**Update System Calls in Core for Event Processing**

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&|Areas                   | Core programming, Kernel APIs |&
&|Good if student knows   | [Tcl], [C], system programming |&
&|Priority                | Medium |&
&|Difficulty              | medium to high |&
&|Benefits to the student | learn about hot new network programming paradigms |&
&|Benefits to Tcl         | Improved performance in core |&
&|Mentor                  | ? |&

**Project Description**

Event-based programming has come into vogue recently for network services; and though historically Tcl has been a pioneering tool in this field, new apps such as [node.js] and [nginx] have been eating Tcl's lunch in the mainstream programming arena.

This is due in part to Tcl's conservative use of less-performant system calls such as select() and its equivalents to retrieve event messages from the OS kernel.  New high-performance alternatives have appeared on some operating systems such as epoll() on Linux and kqueue() on BSD, which the above-mentioned new tools exploit.

The goal of this project would be to investigate ways to integrate the new higher-performance system calls into Tcl's event loop code.

A preliminary patch has already been developed for using epoll() on Linux [http://code.activestate.com/lists/tcl-core/8456/].  This could be used as a starting point for the project.

To resolve concerns about backward- and cross-platform compatibility, various means of instantiating the new calls could be explored as part of the project, such as: a compile-time option, script-level configuration choice, provision of an API allowing loadable libraries to provide custom event-processing code.

**Requirements:**

Knowledge of:

   * C programming

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