[Mesa-dev] [PATCH 1/3] egl: Emit error when EGLSurface is lost

[Chad Versace]

From: Chad Versace <chad at kiwitree.net>

Add a new bool, _EGLSurface::Lost, and check it in eglMakeCurrent and
eglSwapBuffers. The EGL 1.5 spec says that those functions emit errors
when the native surface is no longer valid.

This patch just updates core EGL. No driver sets _EGLSurface::Lost yet.

I discovered that Mesa failed to detect lost surfaces while debugging an
Android CTS camera test,
android.hardware.camera2.cts.RobustnessTest#testAbandonRepeatingRequestSurface.
This patch doesn't fix the test though, though, because the test expects
EGL_BAD_SURFACE when the surface becomes lost, and this patch actually
complies with the EGL spec. If I interpreted the EGL spec correctly,
EGL_BAD_NATIVE_WINDOW or EGL_BAD_CURRENT_SURFACE is the correct error.

Cc: Tomasz Figa <tfiga at chromium.org>
Cc: Nicolas Boichat <drinkcat at chromium.org>
Cc: Tapani Pälli <tapani.palli at intel.com>
---
 src/egl/main/eglapi.c     | 36 ++++++++++++++++++++++++++++++++++++
 src/egl/main/eglsurface.c |  1 +
 src/egl/main/eglsurface.h |  5 +++++
 3 files changed, 42 insertions(+)

diff --git a/src/egl/main/eglapi.c b/src/egl/main/eglapi.c
index fc243a58e8..a459b9ffcd 100644
--- a/src/egl/main/eglapi.c
+++ b/src/egl/main/eglapi.c
@@ -828,6 +828,33 @@ eglMakeCurrent(EGLDisplay dpy, EGLSurface draw, EGLSurface read,
          RETURN_EGL_ERROR(disp, EGL_BAD_MATCH, EGL_FALSE);
    }
 
+   _EGLThreadInfo *t =_eglGetCurrentThread();
+   _EGLContext *old_ctx = t->CurrentContext;
+   _EGLSurface *old_draw_surf = old_ctx ? old_ctx->DrawSurface : NULL;
+   _EGLSurface *old_read_surf = old_ctx ? old_ctx->ReadSurface : NULL;
+
+   /* From the EGL 1.5 spec, Section 3.7.3 Binding Context and Drawables:
+    *
+    *    If the previous context of the calling thread has unflushed commands,
+    *    and the previous surface is no longer valid, an
+    *    EGL_BAD_CURRENT_SURFACE error is generated.
+    *
+    * It's difficult to check if the context has unflushed commands, but it's
+    * easy to check if the surface is no longer valid.
+    */
+   if (old_draw_surf && old_draw_surf->Lost)
+      RETURN_EGL_ERROR(disp, EGL_BAD_CURRENT_SURFACE, EGL_FALSE);
+   if (old_read_surf && old_read_surf->Lost)
+      RETURN_EGL_ERROR(disp, EGL_BAD_CURRENT_SURFACE, EGL_FALSE);
+
+   /*    If a native window underlying either draw or read is no longer valid,
+    *    an EGL_BAD_NATIVE_WINDOW error is generated.
+    */
+   if (draw_surf && draw_surf->Lost)
+      RETURN_EGL_ERROR(disp, EGL_BAD_NATIVE_WINDOW, EGL_FALSE);
+   if (read_surf && read_surf->Lost)
+      RETURN_EGL_ERROR(disp, EGL_BAD_NATIVE_WINDOW, EGL_FALSE);
+
    ret = drv->API.MakeCurrent(drv, disp, draw_surf, read_surf, context);
 
    RETURN_EGL_EVAL(disp, ret);
@@ -1215,6 +1242,15 @@ eglSwapBuffers(EGLDisplay dpy, EGLSurface surface)
       RETURN_EGL_ERROR(disp, EGL_BAD_SURFACE, EGL_FALSE);
    #endif
 
+   /* From the EGL 1.5 spec:
+    *
+    *    If eglSwapBuffers is called and the native window associated with
+    *    surface is no longer valid, an EGL_BAD_NATIVE_WINDOW error is
+    *    generated.
+    */
+   if (surf->Lost)
+      RETURN_EGL_ERROR(disp, EGL_BAD_NATIVE_WINDOW, EGL_FALSE);
+
    ret = drv->API.SwapBuffers(drv, disp, surf);
 
    RETURN_EGL_EVAL(disp, ret);
diff --git a/src/egl/main/eglsurface.c b/src/egl/main/eglsurface.c
index 04f42caf79..e935c83271 100644
--- a/src/egl/main/eglsurface.c
+++ b/src/egl/main/eglsurface.c
@@ -295,6 +295,7 @@ _eglInitSurface(_EGLSurface *surf, _EGLDisplay *dpy, EGLint type,
    _eglInitResource(&surf->Resource, sizeof(*surf), dpy);
    surf->Type = type;
    surf->Config = conf;
+   surf->Lost = EGL_FALSE;
 
    surf->Width = 0;
    surf->Height = 0;
diff --git a/src/egl/main/eglsurface.h b/src/egl/main/eglsurface.h
index fc799ee43d..f13cf49741 100644
--- a/src/egl/main/eglsurface.h
+++ b/src/egl/main/eglsurface.h
@@ -56,6 +56,11 @@ struct _egl_surface
 
    EGLint Type; /* one of EGL_WINDOW_BIT, EGL_PIXMAP_BIT or EGL_PBUFFER_BIT */
 
+   /* The native surface is lost. The EGL spec requires certain functions
+    * to generate EGL_BAD_NATIVE_WINDOW when given this surface.
+    */
+   EGLBoolean Lost;
+
    /* attributes set by attribute list */
    EGLint Width, Height;
    EGLenum TextureFormat;
-- 
2.12.0