Getting thread id of current method call

Question

Is there a way to print out the current thread id on which the current method is executing on?

(objective-c please)

nall answered the question, but not the real question.... why do you want to know? Beyond debugging or asserting correct behavior, basic stuff on currentThread is *generally* a bad idea. — bbum, Oct 24 '09 at 02:15
I for one needed it to create thread-local objects that are attached to another object (i.e. associated to a parent object _and_ thread -- not just the thread). — adib, Dec 15 '10 at 07:01

score 243 · Accepted Answer · answered Oct 24 '09 at 02:13

243

NSLog(@"%@", [NSThread currentThread]);

answered Oct 24 '09 at 02:13

nall

15,899
4
61
65

What is the meaning of name = (null), if thread is main it returns NSThread: 0x60800006cb80>{number = 1, name = main}, Does it means "name = (null)" refers to background thread. – Nirmala Maurya Aug 24 '17 at 04:59
1

And how does one grab that name and number? `name` returns empty description even for main and `number` is nowhere to be found – Hari Honor Oct 17 '17 at 11:24
1

Quick and dirty thread num: `NSString *s = [NSString stringWithFormat:@"%@", [NSThread currentThread]]; int threadNum = -1; sscanf(s.UTF8String, "{number = %d", &threadNum);` – Hari Honor Oct 17 '17 at 11:47

dimohamdy · Answer 2 · 2019-12-18T20:59:39.900

38

In Swift 5

print("Current thread \(Thread.current)")

edited Dec 18 '19 at 20:59

answered Dec 04 '16 at 15:28

dimohamdy

2,917
30
28

neoneye · Answer 3 · 2013-04-28T18:35:23.840

36

#include <pthread.h>
...
mach_port_t machTID = pthread_mach_thread_np(pthread_self());
NSLog(@"current thread: %x", machTID);

edited Apr 28 '13 at 18:35

answered Mar 20 '13 at 12:06

neoneye

50,398
25
166
151

4

@Rajneesh071 Indeed, what else did you expect, display the ID of a different thread? – meaning-matters Mar 13 '14 at 08:45
The `[NSThread currentThread]` class method returns an NSThread object. You can log the address of that thread object, but how do you get the numeric thread ID, like what's displayed in the Xcode debugger? (Thread 1 for the main thread, and increasing numbers for each additional thread that's created by your app.) – Duncan C Oct 02 '15 at 12:43
@Duncan: That's almost certainly a feature of the debugger, not the OS/runtime. – Cameron Dec 15 '15 at 18:29

score 13 · Answer 4 · answered Sep 21 '15 at 20:16

13

In Swift

print("Current thread \(NSThread.currentThread())")

answered Sep 21 '15 at 20:16

Glauco Neves

3,483
1
24
36

score 7 · Answer 5 · edited Feb 23 '21 at 19:46

7

In Swift4

print("\(Thread.current)")

edited Feb 23 '21 at 19:46

Paul Hildebrandt

2,724
28
26

answered Nov 04 '18 at 22:57

Leanid Vouk

460
6
13

score 3 · Answer 6 · answered Oct 29 '14 at 18:51

you can hack something up like this (this just prints pretty, but you can go ahead and split until you get the number):

+ (NSString *)getPrettyCurrentThreadDescription {
    NSString *raw = [NSString stringWithFormat:@"%@", [NSThread currentThread]];

    NSArray *firstSplit = [raw componentsSeparatedByCharactersInSet:[NSCharacterSet characterSetWithCharactersInString:@"{"]];
    if ([firstSplit count] > 1) {
        NSArray *secondSplit     = [firstSplit[1] componentsSeparatedByCharactersInSet:[NSCharacterSet characterSetWithCharactersInString:@"}"]];
        if ([secondSplit count] > 0) {
            NSString *numberAndName = secondSplit[0];
            return numberAndName;
        }
    }

    return raw;
}

score 2 · Answer 7 · answered Jul 17 '21 at 19:36

2

NSLog prints to the console a number (in square brackets after the colon) identifying the thread on which it was called.

answered Jul 17 '21 at 19:36

Artem

373
2
6

score 0 · Answer 8 · answered Mar 29 '22 at 09:30

0

uint64_t tid; pthread_threadid_np(NULL, &tid);

answered Mar 29 '22 at 09:30

fengxing

374
1
4
10

Getting thread id of current method call

8 Answers8

Linked