is krb5_cc_initialize() thread safe

[Olga Kornievskaia]

Hi folks,

I haven't been able to find in documentation whether or not
krb5_cc_initialize() is thread safe? From a practical point of view, I
believe it is not. But a call to "krb5_is_thread_safe() returns true".

In NFS's gssd implementation, while trying to refresh credentials, the
code tries to store creds and as part of calls into
krb5_cc_initialize() to initial credential cache (of either FILE or
MEMORY type). We've observed that if two threads try to update the
same cache and thus call into krb5_cc_initialize(), one succeeds and
the other fails with "Internal credentials cache error". Is that
unexpected?

Thank you.