileFunction)) {
 }
 
 CustomGeometrySource::~CustomGeometrySource() = default;
diff --git a/src/mbgl/style/style.cpp b/src/mbgl/style/style.cpp
index bd8631fc52..783c850097 100644
--- a/src/mbgl/style/style.cpp
+++ b/src/mbgl/style/style.cpp
@@ -8,8 +8,8 @@
 namespace mbgl {
 namespace style {
 
-Style::Style(Scheduler& scheduler, FileSource& fileSource, float pixelRatio)
-    : impl(std::make_unique<Impl>(scheduler, fileSource, pixelRatio)) {
+Style::Style(FileSource& fileSource, float pixelRatio)
+    : impl(std::make_unique<Impl>(fileSource, pixelRatio)) {
 }
 
 Style::~Style() = default;
diff --git a/src/mbgl/style/style_impl.cpp b/src/mbgl/style/style_impl.cpp
index d527b8440b..10fee73cdd 100644
--- a/src/mbgl/style/style_impl.cpp
+++ b/src/mbgl/style/style_impl.cpp
@@ -27,9 +27,8 @@ namespace style {
 
 static Observer nullObserver;
 
-Style::Impl::Impl(Scheduler& scheduler_, FileSource& fileSource_, float pixelRatio)
-    : scheduler(scheduler_),
-      fileSource(fileSource_),
+Style::Impl::Impl(FileSource& fileSource_, float pixelRatio)
+    : fileSource(fileSource_),
       spriteLoader(std::make_unique<SpriteLoader>(pixelRatio)),
       light(std::make_unique<Light>()),
       observer(&nullObserver) {
@@ -111,7 +110,7 @@ void Style::Impl::parse(const std::string& json_) {
     setLight(std::make_unique<Light>(parser.light));
 
     spriteLoaded = false;
-    spriteLoader->load(parser.spriteURL, scheduler, fileSource);
+    spriteLoader->load(parser.spriteURL, fileSource);
     glyphURL = parser.glyphURL;
 
     loaded = true;
diff --git a/src/mbgl/style/style_impl.hpp b/src/mbgl/style/style_impl.hpp
index 3dc222bfad..4c56f6785b 100644
--- a/src/mbgl/style/style_impl.hpp
+++ b/src/mbgl/style/style_impl.hpp
@@ -25,7 +25,6 @@
 
 namespace mbgl {
 
-class Scheduler;
 class FileSource;
 class AsyncRequest;
 class SpriteLoader;
@@ -38,7 +37,7 @@ class Style::Impl : public SpriteLoaderObserver,
                     public LightObserver,
                     public util::noncopyable {
 public:
-    Impl(Scheduler&, FileSource&, float pixelRatio);
+    Impl(FileSource&, float pixelRatio);
     ~Impl() override;
 
     void loadJSON(const std::string&);
@@ -98,7 +97,6 @@ public:
 private:
     void parse(const std::string&);
 
-    Scheduler& scheduler;
     FileSource& fileSource;
 
     std::string url;
diff --git a/src/mbgl/tile/geometry_tile.cpp b/src/mbgl/tile/geometry_tile.cpp
index 029c761e53..d110b2f826 100644
--- a/src/mbgl/tile/geometry_tile.cpp
+++ b/src/mbgl/tile/geometry_tile.cpp
@@ -1,4 +1,5 @@
 #include <mbgl/tile/geometry_tile.hpp>
+
 #include <mbgl/tile/geometry_tile_worker.hpp>
 #include <mbgl/tile/geometry_tile_data.hpp>
 #include <mbgl/tile/tile_observer.hpp>
@@ -45,7 +46,7 @@ GeometryTile::GeometryTile(const OverscaledTileID& id_,
       ImageRequestor(parameters.imageManager),
       sourceID(std::move(sourceID_)),
       mailbox(std::make_shared<Mailbox>(*Scheduler::GetCurrent())),
-      worker(parameters.workerScheduler,
+      worker(Scheduler::GetBackground(),
              ActorRef<GeometryTile>(*this, mailbox),
              id_,
              sourceID,
diff --git a/src/mbgl/tile/raster_dem_tile.cpp b/src/mbgl/tile/raster_dem_tile.cpp
index 224c5c9062..8b4e0113c7 100644
--- a/src/mbgl/tile/raster_dem_tile.cpp
+++ b/src/mbgl/tile/raster_dem_tile.cpp
@@ -1,4 +1,5 @@
 #include <mbgl/tile/raster_dem_tile.hpp>
+
 #include <mbgl/tile/raster_dem_tile_worker.hpp>
 #include <mbgl/tile/tile_observer.hpp>
 #include <mbgl/tile/tile_loader_impl.hpp>
@@ -17,7 +18,7 @@ RasterDEMTile::RasterDEMTile(const OverscaledTileID& id_,
     : Tile(Kind::RasterDEM, id_),
       loader(*this, id_, parameters, tileset),
       mailbox(std::make_shared<Mailbox>(*Scheduler::GetCurrent())),
-      worker(parameters.workerScheduler,
+      worker(Scheduler::GetBackground(),
              ActorRef<RasterDEMTile>(*this, mailbox)) {
 
     encoding = tileset.encoding;
diff --git a/src/mbgl/tile/raster_tile.cpp b/src/mbgl/tile/raster_tile.cpp
index ff02301021..9da11b3595 100644
--- a/src/mbgl/tile/raster_tile.cpp
+++ b/src/mbgl/tile/raster_tile.cpp
@@ -1,4 +1,5 @@
 #include <mbgl/tile/raster_tile.hpp>
+
 #include <mbgl/tile/raster_tile_worker.hpp>
 #include <mbgl/tile/tile_observer.hpp>
 #include <mbgl/tile/tile_loader_impl.hpp>
@@ -17,7 +18,7 @@ RasterTile::RasterTile(const OverscaledTileID& id_,
     : Tile(Kind::Raster, id_),
       loader(*this, id_, parameters, tileset),
       mailbox(std::make_shared<Mailbox>(*Scheduler::GetCurrent())),
-      worker(parameters.workerScheduler,
+      worker(Scheduler::GetBackground(),
              ActorRef<RasterTile>(*this, mailbox)) {
 }
 
diff --git a/platform/default/src/mbgl/util/default_thread_pool.cpp b/src/mbgl/util/thread_pool.cpp
index d3950bb8aa..79c2f75012 100644
--- a/platform/default/src/mbgl/util/default_thread_pool.cpp
+++ b/src/mbgl/util/thread_pool.cpp
@@ -1,5 +1,5 @@
-#include <mbgl/util/default_thread_pool.hpp>
-#include <mbgl/actor/mailbox.hpp>
+#include <mbgl/util/thread_pool.hpp>
+
 #include <mbgl/util/platform.hpp>
 #include <mbgl/util/string.hpp>
 
