[GR-74172] Remove graalpy multiprocessing backend

PullRequest: graalpython/4653

Author: msimacek

graalpython/com.oracle.graal.python.test/src/tests/conftest.toml

@@ -20,7 +20,6 @@ partial_splits_individual_tests = true
 # on Windows, yet, add their files here.
 exclude_on = ['win32', 'win32-github']
 selector = [
-    "test_multiprocessing_graalpy.py", # import _winapi
     "test_pathlib.py",
     "test_posix.py", # import posix
     "test_pyio.py", # pyio imports msvcrt

graalpython/com.oracle.graal.python.test/src/tests/test_entropy_subprocess.py

@@ -48,6 +48,9 @@
 from tests.util import needs_capi
 
 
+POSIX_BACKEND_IS_JAVA = sys.implementation.name == "graalpy" and __graalpython__.posix_module_backend() == "java"
+
+
 @unittest.skipUnless(sys.implementation.name == "graalpy" and sys.platform.startswith("linux"), "Linux GraalPy-specific test")
 class EntropySubprocessTests(unittest.TestCase):
     HASH_SECRET_BYTES = 24
@@ -180,6 +183,7 @@ def test_multiprocessing_process_import_does_not_use_initrandom(self):
             "ok",
         )
 
+    @unittest.skipIf(POSIX_BACKEND_IS_JAVA, "multiprocessing doesn't work on Java POSIX backend")
     def test_multiprocessing_deliver_challenge_does_not_use_additional_initrandom(self):
         self.assert_initrandom_bytes_used(
             self.RANDOM_MODULE_BYTES,

graalpython/com.oracle.graal.python.test/src/tests/test_multiprocessing.py

@@ -1,4 +1,4 @@
-# Copyright (c) 2022, 2024, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2022, 2026, Oracle and/or its affiliates. All rights reserved.
 # DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 #
 # The Universal Permissive License (UPL), Version 1.0
@@ -42,16 +42,16 @@
 import unittest
 
 
+POSIX_BACKEND_IS_JAVA = sys.implementation.name == 'graalpy' and __graalpython__.posix_module_backend() == 'java'
+
+
+@unittest.skipIf(POSIX_BACKEND_IS_JAVA, "multiprocessing doesn't work on emulated backend")
 class MultiprocessingTest(unittest.TestCase):
     @classmethod
     def tearDownClass(cls):
         import multiprocessing.resource_tracker
         multiprocessing.resource_tracker._resource_tracker._stop()
 
-    @unittest.skipIf(
-        sys.implementation.name == 'graalpy' and __graalpython__.posix_module_backend() == 'java',
-        reason="TODO multiprocessing.Array doesn't work on emulated backend",
-    )
     def test_array_read(self):
         # This used to be buggy due to wrong usage of memoryview offsets when two objects were allocated in the same block
         # Don't remove the unused value on the next line

graalpython/com.oracle.graal.python.test/src/tests/test_multiprocessing_graalpy.py

@@ -166,7 +166,6 @@
   "graalpython/com.oracle.graal.python.test/src/tests/test_module_property.py": 0.01,
   "graalpython/com.oracle.graal.python.test/src/tests/test_mro.py": 0.03,
   "graalpython/com.oracle.graal.python.test/src/tests/test_multiprocessing.py": 0.2,
-  "graalpython/com.oracle.graal.python.test/src/tests/test_multiprocessing_graalpy.py": 9.08,
   "graalpython/com.oracle.graal.python.test/src/tests/test_nonlocal.py": 0.0,
   "graalpython/com.oracle.graal.python.test/src/tests/test_object.py": 0.0,
   "graalpython/com.oracle.graal.python.test/src/tests/test_operator.py": 0.01,
@@ -233,4 +232,4 @@
   "graalpython/com.oracle.graal.python.test/src/tests/test_yield_from.py": 0.03,
   "graalpython/com.oracle.graal.python.test/src/tests/test_zipimport.py": 0.05,
   "graalpython/com.oracle.graal.python.test/src/tests/test_zlib.py": 0.02
-}
+}

graalpython/com.oracle.graal.python.test/src/tests/timings-darwin.json

@@ -169,7 +169,6 @@
   "graalpython/com.oracle.graal.python.test/src/tests/test_module_property.py": 0.07999999999999999,
   "graalpython/com.oracle.graal.python.test/src/tests/test_mro.py": 0.0,
   "graalpython/com.oracle.graal.python.test/src/tests/test_multiprocessing.py": 0.36,
-  "graalpython/com.oracle.graal.python.test/src/tests/test_multiprocessing_graalpy.py": 9.059999999999999,
   "graalpython/com.oracle.graal.python.test/src/tests/test_nonlocal.py": 0.0,
   "graalpython/com.oracle.graal.python.test/src/tests/test_object.py": 0.0,
   "graalpython/com.oracle.graal.python.test/src/tests/test_operator.py": 0.0,
@@ -236,4 +235,4 @@
   "graalpython/com.oracle.graal.python.test/src/tests/test_yield_from.py": 0.01,
   "graalpython/com.oracle.graal.python.test/src/tests/test_zipimport.py": 0.060000000000000005,
   "graalpython/com.oracle.graal.python.test/src/tests/test_zlib.py": 0.03
-}
+}

graalpython/com.oracle.graal.python.test/src/tests/timings-linux.json

@@ -45,7 +45,6 @@
 import java.util.Map;
 import java.util.WeakHashMap;
 import java.util.concurrent.ConcurrentHashMap;
-import java.util.concurrent.Semaphore;
 import java.util.logging.Level;
 
 import org.graalvm.collections.EconomicMap;
@@ -343,20 +342,6 @@ public boolean isSingleContext() {
     @CompilationFinal(dimensions = 1) public static final PythonAbstractObject[] CONTEXT_INSENSITIVE_SINGLETONS = new PythonAbstractObject[]{PNone.NONE, PEllipsis.INSTANCE,
                     PNotImplemented.NOT_IMPLEMENTED};
 
