Created
November 24, 2015 16:11
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[NSThread isMainThread] is probably not what you want!
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| #import <Foundation/Foundation.h> | |
| int main (int argc, const char **argv) { | |
| @autoreleasepool { | |
| dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{ | |
| dispatch_sync(dispatch_get_main_queue(), ^{ | |
| NSLog(@"is main thread? %i", (int)[NSThread isMainThread]); | |
| }); | |
| }); | |
| dispatch_main(); | |
| } | |
| return 0; | |
| } |
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| 2015-11-24 16:08:39.545 main[88889:21446128] is main thread? 0 |
@adamkaplan Good point, thanks.
No problem :)
Interesting learnings from this: main thread pumps the main queue – not the other way around – since GCD only has a main queue, which by default, does nothing.
the main thread pumps the main queue – not the other way around – since GCD only has a main queue, which by default, does nothing.
What's that mean? Sorry, a bit of newb here.
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Try again with
UIApplicationMain()orNSApplicationMain(). In all apps environments this code prints "1" and it is safe to assume that blocks executed on the queue returned fromdispatch_get_main_queue()will execute on the thread returned by[NSThread mainThread];