[erlang-questions] Dynamic code reloading

[Jeffm]

When you loaded the new module in the shell did you use c() or l(dbase)? 
If you compiled external to the shell, as you stated, you'll need to use 
l(module_name) to tell the shell to load the new version.

Jeff.

On 20/04/10 1:37 PM, Deryk Barker wrote:
> Please excuse me if this is a daft question...and I am sure there are 
> OTP functions to do all this for you, but I wanted  to show my 
> students some features of "pure" erlang.
>
> Specifically, I'd like to have a server that can call the latest 
> version of itself in response to a message.
>
> Based on my reading of the "old" erlang book (the OOP, sorry out of 
> print, one), it seemed that having a receive pattern something like:
>
>    {dbase, Pid, reload} ->
>        reply (Pid, reloading),
>        dbase:loop (DataBase);
>
> would work. (It's a *very* simple database server in a module called 
> dbase).
>
> Unfortunately, this doesn't cause the new BEAM file, compiled outside 
> the erlang shell, to be loaded.
>
> OK, try compiling in the erlang shell (server is running under same 
> shell), but this takes down the server  - silently. I know it's gone 
> because its registered name (dbserver) is no longer in the registered 
> name table.
>
> Perhaps I need to use code:load_file/1?
>
> But that tells me the module needs to be purged first.
>
> code:soft_purge/1 (which, according to the documentation, leaves 
> existing processes running the module running) fails - with a 
> not_purged error - and code:purge/1 works fine, but takes down the 
> server.
>
> Can anyone tell me how I should be doing this and just how dim I am 
> being?
>
> thanks,
>
> deryk
>