If no cores are available, the current process blocks until a core is available.
requestCore(await, workers = availableCores(),
timeout = getOption("future.wait.timeout", 30 * 24 * 60 * 60),
delta = getOption("future.wait.interval", 0.2),
alpha = getOption("future.wait.alpha", 1.01))
A function used to try to "collect" finished multicore subprocesses.
Total number of workers available.
Maximum waiting time (in seconds) allowed before a timeout error is generated.
Then base interval (in seconds) to wait between each try.
A multiplicative factor used to increase the wait interval after each try.
Invisible TRUE. If no cores are available after extensive waiting, then a timeout error is thrown.