thread pool: add computation, io pools

src/thread_pool.cpp

@@ -26,12 +26,29 @@
 
 namespace dht {
 
+constexpr const size_t IO_THREADS_MAX {64};
+
 struct ThreadPool::ThreadState
 {
     std::thread thread {};
     std::atomic_bool run {true};
 };
 
+ThreadPool&
+ThreadPool::computation()
+{
+    static ThreadPool pool;
+    return pool;
+}
+
+ThreadPool&
+ThreadPool::io()
+{
+    static ThreadPool pool(IO_THREADS_MAX);
+    return pool;
+}
+
+
 ThreadPool::ThreadPool(size_t maxThreads) : maxThreads_(maxThreads)
 {
     threads_.reserve(maxThreads_);

src/thread_pool.h

@@ -29,10 +29,8 @@ namespace dht {
 
 class ThreadPool {
 public:
-    static ThreadPool& instance() {
-        static ThreadPool pool;
-        return pool;
-    }
+    static ThreadPool& computation();
+    static ThreadPool& io();
 
     ThreadPool();
     ThreadPool(size_t maxThreads);