From c7c438f2d6160541dda95cd97a4928bc9fb34828 Mon Sep 17 00:00:00 2001
From: Adrien Moulin <adrien@elyosh.org>
Date: Fri, 5 Aug 2022 23:12:03 +0200
Subject: [PATCH 1/2] qt: fix busy looping with evdev mouse

Replace busy looping which was using 100% cpu with poll()
---
 src/qt/evdev_mouse.cpp | 26 +++++++++++++++++++++-----
 1 file changed, 21 insertions(+), 5 deletions(-)

diff --git a/src/qt/evdev_mouse.cpp b/src/qt/evdev_mouse.cpp
index 120f4572c..186f49813 100644
--- a/src/qt/evdev_mouse.cpp
+++ b/src/qt/evdev_mouse.cpp
@@ -31,6 +31,7 @@ extern "C"
 #include <86box/86box.h>
 #include <86box/plat.h>
 #include <86box/mouse.h>
+#include <poll.h>
 }
 
 static std::vector<std::pair<int, libevdev*>> evdev_mice;
@@ -54,25 +55,40 @@ void evdev_mouse_poll()
 
 void evdev_thread_func()
 {
+    struct pollfd *pfds = (struct pollfd*)calloc(evdev_mice.size(), sizeof(struct pollfd));
+    for (unsigned int i = 0; i < evdev_mice.size(); i++)
+    {
+        pfds[i].fd = libevdev_get_fd(evdev_mice[i].second);
+        pfds[i].events = POLLIN;
+    }
+
     while (!stopped)
     {
+        poll(pfds, evdev_mice.size(), 500);
         for (unsigned int i = 0; i < evdev_mice.size(); i++)
         {
             struct input_event ev;
-            int rc = libevdev_next_event(evdev_mice[i].second, LIBEVDEV_READ_FLAG_NORMAL, &ev);
-            if (rc == 0 && ev.type == EV_REL && mouse_capture)
-            {
-                if (ev.code == REL_X) evdev_mouse_rel_x += ev.value;
-                if (ev.code == REL_Y) evdev_mouse_rel_y += ev.value;
+            if (pfds[i].revents & POLLIN) {
+                int rc;
+                while ((rc = libevdev_next_event(evdev_mice[i].second, LIBEVDEV_READ_FLAG_NORMAL, &ev)) == 0)
+                {
+                    if (ev.type == EV_REL && mouse_capture)
+                    {
+                        if (ev.code == REL_X) evdev_mouse_rel_x += ev.value;
+                        if (ev.code == REL_Y) evdev_mouse_rel_y += ev.value;
+                    }
+                }
             }
         }
     }
+
     for (unsigned int i = 0; i < evdev_mice.size(); i++)
     {
         libevdev_free(evdev_mice[i].second);
         evdev_mice[i].second = nullptr;
         close(evdev_mice[i].first);
     }
+    free(pfds);
     evdev_mice.clear();
 }
 

From ce4d7f9fc886a04ac743b1c85a39dec3b9bf8e1b Mon Sep 17 00:00:00 2001
From: Adrien Moulin <adrien@elyosh.org>
Date: Fri, 5 Aug 2022 23:22:39 +0200
Subject: [PATCH 2/2] Small cleanup

---
 src/qt/evdev_mouse.cpp | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/src/qt/evdev_mouse.cpp b/src/qt/evdev_mouse.cpp
index 186f49813..5ad252f1a 100644
--- a/src/qt/evdev_mouse.cpp
+++ b/src/qt/evdev_mouse.cpp
@@ -69,8 +69,7 @@ void evdev_thread_func()
         {
             struct input_event ev;
             if (pfds[i].revents & POLLIN) {
-                int rc;
-                while ((rc = libevdev_next_event(evdev_mice[i].second, LIBEVDEV_READ_FLAG_NORMAL, &ev)) == 0)
+                while (libevdev_next_event(evdev_mice[i].second, LIBEVDEV_READ_FLAG_NORMAL, &ev) == 0)
                 {
                     if (ev.type == EV_REL && mouse_capture)
                     {