[PATCH] Fix rwlock stall with PREFER_WRITER_NONRECURSIVE_NP (bug 23861)

[Andreas Schwab]

On Dez 11 2018, Florian Weimer <fweimer@redhat.com> wrote:

> * Andreas Schwab:
>
>> On Dez 11 2018, Florian Weimer <fweimer@redhat.com> wrote:
>>
>>> * Andreas Schwab:
>>>
>>>>> No, without atomics, the code has a data race and undefined behavior.
>>>>
>>>> In which way?  There is a single setter, and it doesn't matter how long
>>>> the thread takes to see the transition from zero to non-zero.
>>>
>>> | The execution of a program contains a data race if it contains two
>>> | conflicting actions in different threads,
>>
>> In which way do the actions conflict?
>
> | Two expression evaluations conflict if one of them modifies a memory
> | location and the other one reads or modifies the same memory location.

And how is that a problem in this pariticular case?

Andreas.

-- 
Andreas Schwab, SUSE Labs, schwab@suse.de
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