> On Jun 23, 2017, at 12:44 AM, John Rushford <[email protected]> wrote:
>
> Leif,
>
> The mutex is ref counted but the i look at the code for TSContDestroy, I
> see that the pointer to the mutex is only set to NULL,
> INKContInternal::destroy(). I think that the plugins should call
> TSMutexDestroy() also. Is that correct?
Plugins should *never* call TSMutexDestroy() once the core has refcounted it.
TSMutexDestroy() immediately deallocates the mutex without examining the
refcount. There’s API for plugins to refcount a TSMutex.
The correct pattern is as Peter originally suggests:
TSContCreate(retryCacheUrlLock, TSMutexCreate());
>
> On Thu, Jun 22, 2017 at 6:59 AM, Leif Hedstrom <[email protected]> wrote:
>
>> Yes, this is the correct fix. In earlier versions, the core would create
>> the mutex for you if it needed one, but this had some pretty expensive
>> overhead. So now we just assert instead, so people can fix their plugins
>> (and our plugins apparently).
>>
>> Fwiw, the mutex is needed when the continuation uses a specific set of
>> APIs. This should be documented in the docs somewhere.
>>
>> Cheers,
>>
>> -- Leif
>>
>>> On Jun 21, 2017, at 8:18 PM, John Rushford <[email protected]> wrote:
>>>
>>>
>>> Peter,
>>>
>>> I've found this with a couple of other plugins and fixed them by making
>> exactly the change you you're asking about. In testing i have not run into
>> any issues with the plugins i have changed.
>>>
>>> John
>>>
>>>> On Jun 21, 2017, at 4:22 PM, Chou, Peter <[email protected]> wrote:
>>>>
>>>> Hi,
>>>>
>>>> I am taking a look at the collapsed_connection plugin. There appears to
>> be an assertion failure crash incompatibility between this plugin and
>> changes made in the 6.2.x branch. TS-4387 appears to require all
>> continuations calling TSContSchedule() to have a mutex, but in the plugin
>> no mutex is created in addMutexRetry() since TSContCreate() is called as
>> TSContCreate(retryCacheUrlLock, NULL).
>>>>
>>>> Is it sufficient to change this call to TSContCreate(retryCacheUrlLock,
>> TSMutexCreate())?
>>>>
>>>> Would this possibly cause side-effects such as mutex lock contention
>> the plugin is not designed to deal with, and would the mutex need to be
>> destroyed manually somewhere else in the code? I am still learning on this
>> area of ATS...
>>>>
>>>> Thanks,
>>>> Peter
>>
>>
>
>
> --
> John Rushford
> [email protected]
