egl: Return the same EGL Display for the same native display.

The latest revision of the spec explicitly requires the same handle to
be returned for the same native display.

Signed-off-by: Chia-I Wu <olvaffe@gmail.com>

3 files changed, 34 insertions, 3 deletions

diff --git a/src/egl/main/eglapi.c b/src/egl/main/eglapi.c
index eaee9facd82..f0a6f7f9355 100644
--- a/src/egl/main/eglapi.c
+++ b/src/egl/main/eglapi.c
@@ -51,9 +51,12 @@ eglGetDisplay(NativeDisplayType nativeDisplay)
 {
    _EGLDisplay *dpy;
    _eglInitGlobals();
-   dpy = _eglNewDisplay(nativeDisplay);
-   if (dpy)
-      _eglLinkDisplay(dpy);
+   dpy = _eglFindDisplay(nativeDisplay);
+   if (!dpy) {
+      dpy = _eglNewDisplay(nativeDisplay);
+      if (dpy)
+         _eglLinkDisplay(dpy);
+   }
    return _eglGetDisplayHandle(dpy);
 }
 
diff --git a/src/egl/main/egldisplay.c b/src/egl/main/egldisplay.c
index a30e810b4a5..1f1f41ea71f 100644
--- a/src/egl/main/egldisplay.c
+++ b/src/egl/main/egldisplay.c
@@ -97,6 +97,30 @@ _eglLookupDisplay(EGLDisplay dpy)
 
 
 /**
+ * Find the display corresponding to the specified native display id in all
+ * linked displays.
+ */
+_EGLDisplay *
+_eglFindDisplay(NativeDisplayType nativeDisplay)
+{
+   EGLuint key = _eglHashFirstEntry(_eglGlobal.Displays);
+
+   /* Walk the hash table.  Should switch to list if it is a problem. */
+   while (key) {
+      _EGLDisplay *dpy = (_EGLDisplay *)
+            _eglHashLookup(_eglGlobal.Displays, key);
+      assert(dpy);
+
+      if (dpy->NativeDisplay == nativeDisplay)
+         return dpy;
+      key = _eglHashNextEntry(_eglGlobal.Displays, key);
+   }
+
+   return NULL;
+}
+
+
+/**
  * Free all the data hanging of an _EGLDisplay object, but not
  * the object itself.
  */
diff --git a/src/egl/main/egldisplay.h b/src/egl/main/egldisplay.h
index ac285f52a7e..0a6003f39ea 100644
--- a/src/egl/main/egldisplay.h
+++ b/src/egl/main/egldisplay.h
@@ -52,6 +52,10 @@ extern _EGLDisplay *
 _eglLookupDisplay(EGLDisplay dpy);
 
 
+extern _EGLDisplay *
+_eglFindDisplay(NativeDisplayType nativeDisplay);
+
+
 extern void
 _eglCleanupDisplay(_EGLDisplay *disp);