[GR-78174][GR-77822][GR-78201][GR-78172] Small workarounds/fixes for periodic jobs.

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

@@ -0,0 +1,61 @@
+# Copyright (c) 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
+#
+# Subject to the condition set forth below, permission is hereby granted to any
+# person obtaining a copy of this software, associated documentation and/or
+# data (collectively the "Software"), free of charge and under any and all
+# copyright rights in the Software, and any and all patent rights owned or
+# freely licensable by each licensor hereunder covering either (i) the
+# unmodified Software as contributed to or provided by such licensor, or (ii)
+# the Larger Works (as defined below), to deal in both
+#
+# (a) the Software, and
+#
+# (b) any piece of software and/or hardware listed in the lrgrwrks.txt file if
+# one is included with the Software each a "Larger Work" to which the Software
+# is contributed by such licensors),
+#
+# without restriction, including without limitation the rights to copy, create
+# derivative works of, display, perform, and distribute the Software and make,
+# use, sell, offer for sale, import, export, have made, and have sold the
+# Software and the Larger Work(s), and to sublicense the foregoing rights on
+# either these or other terms.
+#
+# This license is subject to the following condition:
+#
+# The above copyright notice and either this complete permission notice or at a
+# minimum a reference to the UPL must be included in all copies or substantial
+# portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+
+import os
+import sys
+import tempfile
+import unittest
+
+
+@unittest.skipUnless(sys.platform == "win32", "Windows only")
+class MsvcrtTests(unittest.TestCase):
+    def test_setmode(self):
+        import msvcrt
+
+        with tempfile.TemporaryFile() as file:
+            fd = file.fileno()
+            self.assertEqual(msvcrt.setmode(fd, os.O_BINARY), os.O_BINARY)
+            self.assertEqual(msvcrt.setmode(fd, os.O_TEXT), os.O_BINARY)
+            self.assertEqual(msvcrt.setmode(fd, os.O_BINARY), os.O_TEXT)
+
+    def test_setmode_invalid_fd(self):
+        import msvcrt
+
+        with self.assertRaises(OSError):
+            msvcrt.setmode(-1, os.O_BINARY)

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

@@ -11,4 +11,6 @@ test.test_dbm.TestCase_dumb.test_keys @ darwin-arm64,linux-aarch64,linux-aarch64
 test.test_dbm.TestCase_dumb.test_open_with_bytes @ darwin-arm64,linux-aarch64,linux-aarch64-github,linux-x86_64,linux-x86_64-github,win32-AMD64,win32-AMD64-github
 test.test_dbm.TestCase_dumb.test_open_with_pathlib_path @ darwin-arm64,linux-aarch64,linux-aarch64-github,linux-x86_64,linux-x86_64-github,win32-AMD64,win32-AMD64-github
 test.test_dbm.TestCase_dumb.test_open_with_pathlib_path_bytes @ darwin-arm64,linux-aarch64,linux-aarch64-github,linux-x86_64,linux-x86_64-github,win32-AMD64,win32-AMD64-github
-test.test_dbm.WhichDBTestCase.test_whichdb @ darwin-arm64,linux-aarch64,linux-aarch64-github,linux-x86_64,linux-x86_64-github,win32-AMD64,win32-AMD64-github
+test.test_dbm.WhichDBTestCase.test_whichdb @ darwin-arm64,linux-aarch64,linux-aarch64-github,linux-x86_64,linux-x86_64-github
+# GR-78201
+!test.test_dbm.WhichDBTestCase.test_whichdb @ win32-AMD64,win32-AMD64-github

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/modules/MsvcrtModuleBuiltins.java

@@ -118,6 +118,29 @@ protected ArgumentClinicProvider getArgumentClinic() {
         }
     }
 
