Binary package “libpthread-workqueue-dev” in ubuntu bionic

thread pool library (development files)

 The pthread_workqueue library allows you to create one or more workqueues
 and submit work items for processing. The workqueues are serviced by a
 thread pool that is automatically created and dynamically managed by the
 library.
 .
 This package contains files needed to build programs that use the
 pthread_workqueue library.