test: centralize Pyglet GL window setup

cuda_bindings/tests/test_graphics_apis.py

@@ -9,7 +9,7 @@
 
 import pyglet
 import pytest
-from cuda_python_test_helpers.graphics import is_gl_context_unavailable
+from cuda_python_test_helpers.graphics import is_gl_context_unavailable, open_gl_window
 
 from cuda.bindings import runtime as cudart
 
@@ -24,31 +24,6 @@ def _configure_pyglet_headless():
         pyglet.options["headless"] = True
 
 
-def _open_gl_window():
-    """Open a hidden window (or configure EGL headless). Returns the window or None.
-
-    Closes the window if switch_to() fails so a partially-constructed window does not leak.
-    """
-    if not pyglet.options.get("headless"):
-        # Hidden window path (WGL on Windows, GLX/WLS on Linux)
-        from pyglet import gl
-
-        config = gl.Config(double_buffer=False)
-        win = pyglet.window.Window(visible=False, config=config)
-        try:
-            win.switch_to()
-        except Exception:
-            with contextlib.suppress(Exception):
-                win.close()
-            raise
-        return win
-    else:
-        # Headless EGL path; pyglet will arrange a pbuffer-like headless context
-        from pyglet.gl import headless  # noqa: F401
-
-        return None
-
-
 def _allocate_gl_texture(win):
     """Allocate a 2-D RGBA8 texture. Caller must have a current GL context.
 
@@ -80,7 +55,7 @@ def _gl_context():
     _configure_pyglet_headless()
 
     try:
-        win = _open_gl_window()
+        win = open_gl_window()
     except Exception as e:
         if is_gl_context_unavailable(e):
             pytest.skip(f"Could not create GL context: {type(e).__name__}: {e}")

cuda_core/tests/test_graphics.py

@@ -12,7 +12,7 @@
 import numpy as np
 import pyglet
 import pytest
-from cuda_python_test_helpers.graphics import is_gl_context_unavailable
+from cuda_python_test_helpers.graphics import is_gl_context_unavailable, open_gl_window
 
 from cuda.core import (
     Buffer,
@@ -58,41 +58,6 @@ def _configure_pyglet_headless():
         pyglet.options["headless"] = True
 
 
-def _open_gl_window():
-    """Open a hidden window (or configure EGL headless). Returns the window or None.
-
-    Cleans up partial windows and restores the previous GL context if
-    construction fails. Closes the window if switch_to() fails.
-    """
-    if not pyglet.options.get("headless"):
-        from pyglet import gl
-
-        config = gl.Config(double_buffer=False)
-        previous_context = gl.current_context
-        previous_windows = set(pyglet.app.windows)
-        try:
-            win = pyglet.window.Window(visible=False, config=config)
-        except Exception:
-            for window in set(pyglet.app.windows) - previous_windows:
-                with contextlib.suppress(Exception):
-                    window.close()
-            if previous_context is not None:
-                with contextlib.suppress(Exception):
-                    previous_context.set_current()
-            raise
-        try:
-            win.switch_to()
-        except Exception:
-            with contextlib.suppress(Exception):
-                win.close()
-            raise
-        return win
-    else:
-        from pyglet.gl import headless  # noqa: F401
-
-        return None
-
-
 def _allocate_gl_buffer(win, nbytes):
     """Allocate a GL buffer. Caller must have a current GL context.
 
@@ -144,7 +109,7 @@ def _gl_context_and_buffer(nbytes=1024):
     _configure_pyglet_headless()
 
     try:
-        win = _open_gl_window()
+        win = open_gl_window()
     except Exception as e:
         if is_gl_context_unavailable(e):
             pytest.skip(f"Could not create GL context: {type(e).__name__}: {e}")
@@ -172,7 +137,7 @@ def _gl_context_and_texture(width=16, height=16):
     _configure_pyglet_headless()
 
     try:
-        win = _open_gl_window()
+        win = open_gl_window()
     except Exception as e:
         if is_gl_context_unavailable(e):
             pytest.skip(f"Could not create GL context: {type(e).__name__}: {e}")

cuda_core/tests/test_helpers.py

@@ -2,8 +2,10 @@
 #
 # SPDX-License-Identifier: Apache-2.0
 
+import sys
 import time
 import types
+from unittest.mock import Mock
 
 import pytest
 from helpers.buffers import PatternGen, compare_equal_buffers, make_scratch_buffer, thread_unsafe_on_windows
@@ -354,11 +356,36 @@ def test_oom_diagnostics_probe_basics_is_live_and_cheap(init_cuda):
 
