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.

pthread_equal — compare thread IDs

#include <pthread.h>
int pthread_equal(pthread_t t1, pthread_t t2);

This function shall compare the thread IDs t1 and t2.

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.



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.


pthread_create(), pthread_self()

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

Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at .

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2017 IEEE/The Open Group