From fe0f8fd0404e1dfda65b8c14c70cb26ffde26a70 Mon Sep 17 00:00:00 2001
From: Ilya Verbin <iverbin@tarantool.org>
Date: Mon, 28 Aug 2023 21:20:11 +0300
Subject: [PATCH] main: display a message when local console is exited
Consider the following example:
```
tarantool -e "box.cfg{} require('console').start()"
```
When a local console is exited by pressing Ctrl+D, Tarantool seemingly
freezes - console stops to work, typed characters are not echoed. But
the event loop is not stopped because there are background fibers running.
This patch adds a message that Ctrl+C should be pressed in such a case.
Closes #7017
NO_DOC=minor
---
...gh-7017-display-message-on-console-exit.md | 4 ++
src/box/lua/console.c | 13 +++++++
src/box/lua/console.h | 10 +++++
src/box/lua/console.lua | 1 +
src/main.cc | 6 +++
.../gh_7017_message_on_console_exit_test.lua | 37 +++++++++++++++++++
6 files changed, 71 insertions(+)
create mode 100644 changelogs/unreleased/gh-7017-display-message-on-console-exit.md
create mode 100644 test/app-luatest/gh_7017_message_on_console_exit_test.lua
diff --git a/changelogs/unreleased/gh-7017-display-message-on-console-exit.md b/changelogs/unreleased/gh-7017-display-message-on-console-exit.md
new file mode 100644
index 0000000000..5a021f3361
--- /dev/null
+++ b/changelogs/unreleased/gh-7017-display-message-on-console-exit.md
@@ -0,0 +1,4 @@
+## bugfix/core
+
+* Now the "Type Ctrl-C to exit Tarantool" message is displayed when a local
+ console is exited, but background fibers are running (gh-7017).
diff --git a/src/box/lua/console.c b/src/box/lua/console.c
index efa49e5626..493f414e3c 100644
--- a/src/box/lua/console.c
+++ b/src/box/lua/console.c
@@ -54,6 +54,8 @@
#include <string.h>
#include <strings.h>
+bool is_console_exited;
+
struct rlist on_console_eval = RLIST_HEAD_INITIALIZER(on_console_eval);
static struct luaL_serializer *serializer_yaml;
@@ -727,6 +729,16 @@ lbox_console_run_on_eval(struct lua_State *L)
return 0;
}
+/**
+ * Sets `is_console_exited' to true.
+ */
+static int
+lbox_console_console_exited(MAYBE_UNUSED struct lua_State *L)
+{
+ is_console_exited = true;
+ return 0;
+}
+
int
console_session_fd(struct session *session)
{
@@ -897,6 +909,7 @@ tarantool_lua_console_init(struct lua_State *L)
{"format_yaml", lbox_console_format_yaml},
{"format_lua", lbox_console_format_lua},
{"run_on_eval", lbox_console_run_on_eval},
+ {"console_exited", lbox_console_console_exited},
{NULL, NULL}
};
luaT_newmodule(L, "console.lib", consolelib);
diff --git a/src/box/lua/console.h b/src/box/lua/console.h
index 29348f5af3..d0b25272c4 100644
--- a/src/box/lua/console.h
+++ b/src/box/lua/console.h
@@ -31,12 +31,22 @@
* SUCH DAMAGE.
*/
+#include <stdbool.h>
#include "small/rlist.h"
#if defined(__cplusplus)
extern "C" {
#endif /* defined(__cplusplus) */
+/**
+ * If a local console is exited and there are active libev events (e.g. there's
+ * a background fiber running), Tarantool seemingly freezes - console stops to
+ * work, typed characters are not echoed. This flag is used by main() to display
+ * a message to stdout to make things clear.
+ * The flag is false if the local console was never started or still running.
+ */
+extern bool is_console_exited;
+
/**
* Triggers invoked on console eval.
* Passed eval expression string.
diff --git a/src/box/lua/console.lua b/src/box/lua/console.lua
index 59f4f90dc8..05ea4aaf28 100644
--- a/src/box/lua/console.lua
+++ b/src/box/lua/console.lua
@@ -869,6 +869,7 @@ local function start()
session_internal.create(1, "repl") -- stdin fileno
repl(self)
started = false
+ internal.console_exited()
end
--
diff --git a/src/main.cc b/src/main.cc
index 572808c482..933fef626e 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -76,6 +76,7 @@
#include "title.h"
#include <libutil.h>
#include "box/lua/init.h" /* box_lua_init() */
+#include "box/lua/console.h"
#include "box/session.h"
#include "box/memtx_tx.h"
#include "box/module_cache.h"
@@ -968,6 +969,11 @@ main(int argc, char **argv)
if (say_entering_the_event_loop)
say_info("entering the event loop");
systemd_snotify("READY=1");
+ if (is_console_exited) {
+ printf("Exited console. Type Ctrl-C to exit "
+ "Tarantool.\n");
+ fflush(stdout);
+ }
ev_now_update(loop());
ev_run(loop(), 0);
}
diff --git a/test/app-luatest/gh_7017_message_on_console_exit_test.lua b/test/app-luatest/gh_7017_message_on_console_exit_test.lua
new file mode 100644
index 0000000000..0df443fe60
--- /dev/null
+++ b/test/app-luatest/gh_7017_message_on_console_exit_test.lua
@@ -0,0 +1,37 @@
+local popen = require('popen')
+local t = require('luatest')
+local g = t.group('gh-7017')
+
+-- Read from ph:stdout and fail if it doesn't contain a `pattern'.
+local function grep_stdout_or_fail(ph, pattern)
+ local output = ''
+ t.helpers.retrying({}, function()
+ local chunk = ph:read({timeout = 0.05})
+ if chunk ~= nil then
+ output = output .. chunk
+ end
+ t.assert_str_contains(output, pattern)
+ end)
+end
+
+-- Check that the message is printed when local console is exited.
+g.test_message_on_console_exit = function()
+ local tarantool_exe = arg[-1]
+ local lua_code = [[ fiber = require('fiber')
+ fiber.new(function() fiber.sleep(120) end)
+ print('gh-7017 started')
+ require('console').start() ]]
+ local ph = popen.new({tarantool_exe, '-e', lua_code},
+ {stdin = popen.opts.PIPE, stdout = popen.opts.PIPE})
+ t.assert(ph)
+
+ -- Wait for the process startup.
+ grep_stdout_or_fail(ph, "gh-7017 started")
+
+ -- Send EOF to exit console.
+ ph:shutdown({stdin = true})
+
+ -- Check that the message is printed.
+ grep_stdout_or_fail(ph, "Exited console. Type Ctrl-C to exit Tarantool.")
+ ph:close()
+end
--
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