bugfix: prevent vishnu sessions pid files corruption

[hguemar]

add a file lock to disable concurrent accesses to ~/.vishun/sessions/ file fixes #135

[rchakode]

test failed with boost 1.46.1.

The fail occured at core/src/util/sessionUtil.cpp:146 bi::file_lock sessionLock(file);

Exception raised ./bin/vishnu_connect: No such file or directory To get help, try << ./bin/vishnu_connect -h >>

[hguemar]

rebased against current zmq branch

[rchakode]

What about this PR? It doesn't work with boost 1.49.

[hguemar]

I rebased the PR and tested it on morgane against boost 1.46.1, you can reproduce it there using the following steps:

git clone https://github.com/hguemar/vishnu
git checkout zmq
mkdir build && cd build
ccmake28 -DBOOST_ROOT=/opt/boost146 ..
make -j12

[rchakode]

Ne marche toujours pas chez moi avec boost 1.49 et ubuntu 12.04 Quand j'applique le patch : ./bin/vishnu_connect: No such file or directory To get help, try << ./bin/vishnu_connect -h >>

_Je ne sais pas si c'est spécifique à ma machine. _

[hguemar]

Tu peux essayer sur morgane, j'ai également rajouté Boost 1.49 (/opt/boost149), j'arrive à lancer un umssed et me connecter à vishnu.

[rchakode]

c'est certainement mon système, mais je ne saurais expliquer.

[hguemar]

je tente sur une VM morgane

[hguemar]

Testé sur une VM ubuntu 12.04.3 fraiche avec Boost 1.49, ça passe :/

[rchakode]

After further investigations the problem persists. Howeber, I can note that the code lacks of exception handling, notably for boost::interprocess::interprocess_exception.

When I add a try ... catch block as below, it seems that the connection succeed, but due to the lack of exception handling the program fails.

After this change :

./bin/vishnu_connect
No such file or directory 
sessionId: root-2014-Jan-16-11:18:02.921430:31905

Snippet

template <class T>
void
saveIntoFile(SessionContainer& allSessions, const char* file){
  try {
    bi::file_lock sessionLock(file);
    bi::scoped_lock<bi::file_lock> lock(sessionLock);
    std::ofstream ofile (file);
    T ar(ofile);

    ar << bs::make_nvp("sessions",allSessions);

    ofile.close();
  } catch (const bi::interprocess_exception& ex) {
    std::cout << ex.what() <<"\n";
  }

[hguemar]

Thank you for your insight, i'll modify the PR in that way.

[rchakode]

ok, merged