From db5ce8b3843a03c6f83a02a79f033d7e74784dd5 Mon Sep 17 00:00:00 2001
From: Chia-I Wu <olv@lunarg.com>
Date: Wed, 17 Feb 2010 18:39:27 +0800
Subject: [PATCH] egl: Make eglGetDisplay atomic.

Merge _eglNewDisplay and _eglLinkDisplay into _eglFindDisplay.  Remove
unused _eglUnlinkDisplay.
---
 src/egl/main/eglapi.c     | 10 +----
 src/egl/main/egldisplay.c | 91 ++++++++-------------------------------
 src/egl/main/egldisplay.h | 24 +----------
 3 files changed, 22 insertions(+), 103 deletions(-)

diff --git a/src/egl/main/eglapi.c b/src/egl/main/eglapi.c
index 66fbbe219f3..d5e69a6e25c 100644
--- a/src/egl/main/eglapi.c
+++ b/src/egl/main/eglapi.c
@@ -208,18 +208,12 @@ _eglCheckMode(_EGLDisplay *disp, _EGLMode *m, const char *msg)
 
 /**
  * This is typically the first EGL function that an application calls.
- * We initialize our global vars and create a private _EGLDisplay object.
+ * It associates a private _EGLDisplay object to the native display.
  */
 EGLDisplay EGLAPIENTRY
 eglGetDisplay(EGLNativeDisplayType nativeDisplay)
 {
-   _EGLDisplay *dpy;
-   dpy = _eglFindDisplay(nativeDisplay);
-   if (!dpy) {
-      dpy = _eglNewDisplay(nativeDisplay);
-      if (dpy)
-         _eglLinkDisplay(dpy);
-   }
+   _EGLDisplay *dpy = _eglFindDisplay(nativeDisplay);
    return _eglGetDisplayHandle(dpy);
 }
 
diff --git a/src/egl/main/egldisplay.c b/src/egl/main/egldisplay.c
index acf461def06..f7dbe8ec22a 100644
--- a/src/egl/main/egldisplay.c
+++ b/src/egl/main/egldisplay.c
@@ -45,73 +45,8 @@ _eglFiniDisplay(void)
 
 
 /**
- * Allocate a new _EGLDisplay object for the given nativeDisplay handle.
- * We'll also try to determine the device driver name at this time.
- *
- * Note that nativeDisplay may be an X Display ptr, or a string.
- */
-_EGLDisplay *
-_eglNewDisplay(EGLNativeDisplayType nativeDisplay)
-{
-   _EGLDisplay *dpy = (_EGLDisplay *) calloc(1, sizeof(_EGLDisplay));
-   if (dpy) {
-      _eglInitMutex(&dpy->Mutex);
-      dpy->NativeDisplay = nativeDisplay;
-   }
-   return dpy;
-}
-
-
-/**
- * Link a display to itself and return the handle of the link.
- * The handle can be passed to client directly.
- */
-EGLDisplay
-_eglLinkDisplay(_EGLDisplay *dpy)
-{
-   _eglLockMutex(_eglGlobal.Mutex);
-
-   dpy->Next = _eglGlobal.DisplayList;
-   _eglGlobal.DisplayList = dpy;
-
-   _eglUnlockMutex(_eglGlobal.Mutex);
-
-   return (EGLDisplay) dpy;
-}
-
-
-/**
- * Unlink a linked display from itself.
- * Accessing an unlinked display should generate EGL_BAD_DISPLAY error.
- */
-void
-_eglUnlinkDisplay(_EGLDisplay *dpy)
-{
-   _EGLDisplay *prev;
-
-   _eglLockMutex(_eglGlobal.Mutex);
-
-   prev = _eglGlobal.DisplayList;
-   if (prev != dpy) {
-      while (prev) {
-         if (prev->Next == dpy)
-            break;
-         prev = prev->Next;
-      }
-      assert(prev);
-      prev->Next = dpy->Next;
-   }
-   else {
-      _eglGlobal.DisplayList = dpy->Next;
-   }
-
-   _eglUnlockMutex(_eglGlobal.Mutex);
-}
-
-
-/**
- * Find the display corresponding to the specified native display id in all
- * linked displays.
+ * Find the display corresponding to the specified native display, or create a
+ * new one.
  */
 _EGLDisplay *
 _eglFindDisplay(EGLNativeDisplayType nativeDisplay)
@@ -120,18 +55,30 @@ _eglFindDisplay(EGLNativeDisplayType nativeDisplay)
 
    _eglLockMutex(_eglGlobal.Mutex);
 
+   /* search the display list first */
    dpy = _eglGlobal.DisplayList;
    while (dpy) {
-      if (dpy->NativeDisplay == nativeDisplay) {
-         _eglUnlockMutex(_eglGlobal.Mutex);
-         return dpy;
-      }
+      if (dpy->NativeDisplay == nativeDisplay)
+         break;
       dpy = dpy->Next;
    }
 
+   /* create a new display */
+   if (!dpy) {
+      dpy = (_EGLDisplay *) calloc(1, sizeof(_EGLDisplay));
+      if (dpy) {
+         _eglInitMutex(&dpy->Mutex);
+         dpy->NativeDisplay = nativeDisplay;
+
+         /* add to the display list */ 
+         dpy->Next = _eglGlobal.DisplayList;
+         _eglGlobal.DisplayList = dpy;
+      }
+   }
+
    _eglUnlockMutex(_eglGlobal.Mutex);
 
-   return NULL;
+   return dpy;
 }
 
 
diff --git a/src/egl/main/egldisplay.h b/src/egl/main/egldisplay.h
index 36986464430..43b39bda9d8 100644
--- a/src/egl/main/egldisplay.h
+++ b/src/egl/main/egldisplay.h
@@ -88,19 +88,7 @@ _eglFiniDisplay(void);
 
 
 extern _EGLDisplay *
-_eglNewDisplay(EGLNativeDisplayType displayName);
-
-
-extern EGLDisplay
-_eglLinkDisplay(_EGLDisplay *dpy);
-
-
-extern void
-_eglUnlinkDisplay(_EGLDisplay *dpy);
-
-
-extern _EGLDisplay *
-_eglFindDisplay(EGLNativeDisplayType nativeDisplay);
+_eglFindDisplay(EGLNativeDisplayType displayName);
 
 
 PUBLIC void
@@ -167,16 +155,6 @@ _eglGetDisplayHandle(_EGLDisplay *dpy)
 }
 
 
-/**
- * Return true if the display is linked.
- */
-static INLINE EGLBoolean
-_eglIsDisplayLinked(_EGLDisplay *dpy)
-{
-   return (EGLBoolean) (_eglGetDisplayHandle(dpy) != EGL_NO_DISPLAY);
-}
-
-
 extern void
 _eglLinkResource(_EGLResource *res, _EGLResourceType type, _EGLDisplay *dpy);
 
-- 
2.30.2