Adds inotify stress test

score/mw/com/test/common_test_resources/BUILD

@@ -362,6 +362,7 @@ cc_library(
     srcs = ["general_resources.cpp"],
     hdrs = ["general_resources.h"],
     features = COMPILER_WARNING_FEATURES,
+    visibility = ["//score/mw/com/test:__subpackages__"],
     deps = [
         ":check_point_control",
         ":child_process_guard",

score/mw/com/test/inotify_stress_test/BUILD

@@ -0,0 +1,50 @@
+# *******************************************************************************
+# Copyright (c) 2026 Contributors to the Eclipse Foundation
+#
+# See the NOTICE file(s) distributed with this work for additional
+# information regarding copyright ownership.
+#
+# This program and the accompanying materials are made available under the
+# terms of the Apache License Version 2.0 which is available at
+# https://www.apache.org/licenses/LICENSE-2.0
+#
+# SPDX-License-Identifier: Apache-2.0
+# *******************************************************************************
+
+load("@rules_cc//cc:defs.bzl", "cc_binary")
+load("@score_baselibs//score/language/safecpp:toolchain_features.bzl", "COMPILER_WARNING_FEATURES")
+load("//score/mw/com/test:pkg_application.bzl", "pkg_application")
+
+cc_binary(
+    name = "inotify_stress_test",
+    srcs = [
+        "controller.cpp",
+        "controller.h",
+        "inotify_stress_test.cpp",
+        "inotify_stress_test_internal.h",
+        "worker.cpp",
+        "worker.h",
+    ],
+    features = COMPILER_WARNING_FEATURES + [
+        "aborts_upon_exception",
+    ],
+    visibility = ["//score/mw/com/test/inotify_stress_test:__subpackages__"],
+    deps = [
+        "//score/mw/com/test/common_test_resources:check_point_control",
+        "//score/mw/com/test/common_test_resources:general_resources",
+        "@boost.program_options",
+        "@score_baselibs//score/filesystem",
+        "@score_baselibs//score/language/futurecpp",
+        "@score_baselibs//score/mw/log",
+        "@score_baselibs//score/os/utils/inotify:inotify_instance_impl",
+    ],
+)
+
+pkg_application(
+    name = "inotify-stress-test-pkg",
+    app_name = "InotifyStressTestApp",
+    bin = [":inotify_stress_test"],
+    visibility = [
+        "//score/mw/com/test/inotify_stress_test:__subpackages__",
+    ],
+)

score/mw/com/test/inotify_stress_test/README.md

@@ -0,0 +1,63 @@
+# inotify Stress Test
+
+Stress test that exercises the `os::InotifyInstanceImpl` inotify wrapper under heavy
+concurrent load from multiple processes.
+
+## What it does
+
+A controller process spawns `M` worker processes. Each worker owns a dedicated
+sub-directory and file under a shared base folder and is optionally assigned a unique
+UID/GID. The controller and workers synchronise through `CheckPointControl` objects held
+in shared memory, so every cycle is driven in lock-step.
+
+On each of the `N` cycles a worker:
+
+1. Creates its process directory (skipped when it already exists with the correct
+   access rights).
+2. Creates its test file (skipped when it already exists with the correct access rights).
+3. Adds an inotify watch on the shared base folder
+   (`kInCreate | kInDelete`).
+4. Removes the watch immediately.
+5. Reports the cycle as reached via `CheckPointReached`.
+
+The controller signals each worker to start a cycle (`ProceedToNextCheckpoint`), waits for
+every worker to report success or error (`WaitAndVerifyCheckPoint`), removes the per-process
+directories so the next cycle re-exercises the creation path, and after all cycles sends
+`FinishActions` so workers exit cleanly. Any worker failure fails the whole test.
+
+## Arguments
+
+| Argument          | Default | Description                                                        |
+| ----------------- | ------- | ------------------------------------------------------------------ |
+| `--num-processes` | 5       | Number of worker processes to spawn.                               |
+| `--cycles`        | 100     | Number of stress cycles before terminating.                        |
+| `--base-uid`      | 0       | Worker `N` calls `setuid(base-uid + N)`; `0` skips `setuid`.       |
+| `--base-gid`      | 0       | Worker `N` calls `setgid(base-gid + N)`; `0` skips `setgid`.       |
+
+When `--base-uid` / `--base-gid` are non-zero the setuid/setgid must succeed, so the binary
+has to run as root (e.g. inside the Docker integration-test container). Local non-root runs
+should leave these at their default `0`.
+
+## Layout
+
+| File                             | Responsibility                                              |
+| -------------------------------- | ----------------------------------------------------------- |
+| `inotify_stress_test.cpp`        | Entry point: argument parsing, setup, fork orchestration.   |
+| `worker.{h,cpp}`                 | Per-worker cycle loop and UID/GID credential switching.     |
+| `controller.{h,cpp}`             | Controller loop: signals workers, verifies checkpoints.     |
+| `inotify_stress_test_internal.h` | Shared constants and path helpers.                          |
+| `integration_test/`              | pytest wrapper that runs the binary in the test container.  |
+
+## Running
+
+Build and run the binary directly:
+
+```sh
+bazel run //score/mw/com/test/inotify_stress_test:inotify_stress_test -- --num-processes 10 --cycles 100
+```
+
+Run the integration test (10 processes, 300 cycles, distinct UIDs/GIDs from 2000):
+
+```sh
+bazel test //score/mw/com/test/inotify_stress_test/integration_test:test_inotify_stress_test
+```

