egl: Add reference count for resources.

This is a really simple mechanism.  There is no atomicity and the caller
is expected to hold the display lock.

1 files changed, 41 insertions, 1 deletions

diff --git a/src/egl/main/egldisplay.c b/src/egl/main/egldisplay.c
index 47dcc3e05a..565e44d2d2 100644
--- a/src/egl/main/egldisplay.c
+++ b/src/egl/main/egldisplay.c
@@ -233,6 +233,42 @@ _eglCheckResource(void *res, _EGLResourceType type, _EGLDisplay *dpy)
 
 
 /**
+ * Initialize a display resource.
+ */
+void
+_eglInitResource(_EGLResource *res, EGLint size, _EGLDisplay *dpy)
+{
+   memset(res, 0, size);
+   res->Display = dpy;
+   res->RefCount = 1;
+}
+
+
+/**
+ * Increment reference count for the resource.
+ */
+void
+_eglGetResource(_EGLResource *res)
+{
+   assert(res && res->RefCount > 0);
+   /* hopefully a resource is always manipulated with its display locked */
+   res->RefCount++;
+}
+
+
+/**
+ * Decrement reference count for the resource.
+ */
+EGLBoolean
+_eglPutResource(_EGLResource *res)
+{
+   assert(res && res->RefCount > 0);
+   res->RefCount--;
+   return (!res->RefCount);
+}
+
+
+/**
  * Link a resource to its display.
  */
 void
@@ -243,6 +279,7 @@ _eglLinkResource(_EGLResource *res, _EGLResourceType type)
    res->IsLinked = EGL_TRUE;
    res->Next = res->Display->ResourceLists[type];
    res->Display->ResourceLists[type] = res;
+   _eglGetResource(res);
 }
 
 
@@ -269,6 +306,9 @@ _eglUnlinkResource(_EGLResource *res, _EGLResourceType type)
    }
 
    res->Next = NULL;
-   /* do not reset res->Display */
    res->IsLinked = EGL_FALSE;
+   _eglPutResource(res);
+
+   /* We always unlink before destroy.  The driver still owns a reference */
+   assert(res->RefCount);
 }