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pthread_equal - Man Page

compare thread IDs


This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (consult the corresponding Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.


#include <pthread.h>

int pthread_equal(pthread_t t1, pthread_t t2);


This function shall compare the thread IDs t1 and t2.

Return Value

The pthread_equal() function shall return a non-zero value if t1 and t2 are equal; otherwise, zero shall be returned.

If either t1 or t2 are not valid thread IDs, the behavior is undefined.


No errors are defined.

The pthread_equal() function shall not return an error code of [EINTR].

The following sections are informative.



Application Usage



Implementations may choose to define a thread ID as a structure. This allows additional flexibility and robustness over using an int. For example, a thread ID could include a sequence number that allows detection of “dangling IDs” (copies of a thread ID that has been detached). Since the C language does not support comparison on structure types, the pthread_equal() function is provided to compare thread IDs.

Future Directions


See Also

pthread_create(), pthread_self()

The Base Definitions volume of POSIX.1-2017, <pthread.h>

Referenced By

pthread.h(0p), pthread_self(3p).

2017 IEEE/The Open Group POSIX Programmer's Manual