use libuv event loop in the glfw view

Integrates libuv's default loop with GLFW's glfwWaitEvents() call. See https://github.com/joyent/libuv/issues/1246 for more details on integrating event loops.

fixes #149

3 files changed, 99 insertions, 12 deletions

diff --git a/common/curl_request.cpp b/common/curl_request.cpp
index dc9db0269c..7cfe8fcabd 100644
--- a/common/curl_request.cpp
+++ b/common/curl_request.cpp
@@ -341,6 +341,8 @@ void async_cancel_cb(uv_async_t * /*async*/) {
 }
 
 void thread_init_cb() {
+    curl_global_init(CURL_GLOBAL_ALL);
+
     loop = uv_loop_new();
     uv_async_init(loop, &async_add, async_add_cb);
     uv_async_init(loop, &async_cancel, async_cancel_cb);
diff --git a/common/glfw_view.cpp b/common/glfw_view.cpp
index c4fafb69ac..82e9aad745 100644
--- a/common/glfw_view.cpp
+++ b/common/glfw_view.cpp
@@ -1,7 +1,40 @@
 #include "glfw_view.hpp"
 
+
+#ifndef HAVE_KQUEUE
+# if defined(__APPLE__) ||                                                    \
+     defined(__DragonFly__) ||                                                \
+     defined(__FreeBSD__) ||                                                  \
+     defined(__OpenBSD__) ||                                                  \
+     defined(__NetBSD__)
+#  define HAVE_KQUEUE 1
+# endif
+#endif
+
+#ifndef HAVE_EPOLL
+# if defined(__linux__)
+#  define HAVE_EPOLL 1
+# endif
+#endif
+
+#if defined(HAVE_KQUEUE) || defined(HAVE_EPOLL)
+
+#if defined(HAVE_KQUEUE)
+# include <sys/types.h>
+# include <sys/event.h>
+# include <sys/time.h>
+#endif
+
+#if defined(HAVE_EPOLL)
+# include <sys/epoll.h>
+#endif
+
+#endif
+
+
 MapView::MapView(llmr::Settings &settings, bool fullscreen)
-    : fullscreen(fullscreen), settings(settings), map(settings) {}
+    : fullscreen(fullscreen), settings(settings), map(settings),
+    stop_event_listener(false) {}
 
 MapView::~MapView() { glfwTerminate(); }
 
@@ -163,28 +196,70 @@ void MapView::mousemove(GLFWwindow *window, double x, double y) {
     mapView->last_y = y;
 }
 
+void MapView::eventloop(void *arg) {
+    MapView *view = static_cast<MapView *>(arg);
+    int r = 0;
+    int fd = 0;
+    int timeout;
+
+    while (!view->stop_event_listener) {
+        fd = uv_backend_fd(uv_default_loop());
+        timeout = uv_backend_timeout(uv_default_loop());
+
+        do {
+#if defined(HAVE_KQUEUE)
+            struct timespec ts;
+            ts.tv_sec = timeout / 1000;
+            ts.tv_nsec = (timeout % 1000) * 1000000;
+            r = kevent(fd, NULL, 0, NULL, 0, &ts);
+#elif defined(HAVE_EPOLL)
+            {
+                struct epoll_event ev;
+                r = epoll_wait(fd, &ev, 1, timeout);
+            }
+#endif
+        } while (r == -1 && errno == EINTR);
+        glfwPostEmptyEvent();
+        uv_sem_wait(&view->event_listener);
+    }
+}
+
 int MapView::run() {
+    uv_thread_t embed_thread;
+
+    uv_run(uv_default_loop(), UV_RUN_NOWAIT);
+
+    /* Start worker that will interrupt external loop */
+    stop_event_listener = false;
+    uv_sem_init(&event_listener, 0);
+    uv_thread_create(&embed_thread, eventloop, this);
+
     while (!glfwWindowShouldClose(window)) {
-        llmr::platform::cleanup();
 
-        if (dirty) {
-            try {
-                dirty = map.render();
-            }
-            catch (std::exception &ex) {
-                fprintf(stderr, "exception: %s\n", ex.what());
-            }
-            glfwSwapBuffers(window);
-            fps();
+        bool dirty = false;
+        try {
+            dirty = map.render();
         }
+        catch (std::exception &ex) {
+            fprintf(stderr, "exception: %s\n", ex.what());
+        }
+        glfwSwapBuffers(window);
+        fps();
 
         if (dirty) {
             glfwPollEvents();
         } else {
             glfwWaitEvents();
         }
+
+        uv_run(uv_default_loop(), UV_RUN_NOWAIT);
+        uv_sem_post(&event_listener);
     }
 
+    stop_event_listener = true;
+
+    uv_thread_join(&embed_thread);
+
     return 0;
 }
 
@@ -234,5 +309,10 @@ void show_debug_image(std::string name, const char *data, size_t width, size_t h
 
     glfwMakeContextCurrent(current_window);
 }
+
+void restart() {
+    glfwPostEmptyEvent();
+}
+
 }
 }
diff --git a/common/glfw_view.hpp b/common/glfw_view.hpp
index d72debb11d..8647c8ad67 100644
--- a/common/glfw_view.hpp
+++ b/common/glfw_view.hpp
@@ -3,6 +3,7 @@
 
 #include <llmr/llmr.hpp>
 #include <GLFW/glfw3.h>
+#include <uv.h>
 
 class MapView {
 public:
@@ -17,13 +18,14 @@ public:
     static void mouseclick(GLFWwindow *window, int button, int action, int modifiers);
     static void mousemove(GLFWwindow *window, double x, double y);
 
+    static void eventloop(void *arg);
+
     int run();
     void fps();
 
 public:
     bool fullscreen = false;
 
-    bool dirty = true;
     double last_x = 0, last_y = 0;
     bool tracking = false;
 
@@ -34,6 +36,9 @@ public:
     GLFWwindow *window = nullptr;
     llmr::Settings &settings;
     llmr::Map map;
+
+    uv_sem_t event_listener;
+    std::atomic<bool> stop_event_listener;
 };
 
 #endif