Molerat is a framework for writing scalable network server programs in C. It's still at the experimental stage: It works, but a lot of elaboration is needed before it is ready for general use.

Molerat combines an event-driven approach with multithreading support, so applications can support large numbers of connections while easily exploiting all the resources of multicore machines.

Molerat facilitates this with tasklets.

A tasklet is a sequential context of execution. Like a thread, a tasklet can wait for events (such as data arriving on a socket). Unlike a thread, a tasklet does not have its own stack, so tasklet code has to be follow certain idioms. But those idioms are less cumbersome than trying to write callback-based code in C, particularly in a multithreaded context.

Tasklets are very lightweight; many millions of tasklets could fit in the memory of a modern machine. Molerat schedules runnable tasklets onto a much smaller number of threads.

Molerat works on Linux, OS X and FreeBSD (so it might work on other BSDs too). Primary development is on Linux, so it's possible that the other supported platforms get broken from time to time.

There are no dependencies or prerequisites except for gcc and GNU make, so after cloning the repo do:

$ git submodule update --init
$ make

(On FreeBSD, substitute gmake for make.)

Run the tests with:

$ make run_tests

This only takes a few seconds.

The only demo application so far is a rudimentary HTTP server and client.

Run the HTTP server with the port number to listen on:

$ ./http_server 5555

And then point your browser at http://localhost:5555. The server simply spits out a canned HTML page.

Or you can use the HTTP client:

$ ./http_client localhost 5555

There are also a bunch of self-contained test programs which exercise various parts of the framework.

If you are still reading and interested, you should probably poke me for more documentation etc.