+    @Builtin(name = "setmode", minNumOfPositionalArgs = 2, parameterNames = {"fd", "flags"})
+    @ArgumentClinic(name = "fd", conversion = ArgumentClinic.ClinicConversion.Int)
+    @ArgumentClinic(name = "flags", conversion = ArgumentClinic.ClinicConversion.Int)
+    @GenerateNodeFactory
+    public abstract static class SetModeNode extends PythonBinaryClinicBuiltinNode {
+        @Specialization
+        int setMode(VirtualFrame frame, int fd, int flags,
+                        @Bind Node inliningTarget,
+                        @CachedLibrary("getPosixSupport()") PosixSupportLibrary posixLib,
+                        @Cached PConstructAndRaiseNode.Lazy constructAndRaiseNode) {
+            try {
+                return posixLib.setMode(getPosixSupport(), fd, flags);
+            } catch (PosixSupportLibrary.PosixException e) {
+                throw constructAndRaiseNode.get(inliningTarget).raiseOSErrorFromPosixException(frame, e);
+            }
+        }
+
+        @Override
+        protected ArgumentClinicProvider getArgumentClinic() {
+            return MsvcrtModuleBuiltinsClinicProviders.SetModeNodeClinicProviderGen.INSTANCE;
+        }
+    }
+
     @Builtin(name = "get_osfhandle", minNumOfPositionalArgs = 1, parameterNames = {"fd"})
     @ArgumentClinic(name = "fd", conversion = ArgumentClinic.ClinicConversion.Int)
     @GenerateNodeFactory

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/runtime/EmulatedPosixSupport.java

@@ -599,6 +599,20 @@ public int openOsfHandle(long handle, int flags) throws UnsupportedPosixFeatureE
         throw createUnsupportedFeature("open_osfhandle");
     }
 
+    @ExportMessage
+    public int setMode(int fd, int mode) throws PosixException {
+        int binary = PosixConstants.O_BINARY.getValueIfDefined();
+        int text = PosixConstants.O_TEXT.getValueIfDefined();
+        if (mode != binary && mode != text) {
+            throw posixException(OSErrorEnum.EINVAL);
+        }
+        int previousMode = setModeTracked(fd, mode);
+        if (previousMode < 0) {
+            throw posixException(OSErrorEnum.EBADF);
+        }
+        return previousMode;
+    }
+
     @ExportMessage(name = "pipe")
     public int[] pipeMessage(@Shared("eq") @Cached TruffleString.EqualNode eqNode) throws PosixException {
         // TODO: will merge with super.pipe once the super class is merged with this class

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/runtime/LoggingPosixSupport.java

@@ -263,6 +263,17 @@ final int openOsfHandle(long handle, int flags,
         }
     }
 
+    @ExportMessage
+    final int setMode(int fd, int mode,
+                    @CachedLibrary("this.delegate") PosixSupportLibrary lib) throws PosixException {
+        logEnter("setMode", "%d, %d", fd, mode);
+        try {
+            return logExit("setMode", "%d", lib.setMode(delegate, fd, mode));
+        } catch (PosixException e) {
+            throw logException("setMode", e);
+        }
+    }
+
     @ExportMessage
     final int[] pipe(
                     @CachedLibrary("this.delegate") PosixSupportLibrary lib) throws PosixException {

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/runtime/NativePosixSupport.java

@@ -241,6 +241,9 @@ abstract static class PosixNativeFunctionInvoker {
         @DowncallSignature(returnType = SINT32, argumentTypes = {SINT64, SINT32})
         abstract int call_open_osfhandle(long handle, int flags);
 
+        @DowncallSignature(returnType = SINT32, argumentTypes = {SINT32, SINT32})
+        abstract int call_setmode(int fd, int mode);
+
         @DowncallSignature(returnType = SINT32, argumentTypes = {POINTER})
         abstract int call_pipe2(long pipefd);
 
@@ -864,6 +867,15 @@ public int openOsfHandle(long handle, int flags) throws PosixException {
         return fd;
     }
 
+    @ExportMessage
+    public int setMode(int fd, int mode) throws PosixException {
+        int previousMode = posixNativeFunctionInvoker.call_setmode(fd, mode);
+        if (previousMode < 0) {
+            throw getErrnoAndThrowPosixException();
+        }
+        return previousMode;
+    }
+
     @ExportMessage
     public int[] pipe() throws PosixException {
         int[] fds = new int[2];

