[general] moving ios and android project under ./platform folder

platform/android/src/async_task.cpp

@@ -0,0 +1,65 @@
+#include "run_loop_impl.hpp"
+
+#include <mbgl/util/async_task.hpp>
+#include <mbgl/util/run_loop.hpp>
+
+#include <atomic>
+#include <functional>
+
+namespace mbgl {
+namespace util {
+
+class AsyncTask::Impl : public RunLoop::Impl::Runnable {
+public:
+    Impl(std::function<void()>&& fn)
+        : queued(true), task(std::move(fn)) {
+    }
+
+    ~Impl() {
+        queued = true;
+        loop->removeRunnable(this);
+    }
+
+    void maySend() {
+        if (queued) {
+            queued = false;
+            loop->addRunnable(this);
+        }
+    }
+
+    TimePoint dueTime() const override {
+        return due;
+    }
+
+    void runTask() override {
+        if (!queued) {
+            queued = true;
+            loop->removeRunnable(this);
+            task();
+        }
+    }
+
+private:
+    // Always expired, run immediately.
+    const TimePoint due = Clock::now();
+
+    RunLoop::Impl* loop = reinterpret_cast<RunLoop::Impl*>(RunLoop::getLoopHandle());
+
+    // TODO: Use std::atomic_flag if we ever drop
+    // support for ARMv5
+    std::atomic<bool> queued;
+    std::function<void()> task;
+};
+
+AsyncTask::AsyncTask(std::function<void()>&& fn)
+    : impl(std::make_unique<Impl>(std::move(fn))) {
+}
+
+AsyncTask::~AsyncTask() = default;
+
+void AsyncTask::send() {
+    impl->maySend();
+}
+
+} // namespace util
+} // namespace mbgl