@@ -7,6 +7,7 @@ namespace mbgl {
 
 ThreadPool::ThreadPool(std::size_t count) {
     threads.reserve(count);
+
     for (std::size_t i = 0; i < count; ++i) {
         threads.emplace_back([this, i]() {
             platform::setCurrentThreadName(std::string{ "Worker " } + util::toString(i + 1));
diff --git a/platform/default/include/mbgl/util/default_thread_pool.hpp b/src/mbgl/util/thread_pool.hpp
index a14d16d771..509fd06061 100644
--- a/platform/default/include/mbgl/util/default_thread_pool.hpp
+++ b/src/mbgl/util/thread_pool.hpp
@@ -1,5 +1,6 @@
 #pragma once
 
+#include <mbgl/actor/mailbox.hpp>
 #include <mbgl/actor/scheduler.hpp>
 
 #include <condition_variable>
@@ -9,9 +10,9 @@
 
 namespace mbgl {
 
-class ThreadPool : public Scheduler {
+class ThreadPool final : public Scheduler {
 public:
-    ThreadPool(std::size_t count);
+    explicit ThreadPool(std::size_t count);
     ~ThreadPool() override;
 
     void schedule(std::weak_ptr<Mailbox>) override;
@@ -21,7 +22,7 @@ private:
     std::queue<std::weak_ptr<Mailbox>> queue;
     std::mutex mutex;
     std::condition_variable cv;
-    bool terminate { false };
+    bool terminate{ false };
 };
 
 } // namespace mbgl
diff --git a/test/actor/actor.test.cpp b/test/actor/actor.test.cpp
index 02308b7ce0..6db95a83f1 100644
--- a/test/actor/actor.test.cpp
+++ b/test/actor/actor.test.cpp
@@ -1,8 +1,8 @@
 #include <mbgl/actor/actor.hpp>
-#include <mbgl/util/default_thread_pool.hpp>
-#include <mbgl/util/run_loop.hpp>
 
+#include <mbgl/actor/scheduler.hpp>
 #include <mbgl/test/util.hpp>
+#include <mbgl/util/run_loop.hpp>
 
 #include <chrono>
 #include <functional>
@@ -20,9 +20,8 @@ TEST(Actor, Construction) {
         };
     };
 
-    ThreadPool pool { 1 };
     bool constructed = false;
-    Actor<Test> test(pool, std::ref(constructed));
+    Actor<Test> test(Scheduler::GetBackground(), std::ref(constructed));
 
     EXPECT_TRUE(constructed);
 }
@@ -33,14 +32,13 @@ TEST(Actor, Destruction) {
         ~Test() {
             destructed = true;
         }
-        
+
         bool& destructed;
     };
 
-    ThreadPool pool { 1 };
     bool destructed = false;
     {
-        Actor<Test> test(pool, std::ref(destructed));
+        Actor<Test> test(Scheduler::GetBackground(), std::ref(destructed));
     }
 
     EXPECT_TRUE(destructed);
@@ -72,15 +70,13 @@ TEST(Actor, DestructionBlocksOnReceive) {
         }
     };
 
-    ThreadPool pool { 1 };
-
     std::promise<void> enteredPromise;
     std::future<void> enteredFuture = enteredPromise.get_future();
 
     std::promise<void> exitingPromise;
     std::future<void> exitingFuture = exitingPromise.get_future();
 
-    Actor<Test> test(pool, std::move(enteredPromise), std::move(exitingFuture));
+    Actor<Test> test(Scheduler::GetBackground(), std::move(enteredPromise), std::move(exitingFuture));
 
     test.self().invoke(&Test::wait);
     enteredFuture.wait();
@@ -157,11 +153,9 @@ TEST(Actor, DestructionAllowedInReceiveOnSameThread) {
         }
     };
 
-    ThreadPool pool { 1 };
-
     std::promise<void> callbackFiredPromise;
-
-    auto test = std::make_unique<Actor<Test>>(pool);
+    auto retainer = Scheduler::GetBackground();
+    auto test = std::make_unique<Actor<Test>>(retainer);
 
     // Callback (triggered while mutex is locked in Mailbox::receive())
     test->self().invoke(&Test::callMeBack, [&]() {
@@ -189,12 +183,10 @@ TEST(Actor, SelfDestructionDoesntCrashWaitingReceivingThreads) {
     };
 
 
-    ThreadPool pool { 2 };
-
     std::promise<void> actorClosedPromise;
 
-    auto closingActor = std::make_unique<Actor<Test>>(pool);
-    auto waitingActor = std::make_unique<Actor<Test>>(pool);
+    auto closingActor = std::make_unique<Actor<Test>>(Scheduler::GetBackground());
+    auto waitingActor = std::make_unique<Actor<Test>>(Scheduler::GetBackground());
 
     std::atomic<bool> waitingMessageProcessed {false};
 
@@ -251,11 +243,9 @@ TEST(Actor, OrderedMailbox) {
         }
     };
 
-    ThreadPool pool { 1 };
-
     std::promise<void> endedPromise;
     std::future<void> endedFuture = endedPromise.get_future();
-    Actor<Test> test(pool, std::move(endedPromise));
+    Actor<Test> test(Scheduler::GetBackground(), std::move(endedPromise));
 
     for (auto i = 1; i <= 10; ++i) {
         test.self().invoke(&Test::receive, i);
@@ -287,11 +277,9 @@ TEST(Actor, NonConcurrentMailbox) {
         }
     };
 
-    ThreadPool pool { 10 };
-
     std::promise<void> endedPromise;
     std::future<void> endedFuture = endedPromise.get_future();
-    Actor<Test> test(pool, std::move(endedPromise));
+    Actor<Test> test(Scheduler::GetBackground(), std::move(endedPromise));
 
     for (auto i = 1; i <= 10; ++i) {
         test.self().invoke(&Test::receive, i);
@@ -313,13 +301,12 @@ TEST(Actor, Ask) {
         }
     };
 
-    ThreadPool pool { 2 };
-    Actor<Test> test(pool);
+    Actor<Test> test(Scheduler::GetBackground());
 
     auto result = test.self().ask(&Test::doubleIt, 1);
 
     ASSERT_TRUE(result.valid());
-    
+
     auto status = result.wait_for(std::chrono::seconds(1));
     ASSERT_EQ(std::future_status::ready, status);
     ASSERT_EQ(2, result.get());
@@ -339,9 +326,8 @@ TEST(Actor, AskVoid) {
         }
     };
 
-    ThreadPool pool { 1 };
     bool executed = false;
-    Actor<Test> actor(pool, executed);
+    Actor<Test> actor(Scheduler::GetBackground(), executed);
 
     actor.self().ask(&Test::doIt).get();
     EXPECT_TRUE(executed);
@@ -349,31 +335,30 @@ TEST(Actor, AskVoid) {
 
