Re: [boost] Stacktrace review: concern, probable solution and review news

Subject: Re: [boost] Stacktrace review: concern, probable solution and review news
From: Vladimir Batov (Vladimir.Batov_at_[hidden])
Date: 2016-12-21 18:09:52

On 12/22/2016 08:28 AM, Andrey Semashev wrote:
> On 12/21/16 22:43, Antony Polukhin wrote:
>> Hi,
>>
>> * reviewers wish to have a smaller size of the `stacktrace` class,
>> want to avoid template parameter and have a std::vector<frames> like
>> interface (this is async unsafe because  vector does dynamic
>> allocations).
>
> Actually, that depends on the allocator. A stack-based allocator or an 
> allocator backed by static storage could be async-safe, making 
> `vector` async-safe as well.

I am not sure about a stack-based allocator as I'd expect the stack to 
be wiped out but a static-storage allocator sounds like an excellent 
idea to deal with many/all async-related issues. Could that be the 
default? I'd really like the default-deployment case to be as automatic 
as possible... so that I could use it without wrecking my brain and to 
make sure junior developers are not repelled by the complexity and 
actually use it.

> ...
>> * Provide async-safe functions that dump addresses separated by
>> whitespace (format also acceptable by addr2line and atos):
>>     * `void dump_stacktrace(int fd)`
>>     * `void dump_stacktrace(HANDLE fd)`
>>     * `void dump_stacktrace(const char* filename)`
>
> Yes, if that's in addition to the non-async-safe function that decodes 
> the stacktrace in-process.

Yes, please. "Decoding the stacktrace in-process" seems very desirable.

> ...
>> * Provide an example with dumping callstack to a file and printing it
>> on program restart
>
> I would suggest an example of printing the stacktrace by a separate 
> program. Printing the stacktrace upon restart seems like a contrived 
> case.

Printing the stacktrace upon restart does seem like unusual that might 
take some getting used to. Still, I personally find quite an attractive 
alternative to a separate/additional/extra program necessary to retrieve 
the info.