Re: [boost] Boost library submission (poll for interest)

Subject: Re: [boost] Boost library submission (poll for interest)
From: Stefan Strasser (strasser_at_[hidden])
Date: 2010-01-15 05:22:47

Am Friday 15 January 2010 13:50:43 schrieb Vicente Botet Escriba:

> > No.  I should have at least used an auto there to ensure destruction.
> > Actually the whole convention of the "database as factory" for
> > transactions is something I'm going to rework so that you can have the
> > transaction on the stack if you so choose.  I do think I want to
> > continue to support explicit transactions, but am very tempted by
> > something Stefan is doing in Boost.Persistent, in which transaction
> > scope is retained in thread-specific memory (I assume) and passed
> > around implicitly.  Support for that as an optional approach is
> > something I need to do for those who prefer that.
>
> Hi,
> if you can store the transaction on the stack you could use the atomic
> language-like macros Stefan provides in it Persistent library.
>
> I agree that you should support transparent as well as explicit
> transactions. transparent transaction have a cost to access the thread
> specific pointer.
>

what happened to vicente's suggestion to unify this for all 3 libraries?
this is how you implement a resource manager with my library, but if we do 
bring this together it obviously shouldn't be part of my library so there is 
no dependency just for that.

user code:

int main(){
  transaction tx;
  mytransmap->insert(1);
  tx.commit();

  atomic{
    mytransmap->insert(2);
  }retry;
}

behind the scenes:

struct stldb_tag{};

class my_resource_manager{
  typedef stldb::transaction transaction;
  typedef stldb_tag tag;
  void commit_transaction(transaction &tx){ stldb::commit(tx); }
  void rollback_transaction(transaction &tx){ stldb::rollback(tx); }
  ...
};

typedef basic_transaction_manager<my_resource_manager> 
stldb_transaction_manager;

#define BOOST_PERSISTENT_CONFIGURATION stldb_transaction_manager;

#include <boost/persistent/transaction_manager.hpp>
#include <boost/persistent/transaction.hpp>

class trans_map{
  void insert(int){
    stldb::transaction &tx=
      transaction_manager::active().resoure_transaction<stldb_tag>();
    //...do something with transaction
  }
};