 TEST(Actor, NoSelfActorRef) {
     // Not all actors need a reference to self
-    
+
     // Trivially constructable
     struct Trivial {};
-    
-    ThreadPool pool { 2 };
-    Actor<Trivial> trivial(pool);
-    
-    
+
+    Actor<Trivial> trivial(Scheduler::GetBackground());
+
+
     // With arguments
     struct WithArguments {
         std::promise<void> promise;
-        
+
         WithArguments(std::promise<void> promise_)
         : promise(std::move(promise_)) {
         }
-        
+
         void receive() {
             promise.set_value();
         }
     };
-    
+
     std::promise<void> promise;
     auto future = promise.get_future();
-    Actor<WithArguments> withArguments(pool, std::move(promise));
-    
+    Actor<WithArguments> withArguments(Scheduler::GetBackground(), std::move(promise));
+
     withArguments.self().invoke(&WithArguments::receive);
     future.wait();
 }
@@ -386,32 +371,32 @@ TEST(Actor, TwoPhaseConstruction) {
     struct Test {
         Test(ActorRef<Test>, std::shared_ptr<bool> destroyed_)
             : destroyed(std::move(destroyed_)) {};
-        
+
         ~Test() {
             *destroyed = true;
         }
-        
+
         void callMe(std::promise<void> p) {
             p.set_value();
         }
-        
+
         void stop() {
             util::RunLoop::Get()->stop();
         }
-        
+
         std::shared_ptr<bool> destroyed;
     };
 
     AspiringActor<Test> parent;
-    
+
     auto destroyed = std::make_shared<bool>(false);
-    
+
     std::promise<void> queueExecuted;
     auto queueExecutedFuture = queueExecuted.get_future();
-    
+
     parent.self().invoke(&Test::callMe, std::move(queueExecuted));
     parent.self().invoke(&Test::stop);
-    
+
     auto thread = std::thread([
         capturedArgs = std::make_tuple(destroyed),
         &parent
@@ -420,11 +405,11 @@ TEST(Actor, TwoPhaseConstruction) {
         EstablishedActor<Test> test(loop, parent, capturedArgs);
         loop.run();
     });
-    
+
     // should not hang
     queueExecutedFuture.get();
     thread.join();
-    
+
     EXPECT_TRUE(*destroyed);
 }
 
diff --git a/test/actor/actor_ref.test.cpp b/test/actor/actor_ref.test.cpp
index 20aa1c35c1..221a220ed9 100644
--- a/test/actor/actor_ref.test.cpp
+++ b/test/actor/actor_ref.test.cpp
@@ -1,6 +1,6 @@
 #include <mbgl/actor/actor.hpp>
-#include <mbgl/util/default_thread_pool.hpp>
 
+#include <mbgl/actor/scheduler.hpp>
 #include <mbgl/test/util.hpp>
 
 #include <future>
@@ -27,11 +27,10 @@ TEST(ActorRef, CanOutliveActor) {
         }
     };
 
-    ThreadPool pool { 1 };
     bool died = false;
 
     ActorRef<Test> test = [&] () {
-        return Actor<Test>(pool, std::ref(died)).self();
+        return Actor<Test>(Scheduler::GetBackground(), std::ref(died)).self();
     }();
 
     EXPECT_TRUE(died);
@@ -54,8 +53,7 @@ TEST(ActorRef, Ask) {
         }
     };
 
-    ThreadPool pool { 1 };
-    Actor<Test> actor(pool);
+    Actor<Test> actor(Scheduler::GetBackground());
     ActorRef<Test> ref = actor.self();
 
     EXPECT_EQ(20, ref.ask(&Test::gimme).get());
@@ -76,9 +74,8 @@ TEST(ActorRef, AskVoid) {
         }
     };
     
-    ThreadPool pool { 1 };
     bool executed = false;
-    Actor<Test> actor(pool, executed);
+    Actor<Test> actor(Scheduler::GetBackground(), executed);
     ActorRef<Test> ref = actor.self();
     
     ref.ask(&Test::doIt).get();
@@ -104,8 +101,7 @@ TEST(ActorRef, AskOnDestroyedActor) {
     };
     bool died = false;
 
-    ThreadPool pool { 1 };
-    auto actor = std::make_unique<Actor<Test>>(pool, died);
+    auto actor = std::make_unique<Actor<Test>>(Scheduler::GetBackground(), died);
     ActorRef<Test> ref = actor->self();
 
     actor.reset();
diff --git a/test/api/annotations.test.cpp b/test/api/annotations.test.cpp
index 11920d1624..2d76a3d154 100644
--- a/test/api/annotations.test.cpp
+++ b/test/api/annotations.test.cpp
@@ -2,7 +2,6 @@
 #include <mbgl/test/stub_file_source.hpp>
 #include <mbgl/test/map_adapter.hpp>
 
-#include <mbgl/util/default_thread_pool.hpp>
 #include <mbgl/annotation/annotation.hpp>
 #include <mbgl/style/style.hpp>
 #include <mbgl/style/image.hpp>
@@ -28,10 +27,9 @@ std::unique_ptr<style::Image> namedMarker(const std::string& name) {
 class AnnotationTest {
 public:
     util::RunLoop loop;
-    ThreadPool threadPool { 4 };
-    HeadlessFrontend frontend { 1, threadPool };
+    HeadlessFrontend frontend { 1 };
 
-    MapAdapter map { frontend, MapObserver::nullObserver(), std::make_shared<StubFileSource>(), threadPool,
+    MapAdapter map { frontend, MapObserver::nullObserver(), std::make_shared<StubFileSource>(),
                   MapOptions().withMapMode(MapMode::Static).withSize(frontend.getSize())};
 
     void checkRendering(const char * name) {
diff --git a/test/api/api_misuse.test.cpp b/test/api/api_misuse.test.cpp
index b65bdf9918..54d8eb5912 100644
--- a/test/api/api_misuse.test.cpp
+++ b/test/api/api_misuse.test.cpp
@@ -6,7 +6,6 @@
 #include <mbgl/map/map_options.hpp>
 #include <mbgl/gfx/backend_scope.hpp>
 #include <mbgl/gl/headless_frontend.hpp>
-#include <mbgl/util/default_thread_pool.hpp>
 #include <mbgl/util/exception.hpp>
 #include <mbgl/util/run_loop.hpp>
 
@@ -21,11 +20,10 @@ TEST(API, RenderWithoutCallback) {
 
     util::RunLoop loop;
 
