Sets the maximal allowed number of threads for this.
A value of -1 means that the maximal number of threads is unlimited. If this is an exclusive thread pool, setting the maximal number of threads to -1 is not allowed.
max_threads to 0 means stopping all work for this. It is effectively frozen until
max_threads is set to a non-zero value again.
A thread is never terminated while calling
func, as supplied by
ThreadPool.with_owned_data. Instead the maximal
number of threads only has effect for the allocation of new threads in add. A
new thread is allocated, whenever the number of currently running threads in this is smaller than the maximal
throws can be null to ignore errors, or non-null to report errors. An error can only occur when a new thread couldn't be created.
Before version 2.32, this function did not return a success status.
a new maximal number of threads for this, or -1 for unlimited
true on success, false if an error occurred