Refactor Loop::defaultLoop() to Loop::get(), never use "default loops".

src/App.h

@@ -79,7 +79,7 @@ public:
     }
 
     TemplatedApp(us_new_socket_context_options_t options = {}) {
-        httpContext = uWS::HttpContext<SSL>::create(uWS::Loop::defaultLoop(), options);
+        httpContext = uWS::HttpContext<SSL>::create(uWS::Loop::get(), options);
     }
 
     bool constructorFailed() {
@@ -105,7 +105,7 @@ public:
         "µWebSockets cannot satisfy UserData alignment requirements. You need to recompile µSockets with LIBUS_EXT_ALIGNMENT adjusted accordingly.");
 
         /* Every route has its own websocket context with its own behavior and user data type */
-        auto *webSocketContext = WebSocketContext<SSL, true>::create(Loop::defaultLoop(), (us_new_socket_context_t *) httpContext);
+        auto *webSocketContext = WebSocketContext<SSL, true>::create(Loop::get(), (us_new_socket_context_t *) httpContext);
 
         /* We need to clear this later on */
         webSocketContexts.push_back(webSocketContext);

src/Loop.h

@@ -23,9 +23,6 @@
 #include "LoopData.h"
 #include <libusockets_new.h>
 
-#include <iostream>
-#include <thread>
-
 namespace uWS {
 struct Loop {
 private:
@@ -84,33 +81,17 @@ private:
     }
 
 public:
-    /* Returns the default loop if called from one thread, or a dedicated per-thread loop if called from multiple threads */
+    /* Lazily initializes a per-thread loop and returns it. Will automatically free all initialized loops at exit. */
-    static Loop *defaultLoop() {
+    static Loop *get() {
-        /* Lock this whole function */
+        static thread_local Loop *lazyLoop;
-        static std::mutex m;
+        if (!lazyLoop) {
-        std::lock_guard<std::mutex> lock(m);
+            lazyLoop = create(false);
-
-        /* Deliver and attach the default loop to the first thread who calls us */
-        static thread_local bool ownsDefaultLoop;
-        static Loop *defaultLoop;
-        if (!defaultLoop) {
-            ownsDefaultLoop = true;
-            defaultLoop = create(true);
             std::atexit([]() {
-                Loop::defaultLoop()->free();
+                Loop::get()->free();
             });
-            return defaultLoop;
-        } else if (ownsDefaultLoop) {
-            return defaultLoop;
         }
 
-        /* Other threads get their non-default loops lazily created */
+        return lazyLoop;
-        static thread_local Loop *threadLocalLoop;
-        if (!threadLocalLoop) {
-            threadLocalLoop = create(false);
-            return threadLocalLoop;
-        }
-        return threadLocalLoop;
     }
 
     /* Freeing the default loop should be done once */
@@ -166,7 +147,7 @@ public:
 
 /* Can be called from any thread to run the thread local loop */
 inline void run() {
-    Loop::defaultLoop()->run();
+    Loop::get()->run();
 }
 
 }

src/TopicTree.h

@@ -82,7 +82,7 @@ public:
         return;
 
         /* Dynamically hook us up with the Loop post handler */
-        Loop::defaultLoop()->addPostHandler([this](Loop *loop) {
+        Loop::get()->addPostHandler([this](Loop *loop) {
 
             if (!pubNodes.size()) {
                 return;