egl: Add funtions to link contexts and surfaces to displays.

EGL contexts and surfaces are resources of displays.  They should be
managed by displays.  This commit adds a bunch of functions to
egldisplay.c to help establish the links between contexts/surfaces and
displays.  How links are established is considered opaque outside
display.  Functions like _eglGetSurfaceHandle or _eglLookupSurface are
therefore moved to egldisplay.c, with some small modifications.

The idea is also extended to display.  That is, displays need to link to
themselves to be looked up.

This commit only adds the functions.  A commit to use them should
follow.

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

1 files changed, 178 insertions, 24 deletions

diff --git a/src/egl/main/egldisplay.c b/src/egl/main/egldisplay.c
index 01f67f6e47..a30e810b4a 100644
--- a/src/egl/main/egldisplay.c
+++ b/src/egl/main/egldisplay.c
@@ -7,6 +7,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include "eglcontext.h"
+#include "eglsurface.h"
 #include "egldisplay.h"
 #include "egldriver.h"
 #include "eglglobals.h"
@@ -25,11 +26,6 @@ _eglNewDisplay(NativeDisplayType nativeDisplay)
 {
    _EGLDisplay *dpy = (_EGLDisplay *) calloc(1, sizeof(_EGLDisplay));
    if (dpy) {
-      EGLuint key = _eglHashGenKey(_eglGlobal.Displays);
-
-      dpy->Handle = (EGLDisplay) key;
-      _eglHashInsert(_eglGlobal.Displays, key, dpy);
-
       dpy->NativeDisplay = nativeDisplay;
 #if defined(_EGL_PLATFORM_X)
       dpy->Xdpy = (Display *) nativeDisplay;
@@ -46,8 +42,37 @@ _eglNewDisplay(NativeDisplayType nativeDisplay)
 
 
 /**
- * Return the public handle for an internal _EGLDisplay.
- * This is the inverse of _eglLookupDisplay().
+ * Link a display to itself and return the handle of the link.
+ * The handle can be passed to client directly.
+ */
+EGLDisplay
+_eglLinkDisplay(_EGLDisplay *dpy)
+{
+   EGLuint key;
+   key = _eglHashGenKey(_eglGlobal.Displays);
+   assert(key);
+   /* "link" the display to the hash table */
+   _eglHashInsert(_eglGlobal.Displays, key, dpy);
+   dpy->Handle = (EGLDisplay) key;
+
+   return dpy->Handle;
+}
+
+
+/**
+ * Unlink a linked display from itself.
+ * Accessing an unlinked display should generate EGL_BAD_DISPLAY error.
+ */
+void
+_eglUnlinkDisplay(_EGLDisplay *dpy)
+{
+   _eglHashRemove(_eglGlobal.Displays, (EGLuint) dpy->Handle);
+   dpy->Handle = EGL_NO_DISPLAY;
+}
+
+
+/**
+ * Return the handle of a linked display, or EGL_NO_DISPLAY.
  */
 EGLDisplay
 _eglGetDisplayHandle(_EGLDisplay *display)
@@ -60,32 +85,17 @@ _eglGetDisplayHandle(_EGLDisplay *display)
 
  
 /**
- * Return the _EGLDisplay object that corresponds to the given public/
- * opaque display handle.
- * This is the inverse of _eglGetDisplayHandle().
+ * Lookup a handle to find the linked display.
+ * Return NULL if the handle has no corresponding linked display.
  */
 _EGLDisplay *
 _eglLookupDisplay(EGLDisplay dpy)
 {
    EGLuint key = (EGLuint) dpy;
-   if (!_eglGlobal.Displays)
-      return NULL;
    return (_EGLDisplay *) _eglHashLookup(_eglGlobal.Displays, key);
 }
 
 
-void
-_eglSaveDisplay(_EGLDisplay *dpy)
-{
-   EGLuint key = _eglHashGenKey(_eglGlobal.Displays);
-   assert(dpy);
-   assert(!dpy->Handle);
-   dpy->Handle = (EGLDisplay) key;
-   assert(dpy->Handle);
-   _eglHashInsert(_eglGlobal.Displays, key, dpy);
-}
-
-
 /**
  * Free all the data hanging of an _EGLDisplay object, but not
  * the object itself.
@@ -108,3 +118,147 @@ _eglCleanupDisplay(_EGLDisplay *disp)
 
