Ignore EINTR signal for select systemcall. #22
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ffoulkes
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Jan 2, 2023
switchlink/switchlink_main.c
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| ret = select(num_fds, &read_fds, NULL, NULL, NULL); | ||
| if (ret == -1) { | ||
| // Select system call being interrupted by a signal EINTR. |
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Good comment. You explain why you are making this test.
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During automation we saw this issue, where intermittently switchlink_main thread is exited and none of the netlink messages are processed by infrap4d.
Upon debug observed that 'Select' system call is being interrupted by EINTR, this causes thread to exit.
While reading about this issue, figure out this can happen to any Blocking call. In our case we dont have any timeout for Select system call. Hence the chances of getting this interrupt is high.
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Here select is a blocking call since no timeout is specified, so we have chances of interrupting via EINTR. When EINTR is recived, switchlink_main thread is exiting. This causes infrap4d to not process any netlink events and lnp.p4 usecases will fail. With the fix, we are ignoring EINTR error for Select systemcall Signed-off-by: Sandeep N <sandeep.nagapattinam@intel.com>
ffoulkes
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Okay once the indicated change is made
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Here select is a blocking call since no timeout is specified, so we have chances of interrupting via EINTR.
When EINTR is recived, switchlink_main thread is exiting. This causes infrap4d to not process any netlink events and lnp.p4 usecases will fail.
With the fix, we are ignoring EINTR error for Select systemcall
Signed-off-by: Sandeep N sandeep.nagapattinam@intel.com