Introduce a counting process as a test utility

tests/utils/test_helper/BUILD

@@ -20,6 +20,7 @@ exports_files(
         "reporting_process.cpp",
         "verification_process.cpp",
         "complex_reporting_process.cpp",
+        "counting_process.cpp",
     ],
     visibility = ["//tests:__subpackages__"],
 )
@@ -91,3 +92,13 @@ cc_binary(
         "@googletest//:gtest_main",
     ],
 )
+
+cc_binary(
+    name = "counting_process",
+    srcs = ["counting_process.cpp"],
+    visibility = ["//tests:__subpackages__"],
+    deps = [
+        ":test_helper",
+        "//score/launch_manager:lifecycle_cc",
+    ],
+)

tests/utils/test_helper/counting_process.cpp

@@ -0,0 +1,149 @@
+/********************************************************************************
+ * 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
+ ********************************************************************************/
+/*
+ * ./counting_process [--help|-h] [--report-running|-r] [--post-to-semaphore=<name>|-p <name>]
+ *
+ * This process will optionally post to a semaphore and also optionally report running.
+ * This is designed to for hand-in-hand with the waiting_process, which can be used to wait
+ * for a named semaphore to reach a certain value.
+ *
+ * Exit codes:
+ * - Exit code 0: Semaphore was posted to successfully.
+ * - Exit code 1: usage error.
+ * - Exit code 2: Failure posting to semaphore.
+ */
+#include <fcntl.h>
+#include <getopt.h>
+#include <score/mw/lifecycle/report_running.h>
+#include <semaphore.h>
+#include <stdio.h>
+#include <cerrno>
+#include <cstdlib>
+#include <cstring>
+#include <string>
+
+namespace
+{
+/**
+ * @brief Posts to a named POSIX semaphore, creating it if it doesn't exist
+ * @param semaphore_name The name of the semaphore to post to
+ */
+[[nodiscard]] int post_to_named_semaphore(const std::string& semaphore_name)
+{
+    // O_CREAT with an initial value of 0: the first process to get here
+    // creates the semaphore, every later one just re-opens the same one by
+    // name. 0666 permissions so any process (regardless of which user the
+    // supervisor configures it to run as) can post to and wait on it.
+    sem_t* const semaphore = ::sem_open(semaphore_name.c_str(), O_CREAT, 0666, 0);
+    if (semaphore == SEM_FAILED)
+    {
+        std::fprintf(
+            stderr,
+            "post_to_named_semaphore: sem_open(\"%s\") failed: %s\n",
+            semaphore_name.c_str(),
+            std::strerror(errno));
+        return 2;
+    }
+
+    if (::sem_post(semaphore) != 0)
+    {
+        std::fprintf(
+            stderr,
+            "post_to_named_semaphore: sem_post(\"%s\") failed: %s\n",
+            semaphore_name.c_str(),
+            std::strerror(errno));
+        static_cast<void>(::sem_close(semaphore));
+        return 2;
+    }
+
+    static_cast<void>(::sem_close(semaphore));
+
+    return 0;
+}
+
+}  // namespace
+
+/**
+ * @brief Test helper process that can report running status and post to a named semaphore
+ * @param argc Argument count
+ * @param argv Argument values
+ * @return 0 on success, 1 on invalid arguments
+ */
+int main(int argc, char* argv[])
+{
+    bool help = false;
+    bool report_running = false;
+    bool post_to_semaphore = false;
+    std::string semaphore_name;
+
+    static struct option long_options[] = {
+        {"help", no_argument, nullptr, 'h'},
+        {"report-running", no_argument, nullptr, 'r'},
+        {"post-to-semaphore", required_argument, nullptr, 'p'},
+        {nullptr, 0, nullptr, 0}};
+
+    int opt;
+    int option_index = 0;
+
+    while ((opt = getopt_long(argc, argv, "hrp:", long_options, &option_index)) != -1)
+    {
+        switch (opt)
+        {
+            case 'h':
+                help = true;
+                break;
+            case 'r':
+                report_running = true;
+                break;
+            case 'p':
+                semaphore_name = std::string(optarg);
+                post_to_semaphore = true;
+                break;
+            case '?':
+            default:
+                std::fprintf(stderr, "Invalid or missing argument.\n");
+                return 1;
+        }
+    }
+
+    if (!(help || report_running || post_to_semaphore))
+    {
+        std::fprintf(stderr, "Invalid arguments! Must provide at least one option.\n");
+        return 1;
+    }
+
+    if (post_to_semaphore && (semaphore_name.empty() || semaphore_name[0] != '/'))
+    {
+        std::fprintf(stderr, "Invalid semaphore name! Must be non-empty and start with '/'\n");
+        return 1;
+    }
+
+    if (help)
+    {
+        std::printf(
+            "Usage: ./counting_process [--help|-h] [--report-running|-r] [--post-to-semaphore=<name>|-p <name>]\n");
+        return 0;
+    }
+
+    if (report_running)
+    {
+        score::mw::lifecycle::report_running();
+    }
+
+    if (post_to_semaphore)
+    {
+        return post_to_named_semaphore(semaphore_name);
+    }
+
+    return 0;
+}