 
 # ---------------------------------------------------------------------------
-# GL context availability predicate tests
+# GL helper tests
 # ---------------------------------------------------------------------------
 
 import pytest
-from cuda_python_test_helpers.graphics import is_gl_context_unavailable
+from cuda_python_test_helpers.graphics import is_gl_context_unavailable, open_gl_window
+
+
+@pytest.mark.thread_unsafe(reason="patches the process-wide pyglet module")
+@pytest.mark.agent_authored(model="gpt-5.6-sol")
+def test_open_gl_window_cleans_up_failed_construction(monkeypatch):
+    windows = set()
+    partial_window = Mock()
+    previous_context = Mock()
+
+    def fail_window(**_kwargs):
+        windows.add(partial_window)
+        raise RuntimeError
+
+    pyglet = types.ModuleType("pyglet")
+    pyglet.options = {}
+    pyglet.app = types.SimpleNamespace(windows=windows)
+    pyglet.gl = types.SimpleNamespace(Config=Mock(), current_context=previous_context)
+    pyglet.window = types.SimpleNamespace(Window=fail_window)
+    monkeypatch.setitem(sys.modules, "pyglet", pyglet)
+
+    with pytest.raises(RuntimeError):
+        open_gl_window()
+
+    assert partial_window.close.called
+    assert previous_context.set_current.called
 
 
 class _PygletError(Exception):

cuda_python_test_helpers/cuda_python_test_helpers/graphics.py

@@ -2,20 +2,60 @@
 #
 # SPDX-License-Identifier: Apache-2.0
 
-"""GL availability classification for graphics interop tests.
+"""Shared GL helpers for graphics interop tests.
 
 Both ``cuda_core`` and ``cuda_bindings`` graphics tests need to skip
 when the GL backend cannot be made current, and that decision must not
 hide real bugs in the tests' own GL allocation code. This module owns the
 shared predicate so the two test suites stay in sync.
 
-The helper intentionally does **not** import ``pyglet``: importing
-``pyglet.gl`` / ``pyglet.window`` triggers pyglet's shadow-window
-creation, which fails on headless machines before the test has had a
-chance to set ``pyglet.options["headless"]``. Classification is by
-exception module/name and tightly matched built-in loader errors instead.
+This module intentionally does **not** import ``pyglet`` at module load time:
+importing ``pyglet.gl`` / ``pyglet.window`` triggers pyglet's shadow-window
+creation, which fails on headless machines before the test has had a chance to
+set ``pyglet.options["headless"]``.
 """
 
+import contextlib
+
+
+def open_gl_window():
+    """Open a hidden window after the caller has configured pyglet.
+
+    In headless mode, initialize pyglet's headless GL backend and return None.
+    If window construction fails, clean up any partially-created windows and
+    restore the GL context that was current before the attempt.
+    """
+    import pyglet
+
+    if not pyglet.options.get("headless"):
+        from pyglet import gl
+
+        config = gl.Config(double_buffer=False)
+        previous_context = gl.current_context
+        previous_windows = set(pyglet.app.windows)
+        try:
+            win = pyglet.window.Window(visible=False, config=config)
+        except Exception:
+            for window in set(pyglet.app.windows) - previous_windows:
+                with contextlib.suppress(Exception):
+                    window.close()
+            if previous_context is not None:
+                with contextlib.suppress(Exception):
+                    previous_context.set_current()
+            raise
+        try:
+            win.switch_to()
+        except Exception:
+            with contextlib.suppress(Exception):
+                win.close()
+            raise
+        return win
+
+    from pyglet.gl import headless  # noqa: F401
+
+    return None
+
+
 _GL_CONTEXT_UNAVAILABLE_EXC_NAMES = frozenset(
     {
         "NoSuchDisplayException",