PTHREAD_B...ETPSHARED(3P)

💅 PTHREAD_B...ETPSHARED(3P) — get & set the process-shared attribute of the barrier attributes object 💅

okay bestie, welcome to the POSIX Programmer's Manual, section 3P. This page is literally called pthread_barrierattr_getpshared / pthread_barrierattr_setpshared (yeah the title's truncated, the manual does that, it's giving drama). Pull up a chair, we're talking barriers. 🦋

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✨ PROLOG ✨

Real talk: this manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (so go check the corresponding Linux manual page for the actual Linux tea ☕), or the interface might not even be implemented on Linux at all. Not every system shows up to the party. 💀

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🌸 NAME 🌸

pthread_barrierattr_getpshared, pthread_barrierattr_setpshared — get and set the process-shared attribute of the barrier attributes object. Periodt.

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🎀 SYNOPSIS 🎀

#include <pthread.h>

int pthread_barrierattr_getpshared(const pthread_barrierattr_t
    *restrict attr, int *restrict pshared);
int pthread_barrierattr_setpshared(pthread_barrierattr_t *attr,
    int pshared);

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💖 DESCRIPTION 💖

So here's the vibe:

• pthread_barrierattr_getpshared() shall obtain the value of the process-shared attribute from the attributes object referenced by attr.
• pthread_barrierattr_setpshared() shall set the process-shared attribute in an initialized attributes object referenced by attr.

Now, the process-shared attribute gets set to PTHREAD_PROCESS_SHARED to permit a barrier to be operated upon by any thread that has access to the memory where the barrier is allocated. (See Section 2.9.9, Synchronization Object Copies and Alternative Mappings for the extra requirements, iykyk.) The default value of the attribute shall be PTHREAD_PROCESS_PRIVATE. Both constants, PTHREAD_PROCESS_SHARED and PTHREAD_PROCESS_PRIVATE, are defined in <pthread.h>.

Additional attributes, their default values, and the names of the associated functions to get and set those attribute values are implementation-defined. So like, your implementation's business, not ours. 🙈

⚠️ The behavior is undefined if the value specified by the attr argument to pthread_barrierattr_getpshared() or pthread_barrierattr_setpshared() does not refer to an initialized barrier attributes object. Like, don't do that. Not cute.

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⭐ RETURN VALUE ⭐

• If successful, pthread_barrierattr_getpshared() shall return zero and store the value of the process-shared attribute of attr into the object referenced by the pshared parameter. Otherwise, an error number shall be returned to indicate the error.
• If successful, pthread_barrierattr_setpshared() shall return zero; otherwise, an error number shall be returned to indicate the error.

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🔥 ERRORS 🔥

The pthread_barrierattr_setpshared() function may fail if:

• EINVAL — The new value specified for the process-shared attribute is not one of the legal values PTHREAD_PROCESS_SHARED or PTHREAD_PROCESS_PRIVATE. Bestie, pick a real one. 😭

Also: these functions shall not return an error code of [EINTR]. Nope, never, not today.

The following sections are informative. 👑

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🌈 EXAMPLES 🌈

None.

(Yeah. That's the whole section. Iconic minimalism honestly. ✨)

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🧚 APPLICATION USAGE 🧚

The pthread_barrierattr_getpshared() and pthread_barrierattr_setpshared() functions are part of the Thread Process-Shared Synchronization option and need not be provided on all implementations. So if they're missing on your system, it's not you, it's them. 💜

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👑 RATIONALE 👑

If an implementation detects that the value specified by the attr argument to pthread_barrierattr_getpshared() or pthread_barrierattr_setpshared() does not refer to an initialized barrier attributes object, it is recommended that the function should fail and report an [EINVAL] error. Just a lil recommendation, as a treat. 🫶

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🍓 FUTURE DIRECTIONS 🍓

None.

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💜 SEE ALSO 💜

• pthread_barrier_destroy()
• pthread_barrierattr_destroy()

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

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📜 COPYRIGHT 📜

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 http://www.opengroup.org/unix/online.html.

Any typographical or formatting errors that appear in this page are most likely to have been introduced during the conversion of the source files to man page format. To report such errors, see https://www.kernel.org/doc/man-pages/reporting_bugs.html.

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okay that's the whole page bestie, you ate it 💅 this lil masterpiece came from IEEE/The Open Group, 2017 — and that's the official PTHREAD_B...ETPSHARED(3P) footer energy, folded in like a lil bow 🎀 mwah, go set some attributes, no cap ✨🦋