-    ThreadPool threadPool(4);
-    HeadlessFrontend frontend { 1, threadPool };
+    HeadlessFrontend frontend { 1 };
 
     auto map = std::make_unique<MapAdapter>(frontend, MapObserver::nullObserver(),
-                                            std::make_shared<StubFileSource>(), threadPool,
+                                            std::make_shared<StubFileSource>(),
                                             MapOptions().withMapMode(MapMode::Static).withSize(frontend.getSize()));
     map->renderStill(nullptr);
 
diff --git a/test/api/custom_geometry_source.test.cpp b/test/api/custom_geometry_source.test.cpp
index f796e3086b..df65dc2703 100644
--- a/test/api/custom_geometry_source.test.cpp
+++ b/test/api/custom_geometry_source.test.cpp
@@ -2,7 +2,6 @@
 
 #include <mbgl/map/map.hpp>
 #include <mbgl/map/map_options.hpp>
-#include <mbgl/util/shared_thread_pool.hpp>
 #include <mbgl/gl/headless_frontend.hpp>
 #include <mbgl/storage/resource_options.hpp>
 #include <mbgl/style/style.hpp>
@@ -20,9 +19,8 @@ using namespace mbgl::style;
 TEST(CustomGeometrySource, Grid) {
     util::RunLoop loop;
 
-    auto threadPool = sharedThreadPool();
-    HeadlessFrontend frontend { 1, *threadPool };
-    Map map(frontend, MapObserver::nullObserver(), *threadPool,
+    HeadlessFrontend frontend { 1 };
+    Map map(frontend, MapObserver::nullObserver(),
             MapOptions().withMapMode(MapMode::Static).withSize(frontend.getSize()),
             ResourceOptions().withCachePath(":memory:").withAssetPath("test/fixtures/api/assets"));
     map.getStyle().loadJSON(util::read_file("test/fixtures/api/water.json"));
diff --git a/test/api/custom_layer.test.cpp b/test/api/custom_layer.test.cpp
index 4a0a34bafc..e9b9aee9bc 100644
--- a/test/api/custom_layer.test.cpp
+++ b/test/api/custom_layer.test.cpp
@@ -3,7 +3,6 @@
 #include <mbgl/platform/gl_functions.hpp>
 #include <mbgl/map/map.hpp>
 #include <mbgl/map/map_options.hpp>
-#include <mbgl/util/default_thread_pool.hpp>
 #include <mbgl/gl/defines.hpp>
 #include <mbgl/gl/headless_frontend.hpp>
 #include <mbgl/storage/resource_options.hpp>
@@ -90,9 +89,8 @@ public:
 TEST(CustomLayer, Basic) {
     util::RunLoop loop;
 
-    ThreadPool threadPool(4);
-    HeadlessFrontend frontend { 1, threadPool };
-    Map map(frontend, MapObserver::nullObserver(), threadPool,
+    HeadlessFrontend frontend { 1 };
+    Map map(frontend, MapObserver::nullObserver(),
             MapOptions().withMapMode(MapMode::Static).withSize(frontend.getSize()),
             ResourceOptions().withCachePath(":memory:").withAssetPath("test/fixtures/api/assets"));
     map.getStyle().loadJSON(util::read_file("test/fixtures/api/water.json"));
diff --git a/test/api/query.test.cpp b/test/api/query.test.cpp
index ddf5df6aab..b80d3b7d8a 100644
--- a/test/api/query.test.cpp
+++ b/test/api/query.test.cpp
@@ -1,7 +1,6 @@
 #include <mbgl/test/map_adapter.hpp>
 
 #include <mbgl/map/map_options.hpp>
-#include <mbgl/util/default_thread_pool.hpp>
 #include <mbgl/test/stub_file_source.hpp>
 #include <mbgl/test/util.hpp>
 #include <mbgl/util/image.hpp>
@@ -35,9 +34,8 @@ public:
 
     util::RunLoop loop;
     std::shared_ptr<StubFileSource> fileSource = std::make_shared<StubFileSource>();
-    ThreadPool threadPool { 4 };
-    HeadlessFrontend frontend { 1, threadPool };
-    MapAdapter map { frontend, MapObserver::nullObserver(), fileSource, threadPool,
+    HeadlessFrontend frontend { 1 };
+    MapAdapter map { frontend, MapObserver::nullObserver(), fileSource,
                   MapOptions().withMapMode(MapMode::Static).withSize(frontend.getSize())};
 };
 
diff --git a/test/api/recycle_map.cpp b/test/api/recycle_map.cpp
index 18cc9c00aa..55e19e3cd9 100644
--- a/test/api/recycle_map.cpp
+++ b/test/api/recycle_map.cpp
@@ -9,7 +9,6 @@
 #include <mbgl/style/sources/geojson_source.hpp>
 #include <mbgl/style/image.hpp>
 #include <mbgl/style/style.hpp>
-#include <mbgl/util/default_thread_pool.hpp>
 #include <mbgl/util/exception.hpp>
 #include <mbgl/util/geometry.hpp>
 #include <mbgl/util/geojson.hpp>
@@ -23,11 +22,9 @@ using namespace mbgl::style;
 TEST(API, RecycleMapUpdateImages) {
     util::RunLoop loop;
 
-    ThreadPool threadPool(4);
-
-    HeadlessFrontend frontend { 1, threadPool };
+    HeadlessFrontend frontend { 1 };
     auto map = std::make_unique<MapAdapter>(frontend, MapObserver::nullObserver(),
-                                         std::make_shared<StubFileSource>(), threadPool,
+                                         std::make_shared<StubFileSource>(),
                                          MapOptions().withMapMode(MapMode::Static).withSize(frontend.getSize()));
 
     EXPECT_TRUE(map);
diff --git a/test/gl/context.test.cpp b/test/gl/context.test.cpp
index b8fe895c44..756f2c58d4 100644
--- a/test/gl/context.test.cpp
+++ b/test/gl/context.test.cpp
@@ -4,7 +4,6 @@
 #include <mbgl/gl/context.hpp>
 #include <mbgl/map/map.hpp>
 #include <mbgl/map/map_options.hpp>
-#include <mbgl/util/default_thread_pool.hpp>
 #include <mbgl/gfx/backend_scope.hpp>
 #include <mbgl/gl/defines.hpp>
 #include <mbgl/gl/headless_frontend.hpp>
@@ -88,11 +87,9 @@ struct Buffer {
 TEST(GLContextMode, Shared) {
     util::RunLoop loop;
 
-    ThreadPool threadPool(4);
+    HeadlessFrontend frontend { 1, {}, gfx::ContextMode::Shared };
 
