Add async pool (to replace EVENT_LOOP).

[stg.git] / projects / stargazer / async_pool.cpp

diff --git a/projects/stargazer/async_pool.cpp b/projects/stargazer/async_pool.cpp
new file mode 100644 (file)
index 0000000..1d8fec0
--- /dev/null
+++ b/projects/stargazer/async_pool.cpp
@@ -0,0 +1,42 @@
+#include "async_pool.h"
+
+using STG::AsyncPool;
+
+AsyncPool& STG::AsyncPoolST::instance()
+{
+    static AsyncPool pool;
+    return pool;
+}
+
+void AsyncPool::start()
+{
+    if (m_thread.joinable())
+        return;
+    m_thread = std::jthread([this](auto token){ run(std::move(token)); });
+}
+
+void AsyncPool::stop()
+{
+    if (!m_thread.joinable())
+        return;
+    m_thread.request_stop();
+    m_cond.notify_all();
+}
+
+void AsyncPool::run(std::stop_token token) noexcept
+{
+    while (true)
+    {
+        Queue tasks;
+        {
+            std::unique_lock lock(m_mutex);
+            m_cond.wait(lock, [this, &token](){ return !m_tasks.empty() || token.stop_requested(); });
+            if (token.stop_requested())
+                return;
+            if (!m_tasks.empty())
+                tasks.swap(m_tasks);
+        }
+        for (const auto& t : tasks)
+            t();
+    }
+}