From 6cf36a852f05371a7826764771c9bc6c0f79a1be Mon Sep 17 00:00:00 2001
From: Josh Holtrop <jholtrop@gmail.com>
Date: Tue, 7 Jul 2020 16:25:12 -0400
Subject: [PATCH] jtk.c: support multiple threads

---
 src/jtk/jtk.c | 49 ++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 42 insertions(+), 7 deletions(-)

diff --git a/src/jtk/jtk.c b/src/jtk/jtk.c
index 2cb6274..397371c 100644
--- a/src/jtk/jtk.c
+++ b/src/jtk/jtk.c
@@ -28,6 +28,12 @@ bool jtk_init()
         None,
     };
 
+    if (XInitThreads() != 0)
+    {
+        fprintf(stderr, "XInitThreads() failure\n");
+        return false;
+    }
+
     g_display = XOpenDisplay(NULL);
     if (g_display == NULL)
     {
@@ -35,6 +41,8 @@ bool jtk_init()
         return false;
     }
 
+    XLockDisplay(g_display);
+
     g_vi = glXChooseVisual(g_display, DefaultScreen(g_display),
             glx_attribute_list);
     if (g_vi == NULL)
@@ -58,6 +66,8 @@ bool jtk_init()
         KeyPressMask | KeyReleaseMask |
         ButtonPressMask | ButtonReleaseMask;
 
+    XUnlockDisplay(g_display);
+
     return true;
 }
 
@@ -89,44 +99,56 @@ static Bool wait_for_notify(Display * display, XEvent * event, XPointer arg)
 void * jtk_window_create()
 {
     XEvent event;
+
+    XLockDisplay(g_display);
     Window window = XCreateWindow(g_display,
             RootWindow(g_display, g_vi->screen),
             0, 0, 800u, 800u, 0u, g_vi->depth, InputOutput, g_vi->visual,
             CWBorderPixel | CWColormap | CWEventMask, &g_swa);
     XMapWindow(g_display, window);
     XIfEvent(g_display, &event, wait_for_notify, (XPointer)window);
-    if (glXMakeCurrent(g_display, window, g_context) == False)
+    if (glXMakeCurrent(g_display, window, g_context) != False)
+    {
+        /* Disable the window close button. */
+        Atom wm_delete_window_atom = XInternAtom(g_display, "WM_DELETE_WINDOW", False);
+        XSetWMProtocols(g_display, window, &wm_delete_window_atom, 1);
+    }
+    else
     {
         fprintf(stderr, "glXMakeCurrent() failure\n");
         XDestroyWindow(g_display, window);
-        return NULL;
+        window = NULL;
     }
 
-    /* Disable the window close button. */
-    Atom wm_delete_window_atom = XInternAtom(g_display, "WM_DELETE_WINDOW", False);
-    XSetWMProtocols(g_display, window, &wm_delete_window_atom, 1);
+    XUnlockDisplay(g_display);
 
     return (void *)window;
 }
 
 void jtk_window_swap_buffers(void * window)
 {
+    XLockDisplay(g_display);
     glXSwapBuffers(g_display, (Window)window);
+    XUnlockDisplay(g_display);
 }
 
 void jtk_window_close(void * window)
 {
+    XLockDisplay(g_display);
     XDestroyWindow(g_display, (Window)window);
+    XUnlockDisplay(g_display);
 }
 
 void jtk_window_set_title(void * window, const char * title)
 {
+    XLockDisplay(g_display);
     XTextProperty title_property;
     if (XStringListToTextProperty((char **)&title, 1, &title_property) != 0)
     {
         XSetTextProperty(g_display, (Window)window, &title_property, XA_WM_NAME);
         XFree(title_property.value);
     }
+    XUnlockDisplay(g_display);
 }
 
 /**
@@ -145,6 +167,7 @@ void jtk_window_set_title(void * window, const char * title)
 void jtk_window_set_icon(void * window, const uint8_t * data,
         size_t width, size_t height)
 {
+    XLockDisplay(g_display);
     Atom net_wm_icon_atom = XInternAtom(g_display, "_NET_WM_ICON", False);
     size_t property_size = (2u + width * height) * sizeof(long);
     unsigned long * property_data = (unsigned long *)malloc(property_size);
@@ -163,6 +186,7 @@ void jtk_window_set_icon(void * window, const uint8_t * data,
             32, PropModeReplace, (uint8_t *)property_data, property_size);
     XFlush(g_display);
     free(property_data);
+    XUnlockDisplay(g_display);
 }
 
 /**************************************************************************
@@ -631,16 +655,25 @@ static bool process_x_event(XEvent * x_event, jtk_event_t * event)
 
 bool jtk_check_event(jtk_event_t * event)
 {
+    bool event_found = false;
+
+    XLockDisplay(g_display);
+
     /* First check for an X event. */
     while (XPending(g_display) > 0)
     {
         XEvent x_event;
         XNextEvent(g_display, &x_event);
         if (process_x_event(&x_event, event))
-            return true;
+        {
+            event_found = true;
+            break;
+        }
     }
 
-    return false;
+    XUnlockDisplay(g_display);
+
+    return event_found;
 }
 
 void jtk_wait_event(jtk_event_t * event, uint64_t time_to_wait)
@@ -656,7 +689,9 @@ void jtk_wait_event(jtk_event_t * event, uint64_t time_to_wait)
             time_to_wait = MAX_WAIT_TIME;
         }
 
+        XLockDisplay(g_display);
         int x_fd = ConnectionNumber(g_display);
+        XUnlockDisplay(g_display);
         fd_set fds;
         FD_ZERO(&fds);
         FD_SET(x_fd, &fds);