-    HeadlessFrontend frontend { 1, threadPool, {}, gfx::ContextMode::Shared };
-
-    Map map(frontend, MapObserver::nullObserver(), threadPool,
+    Map map(frontend, MapObserver::nullObserver(),
             MapOptions().withMapMode(MapMode::Static).withSize(frontend.getSize()),
             ResourceOptions().withCachePath(":memory:").withAssetPath("test/fixtures/api/assets"));
     map.getStyle().loadJSON(util::read_file("test/fixtures/api/water.json"));
diff --git a/test/map/map.test.cpp b/test/map/map.test.cpp
index 3af2acdb8b..ee86ce7f77 100644
--- a/test/map/map.test.cpp
+++ b/test/map/map.test.cpp
@@ -9,7 +9,6 @@
 #include <mbgl/gfx/backend_scope.hpp>
 #include <mbgl/gl/context.hpp>
 #include <mbgl/gl/headless_frontend.hpp>
-#include <mbgl/util/default_thread_pool.hpp>
 #include <mbgl/storage/resource_options.hpp>
 #include <mbgl/storage/network_status.hpp>
 #include <mbgl/storage/default_file_source.hpp>
@@ -34,15 +33,14 @@ class MapTest {
 public:
     util::RunLoop runLoop;
     std::shared_ptr<FileSource> fileSource;
-    ThreadPool threadPool { 4 };
     StubMapObserver observer;
     HeadlessFrontend frontend;
     MapAdapter map;
 
     MapTest(float pixelRatio = 1, MapMode mode = MapMode::Static)
         : fileSource(std::make_shared<FileSource>())
-        , frontend(pixelRatio, threadPool)
-        , map(frontend, observer, fileSource, threadPool,
+        , frontend(pixelRatio)
+        , map(frontend, observer, fileSource,
               MapOptions().withMapMode(mode).withSize(frontend.getSize()).withPixelRatio(pixelRatio)) {}
 
     template <typename T = FileSource>
@@ -50,8 +48,8 @@ public:
             float pixelRatio = 1, MapMode mode = MapMode::Static,
             typename std::enable_if<std::is_same<T, DefaultFileSource>::value>::type* = nullptr)
             : fileSource(std::make_shared<T>(cachePath, assetPath))
-            , frontend(pixelRatio, threadPool)
-            , map(frontend, observer, fileSource, threadPool,
+            , frontend(pixelRatio)
+            , map(frontend, observer, fileSource,
                   MapOptions().withMapMode(mode).withSize(frontend.getSize()).withPixelRatio(pixelRatio)) {}
 };
 
@@ -744,7 +742,6 @@ TEST(Map, DontLoadUnneededTiles) {
 
 TEST(Map, TEST_DISABLED_ON_CI(ContinuousRendering)) {
     util::RunLoop runLoop;
-    ThreadPool threadPool { 4 };
 
     using namespace std::chrono_literals;
 
@@ -756,7 +753,7 @@ TEST(Map, TEST_DISABLED_ON_CI(ContinuousRendering)) {
 
     util::Timer timer;
 
-    HeadlessFrontend frontend(1, threadPool);
+    HeadlessFrontend frontend(1);
 
     StubMapObserver observer;
     observer.didFinishRenderingFrameCallback = [&] (MapObserver::RenderMode) {
@@ -768,7 +765,7 @@ TEST(Map, TEST_DISABLED_ON_CI(ContinuousRendering)) {
         });
     };
 
-    Map map(frontend, observer, threadPool,
+    Map map(frontend, observer,
             MapOptions().withMapMode(MapMode::Continuous).withSize(frontend.getSize()),
             ResourceOptions().withCachePath(":memory:").withAssetPath("test/fixtures/api/assets"));
     map.getStyle().loadJSON(util::read_file("test/fixtures/api/water.json"));
diff --git a/test/map/prefetch.test.cpp b/test/map/prefetch.test.cpp
index 3232c99a22..071c918427 100644
--- a/test/map/prefetch.test.cpp
+++ b/test/map/prefetch.test.cpp
@@ -6,7 +6,6 @@
 #include <mbgl/map/map_options.hpp>
 #include <mbgl/gl/headless_frontend.hpp>
 #include <mbgl/style/style.hpp>
-#include <mbgl/util/default_thread_pool.hpp>
 #include <mbgl/util/image.hpp>
 #include <mbgl/util/io.hpp>
 #include <mbgl/util/run_loop.hpp>
@@ -22,7 +21,6 @@ using namespace std::chrono_literals;
 
 TEST(Map, PrefetchTiles) {
     util::RunLoop runLoop;
-    ThreadPool threadPool(4);
     std::shared_ptr<StubFileSource> fileSource = std::make_shared<StubFileSource>();
 
     util::Timer emergencyShutoff;
@@ -36,8 +34,8 @@ TEST(Map, PrefetchTiles) {
         runLoop.stop();
     };
 
-    HeadlessFrontend frontend { { 512, 512 }, 1, threadPool };
-    MapAdapter map(frontend, observer, fileSource, threadPool,
+    HeadlessFrontend frontend { { 512, 512 }, 1 };
+    MapAdapter map(frontend, observer, fileSource,
                 MapOptions().withMapMode(MapMode::Continuous).withSize(frontend.getSize()));
 
     std::vector<int> tiles;
diff --git a/test/renderer/image_manager.test.cpp b/test/renderer/image_manager.test.cpp
index 7f0d670846..87a24e3bd3 100644
--- a/test/renderer/image_manager.test.cpp
+++ b/test/renderer/image_manager.test.cpp
@@ -9,7 +9,6 @@
 #include <mbgl/util/io.hpp>
 #include <mbgl/util/image.hpp>
 #include <mbgl/util/run_loop.hpp>
-#include <mbgl/util/default_thread_pool.hpp>
 #include <mbgl/util/string.hpp>
 
 #include <utility>
diff --git a/test/sprite/sprite_loader.test.cpp b/test/sprite/sprite_loader.test.cpp
index 3691572265..122e711f51 100644
--- a/test/sprite/sprite_loader.test.cpp
+++ b/test/sprite/sprite_loader.test.cpp
@@ -8,7 +8,6 @@
 #include <mbgl/util/io.hpp>
 #include <mbgl/util/image.hpp>
 #include <mbgl/util/run_loop.hpp>
-#include <mbgl/util/default_thread_pool.hpp>
 #include <mbgl/util/string.hpp>
 
 #include <utility>
@@ -37,7 +36,6 @@ public:
     util::RunLoop loop;
     StubFileSource fileSource;
     StubSpriteLoaderObserver observer;
-    ThreadPool threadPool { 1 };
     SpriteLoader spriteLoader{ 1 };
 
     void run() {
@@ -45,7 +43,7 @@ public:
         Log::setObserver(std::make_unique<Log::NullObserver>());
 
         spriteLoader.setObserver(&observer);
-        spriteLoader.load("test/fixtures/resources/sprite", threadPool, fileSource);
+        spriteLoader.load("test/fixtures/resources/sprite", fileSource);
 
         loop.run();
     }
diff --git a/test/src/mbgl/test/map_adapter.hpp b/test/src/mbgl/test/map_adapter.hpp
index 5bdab1d164..d4af579ae1 100644
--- a/test/src/mbgl/test/map_adapter.hpp
+++ b/test/src/mbgl/test/map_adapter.hpp
@@ -13,9 +13,8 @@ public:
     explicit MapAdapter(RendererFrontend& frontend,
                         MapObserver& observer,
                         std::shared_ptr<FileSource> fileSource,
-                        Scheduler& scheduler,
                         const MapOptions& options)
-        : Map(std::make_unique<Map::Impl>(frontend, observer, scheduler, std::move(fileSource), options)) {}
+        : Map(std::make_unique<Map::Impl>(frontend, observer, std::move(fileSource), options)) {}
 };
 
