A skirmish is a lock that can be held by zero or one holders at any time, and you can block waiting for the lock if you like. In other words, it’s a mutex. You initialize the lock variable with fusion_skirmish_init(). When you’re done with it fusion_skirmish_destroy() releases whatever resources it’s using.
In the single-app configuration, the lock maps directly to a pthread mutex as follows:
Multi-app: In the multi-app configuration the fusion device keeps the actual lock information. A fusionee may lock a skirmish multiple times, and it must unlock it just as many times before it can be locked by another fusionee.