When a build is scheduled, it will attempt to lock the specified resources. If some (or all) the resources are already locked by another build, the build will be queued until they are released.
By default, all builds have the same lock priority (defined in the global
configuration). If you want a specific job to have a different priority, you
need to add a parameter to the job. The priority must be an integer (lowest
priority will start first). The parameter name is also defined in the global
configuration (LOCK_PRIORITY
by default).