+- 0Day Forums (https://zeroday.vip)
+-- Forum: Coding (https://zeroday.vip/Forum-Coding)
+--- Forum: Objective-C (https://zeroday.vip/Forum-Objective-C)
+--- Thread: Check whether or not the current thread is the main thread (/Thread-Check-whether-or-not-the-current-thread-is-the-main-thread)
Pages:
1
2
Check whether or not the current thread is the main thread - acknowledgment715152 - 07-21-2023
Is there any way to check whether or not the current thread is the main thread in Objective-C?
I want to do something like this.
- (void)someMethod
{
if (IS_THIS_MAIN_THREAD?) {
NSLog(@"ok. this is main thread.");
} else {
NSLog(@"don't call this method from other thread!");
}
}
RE: Check whether or not the current thread is the main thread - sarahucxajavab - 07-21-2023
If you want a method to be executed on the main thread, you can:
- (void)someMethod
{
dispatch_block_t block = ^{
// Code for the method goes here
};
if ([NSThread isMainThread])
{
block();
}
else
{
dispatch_async(dispatch_get_main_queue(), block);
}
}
RE: Check whether or not the current thread is the main thread - rashidki - 07-21-2023
If you want to know whether or not you're on the main thread, you can simply use the debugger. Set a breakpoint at the line you're interested in, and when your program reaches it, call this:
`(lldb) thread info`
This will display information about the thread you're on:
```(lldb) thread info
thread #1: tid = 0xe8ad0, 0x00000001083515a0 MyApp`MyApp.ViewController.sliderMoved (sender=0x00007fd221486340, self=0x00007fd22161c1a0)(ObjectiveC.UISlider) -> () + 112 at ViewController.swift:20, queue = 'com.apple.main-thread', stop reason = breakpoint 2.1
```
If the value for `queue` is `com.apple.main-thread`, then you're on the main thread.
RE: Check whether or not the current thread is the main thread - Projolexfjjaqm - 07-21-2023
**UPDATE:** seems that is not correct solution, according to queue.h header as mentioned @demosten
The first thought was brought to me, when I was needed this functionality was the line:
dispatch_get_main_queue() == dispatch_get_current_queue();
And had looked to the accepted solution:
[NSThread isMainThread];
mine solution 2.5 times faster.
PS And yes, I'd checked, it works for all threads
RE: Check whether or not the current thread is the main thread - naumachia404 - 07-21-2023
Two ways. From @rano's answer,
[[NSThread currentThread] isMainThread] ? NSLog(@"MAIN THREAD") : NSLog(@"NOT MAIN THREAD");
Also,
[[NSThread mainThread] isEqual:[NSThread currentThread]] ? NSLog(@"MAIN THREAD") : NSLog(@"NOT MAIN THREAD");
RE: Check whether or not the current thread is the main thread - colobus41 - 07-21-2023
For Monotouch / Xamarin iOS you can perform the check in this way:
if (NSThread.Current.IsMainThread)
{
DoSomething();
}
else
{
BeginInvokeOnMainThread(() => DoSomething());
}
RE: Check whether or not the current thread is the main thread - obedientialness469574 - 07-21-2023
Swift Version
- - - -
if (NSThread.isMainThread()) {
print("Main Thread")
}
RE: Check whether or not the current thread is the main thread - hammerwort506403 - 07-21-2023
**In Swift3**
if Thread.isMainThread {
print("Main Thread")
}
RE: Check whether or not the current thread is the main thread - understrike193902 - 07-21-2023
> let isOnMainQueue =
> (dispatch_queue_get_label(dispatch_get_main_queue()) ==
> dispatch_queue_get_label(DISPATCH_CURRENT_QUEUE_LABEL))
check this answer from
[To see links please register here]
RE: Check whether or not the current thread is the main thread - Mrnonschematizedsev - 07-21-2023
The following pattern will assure a method is executed on the main thread:
- (void)yourMethod {
// make sure this runs on the main thread
if (![NSThread isMainThread]) {
[self performSelectorOnMainThread:_cmd/*@selector(yourMethod)*/
withObject:nil
waitUntilDone:YES];
return;
}
// put your code for yourMethod here
}