1 files changed, 83 insertions, 0 deletions
diff --git a/src/mbgl/util/thread_pool.cpp b/src/mbgl/util/thread_pool.cpp
new file mode 100644
index 0000000000..d213aab71c
--- /dev/null
+++ b/src/mbgl/util/thread_pool.cpp
@@ -0,0 +1,83 @@
+#include <mbgl/actor/scheduler.hpp>
+#include <mbgl/actor/mailbox.hpp>
+#include <mbgl/util/platform.hpp>
+#include <mbgl/util/string.hpp>
+
+#include <condition_variable>
+#include <mutex>
+#include <queue>
+#include <thread>
+
+namespace mbgl {
+
+class ThreadPool final : public Scheduler {
+public:
+    explicit ThreadPool(std::size_t count);
+    ~ThreadPool() override;
+
+    void schedule(std::weak_ptr<Mailbox>) override;
+
+private:
+    std::vector<std::thread> threads;
+    std::queue<std::weak_ptr<Mailbox>> queue;
+    std::mutex mutex;
+    std::condition_variable cv;
+    bool terminate { false };
+};
+
+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));
+
+            while (true) {
+                std::unique_lock<std::mutex> lock(mutex);
+
+                cv.wait(lock, [this] {
+                    return !queue.empty() || terminate;
+                });
+
+                if (terminate) {
+                    return;
+                }
+
+                auto mailbox = queue.front();
+                queue.pop();
+                lock.unlock();
+
+                Mailbox::maybeReceive(mailbox);
+            }
+        });
+    }
+}
+
+ThreadPool::~ThreadPool() {
+    {
+        std::lock_guard<std::mutex> lock(mutex);
+        terminate = true;
+    }
+
+    cv.notify_all();
+
+    for (auto& thread : threads) {
+        thread.join();
+    }
+}
+
+void ThreadPool::schedule(std::weak_ptr<Mailbox> mailbox) {
+    {
+        std::lock_guard<std::mutex> lock(mutex);
+        queue.push(mailbox);
+    }
+
+    cv.notify_one();
+}
+
+Scheduler& Scheduler::GetBackground() {
+    static std::unique_ptr<ThreadPool> pool(new ThreadPool(4));
+    return *pool;
+}
+
+} // namespace mbgl