 } // namespace mbgl
diff --git a/test/src/mbgl/test/test.cpp b/test/src/mbgl/test/test.cpp
index 4c3dad1727..1c77aae2a1 100644
--- a/test/src/mbgl/test/test.cpp
+++ b/test/src/mbgl/test/test.cpp
@@ -1,3 +1,4 @@
+#include <mbgl/actor/scheduler.hpp>
 #include <mbgl/test.hpp>
 #include <mbgl/test/util.hpp>
 
diff --git a/test/style/source.test.cpp b/test/style/source.test.cpp
index f0ff1f81b4..289e41c75f 100644
--- a/test/style/source.test.cpp
+++ b/test/style/source.test.cpp
@@ -31,7 +31,6 @@
 #include <mbgl/util/image.hpp>
 
 #include <mbgl/util/tileset.hpp>
-#include <mbgl/util/shared_thread_pool.hpp>
 #include <mbgl/util/logging.hpp>
 #include <mbgl/util/optional.hpp>
 #include <mbgl/util/range.hpp>
@@ -55,8 +54,7 @@ public:
     StubRenderSourceObserver renderSourceObserver;
     Transform transform;
     TransformState transformState;
-    ThreadPool threadPool { 1 };
-    Style style { loop, fileSource, 1 };
+    Style style { fileSource, 1 };
     AnnotationManager annotationManager { style };
     ImageManager imageManager;
     GlyphManager glyphManager { fileSource };
@@ -65,7 +63,6 @@ public:
         1.0,
         MapDebugOptions(),
         transformState,
-        threadPool,
         fileSource,
         MapMode::Continuous,
         annotationManager,
@@ -763,7 +760,6 @@ TEST(Source, ImageSourceImageUpdate) {
 
 TEST(Source, CustomGeometrySourceSetTileData) {
     SourceTest test;
-    std::shared_ptr<ThreadPool> threadPool = sharedThreadPool();
     CustomGeometrySource source("source", CustomGeometrySource::Options());
     source.loadDescription(test.fileSource);
 
diff --git a/test/style/style.test.cpp b/test/style/style.test.cpp
index 7f57651331..72f74d3b01 100644
--- a/test/style/style.test.cpp
+++ b/test/style/style.test.cpp
@@ -9,7 +9,6 @@
 #include <mbgl/style/layers/line_layer.hpp>
 #include <mbgl/util/io.hpp>
 #include <mbgl/util/run_loop.hpp>
-#include <mbgl/util/default_thread_pool.hpp>
 
 #include <memory>
 
@@ -19,9 +18,8 @@ using namespace mbgl::style;
 TEST(Style, Properties) {
     util::RunLoop loop;
 
-    ThreadPool threadPool{ 1 };
     StubFileSource fileSource;
-    Style::Impl style { threadPool, fileSource, 1.0 };
+    Style::Impl style { fileSource, 1.0 };
 
     style.loadJSON(R"STYLE({"name": "Test"})STYLE");
     ASSERT_EQ("Test", style.getName());
@@ -62,9 +60,8 @@ TEST(Style, Properties) {
 TEST(Style, DuplicateSource) {
     util::RunLoop loop;
 
-    ThreadPool threadPool{ 1 };
     StubFileSource fileSource;
-    Style::Impl style { threadPool, fileSource, 1.0 };
+    Style::Impl style { fileSource, 1.0 };
 
     style.loadJSON(util::read_file("test/fixtures/resources/style-unused-sources.json"));
 
@@ -84,9 +81,8 @@ TEST(Style, RemoveSourceInUse) {
     auto log = new FixtureLogObserver();
     Log::setObserver(std::unique_ptr<Log::Observer>(log));
 
-    ThreadPool threadPool{ 1 };
     StubFileSource fileSource;
-    Style::Impl style { threadPool, fileSource, 1.0 };
+    Style::Impl style { fileSource, 1.0 };
 
     style.loadJSON(util::read_file("test/fixtures/resources/style-unused-sources.json"));
 
diff --git a/test/style/style_layer.test.cpp b/test/style/style_layer.test.cpp
index 7598d888e9..d6a926c631 100644
--- a/test/style/style_layer.test.cpp
+++ b/test/style/style_layer.test.cpp
@@ -21,7 +21,6 @@
 #include <mbgl/test/stub_file_source.hpp>
 #include <mbgl/util/color.hpp>
 #include <mbgl/util/run_loop.hpp>
-#include <mbgl/util/default_thread_pool.hpp>
 #include <mbgl/util/io.hpp>
 
 #include <memory>
@@ -283,9 +282,8 @@ TEST(Layer, DuplicateLayer) {
     util::RunLoop loop;
 
     // Setup style
-    ThreadPool threadPool{ 1 };
     StubFileSource fileSource;
-    Style::Impl style { threadPool, fileSource, 1.0 };
+    Style::Impl style { fileSource, 1.0 };
     style.loadJSON(util::read_file("test/fixtures/resources/style-unused-sources.json"));
 
     // Add initial layer
diff --git a/test/text/local_glyph_rasterizer.test.cpp b/test/text/local_glyph_rasterizer.test.cpp
index f21ac0b883..4c0719e16c 100644
--- a/test/text/local_glyph_rasterizer.test.cpp
+++ b/test/text/local_glyph_rasterizer.test.cpp
@@ -8,7 +8,6 @@
 #include <mbgl/util/color.hpp>
 #include <mbgl/renderer/renderer.hpp>
 #include <mbgl/gl/headless_frontend.hpp>
-#include <mbgl/util/default_thread_pool.hpp>
 #include <mbgl/style/style.hpp>
 