-    /**
-     * Named semaphores are shared between all processes in a system, and they persist until the
-     * system is shut down, unless explicitly removed. We interpret this as meaning they all exist
-     * globally per language instance, that is, they are shared between different Contexts in the
-     * same engine.
-     *
-     * Top level contexts use this map to initialize their shared multiprocessing data. Inner
-     * children contexts created for the multiprocessing module ignore this map in
-     * {@link PythonLanguage} and instead inherit it in the shared multiprocessing data from their
-     * parent context. This way, the child inner contexts do not have to run in the same engine
-     * (have the same language instance), but can still share the named semaphores.
-     */
-    public final ConcurrentHashMap<TruffleString, Semaphore> namedSemaphores = new ConcurrentHashMap<>();
-
     @CompilationFinal(dimensions = 1) private volatile Object[] engineOptionsStorage;
     @CompilationFinal private volatile OptionValues engineOptions;
     @CompilationFinal private boolean useNativePrimitiveStorage;

graalpython/com.oracle.graal.python.test/src/tests/unittest_tags/test_multiprocessing_graalpy.txt

@@ -195,8 +195,6 @@
 import com.oracle.graal.python.builtins.modules.lzma.LZMACompressorBuiltins;
 import com.oracle.graal.python.builtins.modules.lzma.LZMADecompressorBuiltins;
 import com.oracle.graal.python.builtins.modules.lzma.LZMAModuleBuiltins;
-import com.oracle.graal.python.builtins.modules.multiprocessing.GraalPySemLockBuiltins;
-import com.oracle.graal.python.builtins.modules.multiprocessing.MultiprocessingGraalPyModuleBuiltins;
 import com.oracle.graal.python.builtins.modules.multiprocessing.MultiprocessingModuleBuiltins;
 import com.oracle.graal.python.builtins.modules.multiprocessing.SemLockBuiltins;
 import com.oracle.graal.python.builtins.modules.pickle.PickleBufferBuiltins;
@@ -765,8 +763,6 @@ private static PythonBuiltins[] initializeBuiltins(TruffleLanguage.Env env) {
                         // _multiprocessing
                         PythonImageBuildOptions.WITHOUT_NATIVE_POSIX ? null : new MultiprocessingModuleBuiltins(),
                         PythonImageBuildOptions.WITHOUT_NATIVE_POSIX ? null : new SemLockBuiltins(),
-                        new MultiprocessingGraalPyModuleBuiltins(),
-                        new GraalPySemLockBuiltins(),
 
                         new WarningsModuleBuiltins(),
                         new GraalPythonModuleBuiltins(),

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/PythonLanguage.java

@@ -124,7 +124,6 @@
 import com.oracle.graal.python.builtins.modules.lsprof.ProfilerBuiltins;
 import com.oracle.graal.python.builtins.modules.lzma.LZMACompressorBuiltins;
 import com.oracle.graal.python.builtins.modules.lzma.LZMADecompressorBuiltins;
-import com.oracle.graal.python.builtins.modules.multiprocessing.GraalPySemLockBuiltins;
 import com.oracle.graal.python.builtins.modules.multiprocessing.SemLockBuiltins;
 import com.oracle.graal.python.builtins.modules.pickle.PickleBufferBuiltins;
 import com.oracle.graal.python.builtins.modules.pickle.PicklerBuiltins;
@@ -635,7 +634,6 @@ passed as positional arguments to zip().  The i-th element in every tuple
     PLock("LockType", PythonObject, newBuilder().publishInModule(J__THREAD).disallowInstantiation().slots(CommonLockBuiltins.SLOTS, LockTypeBuiltins.SLOTS)),
     PRLock("RLock", PythonObject, newBuilder().publishInModule(J__THREAD).basetype().slots(CommonLockBuiltins.SLOTS, RLockBuiltins.SLOTS)),
     PSemLock("SemLock", PythonObject, newBuilder().publishInModule("_multiprocessing").basetype().slots(SemLockBuiltins.SLOTS)),
-    PGraalPySemLock("SemLock", PythonObject, newBuilder().publishInModule("_multiprocessing_graalpy").basetype().slots(GraalPySemLockBuiltins.SLOTS)),
     PSocket("socket", PythonObject, newBuilder().publishInModule(J__SOCKET).basetype().slots(SocketBuiltins.SLOTS)),
     PStaticmethod("staticmethod", PythonObject, newBuilder().publishInModule(J_BUILTINS).basetype().addDict(24).slots(StaticmethodBuiltins.SLOTS).doc("""
                     staticmethod(function) -> method