[core] Added the ThreadedRunLoop

Actor model version of util::Thread.

2 files changed, 76 insertions, 0 deletions

diff --git a/platform/default/mbgl/util/threaded_run_loop.cpp b/platform/default/mbgl/util/threaded_run_loop.cpp
new file mode 100644
index 0000000000..e27e6379b6
--- /dev/null
+++ b/platform/default/mbgl/util/threaded_run_loop.cpp
@@ -0,0 +1,45 @@
+#include <mbgl/actor/mailbox.hpp>
+#include <mbgl/util/platform.hpp>
+#include <mbgl/util/run_loop.hpp>
+#include <mbgl/util/threaded_run_loop.hpp>
+
+namespace mbgl {
+
+ThreadedRunLoop::ThreadedRunLoop(const std::string& name)
+    : thread([&]() {
+        platform::setCurrentThreadName(name);
+
+        loop = std::make_unique<util::RunLoop>(util::RunLoop::Type::New);
+        running.set_value();
+
+        loop->run();
+        loop.reset();
+    }) {
+    running.get_future();
+}
+
+ThreadedRunLoop::~ThreadedRunLoop() {
+    loop->stop();
+    thread.join();
+}
+
+void ThreadedRunLoop::schedule(std::weak_ptr<Mailbox> mailbox) {
+    {
+        std::lock_guard<std::mutex> lock(mutex);
+        queue.push(mailbox);
+    }
+
+    loop->invoke([this] { receive(); });
+}
+
+void ThreadedRunLoop::receive() {
+    std::unique_lock<std::mutex> lock(mutex);
+
+    auto mailbox = queue.front();
+    queue.pop();
+    lock.unlock();
+
+    Mailbox::maybeReceive(mailbox);
+}
+
+} // namespace mbgl
diff --git a/platform/default/mbgl/util/threaded_run_loop.hpp b/platform/default/mbgl/util/threaded_run_loop.hpp
new file mode 100644
index 0000000000..f7f9fcfd65
--- /dev/null
+++ b/platform/default/mbgl/util/threaded_run_loop.hpp
@@ -0,0 +1,31 @@
+#pragma once
+
+#include <mbgl/actor/scheduler.hpp>
+
+#include <future>
+#include <memory>
+#include <mutex>
+#include <queue>
+#include <string>
+#include <thread>
+
+namespace mbgl {
+
+class ThreadedRunLoop : public Scheduler {
+public:
+    ThreadedRunLoop(const std::string& name);
+    ~ThreadedRunLoop() override;
+
+    void schedule(std::weak_ptr<Mailbox>) override;
+
+private:
+    void receive();
+
+    std::mutex mutex;
+    std::promise<void> running;
+    std::queue<std::weak_ptr<Mailbox>> queue;
+    std::thread thread;
+    std::unique_ptr<util::RunLoop> loop;
+};
+
+} // namespace mbgl