 /*
@@ -34,15 +33,14 @@ namespace {
 class LocalGlyphRasterizerTest {
 public:
     LocalGlyphRasterizerTest(const optional<std::string> fontFamily)
-        : frontend(1, threadPool, optional<std::string>(), gfx::ContextMode::Unique, fontFamily)
+        : frontend(1, optional<std::string>(), gfx::ContextMode::Unique, fontFamily)
     {
     }
 
     util::RunLoop loop;
     std::shared_ptr<StubFileSource> fileSource = std::make_shared<StubFileSource>();
-    ThreadPool threadPool { 4 };
     HeadlessFrontend frontend;
-    MapAdapter map { frontend, MapObserver::nullObserver(), fileSource, threadPool,
+    MapAdapter map { frontend, MapObserver::nullObserver(), fileSource,
                   MapOptions().withMapMode(MapMode::Static).withSize(frontend.getSize())};
 
     void checkRendering(const char * name) {
diff --git a/test/tile/custom_geometry_tile.test.cpp b/test/tile/custom_geometry_tile.test.cpp
index 7a627bad88..50bc7d0e8f 100644
--- a/test/tile/custom_geometry_tile.test.cpp
+++ b/test/tile/custom_geometry_tile.test.cpp
@@ -5,7 +5,6 @@
 #include <mbgl/tile/custom_geometry_tile.hpp>
 #include <mbgl/style/custom_tile_loader.hpp>
 
-#include <mbgl/util/default_thread_pool.hpp>
 #include <mbgl/util/run_loop.hpp>
 #include <mbgl/map/transform.hpp>
 #include <mbgl/renderer/tile_parameters.hpp>
@@ -26,8 +25,7 @@ public:
     FakeFileSource fileSource;
     TransformState transformState;
     util::RunLoop loop;
-    ThreadPool threadPool { 1 };
-    style::Style style { loop, fileSource, 1 };
+    style::Style style { fileSource, 1 };
     AnnotationManager annotationManager { style };
     ImageManager imageManager;
     GlyphManager glyphManager { fileSource };
@@ -36,7 +34,6 @@ public:
         1.0,
         MapDebugOptions(),
         transformState,
-        threadPool,
         fileSource,
         MapMode::Continuous,
         annotationManager,
diff --git a/test/tile/geojson_tile.test.cpp b/test/tile/geojson_tile.test.cpp
index 772590efb2..4f4435182f 100644
--- a/test/tile/geojson_tile.test.cpp
+++ b/test/tile/geojson_tile.test.cpp
@@ -4,7 +4,6 @@
 #include <mbgl/tile/geojson_tile.hpp>
 #include <mbgl/tile/tile_loader_impl.hpp>
 
-#include <mbgl/util/default_thread_pool.hpp>
 #include <mbgl/util/run_loop.hpp>
 #include <mbgl/map/transform.hpp>
 #include <mbgl/renderer/tile_parameters.hpp>
@@ -25,8 +24,7 @@ public:
     FakeFileSource fileSource;
     TransformState transformState;
     util::RunLoop loop;
-    ThreadPool threadPool { 1 };
-    style::Style style { loop, fileSource, 1 };
+    style::Style style { fileSource, 1 };
     AnnotationManager annotationManager { style };
     ImageManager imageManager;
     GlyphManager glyphManager { fileSource };
@@ -36,7 +34,6 @@ public:
         1.0,
         MapDebugOptions(),
         transformState,
-        threadPool,
         fileSource,
         MapMode::Continuous,
         annotationManager,
diff --git a/test/tile/raster_dem_tile.test.cpp b/test/tile/raster_dem_tile.test.cpp
index 5a6f5a8c9a..e2e7d44b9b 100644
--- a/test/tile/raster_dem_tile.test.cpp
+++ b/test/tile/raster_dem_tile.test.cpp
@@ -4,7 +4,6 @@
 #include <mbgl/tile/tile_loader_impl.hpp>
 
 #include <mbgl/style/style.hpp>
-#include <mbgl/util/default_thread_pool.hpp>
 #include <mbgl/util/run_loop.hpp>
 #include <mbgl/map/transform.hpp>
 #include <mbgl/annotation/annotation_manager.hpp>
@@ -20,8 +19,7 @@ public:
     FakeFileSource fileSource;
     TransformState transformState;
     util::RunLoop loop;
-    ThreadPool threadPool { 1 };
-    style::Style style { loop, fileSource, 1 };
+    style::Style style { fileSource, 1 };
     AnnotationManager annotationManager { style };
     ImageManager imageManager;
     GlyphManager glyphManager { fileSource };
@@ -31,7 +29,6 @@ public:
         1.0,
         MapDebugOptions(),
         transformState,
-        threadPool,
         fileSource,
         MapMode::Continuous,
         annotationManager,
diff --git a/test/tile/raster_tile.test.cpp b/test/tile/raster_tile.test.cpp
index 8b2b3dee61..2e35a94025 100644
--- a/test/tile/raster_tile.test.cpp
+++ b/test/tile/raster_tile.test.cpp
@@ -4,7 +4,6 @@
 #include <mbgl/tile/tile_loader_impl.hpp>
 
 #include <mbgl/style/style.hpp>
-#include <mbgl/util/default_thread_pool.hpp>
 #include <mbgl/util/run_loop.hpp>
 #include <mbgl/map/transform.hpp>
 #include <mbgl/annotation/annotation_manager.hpp>
@@ -20,8 +19,7 @@ public:
     FakeFileSource fileSource;
     TransformState transformState;
     util::RunLoop loop;
-    ThreadPool threadPool { 1 };
-    style::Style style { loop, fileSource, 1 };
+    style::Style style { fileSource, 1 };
     AnnotationManager annotationManager { style };
     ImageManager imageManager;
     GlyphManager glyphManager { fileSource };
@@ -31,7 +29,6 @@ public:
         1.0,
         MapDebugOptions(),
         transformState,
-        threadPool,
         fileSource,
         MapMode::Continuous,
         annotationManager,
diff --git a/test/tile/vector_tile.test.cpp b/test/tile/vector_tile.test.cpp
index ed3eda7863..c610d8c1a7 100644
--- a/test/tile/vector_tile.test.cpp
+++ b/test/tile/vector_tile.test.cpp
@@ -4,7 +4,6 @@
 #include <mbgl/tile/vector_tile_data.hpp>
 #include <mbgl/tile/tile_loader_impl.hpp>
 
-#include <mbgl/util/default_thread_pool.hpp>
 #include <mbgl/util/run_loop.hpp>
 #include <mbgl/map/transform.hpp>
 #include <mbgl/style/style.hpp>
@@ -26,8 +25,7 @@ public:
     FakeFileSource fileSource;
     TransformState transformState;
     util::RunLoop loop;
-    ThreadPool threadPool { 1 };
-    style::Style style { loop, fileSource, 1 };
+    style::Style style { fileSource, 1 };
     AnnotationManager annotationManager { style };
     ImageManager imageManager;
     GlyphManager glyphManager { fileSource };
@@ -37,7 +35,6 @@ public:
         1.0,
         MapDebugOptions(),
         transformState,
-        threadPool,
         fileSource,
         MapMode::Continuous,
         annotationManager,
diff --git a/test/util/async_task.test.cpp b/test/util/async_task.test.cpp
index f3025e8952..682926a17d 100644
--- a/test/util/async_task.test.cpp
+++ b/test/util/async_task.test.cpp
@@ -1,14 +1,15 @@
 #include <mbgl/util/async_task.hpp>
-#include <mbgl/util/run_loop.hpp>
-#include <mbgl/util/default_thread_pool.hpp>
-#include <mbgl/actor/actor_ref.hpp>
 
