[core] Naive atomic type for ARMv5

std::atomic<bool> is implemented lock free which doesn't work
on ARMv5 and seems like the compiler is generating bogus code.

This workaround is a naive implementation using regular mutexes.

include/mbgl/storage/network_status.hpp

@@ -1,6 +1,7 @@
 #pragma once
 
-#include <atomic>
+#include <mbgl/util/atomic.hpp>
+
 #include <mutex>
 #include <set>
 
@@ -26,7 +27,7 @@ public:
     static void Unsubscribe(util::AsyncTask* async);
 
 private:
-    static std::atomic<bool> online;
+    static util::Atomic<bool> online;
     static std::mutex mtx;
     static std::set<util::AsyncTask*> observers;
 };

include/mbgl/util/run_loop.hpp

@@ -1,5 +1,6 @@
 #pragma once
 
+#include <mbgl/util/atomic.hpp>
 #include <mbgl/util/noncopyable.hpp>
 #include <mbgl/util/util.hpp>
 #include <mbgl/util/work_task.hpp>
@@ -9,7 +10,6 @@
 #include <utility>
 #include <queue>
 #include <mutex>
-#include <atomic>
 
 namespace mbgl {
 namespace util {
@@ -59,7 +59,7 @@ public:
     template <class Fn, class... Args>
     std::unique_ptr<AsyncRequest>
     invokeCancellable(Fn&& fn, Args&&... args) {
-        auto flag = std::make_shared<std::atomic<bool>>();
+        auto flag = std::make_shared<util::Atomic<bool>>();
         *flag = false;
 
         auto tuple = std::make_tuple(std::move(args)...);
@@ -77,7 +77,7 @@ public:
     template <class Fn, class Cb, class... Args>
     std::unique_ptr<AsyncRequest>
     invokeWithCallback(Fn&& fn, Cb&& callback, Args&&... args) {
-        auto flag = std::make_shared<std::atomic<bool>>();
+        auto flag = std::make_shared<util::Atomic<bool>>();
         *flag = false;
 
         // Create a lambda L1 that invokes another lambda L2 on the current RunLoop R, that calls
@@ -114,7 +114,7 @@ private:
     template <class F, class P>
     class Invoker : public WorkTask {
     public:
-        Invoker(F&& f, P&& p, std::shared_ptr<std::atomic<bool>> canceled_ = nullptr)
+        Invoker(F&& f, P&& p, std::shared_ptr<util::Atomic<bool>> canceled_ = nullptr)
           : canceled(std::move(canceled_)),
             func(std::move(f)),
             params(std::move(p)) {
@@ -148,7 +148,7 @@ private:
         }
 
         std::recursive_mutex mutex;
-        std::shared_ptr<std::atomic<bool>> canceled;
+        std::shared_ptr<util::Atomic<bool>> canceled;
 
         F func;
         P params;

platform/android/src/async_task.cpp

@@ -1,9 +1,9 @@
 #include "run_loop_impl.hpp"
 
 #include <mbgl/util/async_task.hpp>
+#include <mbgl/util/atomic.hpp>
 #include <mbgl/util/run_loop.hpp>
 
-#include <atomic>
 #include <functional>
 
 namespace mbgl {
@@ -45,7 +45,7 @@ private:
 
     // TODO: Use std::atomic_flag if we ever drop
     // support for ARMv5
-    std::atomic<bool> queued;
+    util::Atomic<bool> queued;
     std::function<void()> task;
 };
 

platform/android/src/run_loop_impl.hpp

@@ -2,10 +2,10 @@
 
 #include "jni.hpp"
 
+#include <mbgl/util/atomic.hpp>
 #include <mbgl/util/chrono.hpp>
 #include <mbgl/util/run_loop.hpp>
 
-#include <atomic>
 #include <list>
 #include <memory>
 #include <mutex>
@@ -47,7 +47,7 @@ private:
     bool detach = false;
 
