posix-api

Based on @Kametrixom answer , I have made some test application for parallel calculation of sum in an array. My test application looks like this: import UIKit import Metal class ViewController: UIViewController { // Data type, has to be the same as in the shader typealias DataType = CInt override func viewDidLoad() { super.viewDidLoad() let data = (0..<10000000).map{ _ in DataType(200) } // Our data, randomly generated var start, end : UInt64 var result:DataType = 0 start = mach_absolute_time() data.withUnsafeBufferPointer { buffer in for elem in buffer { result += elem } } end = mach_absolute

From what I have been reading on The Open Group website on fcntl , open , read , and write , I get the impression that whether O_NONBLOCK is set on a file descriptor, and hence whether non-blocking I/O is used with the descriptor, should be a property of that file descriptor rather than the underlying file. Being a property of the file descriptor means, for example, that if I duplicate a file descriptor or open another descriptor to the same file, then I can use blocking I/O with one and non-blocking I/O with the other. Experimenting with a FIFO, however, it appears that it is not possible to

If a linux process is waiting for I/O (i.e it is in SLEEP state) and a SIGKILL signal is issued against it, upon termination ( STOPPED state) will it pass through RUNNING or READY state? In other words, for a process to handle a system interrupt such as one generated by SIGKILL is it necessary to pass through RUNNING or READY state ? Knowing that under normal circumstances a process can handle an interrupt from kernel and knowing that SIGKILL has a quite contradictory purpose of killing an unresponsive signal, I was doubtful about how much control is given to the process being killed, if any