Re: [Boost-users] [interprocesss] managed_mapped_file mutex question

Subject: Re: [Boost-users] [interprocesss] managed_mapped_file mutex question
From: Brett Gmoser (bgmoser_at_[hidden])
Date: 2010-03-19 12:31:52

> I have a couple of questions about crash protection, which is very 
> important in this case:
> 1. I am using only file_lock, because it is guaranteed to be released 
> if the process crashes (if I understand correctly). However, file_lock 
> has its limitations. If I use a named_recursive_mutex instead, is 
> there any way to clear the mutex if the process terminates while 
> holding the mutex?
> 2. If the mapped file gets corrupted, e.g. if a process gets killed 
> while writing the file, I need to be able to detect that case and 
> rebuild the file, but the file is certain death to any process that 
> touches it, so validating it seems messy. Any suggestions how to 
> detect a bad file?
>
> Andy
>
Yeah, I think our problems are pretty similar. Unfortunately I haven't 
gotten much input on it - I posted it before, and didn't get and 
responses. I posted it again because I had seen that Ion was active here 
recently.

The only input I can offer you (I'm not much of an expert with the 
Interprocess library) is that I believe that named_recursive_mutex also 
has filesystem persistence.  It creates files in 
/tmp/boost_interprocess/XXXXX/name, where XXXXX seems to be a hash of 
the machine's boot time.