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/runtime/PosixResources.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 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
@@ -82,6 +82,7 @@ abstract class PosixResources extends PosixSupport {
     /** Context-local file-descriptor mappings and PID mappings */
     protected final PythonContext context;
     private final SortedMap<Integer, ChannelWrapper> files;
+    private final Map<Integer, Integer> fileModes;
     protected final Map<Integer, String> filePaths;
     private final List<Process> children;
     private final Map<String, Integer> inodes;
@@ -222,12 +223,16 @@ void setNewChannel(OutputStream outputStream) {
     protected PosixResources(PythonContext context) {
         this.context = context;
         files = Collections.synchronizedSortedMap(new TreeMap<>());
+        fileModes = Collections.synchronizedMap(new HashMap<>());
         filePaths = Collections.synchronizedMap(new HashMap<>());
         children = Collections.synchronizedList(new ArrayList<>());
 
         files.put(FD_STDIN, ChannelWrapper.createForStandardStream());
         files.put(FD_STDOUT, ChannelWrapper.createForStandardStream());
         files.put(FD_STDERR, ChannelWrapper.createForStandardStream());
+        fileModes.put(FD_STDIN, defaultFileMode());
+        fileModes.put(FD_STDOUT, defaultFileMode());
+        fileModes.put(FD_STDERR, defaultFileMode());
         if (PythonLanguage.getPythonOS() == PythonOS.PLATFORM_WIN32) {
             filePaths.put(FD_STDIN, "STDIN");
             filePaths.put(FD_STDOUT, "STDOUT");
@@ -260,6 +265,7 @@ private void addFD(int fd, Channel channel) {
     @TruffleBoundary
     private void addFD(int fd, Channel channel, String path) {
         files.put(fd, new ChannelWrapper(channel));
+        fileModes.put(fd, defaultFileMode());
         if (path != null) {
             filePaths.put(fd, path);
         }
@@ -278,6 +284,7 @@ protected boolean removeFD(int fd) throws IOException {
                 }
 
                 files.remove(fd);
+                fileModes.remove(fd);
                 filePaths.remove(fd);
             }
             return true;
@@ -295,12 +302,23 @@ private void dupFD(int fd1, int fd2) {
         if (channelWrapper != null) {
             channelWrapper.cnt += 1;
             files.put(fd2, channelWrapper);
+            fileModes.put(fd2, fileModes.get(fd1));
             if (path != null) {
                 filePaths.put(fd2, path);
             }
         }
     }
 
+    private static int defaultFileMode() {
+        return PythonLanguage.getPythonOS() == PythonOS.PLATFORM_WIN32 ? PosixConstants.O_BINARY.getValueIfDefined() : 0;
+    }
+
+    @TruffleBoundary
+    protected int setModeTracked(int fd, int mode) {
+        Integer previousMode = fileModes.replace(fd, mode);
+        return previousMode == null ? -1 : previousMode;
+    }
+
     protected boolean isStandardStream(int fd) {
         ChannelWrapper channelWrapper = files.get(fd);
         return channelWrapper != null && channelWrapper.isStandardStream;

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/runtime/PosixSupportLibrary.java

@@ -108,6 +108,8 @@ public abstract class PosixSupportLibrary extends Library {
 
     public abstract int openOsfHandle(Object receiver, long handle, int flags) throws PosixException;
 
+    public abstract int setMode(Object receiver, int fd, int mode) throws PosixException;
+
     public abstract int[] pipe(Object receiver) throws PosixException;
 
     public abstract SelectResult select(Object receiver, int[] readfds, int[] writefds, int[] errorfds, Timeval timeout) throws PosixException;

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/runtime/PreInitPosixSupport.java

@@ -256,6 +256,13 @@ final int openOsfHandle(long handle, int flags,
         return nativeLib.openOsfHandle(nativePosixSupport, handle, flags);
     }
 
+    @ExportMessage
+    final int setMode(int fd, int mode,
+                    @CachedLibrary("this.nativePosixSupport") PosixSupportLibrary nativeLib) throws PosixException {
+        checkNotInPreInitialization();
+        return nativeLib.setMode(nativePosixSupport, fd, mode);
+    }
+
     @ExportMessage
     final int[] pipe(@CachedLibrary("this.nativePosixSupport") PosixSupportLibrary nativeLib) throws PosixException {
         checkNotInPreInitialization();

graalpython/lib-python/3/test/test_concurrent_futures/test_deadlock.py

@@ -25,6 +25,15 @@ def _crash(delay=None):
     faulthandler._sigsegv()
 