score/mw/com/test/inotify_stress_test/controller.cpp

@@ -0,0 +1,91 @@
+/*******************************************************************************
+ * Copyright (c) 2026 Contributors to the Eclipse Foundation
+ *
+ * See the NOTICE file(s) distributed with this work for additional
+ * information regarding copyright ownership.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *******************************************************************************/
+
+#include "score/mw/com/test/inotify_stress_test/controller.h"
+
+#include "score/filesystem/details/standard_filesystem.h"
+#include "score/mw/com/test/common_test_resources/check_point_control.h"
+#include "score/mw/com/test/inotify_stress_test/inotify_stress_test_internal.h"
+
+#include <score/stop_token.hpp>
+#include <unistd.h>
+#include <chrono>
+#include <cstdlib>
+#include <iostream>
+#include <string>
+#include <vector>
+
+namespace score::mw::com::test
+{
+
+bool RunController(std::vector<CheckPointControl*>& checkpoint_controls,
+                   const std::size_t num_processes,
+                   const std::size_t cycles,
+                   const score::cpp::stop_token& stop_token)
+{
+    const auto pid{getpid()};
+    bool test_passed{true};
+
+    for (std::size_t i{0U}; i < cycles; ++i)
+    {
+        // Signal all workers to begin this cycle
+        for (std::size_t j{0U}; j < checkpoint_controls.size(); ++j)
+        {
+            std::cerr << pid << ": Signalling worker " << j << " to start (cycle " << i << ")" << std::endl;
+            checkpoint_controls[j]->ProceedToNextCheckpoint();
+        }
+
+        // Wait for every worker to report checkpoint or error — collect all before deciding to abort
+        for (std::size_t j{0U}; j < checkpoint_controls.size(); ++j)
+        {
+            const std::string tag{"[cycle=" + std::to_string(i) + " worker=" + std::to_string(j) + "] "};
+            const int result =
+                WaitAndVerifyCheckPoint(tag,
+                                        *checkpoint_controls[j],
+                                        kCycleDoneCheckpoint,
+                                        stop_token,
+                                        std::chrono::duration_cast<std::chrono::milliseconds>(kCheckpointWaitDuration));
+            if (result != EXIT_SUCCESS)
+            {
+                std::cerr << pid << ": Worker " << j << " failed at cycle " << i << std::endl;
+                test_passed = false;
+            }
+        }
+
+        // Remove the shared test directory so the next cycle exercises the creation path again
+        static_cast<void>(num_processes);
+        const score::filesystem::StandardFilesystem fs;
+        const std::string test_dir{TestDir()};
+        const auto remove = fs.RemoveAll(test_dir);
+        if (!remove.has_value())
+        {
+            // Non-fatal: directory may not have been created (all workers errored before mkdir)
+            std::cerr << pid << ": Remove " << test_dir << " info: " << remove.error() << std::endl;
+        }
+
+        if (!test_passed)
+        {
+            break;
+        }
+    }
+
+    // Unblock all workers regardless of outcome so they exit cleanly
+    for (auto* const cp : checkpoint_controls)
+    {
+        cp->FinishActions();
+    }
+
+    return test_passed;
+}
+
+}  // namespace score::mw::com::test

score/mw/com/test/inotify_stress_test/controller.h

@@ -0,0 +1,44 @@
+/*******************************************************************************
+ * Copyright (c) 2026 Contributors to the Eclipse Foundation
+ *
+ * See the NOTICE file(s) distributed with this work for additional
+ * information regarding copyright ownership.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *******************************************************************************/
+
+#ifndef SCORE_MW_COM_TEST_INOTIFY_STRESS_TEST_CONTROLLER_H
+#define SCORE_MW_COM_TEST_INOTIFY_STRESS_TEST_CONTROLLER_H
+
+#include "score/mw/com/test/common_test_resources/check_point_control.h"
+
+#include <score/stop_token.hpp>
+
+#include <cstddef>
+#include <vector>
+
+namespace score::mw::com::test
+{
+
+/// \brief Runs the controller loop for \p cycles iterations.
+///
+/// Each iteration:
+///   1. Signals every worker via ProceedToNextCheckpoint().
+///   2. Waits for every worker to report CheckPointReached or ErrorOccurred.
+///   3. Removes per-worker directories so the next cycle exercises the creation path.
+///
+/// Sends FinishActions() to all workers before returning regardless of outcome.
+///
+/// \return true if all cycles completed without any worker error; false otherwise.
+bool RunController(std::vector<CheckPointControl*>& checkpoint_controls,
+                   std::size_t num_processes,
+                   std::size_t cycles,
+                   const score::cpp::stop_token& stop_token);
+
+}  // namespace score::mw::com::test
+
+#endif  // SCORE_MW_COM_TEST_INOTIFY_STRESS_TEST_CONTROLLER_H