Fix IPC memory pool leak in nightly repeated test runs

IPC test fixtures and test methods create DeviceMemoryResource and
PinnedMemoryResource instances that are never closed. Under single-run
CI this is harmless, but nightly CI runs tests with pytest-repeat
--count=100, accumulating ~200+ leaked CUDA mempools and POSIX fd
exports per test file until the process segfaults around iteration 83.

Convert the ipc_memory_resource fixture from return to yield with
explicit close() teardown, and close locally-created memory resources
in test_errors, test_send_buffers, and test_workerpool after use.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: cpcloud

cuda_core/tests/conftest.py

@@ -183,7 +183,8 @@ def ipc_memory_resource(request, ipc_device):
         mr = PinnedMemoryResource(options=options)
 
     assert mr.is_ipc_enabled
-    return mr
+    yield mr
+    mr.close()
 
 
 @pytest.fixture

cuda_core/tests/memory_ipc/test_errors.py

@@ -26,6 +26,7 @@ def test_main(self, ipc_device, ipc_memory_resource):
         # from PARENT_ACTION.
         self.device = ipc_device
         self.mr = ipc_memory_resource
+        self._extra_mrs = []
 
         # Start a child process to generate error info.
         pipe = [multiprocessing.Queue() for _ in range(2)]
@@ -43,6 +44,9 @@ def test_main(self, ipc_device, ipc_memory_resource):
         process.join(timeout=CHILD_TIMEOUT_SEC)
         assert process.exitcode == 0
 
+        for mr in self._extra_mrs:
+            mr.close()
+
     def child_main(self, pipe, device, mr):
         """Child process that pushes IPC errors to a shared pipe for testing."""
         self.device = device
@@ -78,6 +82,7 @@ class TestImportWrongMR(ChildErrorHarness):
     def PARENT_ACTION(self, queue):
         options = DeviceMemoryResourceOptions(max_size=POOL_SIZE, ipc_enabled=True)
         mr2 = DeviceMemoryResource(self.device, options=options)
+        self._extra_mrs.append(mr2)
         buffer = mr2.allocate(NBYTES)
         queue.put([self.mr, buffer.get_ipc_descriptor()])  # Note: mr does not own this buffer
 
@@ -117,6 +122,7 @@ class TestDanglingBuffer(ChildErrorHarness):
     def PARENT_ACTION(self, queue):
         options = DeviceMemoryResourceOptions(max_size=POOL_SIZE, ipc_enabled=True)
         mr2 = DeviceMemoryResource(self.device, options=options)
+        self._extra_mrs.append(mr2)
         self.buffer = mr2.allocate(NBYTES)
         buffer_s = pickle.dumps(self.buffer)
         queue.put(buffer_s)  # Note: mr2 not sent

cuda_core/tests/memory_ipc/test_send_buffers.py

@@ -45,6 +45,8 @@ def test_main(self, ipc_device, nmrs):
         for buffer in buffers:
             pgen.verify_buffer(buffer, seed=True)
             buffer.close()
+        for mr in mrs:
+            mr.close()
 
     def child_main(self, device, buffers):
         device.set_current()

cuda_core/tests/memory_ipc/test_workerpool.py

@@ -42,6 +42,8 @@ def test_main(self, ipc_device, nmrs):
         for buffer in buffers:
             pgen.verify_buffer(buffer, seed=True)
             buffer.close()
+        for mr in mrs:
+            mr.close()
 
     def process_buffer(self, buffer):
         device = Device(buffer.memory_resource.device_id)
@@ -82,6 +84,8 @@ def test_main(self, ipc_device, nmrs):
         for buffer in buffers:
             pgen.verify_buffer(buffer, seed=True)
             buffer.close()
+        for mr in mrs:
+            mr.close()
 
     def process_buffer(self, mr_idx, buffer_desc):
         mr = self.mrs[mr_idx]
@@ -124,6 +128,8 @@ def test_main(self, ipc_device, nmrs):
         for buffer in buffers:
             pgen.verify_buffer(buffer, seed=True)
             buffer.close()
+        for mr in mrs:
+            mr.close()
 
     def process_buffer(self, device, buffer_s):
         device.set_current()