04ac8768ef
With current code, in single-threaded context, a pool of task may never be executed until one calls BLI_task_pool_work_and_wait() on it, this is not acceptable for asynchronous tasks where you never want to actually lock the main thread. This commits adds an extra thread in single-threaded case, and a new 'type' of pool, such that one can create real background pools of tasks. See code for details. Review: D1565