glxdisplay: grab X11 lock around various GLX calls

panda/src/glxdisplay/glxGraphicsBuffer.cxx

@@ -71,7 +71,10 @@ begin_frame(FrameMode mode, Thread *current_thread) {
 
   glxGraphicsStateGuardian *glxgsg;
   DCAST_INTO_R(glxgsg, _gsg, false);
-  glXMakeCurrent(_display, _pbuffer, glxgsg->_context);
+  {
+    LightReMutexHolder holder(glxGraphicsPipe::_x_mutex);
+    glXMakeCurrent(_display, _pbuffer, glxgsg->_context);
+  }
 
   // Now that we have made the context current to a window, we can reset the
   // GSG state if this is the first time it has been used.  (We can't just
@@ -125,6 +128,7 @@ end_frame(FrameMode mode, Thread *current_thread) {
 void glxGraphicsBuffer::
 close_buffer() {
   if (_gsg != nullptr) {
+    LightReMutexHolder holder(glxGraphicsPipe::_x_mutex);
     glXMakeCurrent(_display, None, nullptr);
 
     if (_pbuffer != None) {
@@ -179,6 +183,8 @@ open_buffer() {
 
   nassertr(glxgsg->_supports_pbuffer, false);
 
+  LightReMutexHolder holder(glxGraphicsPipe::_x_mutex);
+
   static const int max_attrib_list = 32;
   int attrib_list[max_attrib_list];
   int n = 0;

panda/src/glxdisplay/glxGraphicsPixmap.cxx

@@ -74,7 +74,10 @@ begin_frame(FrameMode mode, Thread *current_thread) {
 
   glxGraphicsStateGuardian *glxgsg;
   DCAST_INTO_R(glxgsg, _gsg, false);
-  glXMakeCurrent(_display, _glx_pixmap, glxgsg->_context);
+  {
+    LightReMutexHolder holder(glxGraphicsPipe::_x_mutex);
+    glXMakeCurrent(_display, _glx_pixmap, glxgsg->_context);
+  }
 
   // Now that we have made the context current to a window, we can reset the
   // GSG state if this is the first time it has been used.  (We can't just
@@ -127,6 +130,7 @@ end_frame(FrameMode mode, Thread *current_thread) {
  */
 void glxGraphicsPixmap::
 close_buffer() {
+  LightReMutexHolder holder(glxGraphicsPipe::_x_mutex);
   if (_gsg != nullptr) {
     glXMakeCurrent(_display, None, nullptr);
     _gsg.clear();
@@ -197,6 +201,7 @@ open_buffer() {
     }
   }
 
+  LightReMutexHolder holder(glxGraphicsPipe::_x_mutex);
   _x_pixmap = XCreatePixmap(_display, _drawable,
                             get_x_size(), get_y_size(), visual_info->depth);
   if (_x_pixmap == None) {

panda/src/glxdisplay/glxGraphicsStateGuardian.cxx

@@ -64,6 +64,7 @@ glxGraphicsStateGuardian(GraphicsEngine *engine, GraphicsPipe *pipe,
  */
 glxGraphicsStateGuardian::
 ~glxGraphicsStateGuardian() {
+  LightReMutexHolder holder(glxGraphicsPipe::_x_mutex);
   destroy_temp_xwindow();
   if (_visuals != nullptr) {
     XFree(_visuals);
@@ -224,6 +225,7 @@ choose_pixel_format(const FrameBufferProperties &properties,
                     X11_Display *display,
                     int screen, bool need_pbuffer, bool need_pixmap) {
 
+  LightReMutexHolder holder(glxGraphicsPipe::_x_mutex);
   _display = display;
   _screen = screen;
   _context = nullptr;
@@ -457,6 +459,7 @@ gl_get_error() const {
  */
 void glxGraphicsStateGuardian::
 query_gl_version() {
+  LightReMutexHolder holder(glxGraphicsPipe::_x_mutex);
   PosixGraphicsStateGuardian::query_gl_version();
 
   show_glx_client_string("GLX_VENDOR", GLX_VENDOR);
@@ -483,6 +486,7 @@ query_gl_version() {
  */
 void glxGraphicsStateGuardian::
 get_extra_extensions() {
+  LightReMutexHolder holder(glxGraphicsPipe::_x_mutex);
   save_extensions(glXQueryExtensionsString(_display, _screen));
 }
 
@@ -497,6 +501,8 @@ do_get_extension_func(const char *name) {
   nassertr(name != nullptr, nullptr);
 
   if (glx_get_proc_address) {
+    LightReMutexHolder holder(glxGraphicsPipe::_x_mutex);
+
     // First, check if we have glXGetProcAddress available.  This will be
     // superior if we can get it.
 

panda/src/glxdisplay/glxGraphicsWindow.cxx

@@ -154,6 +154,8 @@ end_flip() {
  */
 void glxGraphicsWindow::
 close_window() {
+  LightReMutexHolder holder(glxGraphicsPipe::_x_mutex);
+
   if (_gsg != nullptr) {
     glXMakeCurrent(_display, None, nullptr);
     _gsg.clear();
@@ -204,6 +206,8 @@ open_window() {
     return false;
   }
 
+  LightReMutexHolder holder(glxGraphicsPipe::_x_mutex);
+
   if (glxgsg->_fbconfig != None) {
     setup_colormap(glxgsg->_fbconfig);
   } else {