Re: [Tcl-tdbc] tdbc::mysql and multiple threads...

[Donal K. F. <don...@ma...>]

On 02/09/2016 12:11, to...@tu... wrote:
> Given what you write, it might be some part of tdbc (perhaps the *dbc
> library?) isn't thread safe?

The core of TDBC is thread-agnostic in the usual Tcl way; it's just 
bound to an interpreter. If there is a problem, it's in the tdbc::mysql 
driver package. If we look at the code:

   http://core.tcl-lang.org/tdbcmysql/artifact/47de19173a3e0d14?ln=1296-1306

... I might wonder based on the comment whether there is a problem. 
There might be, but I don't know the mysql client library. Once open, 
I'd expect connections to be interpreter-bound; that's how all of TDBC 
is designed to work. (Heh, scanning through the code overall indicates 
three places with “TODO” that might indicate something relevant, but I 
don't know for sure.)

I assume that if you put the actual connection creation guarded by a 
mutex, which you can do easily enough from user code via the primitives 
in the Thread package (i.e., you can check without changing or 
recompiling the tdbc::mysql code), everything else after that will work 
as well as the DB permits.

Donal.