Add broker management and writer transfer UI

tests/session_broker_diagnostics/test.c

@@ -150,6 +150,61 @@ int main(void) {
     comparison(1); comparison(2);
     assert(allocations == initial_allocations);
     puts("PASS no post-init broker allocations; 7 diagnostic groups passed");
+    session_broker_management_snapshot_t management;
+    assert(session_broker_get_management_snapshot(NULL) == ESP_ERR_INVALID_ARG);
+    mutex = 1; assert(session_broker_get_management_snapshot(&management) == ESP_ERR_TIMEOUT); mutex = 0;
+    session_broker_client_id_t usb = connect_type(SESSION_BROKER_CLIENT_USB);
+    session_broker_client_id_t ssh = connect_type(SESSION_BROKER_CLIENT_SSH);
+    session_broker_client_id_t web = connect_type(SESSION_BROKER_CLIENT_WEB);
+    assert(session_broker_request_writer(usb) == ESP_OK);
+    feed(128);
+    assert(session_broker_get_management_snapshot(&management) == ESP_OK);
+    assert(management.count == 3 && management.writer_id == usb && management.clients[0].pending == 128);
+    uint32_t generation = management.generation;
+    before = global();
+    assert(session_broker_assign_writer_current(0, generation) == ESP_ERR_INVALID_ARG);
+    assert(session_broker_assign_writer_current(ssh, 0) == ESP_ERR_INVALID_ARG);
+    assert(session_broker_get_management_snapshot(&management) == ESP_OK && management.generation == generation);
+    assert(global().latest_event_sequence == before.latest_event_sequence && snapshot(usb).output_bytes_pending == 128);
+    assert(session_broker_assign_writer_current(ssh, generation) == ESP_OK);
+    assert(global().writer_id == ssh && !snapshot(usb).is_writer && snapshot(ssh).is_writer);
+    before = global();
+    assert(session_broker_assign_writer_current(web, generation) == ESP_ERR_INVALID_STATE);
+    assert(global().writer_id == ssh && global().latest_event_sequence == before.latest_event_sequence);
+    assert(session_broker_get_management_snapshot(&management) == ESP_OK); generation = management.generation;
+    assert(session_broker_release_writer(ssh) == ESP_OK && session_broker_request_writer(ssh) == ESP_OK);
+    assert(session_broker_assign_writer_current(web, generation) == ESP_ERR_INVALID_STATE);
+    assert(session_broker_get_management_snapshot(&management) == ESP_OK); generation = management.generation;
+    assert(session_broker_disconnect(web) == ESP_OK);
+    session_broker_client_id_t reused = connect_type(SESSION_BROKER_CLIENT_WEB);
+    assert(reused != web && (reused & 7) == (web & 7));
+    before = global();
+    assert(session_broker_assign_writer_current(web, generation) == ESP_ERR_NOT_FOUND);
+    assert(global().writer_id == ssh && global().latest_event_sequence == before.latest_event_sequence);
+    assert(session_broker_clear_counters() == ESP_OK);
+    assert(session_broker_get_management_snapshot(&management) == ESP_OK && management.generation == generation);
+    assert(session_broker_assign_writer_current(reused, generation) == ESP_OK);
+    assert(session_broker_get_management_snapshot(&management) == ESP_OK); generation = management.generation;
+    assert(session_broker_force_release_writer(reused) == ESP_OK);
+    assert(session_broker_assign_writer_current(usb, generation) == ESP_ERR_INVALID_STATE);
+    assert(session_broker_request_writer(usb) == ESP_OK);
+    assert(session_broker_get_management_snapshot(&management) == ESP_OK); generation = management.generation;
+    assert(session_broker_disconnect(usb) == ESP_OK);
+    assert(session_broker_assign_writer_current(ssh, generation) == ESP_ERR_INVALID_STATE);
+    puts("PASS Broker management: atomic nonconsuming snapshot, one writer, USB/SSH/Web interleavings, stale target/reuse/ABA and counter-clear fencing");
+    s_writer_generation = UINT32_MAX - 1;
+    assert(session_broker_request_writer(ssh) == ESP_OK && s_writer_generation == UINT32_MAX);
+    assert(session_broker_assign_writer_current(reused, UINT32_MAX) == ESP_ERR_INVALID_STATE);
+    assert(session_broker_force_writer(reused) == ESP_OK && s_writer_generation == UINT32_MAX);
+    disconnect_all();
+    for (size_t i = 0; i < SESSION_BROKER_MAX_CLIENTS; ++i) s_slots[i].generation = SESSION_BROKER_MAX_GENERATION;
+    s_slots[7].generation--;
+    session_broker_client_id_t last = connect_type(SESSION_BROKER_CLIENT_USB);
+    assert(last == UINT32_MAX);
+    assert(session_broker_disconnect(last) == ESP_OK);
+    assert(session_broker_connect(SESSION_BROKER_CLIENT_USB, "exhausted", &last) == ESP_ERR_NO_MEM);
+    assert(!global().connected_clients && !global().writer_id);
+    puts("PASS Broker wrap: saturated confirmation rejects, ordinary recovery remains; all 29-bit client generations retire without reuse");
     cleanup_allocations();
     return 0;
 }