     ALooper* loop = nullptr;
-    std::atomic<bool> running;
+    util::Atomic<bool> running;
 
     std::recursive_mutex mtx;
     std::list<Runnable*> runnables;

src/mbgl/geometry/glyph_atlas.hpp

@@ -2,6 +2,7 @@
 
 #include <mbgl/geometry/binpack.hpp>
 #include <mbgl/text/glyph_store.hpp>
+#include <mbgl/util/atomic.hpp>
 #include <mbgl/util/noncopyable.hpp>
 #include <mbgl/util/optional.hpp>
 #include <mbgl/gl/gl.hpp>
@@ -11,7 +12,6 @@
 #include <set>
 #include <unordered_map>
 #include <mutex>
-#include <atomic>
 
 namespace mbgl {
 
@@ -53,7 +53,7 @@ private:
     BinPack<uint16_t> bin;
     std::unordered_map<FontStack, std::map<uint32_t, GlyphValue>, FontStackHash> index;
     const std::unique_ptr<uint8_t[]> data;
-    std::atomic<bool> dirty;
+    util::Atomic<bool> dirty;
     mbgl::optional<gl::UniqueTexture> texture;
 };
 

src/mbgl/renderer/bucket.hpp

@@ -2,11 +2,10 @@
 
 #include <mbgl/gl/gl.hpp>
 #include <mbgl/renderer/render_pass.hpp>
+#include <mbgl/util/atomic.hpp>
 #include <mbgl/util/noncopyable.hpp>
 #include <mbgl/util/mat4.hpp>
 
-#include <atomic>
-
 #define BUFFER_OFFSET_0  ((GLbyte*)nullptr)
 #define BUFFER_OFFSET(i) ((BUFFER_OFFSET_0) + (i))
 
@@ -50,7 +49,7 @@ public:
     virtual void swapRenderData() {}
 
 protected:
-    std::atomic<bool> uploaded;
+    util::Atomic<bool> uploaded;
 
 };
 

src/mbgl/sprite/sprite_atlas.hpp

@@ -3,6 +3,7 @@
 #include <mbgl/geometry/binpack.hpp>
 #include <mbgl/gl/gl.hpp>
 #include <mbgl/gl/object_store.hpp>
+#include <mbgl/util/atomic.hpp>
 #include <mbgl/util/noncopyable.hpp>
 #include <mbgl/util/ptr.hpp>
 #include <mbgl/util/optional.hpp>
@@ -10,7 +11,6 @@
 #include <string>
 #include <map>
 #include <mutex>
-#include <atomic>
 #include <set>
 #include <array>
 
@@ -92,7 +92,7 @@ private:
     std::map<Key, Holder> images;
     std::set<std::string> uninitialized;
     std::unique_ptr<uint32_t[]> data;
-    std::atomic<bool> dirty;
+    util::Atomic<bool> dirty;
     bool fullUploadRequired = true;
     mbgl::optional<gl::UniqueTexture> texture;
     uint32_t filter = 0;

src/mbgl/storage/network_status.cpp

@@ -9,7 +9,7 @@
 
 namespace mbgl {
 
-std::atomic<bool> NetworkStatus::online(true);
+util::Atomic<bool> NetworkStatus::online(true);
 std::mutex NetworkStatus::mtx;
 std::set<util::AsyncTask *> NetworkStatus::observers;
 

src/mbgl/style/bucket_parameters.hpp

@@ -3,9 +3,9 @@
 #include <mbgl/map/mode.hpp>
 #include <mbgl/tile/tile_id.hpp>
 #include <mbgl/style/filter.hpp>
+#include <mbgl/util/atomic.hpp>
 
 #include <functional>
-#include <atomic>
 
 namespace mbgl {
 
@@ -24,7 +24,7 @@ class BucketParameters {
 public:
     BucketParameters(const OverscaledTileID& tileID_,
                           const GeometryTileLayer& layer_,
-                          const std::atomic<bool>& obsolete_,
+                          const util::Atomic<bool>& obsolete_,
                           uintptr_t tileUID_,
                           bool& partialParse_,
                           SpriteStore& spriteStore_,
@@ -51,7 +51,7 @@ public:
 
     const OverscaledTileID& tileID;
     const GeometryTileLayer& layer;
-    const std::atomic<bool>& obsolete;
+    const util::Atomic<bool>& obsolete;
     uintptr_t tileUID;
     bool& partialParse;
     SpriteStore& spriteStore;

src/mbgl/text/glyph_pbf.hpp

@@ -2,10 +2,10 @@
 
 #include <mbgl/text/glyph.hpp>
 #include <mbgl/text/glyph_store.hpp>
+#include <mbgl/util/atomic.hpp>
 #include <mbgl/util/font_stack.hpp>
 #include <mbgl/util/noncopyable.hpp>
 
