PTHREAD_ATTR(3)

💅 PTHREAD_ATTR(3) — thread attribute operations, bestie edition ✨

Ok so this is the pthread_attr page from the Library Functions Manual (section 3, iykyk) and it's literally the whole glow-up kit for threads. Gonna walk you through every single one, no skips, no cap. 🫶

---

🌸 LIBRARY

POSIX Threads Library, aka libpthread, aka -lpthread when you're linking. She's iconic, she's classic. 👑

---

✨ SYNOPSIS ✨

First things first, the include:

#include <pthread.h>

Then the whole squad, one by one 💅:

int
pthread_attr_init(pthread_attr_t *attr);

int
pthread_attr_destroy(pthread_attr_t *attr);

int
pthread_attr_setstack(pthread_attr_t *attr, void *stackaddr,
    size_t stacksize);

int
pthread_attr_getstack(const pthread_attr_t * restrict attr,
    void ** restrict stackaddr, size_t * restrict stacksize);

int
pthread_attr_setstacksize(pthread_attr_t *attr, size_t stacksize);

int
pthread_attr_getstacksize(const pthread_attr_t *restrict attr,
    size_t *restrict stacksize);

int
pthread_attr_setguardsize(pthread_attr_t *attr, size_t guardsize);

int
pthread_attr_getguardsize(const pthread_attr_t * restrict attr,
    size_t * restrict guardsize);

int
pthread_attr_setstackaddr(pthread_attr_t *attr, void *stackaddr);

int
pthread_attr_getstackaddr(const pthread_attr_t *attr, void **stackaddr);

int
pthread_attr_setdetachstate(pthread_attr_t *attr, int detachstate);

int
pthread_attr_getdetachstate(const pthread_attr_t *attr,
    int *detachstate);

int
pthread_attr_setinheritsched(pthread_attr_t *attr, int inheritsched);

int
pthread_attr_getinheritsched(const pthread_attr_t *restrict attr,
    int *restrct inheritsched);

int
pthread_attr_setschedparam(pthread_attr_t *attr,
    const struct sched_param *param);

int
pthread_attr_getschedparam(const pthread_attr_t *attr,
    struct sched_param *param);

int
pthread_attr_setschedpolicy(pthread_attr_t *attr, int policy);

int
pthread_attr_getschedpolicy(const pthread_attr_t *restrict attr,
    int *restrict policy);

int
pthread_attr_setscope(pthread_attr_t *attr, int contentionscope);

int
pthread_attr_getscope(const pthread_attr_t *restrict attr,
    int *restrict contentionscope);

🎀 bestie heads up: copy these signatures exactly as written, character for character. Yes, including restrct. That's literally what the page says and I am not out here editing source material. 🙈

---

💖 DESCRIPTION 💖

So. Thread attributes. They're the little parameter bag you hand to pthread_create() to tell it how you want your shiny new thread to be built. 🌈

The cute part? One attribute object can be used in multiple calls to pthread_create() — with or without modifications between calls. Reuse her, she's flexible. ♻️

• pthread_attr_init() — initializes attr with all the default thread attributes. The blank-slate, fresh-face start. ✨
• pthread_attr_destroy() — destroys attr. She's done, say bye. 💀
• pthread_attr_set*() — the setter squad: each one sets the attribute that matches its own name. Set it, slay it. 💅
• pthread_attr_get*() — the getter squad: each one copies the value of the attribute that matches its name into the location pointed to by the second function parameter. Reading is fundamental, fr fr. 📖

---

🔥 RETURN VALUES 🔥

If everything's good: 0. That's the win, that's the vibe check passed. ✅

Otherwise you get an error number back to tell you what went wrong. Not -1, bestie — an actual error number. Note it. 🫡

---

💀 ERRORS 💀

pthread_attr_init() will fail if:

• [ENOMEM] — out of memory. 😭 ran out of room, tragic.

pthread_attr_destroy() will fail if:

• [EINVAL] — invalid value for attr.

pthread_attr_setstacksize() and pthread_attr_setstack() will fail if:

• [EINVAL] — stacksize is less than PTHREAD_STACK_MIN. Too smol. Do not do that. 🙅‍♀️

pthread_attr_setdetachstate() will fail if:

• [EINVAL] — invalid value for detachstate.

pthread_attr_setinheritsched() will fail if:

• [EINVAL] — invalid value for attr.

pthread_attr_setschedparam() will fail if:

• [EINVAL] — invalid value for attr.
• [ENOTSUP] — invalid value for param.

pthread_attr_setschedpolicy() will fail if:

• [EINVAL] — invalid value for attr.
• [ENOTSUP] — invalid or unsupported value for policy.

pthread_attr_setscope() will fail if:

• [EINVAL] — invalid value for attr.
• [ENOTSUP] — invalid or unsupported value for contentionscope.

---

🦋 SEE ALSO 🦋

Go read these next, they're all part of the lore:

• pthread_attr_affinity_np(3)
• pthread_attr_get_np(3)
• pthread_create(3)

---

👑 STANDARDS 👑

Some of these are POSIX.1 girlies, some are SUSv2. Both valid, both iconic, just different eras. 💐

• pthread_attr_init(), pthread_attr_destroy(), pthread_attr_setstacksize(), pthread_attr_getstacksize(), pthread_attr_setstackaddr(), pthread_attr_getstackaddr(), pthread_attr_setdetachstate(), and pthread_attr_getdetachstate() conform to ISO/IEC 9945-1:1996 (“POSIX.1”). ⭐
• pthread_attr_setinheritsched(), pthread_attr_getinheritsched(), pthread_attr_setschedparam(), pthread_attr_getschedparam(), pthread_attr_setschedpolicy(), pthread_attr_getschedpolicy(), pthread_attr_setscope(), and pthread_attr_getscope() conform to Version 2 of the Single UNIX Specification (“SUSv2”). 🌸

---

Ok that's the whole page, you ate that. 🍓 Go forth and set your attributes, bestie — this was the Debian edition, dated August 17, 2018. Mwah. 💋🫶✨