From e7a7c314c94cc390110b450541ccacd8a55e0500 Mon Sep 17 00:00:00 2001
From: Richard Qin <richard.qin.x@gmail.com>
Date: Sat, 2 May 2026 23:37:39 +0800
Subject: feat: add klog self-test suite with various test cases

---
 na/test/test_klog.cc | 175 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 175 insertions(+)
 create mode 100644 na/test/test_klog.cc

diff --git a/na/test/test_klog.cc b/na/test/test_klog.cc
new file mode 100644
index 0000000..896e7ed
--- /dev/null
+++ b/na/test/test_klog.cc
@@ -0,0 +1,175 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* Copyright (C) 2026 Richard Qin */
+
+/*
+ * Boot Self-Test: klog
+ *
+ * Tests:
+ *   1. read vs read_consume semantics
+ *   2. subsystem mask filtering
+ *   3. ratelimit bookkeeping
+ *   4. flush advances console tail when console filtering is active
+ *   5. seq counter increments on writes
+ */
+
+#include <lume/selftest.h>
+#include <lume/klog.h>
+#include <string.h>
+
+static void drain_klog()
+{
+    static char buf[512];
+    while (true) {
+        int n = klog_read_consume(buf, sizeof(buf));
+        if (n <= 0) {
+            break;
+        }
+    }
+}
+
+static bool test_read_peek_and_consume()
+{
+    drain_klog();
+
+    klog_ex(KLOG_INFO, KLOG_SUBSYS_TEST, "klog_test_a");
+    klog_ex(KLOG_INFO, KLOG_SUBSYS_TEST, "klog_test_b");
+
+    KlogStats s0;
+    klog_stats(&s0);
+
+    char buf[1024];
+    int n = klog_read(buf, sizeof(buf) - 1);
+    if (n <= 0) {
+        return false;
+    }
+    buf[n] = '\0';
+    if (!strstr(buf, "klog_test_a") || !strstr(buf, "klog_test_b")) {
+        return false;
+    }
+
+    KlogStats s1;
+    klog_stats(&s1);
+    if (s1.tail != s0.tail) {
+        return false;
+    }
+
+    int n2 = klog_read_consume(buf, sizeof(buf) - 1);
+    if (n2 <= 0) {
+        return false;
+    }
+    buf[n2] = '\0';
+    if (!strstr(buf, "klog_test_a") || !strstr(buf, "klog_test_b")) {
+        return false;
+    }
+
+    KlogStats s2;
+    klog_stats(&s2);
+    return s2.tail != s0.tail;
+}
+
+static bool test_subsys_mask()
+{
+    drain_klog();
+
+    const uint64 all_mask = (1ULL << KLOG_SUBSYS_MAX) - 1;
+    klog_set_subsys_mask(1ULL << KLOG_SUBSYS_TEST);
+
+    klog_ex(KLOG_INFO, KLOG_SUBSYS_TEST, "klog_subsys_ok");
+    klog_ex(KLOG_INFO, KLOG_SUBSYS_GENERIC, "klog_subsys_drop");
+
+    char buf[1024];
+    int n = klog_read_consume(buf, sizeof(buf) - 1);
+    klog_set_subsys_mask(all_mask);
+
+    if (n <= 0) {
+        return false;
+    }
+    buf[n] = '\0';
+    return strstr(buf, "klog_subsys_ok") && !strstr(buf, "klog_subsys_drop");
+}
+
+static bool test_ratelimit()
+{
+    KlogRateLimit rl = {};
+    rl.interval = 100;
+    rl.burst = 2;
+
+    bool a = klog_ratelimit(&rl, 10);
+    bool b = klog_ratelimit(&rl, 20);
+    bool c = klog_ratelimit(&rl, 30);
+
+    if (!a || !b || c) {
+        return false;
+    }
+    if (rl.printed != 2 || rl.suppressed != 1) {
+        return false;
+    }
+
+    bool d = klog_ratelimit(&rl, 200);
+    if (!d) {
+        return false;
+    }
+    return rl.printed == 1 && rl.suppressed == 0;
+}
+
+static bool test_flush_advances_console_tail()
+{
+    drain_klog();
+
+    klog_set_level(KLOG_ERR);
+    klog_ex(KLOG_INFO, KLOG_SUBSYS_TEST, "klog_flush_msg");
+
+    KlogStats s1;
+    klog_stats(&s1);
+    if (s1.console_tail == s1.head) {
+        klog_set_level(static_cast<KlogLevel>(KLOG_DEFAULT_LEVEL));
+        return false;
+    }
+
+    klog_flush();
+
+    KlogStats s2;
+    klog_stats(&s2);
+
+    klog_set_level(static_cast<KlogLevel>(KLOG_DEFAULT_LEVEL));
+    return s2.console_tail == s2.head;
+}
+
+static bool test_seq_increments()
+{
+    drain_klog();
+
+    KlogStats s0;
+    klog_stats(&s0);
+
+    klog_ex(KLOG_INFO, KLOG_SUBSYS_TEST, "klog_seq_1");
+    klog_ex(KLOG_INFO, KLOG_SUBSYS_TEST, "klog_seq_2");
+
+    KlogStats s1;
+    klog_stats(&s1);
+
+    return s1.seq >= s0.seq + 2;
+}
+
+void selftest_klog()
+{
+    st_begin("klog: read vs read_consume");
+    ST_ASSERT(test_read_peek_and_consume());
+    st_pass();
+
+    st_begin("klog: subsys mask filters");
+    ST_ASSERT(test_subsys_mask());
+    st_pass();
+
+    st_begin("klog: ratelimit bookkeeping");
+    ST_ASSERT(test_ratelimit());
+    st_pass();
+
+    st_begin("klog: flush advances console tail");
+    ST_ASSERT(test_flush_advances_console_tail());
+    st_pass();
+
+    st_begin("klog: seq increments on write");
+    ST_ASSERT(test_seq_increments());
+    st_pass();
+}
-- 
cgit v1.2.3