The Open Group Base Specifications Issue 6
IEEE Std 1003.1, 2004 Edition
Copyright © 2001-2004 The IEEE and The Open Group, All Rights reserved.

NAME

pthread_equal - compare thread IDs

SYNOPSIS

[THR] [Option Start] #include <pthread.h>

int pthread_equal(pthread_t t1, pthread_t t2); [Option End]

DESCRIPTION

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.

ERRORS

No errors are defined.

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

The following sections are informative.

EXAMPLES

None.

APPLICATION USAGE

None.

RATIONALE

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

None.

SEE ALSO

pthread_create(), pthread_self(), the Base Definitions volume of IEEE Std 1003.1-2001, <pthread.h>

CHANGE HISTORY

First released in Issue 5. Included for alignment with the POSIX Threads Extension.

Issue 6

The pthread_equal() function is marked as part of the Threads option.

End of informative text.
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