Question

I’m working on a multithreaded server in c++ using boost-asio. Currently a design problem I’m running into deals with erasing a connection.

I have a single server instance which holds a vector of connection objects. These connections receive commands which I parse. One command in particular deals with sending data to ALL connections in my vector.

Now when a connection disconnects I’m currently erasing this connection from the vector and calling the destructor. It seems like I’m going to run into problems when someone ‘SendAll’ at the same time someone ‘Disconnect’.

Could anyone recommend a better design or just point me in the right direction? Any help greatly appreciated. Thanks

Answer 1

Whatever class maintains this vector of connections needs a strand. Use strand::post or strand::dispatch when accessing, adding to, or removing from the vector. The strand concept is explained in detail in the documentation.

A strand is defined as a strictly
sequential invocation of event
handlers (i.e. no concurrent
invocation). Use of strands allows
execution of code in a multithreaded
program without the need for explicit
locking (e.g. using mutexes).