net: tcp: Wake pending threads if non-blocking connect fails #99411
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zephyrbot
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area: Sockets
pdgendt
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Nov 14, 2025
If a thread was sleeping in poll(), monitoring POLLIN only, it should still be notified if an asynchronous connection, triggered by non-blocking connect(), failed. Currently that's not the case. In result the application would never know whether the connection was successful or not and would be stuck with a disconnected socket that would not report anything with poll(). This was not an issue if POLLOUT was monitored as well, because POLLOUT sets up a connect semaphore that was reset in case of errors. POLLIN however only monitors the recv fifo, which was not waken up in such case. Fix this by canceling any pending waits on recv fifo and recv condition variable. Signed-off-by: Robert Lubos <[email protected]>
Verify that if the application triggers asynchronous connect with non-blocking sockets, and starts to monitor the socket with poll() immediately but with POLLIN only set, the poll() is still able to report an error if the connection fails. As no POLLOUT is monitored, the application won't know when the connection is done in case of success, but it should still be notified in case of errors. To achieve this, modify the existing test case to allow to specify what events should be monitored by poll(). Additionally monitor the time spent in poll() - an error should cause poll() to exit immediately, not after the specified timeout. Signed-off-by: Robert Lubos <[email protected]>
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jukkar
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Nov 15, 2025
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If a thread was sleeping in poll(), monitoring POLLIN only, it should
still be notified if an asynchronous connection, triggered by
non-blocking connect(), failed. Currently that's not the case.
In result the application would never know whether the connection
was successful or not and would be stuck with a disconnected socket
that would not report anything with poll().
This was not an issue if POLLOUT was monitored as well, because POLLOUT
sets up a connect semaphore that was reset in case of errors. POLLIN
however only monitors the recv fifo, which was not waken up in such
case.
Fix this by canceling any pending waits on recv fifo and recv
condition variable.