On 12/7/20 2:20 PM, Stefan Hajnoczi wrote:
> Add a function to remove previously-added abrt handler functions.
>
> Now that a symmetric pair of add/remove functions exists we can also
> balance the SIGABRT handler installation. The signal handler was
> installed each time qtest_add_abrt_handler() was called. Now it is
> installed when the abrt handler list becomes non-empty and removed again
> when the list becomes empty.
>
> The qtest_remove_abrt_handler() function will be used by
> vhost-user-blk-test.
>
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---
> tests/qtest/libqos/libqtest.h | 18 ++++++++++++++++++
> tests/qtest/libqtest.c | 35 +++++++++++++++++++++++++++++------
> 2 files changed, 47 insertions(+), 6 deletions(-)
Reviewed-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
>
> diff --git a/tests/qtest/libqos/libqtest.h b/tests/qtest/libqos/libqtest.h
> index 51287b9276..a68dcd79d4 100644
> --- a/tests/qtest/libqos/libqtest.h
> +++ b/tests/qtest/libqos/libqtest.h
> @@ -649,8 +649,26 @@ void qtest_add_data_func_full(const char *str, void *data,
> g_free(path); \
> } while (0)
>
> +/**
> + * qtest_add_abrt_handler:
> + * @fn: Handler function
> + * @data: Argument that is passed to the handler
> + *
> + * Add a handler function that is invoked on SIGABRT. This can be used to
> + * terminate processes and perform other cleanup. The handler can be removed
> + * with qtest_remove_abrt_handler().
> + */
> void qtest_add_abrt_handler(GHookFunc fn, const void *data);
>
> +/**
> + * qtest_remove_abrt_handler:
> + * @data: Argument previously passed to qtest_add_abrt_handler()
> + *
> + * Remove an abrt handler that was previously added with
> + * qtest_add_abrt_handler().
> + */
> +void qtest_remove_abrt_handler(void *data);
> +
> /**
> * qtest_qmp_assert_success:
> * @qts: QTestState instance to operate on
> diff --git a/tests/qtest/libqtest.c b/tests/qtest/libqtest.c
> index cc2cec4a35..7cf247baf0 100644
> --- a/tests/qtest/libqtest.c
> +++ b/tests/qtest/libqtest.c
> @@ -196,15 +196,30 @@ static void cleanup_sigabrt_handler(void)
> sigaction(SIGABRT, &sigact_old, NULL);
> }
>
> +static bool hook_list_is_empty(GHookList *hook_list)
> +{
> + GHook *hook = g_hook_first_valid(hook_list, TRUE);
> +
> + if (!hook) {
> + return false;
> + }
> +
> + g_hook_unref(hook_list, hook);
> + return true;
> +}
> +
> void qtest_add_abrt_handler(GHookFunc fn, const void *data)
> {
> GHook *hook;
>
> - /* Only install SIGABRT handler once */
> if (!abrt_hooks.is_setup) {
> g_hook_list_init(&abrt_hooks, sizeof(GHook));
> }
> - setup_sigabrt_handler();
> +
> + /* Only install SIGABRT handler once */
> + if (hook_list_is_empty(&abrt_hooks)) {
> + setup_sigabrt_handler();
> + }
>
> hook = g_hook_alloc(&abrt_hooks);
> hook->func = fn;
> @@ -213,6 +228,17 @@ void qtest_add_abrt_handler(GHookFunc fn, const void *data)
> g_hook_prepend(&abrt_hooks, hook);
> }
>
> +void qtest_remove_abrt_handler(void *data)
> +{
> + GHook *hook = g_hook_find_data(&abrt_hooks, TRUE, data);
> + g_hook_destroy_link(&abrt_hooks, hook);
> +
> + /* Uninstall SIGABRT handler on last instance */
> + if (hook_list_is_empty(&abrt_hooks)) {
> + cleanup_sigabrt_handler();
> + }
> +}
> +
> static const char *qtest_qemu_binary(void)
> {
> const char *qemu_bin;
> @@ -369,10 +395,7 @@ QTestState *qtest_init_with_serial(const char *extra_args, int *sock_fd)
>
> void qtest_quit(QTestState *s)
> {
> - g_hook_destroy_link(&abrt_hooks, g_hook_find_data(&abrt_hooks, TRUE, s));
> -
> - /* Uninstall SIGABRT handler on last instance */
> - cleanup_sigabrt_handler();
> + qtest_remove_abrt_handler(s);
>
> qtest_kill_qemu(s);
> close(s->fd);