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From: "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com>
Newsgroups: comp.arch
Subject: Re: MSI interrupts
Date: Mon, 24 Mar 2025 19:02:51 -0700
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On 3/24/2025 1:14 PM, Dan Cross wrote:
> In article <vrsaro$1faj3$9@dont-email.me>,
> Chris M. Thomasson <chris.m.thomasson.1@gmail.com> wrote:
>> On 3/24/2025 11:49 AM, Dan Cross wrote:
>>> [snip]
>>> I'm sure one could do a lockless pop using a cmp exchange, but I
>>> wanted to a scenario where one would want to hold onto both
>>> locks throughout the critical section for some reason.
>>> I just don't see how this works in the proposed scenario.
>>
>> You want to hold lock A while lock B us being used? That can be tricky.
> 
> Really?  This happens all the time.  Of course it can be tricky,
> as concurrent programming always is, but it's incredibly normal.

Locking order comes into play here. Uggg... I have seen nightmare code 
that was using recursion as well... It deadlocked at a certain depth, 
only under the right conditions. The locking order was not properly 
respected...


> 
>> Well, there is a locking order. Check out this older work of mine, multex:
>>
>> https://groups.google.com/g/comp.lang.c++/c/sV4WC_cBb9Q/m/SkSqpSxGCAAJ
>>
>> Not sure if this is relevant or not.
> 
> It doesn't appear to be; sorry.
> 
> 	- Dan C.
>