+#include <mbgl/actor/actor_ref.hpp>
+#include <mbgl/actor/scheduler.hpp>
 #include <mbgl/test/util.hpp>
+#include <mbgl/util/run_loop.hpp>
 
 #include <atomic>
 #include <future>
 #include <vector>
 
+using namespace mbgl;
 using namespace mbgl::util;
 
 namespace {
@@ -104,11 +105,11 @@ TEST(AsyncTask, RequestCoalescingMultithreaded) {
     unsigned count = 0, numThreads = 25;
     AsyncTask async([&count] { ++count; });
 
-    mbgl::ThreadPool threads(numThreads);
-    auto mailbox = std::make_shared<mbgl::Mailbox>(threads);
+    auto retainer = Scheduler::GetBackground();
+    auto mailbox = std::make_shared<Mailbox>(*retainer);
 
     TestWorker worker(&async);
-    mbgl::ActorRef<TestWorker> workerRef(worker, mailbox);
+    ActorRef<TestWorker> workerRef(worker, mailbox);
 
     for (unsigned i = 0; i < numThreads; ++i) {
         workerRef.invoke(&TestWorker::run);
@@ -133,11 +134,11 @@ TEST(AsyncTask, ThreadSafety) {
 
     AsyncTask async([&count] { ++count; });
 
-    mbgl::ThreadPool threads(numThreads);
-    auto mailbox = std::make_shared<mbgl::Mailbox>(threads);
+    auto retainer = Scheduler::GetBackground();
+    auto mailbox = std::make_shared<Mailbox>(*retainer);
 
     TestWorker worker(&async);
-    mbgl::ActorRef<TestWorker> workerRef(worker, mailbox);
+    ActorRef<TestWorker> workerRef(worker, mailbox);
 
     for (unsigned i = 0; i < numThreads; ++i) {
         // The callback runs on the worker, thus the atomic type.
diff --git a/test/util/memory.test.cpp b/test/util/memory.test.cpp
index e3ad976432..8602e6ac5b 100644
--- a/test/util/memory.test.cpp
+++ b/test/util/memory.test.cpp
@@ -5,7 +5,6 @@
 
 #include <mbgl/map/map_options.hpp>
 #include <mbgl/gl/headless_frontend.hpp>
-#include <mbgl/util/default_thread_pool.hpp>
 #include <mbgl/util/io.hpp>
 #include <mbgl/util/run_loop.hpp>
 #include <mbgl/style/style.hpp>
@@ -37,7 +36,6 @@ public:
 
     util::RunLoop runLoop;
     std::shared_ptr<StubFileSource> fileSource = std::make_shared<StubFileSource>();
-    ThreadPool threadPool { 4 };
 
 private:
     Response response(const std::string& path) {
@@ -72,8 +70,8 @@ TEST(Memory, Vector) {
     MemoryTest test;
     float ratio { 2 };
 
-    HeadlessFrontend frontend { { 256, 256 }, ratio, test.threadPool };
-    MapAdapter map(frontend, MapObserver::nullObserver(), test.fileSource, test.threadPool,
+    HeadlessFrontend frontend { { 256, 256 }, ratio };
+    MapAdapter map(frontend, MapObserver::nullObserver(), test.fileSource,
                    MapOptions().withMapMode(MapMode::Static).withSize(frontend.getSize()).withPixelRatio(ratio));
     map.jumpTo(CameraOptions().withZoom(16));
     map.getStyle().loadURL("mapbox://streets");
@@ -85,8 +83,8 @@ TEST(Memory, Raster) {
     MemoryTest test;
     float ratio { 2 };
 
-    HeadlessFrontend frontend { { 256, 256 }, ratio, test.threadPool };
-    MapAdapter map(frontend, MapObserver::nullObserver(), test.fileSource, test.threadPool,
+    HeadlessFrontend frontend { { 256, 256 }, ratio };
+    MapAdapter map(frontend, MapObserver::nullObserver(), test.fileSource,
                    MapOptions().withMapMode(MapMode::Static).withSize(frontend.getSize()).withPixelRatio(ratio));
     map.getStyle().loadURL("mapbox://satellite");
 
@@ -123,8 +121,8 @@ TEST(Memory, Footprint) {
     class FrontendAndMap {
     public:
         FrontendAndMap(MemoryTest& test_, const char* style)
-            : frontend(Size{ 256, 256 }, 2, test_.threadPool)
-            , map(frontend, MapObserver::nullObserver(), test_.fileSource, test_.threadPool,
+            : frontend(Size{ 256, 256 }, 2)
+            , map(frontend, MapObserver::nullObserver(), test_.fileSource,
                   MapOptions().withMapMode(MapMode::Static).withSize(frontend.getSize()).withPixelRatio(2)) {
             map.jumpTo(CameraOptions().withZoom(16));
             map.getStyle().loadURL(style);
diff --git a/test/util/thread.test.cpp b/test/util/thread.test.cpp
index 2bcb9d8959..49735585c6 100644
--- a/test/util/thread.test.cpp
+++ b/test/util/thread.test.cpp
@@ -1,8 +1,9 @@
+#include <mbgl/util/thread.hpp>
+
 #include <mbgl/actor/actor_ref.hpp>
+#include <mbgl/actor/scheduler.hpp>
 #include <mbgl/test/util.hpp>
-#include <mbgl/util/default_thread_pool.hpp>
 #include <mbgl/util/run_loop.hpp>
-#include <mbgl/util/thread.hpp>
 #include <mbgl/util/timer.hpp>
 
 #include <atomic>
@@ -139,8 +140,7 @@ TEST(Thread, Concurrency) {
     unsigned numMessages = 100000;
     std::atomic_uint completed(numMessages);
 
-    ThreadPool threadPool(10);
-    Actor<TestWorker> poolWorker(threadPool);
+    Actor<TestWorker> poolWorker(Scheduler::GetBackground());
     auto poolWorkerRef = poolWorker.self();
 
     Thread<TestWorker> threadedObject("Test");
@@ -165,8 +165,7 @@ TEST(Thread, Concurrency) {
 TEST(Thread, ThreadPoolMessaging) {
     auto loop = std::make_shared<RunLoop>();
 
-    ThreadPool threadPool(1);
-    Actor<TestWorker> poolWorker(threadPool);
+    Actor<TestWorker> poolWorker(Scheduler::GetBackground());
     auto poolWorkerRef = poolWorker.self();
 
     Thread<TestWorker> threadedObject("Test");