Note that the IORegisterForSystemPower callback doesn't get called for wake/sleep cycles in Power Nap mode. That doesn't make sense to me, but when I filed a bug about it, Apple closed it with

Let’s define sleeping = time between NSWorkspaceWillSleepNotification and NSWorkspaceDidWakeNotification (or the equivalent kIOMessageSystemWillSleep and kIOMessageSystemHasPoweredOn); and awake =

Create your own thread and give it a run loop, then use IORegisterForSystemPower on that run loop. -- Chris

Neither of these statements is correct: (1) File handles are per-process, not per-thread. It’s the developer’s responsibility not to try to manipulate the same file handle from multiple threads at

This is too low level a task for the view controller to be handling. That’s more reasonable, though there’s no reason this has to be a singleton, and “Connection” might be a better class

Don’t use dispatch queues for long blocking operations. It messes up libDispatch’s scheduling. For a task like this, you should explicitly create a thread using either NSThread or pthreads. (Also,

That’s not true. All threads accessible to you are by definition running in your process. Dispatch queues run on regular threads in your process just like everything else. —Jens

If a process is doing anything, it’s awake. Asking “is my process asleep?” is kind of like asking a person “are you asleep?” :) You can start a background thread and run a runloop on it. Are

Yeah, you do know. You can’t do it. TBH, I think you’re barking up the wrong tree — though the correct tree is just one tree to the left. If your “management” is serious about try to help

This is iOS, by the way. The context implies it but things go better if you make the platform explicit. — F

My app may need to - send an SMS message; or - place what looks like a phone call to a paging system … without user intervention. In other words MessageUI.framework and tel: URLs are out. Is

All, I sort of came down with "paralysis analysis" last night. I am developing a small chat app on iOS. I am going to use Foundation's InputStream, OutputStream, and StreamDelegate. I became stuck

If file handlers were thread-specific you would not be able to read files on other threads. They are process-specific, not thread-specific. At its core, select is very much synchronous. This haunted

I don’t think file descriptors are thread specific. Most of your parameters to select are pointers. But what do they point to? If they point to structures on the stack, that would be bad, because

yes of course file handles are thread-specific, you wouldn’t want random bits of code trying 0, 1, 2 … to see what it could get. Actually they are process-specific, but the process running your

I need to do select() with a rather large timeout value (several minutes). So in order not to block the runLoop / mainThread I tried: dispatch_queue_t myQueue = dispatch_get_global_queue(

Hi All, Its installing now. On the machine I’m trying to update, the purchases section said “Install” for El Capitan, but if I tried this it gave an error saying the update couldn’t be

In the applications folder. If you think about it, it is an app, right? By the way, the version from the app store is the latest (10.11.6). No need to apply further combo updates. - Jack

In /Applications Nimesh

One one question, where does the App Store it put the downloaded file?