-#include <atomic>
 #include <functional>
 #include <string>
 #include <memory>
@@ -29,7 +29,7 @@ public:
     }
 
 private:
-    std::atomic<bool> parsed;
+    util::Atomic<bool> parsed;
     std::unique_ptr<AsyncRequest> req;
     GlyphStoreObserver* observer = nullptr;
 };

src/mbgl/tile/tile_worker.cpp

@@ -24,7 +24,7 @@ TileWorker::TileWorker(const OverscaledTileID& id_,
                        SpriteStore& spriteStore_,
                        GlyphAtlas& glyphAtlas_,
                        GlyphStore& glyphStore_,
-                       const std::atomic<bool>& obsolete_,
+                       const util::Atomic<bool>& obsolete_,
                        const MapMode mode_)
     : id(id_),
       sourceID(std::move(sourceID_)),

src/mbgl/tile/tile_worker.hpp

@@ -2,6 +2,7 @@
 
 #include <mbgl/map/mode.hpp>
 #include <mbgl/tile/tile_id.hpp>
+#include <mbgl/util/atomic.hpp>
 #include <mbgl/util/noncopyable.hpp>
 #include <mbgl/util/variant.hpp>
 #include <mbgl/util/ptr.hpp>
@@ -12,7 +13,6 @@
 #include <memory>
 #include <mutex>
 #include <list>
-#include <atomic>
 #include <unordered_map>
 
 namespace mbgl {
@@ -50,7 +50,7 @@ public:
                SpriteStore&,
                GlyphAtlas&,
                GlyphStore&,
-               const std::atomic<bool>&,
+               const util::Atomic<bool>&,
                const MapMode);
     ~TileWorker();
 
@@ -75,7 +75,7 @@ private:
     SpriteStore& spriteStore;
     GlyphAtlas& glyphAtlas;
     GlyphStore& glyphStore;
-    const std::atomic<bool>& obsolete;
+    const util::Atomic<bool>& obsolete;
     const MapMode mode;
 
     bool partialParse = false;

src/mbgl/tile/vector_tile_data.hpp

@@ -3,9 +3,9 @@
 #include <mbgl/tile/tile_data.hpp>
 #include <mbgl/tile/tile_worker.hpp>
 #include <mbgl/text/placement_config.hpp>
+#include <mbgl/util/atomic.hpp>
 #include <mbgl/util/feature.hpp>
 
-#include <atomic>
 #include <memory>
 #include <unordered_map>
 
@@ -69,7 +69,7 @@ private:
     PlacementConfig targetConfig;
 
     // Used to signal the worker that it should abandon parsing this tile as soon as possible.
-    std::atomic<bool> obsolete { false };
+    util::Atomic<bool> obsolete { false };
 };
 
 } // namespace mbgl

src/mbgl/util/atomic.hpp

@@ -0,0 +1,45 @@
+#pragma once
+
+#include <atomic>
+#include <mutex>
+
+namespace mbgl {
+namespace util {
+
+// std::atomic<bool> is implemented lock free which
+// is not supported by ARMv5 but the code generated
+// seems to be using that and not working at all,
+// thus, this naive implementation using mutexes.
+#if defined(__ANDROID__) && defined(__ARM_ARCH_5TE__)
+
+template <typename T>
+class Atomic {
+public:
+    Atomic() = default;
+    explicit Atomic(const T& data_) : data(data_) {}
+
+    void operator=(const T& other) {
+        std::lock_guard<std::mutex> lock(mtx);
+        data = other;
+    }
+
+    operator bool() const {
+        std::lock_guard<std::mutex> lock(mtx);
+
+        return data;
+    }
+
+private:
+    T data;
+    mutable std::mutex mtx;
+};
+
+#else
+
+template <typename T>
+using Atomic = std::atomic<T>;
+
+#endif
+
+} // namespace util
+} // namespace mbgl

src/mbgl/util/thread.hpp

@@ -6,6 +6,7 @@
 #include <utility>
 #include <functional>
 
+#include <mbgl/util/atomic.hpp>
 #include <mbgl/util/run_loop.hpp>
 #include <mbgl/util/thread_context.hpp>
 #include <mbgl/platform/platform.hpp>