Re: [Boost-users] boost interprocess library and concurrency

Subject: Re: [Boost-users] boost interprocess library and concurrency
From: Ion Gaztañaga (igaztanaga_at_[hidden])
Date: 2010-09-04 19:28:48

El 04/09/2010 22:46, Shane Miller escribió:
> Hi,
>
> After reading through the BOOST interprocess library documentation I cannot workout whether
>
> - its STL set/hash/vector containers are multi-threaded safe. (Seeming, no, is the answer)

No, they have the same guarantees as common STL containers.

> - if a program cores in the middle of write operation to a STL container in shared memory
> then clearly the container is in an undefined state. Locks might be left locked (if this BOOST
> library uses locks say in a STL set or hash map insert/update). Now what? We just throw away
> the shared memory segment and start again?

Same as if a thread dies when updating a STL container

> - aside from these issues, suppose one allocates a 2GB shared memory segment and all
> 2GB is used by a STL set. Does this BOOST interprocess library support adding more shared
> memory segments so this STL set can grow larger? Does doing so  require relocating it which
> is a slow operation? What are the details here.

No, the library only supports offline "grow".

> I am looking for a crash recoverable, concurrent shared memory implementation of STL. Mainly
> I have a cache of items that will be read-intensive with some periodic updates and insertions
> throughout the day. Key-value pairs won't work; it must operate on pointers to C++ structs.

Maybe you are asking too much ;-) Now, seriously maybe a DB is what you 
need.

Best,

Ion