    /* driver deletes the _EGLDisplay object */
 }
+
+
+/**
+ * Link a context to a display and return the handle of the link.
+ * The handle can be passed to client directly.
+ */
+EGLContext
+_eglLinkContext(_EGLContext *ctx, _EGLDisplay *dpy)
+{
+   ctx->Display = dpy;
+   ctx->Next = dpy->ContextList;
+   dpy->ContextList = ctx;
+   return (EGLContext) ctx;
+}
+
+
+/**
+ * Unlink a linked context from its display.
+ * Accessing an unlinked context should generate EGL_BAD_CONTEXT error.
+ */
+void
+_eglUnlinkContext(_EGLContext *ctx)
+{
+   _EGLContext *prev;
+
+   prev = ctx->Display->ContextList;
+   if (prev != ctx) {
+      while (prev) {
+         if (prev->Next == ctx)
+            break;
+         prev = prev->Next;
+      }
+      assert(prev);
+      prev->Next = ctx->Next;
+   }
+   else {
+      ctx->Display->ContextList = ctx->Next;
+   }
+
+   ctx->Next = NULL;
+   ctx->Display = NULL;
+}
+
+
+/**
+ * Return the handle of a linked context, or EGL_NO_CONTEXT.
+ */
+EGLContext
+_eglGetContextHandle(_EGLContext *ctx)
+{
+   return (EGLContext) (ctx && ctx->Display) ? ctx : EGL_NO_CONTEXT;
+}
+
+
+/**
+ * Lookup a handle to find the linked context.
+ * Return NULL if the handle has no corresponding linked context.
+ */
+_EGLContext *
+_eglLookupContext(EGLContext ctx)
+{
+   _EGLContext *context = (_EGLContext *) ctx;
+   return (context && context->Display) ? context : NULL;
+}
+
+
+/**
+ * Link a surface to a display and return the handle of the link.
+ * The handle can be passed to client directly.
+ */
+EGLSurface
+_eglLinkSurface(_EGLSurface *surf, _EGLDisplay *dpy)
+{
+   EGLuint key;
+
+   surf->Display = dpy;
+   surf->Next = dpy->SurfaceList;
+   dpy->SurfaceList = surf;
+
+   key = _eglHashGenKey(_eglGlobal.Surfaces);
+   assert(key);
+   _eglHashInsert(_eglGlobal.Surfaces, key, surf);
+
+   surf->Handle = (EGLSurface) key;
+   return surf->Handle;
+}
+
+
+/**
+ * Unlink a linked surface from its display.
+ * Accessing an unlinked surface should generate EGL_BAD_SURFACE error.
+ */
+void
+_eglUnlinkSurface(_EGLSurface *surf)
+{
+   _EGLSurface *prev;
+
+   _eglHashRemove(_eglGlobal.Surfaces, (EGLuint) surf->Handle);
+   surf->Handle = EGL_NO_SURFACE;
+
+   prev = surf->Display->SurfaceList;
+   if (prev != surf) {
+      while (prev) {
+         if (prev->Next == surf)
+            break;
+         prev = prev->Next;
+      }
+      assert(prev);
+      prev->Next = surf->Next;
+   }
+   else {
+      prev = NULL;
+      surf->Display->SurfaceList = surf->Next;
+   }
+
+   surf->Next = NULL;
+   surf->Display = NULL;
+}
+
+
+/**
+ * Return the handle of a linked surface, or EGL_NO_SURFACE.
+ */
+EGLSurface
+_eglGetSurfaceHandle(_EGLSurface *surface)
+{
+   if (surface)
+      return surface->Handle;
+   else
+      return EGL_NO_SURFACE;
+}
+
+
+/**
+ * Lookup a handle to find the linked surface.
+ * Return NULL if the handle has no corresponding linked surface.
+ */
+_EGLSurface *
+_eglLookupSurface(EGLSurface surf)
+{
+   _EGLSurface *c = (_EGLSurface *) _eglHashLookup(_eglGlobal.Surfaces,
+                                                   (EGLuint) surf);
+   return c;
+}