The libc monitor facility enables the execution of monitor jobs by the
main thread when the monitor pool was charged. In comparison to the
current suspend/resume_all mechanism the main thread iterates over all
job functions in contrast to waking up all threads to check their
conditions by themselves. Threads are only woken up if the completion
condition was met.
This commit is the result of a collaboration with Christian Prochaska.
Many thanks for your support, Christian.
Fixes#3550
Christian Helmuth