test(ha-convergence-recovery): RED demotion-convergence + self-restart tests + seams (task 2.1)

src/controller/ha_convergence.c

@@ -0,0 +1,70 @@
+/*
+ * ha_convergence.c — demotion convergence + self-restart primitive
+ * (ha-convergence-recovery Requirement 1).
+ *
+ * ───────────────────────────────────────────────────────────────────────────
+ * RED SCAFFOLD (task 2.1) — task 2.2 REPLACES the bodies below with the real
+ * implementation (and moves controller_saved_argv's backing store into main.c).
+ *
+ * This file currently provides ONLY the link-time definitions the task-2.1 RED
+ * tests need to compile and link:
+ *   - controller_saved_argv()  — stub returning NULL (real argv capture is in
+ *                                main.c, task 2.2)
+ *   - ha_self_restart()        — RED stub: does NOT yet honor the ha_restart_hook
+ *                                / ha_fatal_hook contract, so the fatal-hook test
+ *                                FAILS until task 2.2 implements the real
+ *                                flush → execv → abort sequence (and the
+ *                                XCE_TESTING seam routing).
+ *   - ha_restart_hook / ha_fatal_hook — the XCE_TESTING function-pointer seams,
+ *                                defined =NULL in exactly one TU (this one),
+ *                                mirroring the ha_*_hook seam pattern in ha.c.
+ *
+ * The DEMOTION-SEQUENCE behavior (hook disable on become-follower-from-PRIMARY,
+ * scheduled truncate-above-committed_lsn, restart) lives in raft_cb_become_
+ * follower (ha.c) and is NOT implemented here or there yet — that is task 2.2.
+ * Consequently every demotion-convergence test in test_demotion_convergence.c
+ * is RED against the current tree.
+ * ───────────────────────────────────────────────────────────────────────────
+ */
+
+#include <stddef.h>
+
+#include "cluster.h"
+#include "ha.h"
+#include "xce/cluster_def.h"
+
+#ifdef XCE_TESTING
+/* XCE_TESTING seams (Req 1.6, 1.4) — defined here, declared in ha.h.
+ * Tests set these before exercising the restart/fatal contract. */
+int  (*ha_restart_hook)(cluster_t *c)   = NULL;
+void (*ha_fatal_hook)(const char *msg)  = NULL;
+#endif
+
+/*
+ * controller_saved_argv — RED stub (task 2.2 moves the real, main()-populated
+ * accessor into main.c).  Returns NULL: no argv has been captured in the
+ * scaffold, so a production execv would have nothing to exec.
+ */
+char **controller_saved_argv(void)
+{
+    return NULL;
+}
+
+/*
+ * ha_self_restart — RED stub.
+ *
+ * Task 2.2 replaces this with the real primitive:
+ *   - production: flush logs, execv(controller_saved_argv()); on exec return,
+ *     ERROR + abort() (FATAL — Req 1.4); never returns.
+ *   - XCE_TESTING: invoke ha_restart_hook(c) instead of execv (Req 1.6); if it
+ *     reports failure (or is unset), invoke ha_fatal_hook in place of abort.
+ *
+ * Until then this stub deliberately does NOTHING (no hook routing), so the
+ * task-2.1 fatal-hook test — which asserts a failing restart hook drives
+ * ha_fatal_hook — FAILS (RED).
+ */
+int ha_self_restart(cluster_t *c)
+{
+    (void)c;
+    return 0; /* RED scaffold — task 2.2 implements exec/abort + seam routing */
+}