Thanks for your patch. LGTM.

Best regards
Yaroslav Dynnikov


On Fri, 13 Aug 2021 at 13:27, Vladimir Davydov <vdavydov@tarantool.org>
wrote:

> It didn't yield before commit 954194a1ca5c ("net.box: rewrite request
> implementation in C"). It shouldn't yield now.
>
> Follow-up #6241
> ---
>
> https://github.com/tarantool/tarantool/tree/vdavydov/netbox-dont-yield-in-future-wait-result-if-timeout-is-0
>
>  src/box/lua/net_box.c                         |  2 ++
>  test/box/net.box_fiber-async_gh-3107.result   | 26 +++++++++++++++++++
>  test/box/net.box_fiber-async_gh-3107.test.lua | 12 +++++++++
>  3 files changed, 40 insertions(+)
>
> diff --git a/src/box/lua/net_box.c b/src/box/lua/net_box.c
> index 229dec590cf9..43a7d78a1122 100644
> --- a/src/box/lua/net_box.c
> +++ b/src/box/lua/net_box.c
> @@ -235,6 +235,8 @@ netbox_request_complete(struct netbox_request *request)
>  static inline bool
>  netbox_request_wait(struct netbox_request *request, double *timeout)
>  {
> +       if (*timeout == 0)
> +               return false;
>         double ts = ev_monotonic_now(loop());
>         int rc = fiber_cond_wait_timeout(&request->cond, *timeout);
>         *timeout -= ev_monotonic_now(loop()) - ts;
> diff --git a/test/box/net.box_fiber-async_gh-3107.result
> b/test/box/net.box_fiber-async_gh-3107.result
> index aaaca351a579..60f084ca3130 100644
> --- a/test/box/net.box_fiber-async_gh-3107.result
> +++ b/test/box/net.box_fiber-async_gh-3107.result
> @@ -104,6 +104,32 @@ err:find('Usage') ~= nil
>  ---
>  - true
>  ...
> +--
> +-- Check that wait_result(0) doesn't yield.
> +--
> +future = c:call('long_function', {1, 2, 3}, {is_async = true})
> +---
> +...
> +csw1 = fiber.info()[fiber.id()].csw \
> +ret = future:wait_result(0)         \
> +csw2 = fiber.info()[fiber.id()].csw
> +---
> +...
> +ret -- timeout
> +---
> +- null
> +...
> +csw2 - csw1 -- 0
> +---
> +- 0
> +...
> +finalize_long()
> +---
> +...
> +future:wait_result()
> +---
> +- [1, 2, 3]
> +...
>  box.schema.func.drop('long_function')
>  ---
>  ...
> diff --git a/test/box/net.box_fiber-async_gh-3107.test.lua
> b/test/box/net.box_fiber-async_gh-3107.test.lua
> index d23f368cbce4..9632e9228bbb 100644
> --- a/test/box/net.box_fiber-async_gh-3107.test.lua
> +++ b/test/box/net.box_fiber-async_gh-3107.test.lua
> @@ -36,6 +36,18 @@ err:find('Usage') ~= nil
>  _, err = pcall(future.wait_result, future, '100')
>  err:find('Usage') ~= nil
>
> +--
> +-- Check that wait_result(0) doesn't yield.
> +--
> +future = c:call('long_function', {1, 2, 3}, {is_async = true})
> +csw1 = fiber.info()[fiber.id()].csw \
> +ret = future:wait_result(0)         \
> +csw2 = fiber.info()[fiber.id()].csw
> +ret -- timeout
> +csw2 - csw1 -- 0
> +finalize_long()
> +future:wait_result()
> +
>  box.schema.func.drop('long_function')
>
>  c:close()
> --
> 2.25.1
>
>