 
+# Self-signals are only supported in native standalones (GR-74243); skip these
+# tests on JVM coverage runs rather than re-tagging them (GR-77822).
+def _is_native():
+    try:
+        return __graalpython__.is_native
+    except NameError:
+        return True  # CPython
+
+
 def _crash_with_data(data):
     """Induces a segfault with dummy data in input."""
     _crash()
@@ -155,6 +164,7 @@ def test_crash_at_task_unpickle(self):
         # Check problem occurring while unpickling a task on workers
         self._check_crash(BrokenProcessPool, id, CrashAtUnpickle())
 
+    @unittest.skipUnless(_is_native(), "self-signals are only supported in native standalone")
     def test_crash_during_func_exec_on_worker(self):
         # Check problem occurring during func execution on workers
         self._check_crash(BrokenProcessPool, _crash)
@@ -167,6 +177,7 @@ def test_error_during_func_exec_on_worker(self):
         # Check problem occurring during func execution on workers
         self._check_crash(RuntimeError, _raise_error, RuntimeError)
 
+    @unittest.skipUnless(_is_native(), "self-signals are only supported in native standalone")
     def test_crash_during_result_pickle_on_worker(self):
         # Check problem occurring while pickling a task result
         # on workers
@@ -197,6 +208,7 @@ def test_exit_during_result_unpickle_in_result_handler(self):
         # the result_handler thread
         self._check_crash(BrokenProcessPool, _return_instance, ExitAtUnpickle)
 
+    @unittest.skipUnless(_is_native(), "self-signals are only supported in native standalone")
     def test_shutdown_deadlock(self):
         # Test that the pool calling shutdown do not cause deadlock
         # if a worker fails after the shutdown call.
@@ -235,6 +247,7 @@ def test_shutdown_deadlock_pickle(self):
         # dangling threads
         executor_manager.join()
 
+    @unittest.skipUnless(_is_native(), "self-signals are only supported in native standalone")
     def test_crash_big_data(self):
         # Test that there is a clean exception instad of a deadlock when a
         # child process crashes while some data is being written into the

graalpython/python-libposix/src/posix.c

@@ -1073,6 +1073,17 @@ GP_EXPORT int32_t call_open_osfhandle(int64_t handle, int32_t flags) {
     return open_osfhandle_noraise(handle, flags);
 }
 
+GP_EXPORT int32_t call_setmode(int32_t fd, int32_t mode) {
+    int previous_mode;
+    BEGIN_SUPPRESS_IPH
+    previous_mode = _setmode(fd, mode);
+    END_SUPPRESS_IPH
+    if (previous_mode < 0) {
+        capture_errno();
+    }
+    return previous_mode;
+}
+
 GP_EXPORT int32_t call_pipe2(int32_t *pipefd) {
     int result = _pipe(pipefd, 8192, _O_BINARY | _O_NOINHERIT);
     if (result < 0) {
@@ -2170,6 +2181,14 @@ int32_t call_open_osfhandle(int64_t handle, int32_t flags) {
     return -1;
 }
 
+int32_t call_setmode(int32_t fd, int32_t mode) {
+    (void) fd;
+    (void) mode;
+    errno = ENOSYS;
+    capture_errno();
+    return -1;
+}
+
 int32_t call_pipe2(int32_t *pipefd) {
 #ifdef __gnu_linux__
     CAPTURE_ERRNO_AND_RETURN(-1, pipe2(pipefd, O_CLOEXEC));

mx.graalpython/mx_graalpython.py

@@ -1701,6 +1701,11 @@ def run_python_unittests(python_binary, args=None, paths=None, exclude=None, env
         if GITHUB_CI:
             parallel = 0
 
+    if mx_gate.get_jacoco_agent_args():
+        # JaCoCo execution data is appended to a shared file and cannot be
+        # safely written by multiple instrumented JVM test workers at once.
+        parallel = 1
+
     parallelism = str(min(os.cpu_count() or 1, parallel))
 
     args = args or []