Re: Proper way to de initialize library

[Tobias Ljunggren <tljunggren@gmail.com>]

On 2014-10-19 06:07, Howard Chu wrote:
> Tobias Ljunggren wrote:
> > Hello,
> >
> > What is the proper way to de-initialize openLDAP library?
> >
> > Let's assume I have
> > ldap_initialize (ldaps://....)
> > a couple of general ldap_set_option
> > some ldap_set_option for TLS
> > ldap_sasl_bind_s
> >
> > Is ldap_unbind_s all that's required?
> >
> > My problem is that if I do it this way when using openLDAP from a shared object and the process unloads the shared object and
> > then loads it again (restarts my library) TLS won't work anymore. Probably there is one or more global variables in openLDAP
> > that needs to be reset before unload to make sure the initialization works.
>
> libldap only has one set of global variables, and they are maintained in a single structure. Unloading the library will wipe
> out that structure, reloading the library will force a new initialization.
>
> It sounds like, however, your TLS library is not being fully unloaded. If your app has another reference to that, it would
> cause a problem like this.

Yes only a few of the nss (and nspr) modules are unloaded. But I thought that was because I didn't de inititialize things the 
proper way.
This is whats loadeded on start (shim.dll is the module I'm developing):
shim.dll
msvcp110d.dll
msvcr110d.dll
libldap_r.dll
liblber.dll
nspr4.dll
plc4.dll
ssl3.dll
nss3.dll
winmm.dll
nssutil3.dll
plds4.dll
winmmbase.dll
cfgmgr32.dll
devobj.dll
softokn3.dll
sqlite3.dll
nssdbm3.dll
freebl3.dll

But when I shut down this whats unloaded:
nss3.dll
ssl3.dll
liblber.dll
libldap_r.dll
msvcp110d.dll
shim.dll

I haven't checked whats unloaded on linux but I have the same problem after a restart so I guess it looks the same.


> Why do you bother to unload the library if you're just going to need to load it again later?

Problem is that my module is built using an api from a service. It must support start, stop and restart. I load libldap_r and 
liblber with dlopen (or LoadLibrary on Windows) and don't unload until I have to.

> > I looked at the ldapsearch example provided, in common.c, and noticed a call to ldap_pvt_tls_destroy. I tried that but it
> > doesn't make any difference.
> >
> > I've compiled openLDAP to use Mozilla NSS.
>
> RedHat supports the MozNSS code, ask them for suggestions.

Thanks for the tip, I will.

--
 Tobias