Add a threadAttach callback for entrypoint patching.

The threadAttach callback is used so that a vendor library can go through any
thread initialization it needs to in order to deal with any later OpenGL calls.

This allows a vendor library to work around broken applications that try to
call OpenGL functions without a current context.

2 files changed, 22 insertions, 1 deletions

diff --git a/include/glvnd/GLdispatchABI.h b/include/glvnd/GLdispatchABI.h
index d16de2d..ab70361 100644
--- a/include/glvnd/GLdispatchABI.h
+++ b/include/glvnd/GLdispatchABI.h
@@ -138,6 +138,27 @@ typedef struct __GLdispatchPatchCallbacksRec {
      * original state. The vendor library must not try to modify them.
      */
     void (*releasePatch)(void);
+
+    /*!
+     * Called at the start of window-system functions (GLX and EGL). This
+     * callback allows vendor libraries to perform any per-thread
+     * initialization.
+     *
+     * This is basically a workaround for broken applications. A lot of apps
+     * will make one or more invalid GLX/EGL calls on a thread (often including
+     * a MakeCurrent with invalid parameters), and then will try to call an
+     * OpenGL function.
+     *
+     * A non-libglvnd-based driver would be able to initialize any thread state
+     * even on a bogus GLX call, but with libglvnd, those calls wouldn't get
+     * past libGLX.
+     *
+     * This function is optional. If it's \c NULL, then libGLdispatch will
+     * simply ignore it.
+     *
+     * \note This function may be called concurrently from multiple threads.
+     */
+    void (*threadAttach)(void);
 } __GLdispatchPatchCallbacks;
 
 #if defined(__cplusplus)
diff --git a/include/glvnd/libglxabi.h b/include/glvnd/libglxabi.h
index 3a59691..23b8303 100644
--- a/include/glvnd/libglxabi.h
+++ b/include/glvnd/libglxabi.h
@@ -91,7 +91,7 @@ extern "C" {
 /*!
  * Current version of the ABI.
  */
-#define GLX_VENDOR_ABI_VERSION 0
+#define GLX_VENDOR_ABI_VERSION 1
 
 
 /*!