Embedding TclHttpd

How to shutdown embedded TclHttpd

John Buckman of Lyris Technology

Here is our scenario: we link Tcl into our multithreaded application, and one thread launches Tcl and runs TclHttpd. This works great, but when our application is told to exit, how do we tell TclHttpd to exit in a thread safe manner? After all, we have TclHttpd in a "vwait forever" loop, from which it never wants to exit

The solution that we adopted was to create a async event handler beforehand to signal program exit, use a separate thread to notify the async event when it is time to shutdown, and then Tcl runs our C code at a safe time from inside its own thread, which modifies the global "forever" variable, thus causing TclHttpd to gracefully exit. This works nicely, with no memory leaks, and no need to wait for someone to cause an event.

We looked at the Tcl source code for the asynchronous operations, and all of it is semaphore protected and thread safe (beautiful, clean source code, by the way) so I assume that this is the proper way to do it since it appears from looking at the Tcl code that it was made for this sort of thing.
HomeStatusLearnCGI TestsTemplatesAccess ControlReference Manual