1 files changed, 76 insertions, 0 deletions
diff --git a/src/test/test-procfs-util.c b/src/test/test-procfs-util.c
new file mode 100644
index 0000000..2b19a98
--- /dev/null
+++ b/src/test/test-procfs-util.c
@@ -0,0 +1,76 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <errno.h>
+
+#include "errno-util.h"
+#include "format-util.h"
+#include "log.h"
+#include "procfs-util.h"
+#include "process-util.h"
+#include "tests.h"
+
+int main(int argc, char *argv[]) {
+        nsec_t nsec;
+        uint64_t v, pid_max, threads_max, limit;
+        int r;
+
+        test_setup_logging(LOG_DEBUG);
+
+        assert_se(procfs_cpu_get_usage(&nsec) >= 0);
+        log_info("Current system CPU time: %s", FORMAT_TIMESPAN(nsec/NSEC_PER_USEC, 1));
+
+        assert_se(procfs_memory_get_used(&v) >= 0);
+        log_info("Current memory usage: %s", FORMAT_BYTES(v));
+
+        assert_se(procfs_tasks_get_current(&v) >= 0);
+        log_info("Current number of tasks: %" PRIu64, v);
+
+        pid_max = TASKS_MAX;
+        r = procfs_get_pid_max(&pid_max);
+        if (r == -ENOENT || ERRNO_IS_NEG_PRIVILEGE(r))
+                return log_tests_skipped_errno(r, "can't get pid max");
+        assert(r >= 0);
+        log_info("kernel.pid_max: %"PRIu64, pid_max);
+
+        threads_max = TASKS_MAX;
+        r = procfs_get_threads_max(&threads_max);
+        if (r == -ENOENT || ERRNO_IS_NEG_PRIVILEGE(r))
+                return log_tests_skipped_errno(r, "can't get threads max");
+        assert(r >= 0);
+        log_info("kernel.threads-max: %"PRIu64, threads_max);
+
+        limit = MIN(pid_max - (pid_max > 0), threads_max);
+
+        assert_se(r >= 0);
+        log_info("Limit of tasks: %" PRIu64, limit);
+        assert_se(limit > 0);
+
+        /* This call should never fail, as we're trying to set it to the same limit */
+        assert(procfs_tasks_set_limit(limit) >= 0);
+
+        if (limit > 100) {
+                log_info("Reducing limit by one to %"PRIu64"…", limit-1);
+
+                r = procfs_tasks_set_limit(limit-1);
+                if (IN_SET(r, -ENOENT, -EROFS) || ERRNO_IS_PRIVILEGE(r))
+                        return log_tests_skipped_errno(r, "can't set tasks limit");
+                assert_se(r >= 0);
+
+                assert_se(procfs_get_pid_max(&v) >= 0);
+                /* We never decrease the pid_max, so it shouldn't have changed */
+                assert_se(v == pid_max);
+
+                assert_se(procfs_get_threads_max(&v) >= 0);
+                assert_se(v == limit-1);
+
+                assert_se(procfs_tasks_set_limit(limit) >= 0);
+
+                assert_se(procfs_get_pid_max(&v) >= 0);
+                assert_se(v == pid_max);
+
+                assert_se(procfs_get_threads_max(&v) >= 0);
+                assert_se(v == limit);
+        }
+
+        return 0;
+}