pthread.h(7POSIX)

📦 version 2017a, in debian bookworm, debian trixie, ubuntu jammy, ubuntu noble, ubuntu resolute, ubuntu stonking

🦋 PROLOG 🦋

okay bestie, housekeeping first, then we get to the good stuff. 💖 this page is pthread.h(7POSIX), and it lives in the POSIX Programmer's Manual — so like, it's the official standards tea, not necessarily the Linux tea. 🌸

  • This manual page is part of the POSIX Programmer's Manual.
  • The Linux implementation of this interface may differ — so go consult the corresponding Linux manual page for the details of Linux behavior, fr.
  • ...or honestly? The interface may not be implemented on Linux at all. 🙈
not me warning you twice but like, please check your platform before you go hard on threads. it's giving ✨due diligence✨.

✨ NAME ✨

pthread.h — threads. that's it, that's the whole entire vibe. 🧵✨

🌸 SYNOPSIS 🌸

#include <pthread.h>

💅 DESCRIPTION 💅

the symbolic constants roster 👑

so <pthread.h> shall define the following symbolic constants, and bestie there are a LOT of them, we are listing every single one, no skips, periodt:

  • PTHREAD_BARRIER_SERIAL_THREAD
  • PTHREAD_CANCEL_ASYNCHRONOUS
  • PTHREAD_CANCEL_ENABLE
  • PTHREAD_CANCEL_DEFERRED
  • PTHREAD_CANCEL_DISABLE
  • PTHREAD_CANCELED
  • PTHREAD_CREATE_DETACHED
  • PTHREAD_CREATE_JOINABLE
  • PTHREAD_EXPLICIT_SCHED
  • PTHREAD_INHERIT_SCHED
  • PTHREAD_MUTEX_DEFAULT
  • PTHREAD_MUTEX_ERRORCHECK
  • PTHREAD_MUTEX_NORMAL
  • PTHREAD_MUTEX_RECURSIVE
  • PTHREAD_MUTEX_ROBUST
  • PTHREAD_MUTEX_STALLED
  • PTHREAD_ONCE_INIT
  • PTHREAD_PRIO_INHERIT
  • PTHREAD_PRIO_NONE
  • PTHREAD_PRIO_PROTECT
  • PTHREAD_PROCESS_SHARED
  • PTHREAD_PROCESS_PRIVATE
  • PTHREAD_SCOPE_PROCESS
  • PTHREAD_SCOPE_SYSTEM

the initializers (the "just set it up already" squad) 🎀

and <pthread.h> shall define the following compile-time constant expressions, which are valid as initializers for the types listed next to them:

  • PTHREAD_COND_INITIALIZER — initializer for the type pthread_cond_t
  • PTHREAD_MUTEX_INITIALIZER — initializer for the type pthread_mutex_t
  • PTHREAD_RWLOCK_INITIALIZER — initializer for the type pthread_rwlock_t

the types 💜

<pthread.h> shall define these types as described in <sys/types.h>:

  • pthread_attr_t
  • pthread_barrier_t
  • pthread_barrierattr_t
  • pthread_cond_t
  • pthread_condattr_t
  • pthread_key_t
  • pthread_mutex_t
  • pthread_mutexattr_t
  • pthread_once_t
  • pthread_rwlock_t
  • pthread_rwlockattr_t
  • pthread_spinlock_t
  • pthread_t

the functions 🫶

okay this is the main character section, lowkey. the following shall be declared as functions, and they may also be defined as macros. function prototypes shall be provided. here's the whole list, verbatim, because we do not gatekeep: 🔥

int   pthread_atfork(void (*)(void), void (*)(void),
          void(*)(void));
int   pthread_attr_destroy(pthread_attr_t *);
int   pthread_attr_getdetachstate(const pthread_attr_t *, int *);
int   pthread_attr_getguardsize(const pthread_attr_t *restrict,
          size_t *restrict);
int   pthread_attr_getinheritsched(const pthread_attr_t *restrict,
          int *restrict);
int   pthread_attr_getschedparam(const pthread_attr_t *restrict,
          struct sched_param *restrict);
int   pthread_attr_getschedpolicy(const pthread_attr_t *restrict,
          int *restrict);
int   pthread_attr_getscope(const pthread_attr_t *restrict,
          int *restrict);
int   pthread_attr_getstack(const pthread_attr_t *restrict,
          void **restrict, size_t *restrict);
int   pthread_attr_getstacksize(const pthread_attr_t *restrict,
          size_t *restrict);
int   pthread_attr_init(pthread_attr_t *);
int   pthread_attr_setdetachstate(pthread_attr_t *, int);
int   pthread_attr_setguardsize(pthread_attr_t *, size_t);
int   pthread_attr_setinheritsched(pthread_attr_t *, int);
int   pthread_attr_setschedparam(pthread_attr_t *restrict,
          const struct sched_param *restrict);
int   pthread_attr_setschedpolicy(pthread_attr_t *, int);
int   pthread_attr_setscope(pthread_attr_t *, int);
int   pthread_attr_setstack(pthread_attr_t *, void *, size_t);
int   pthread_attr_setstacksize(pthread_attr_t *, size_t);
int   pthread_barrier_destroy(pthread_barrier_t *);
int   pthread_barrier_init(pthread_barrier_t *restrict,
          const pthread_barrierattr_t *restrict, unsigned);
int   pthread_barrier_wait(pthread_barrier_t *);
int   pthread_barrierattr_destroy(pthread_barrierattr_t *);
int   pthread_barrierattr_getpshared(
          const pthread_barrierattr_t *restrict, int *restrict);
int   pthread_barrierattr_init(pthread_barrierattr_t *);
int   pthread_barrierattr_setpshared(pthread_barrierattr_t *, int);
int   pthread_cancel(pthread_t);
int   pthread_cond_broadcast(pthread_cond_t *);
int   pthread_cond_destroy(pthread_cond_t *);
int   pthread_cond_init(pthread_cond_t *restrict,
          const pthread_condattr_t *restrict);
int   pthread_cond_signal(pthread_cond_t *);
int   pthread_cond_timedwait(pthread_cond_t *restrict,
          pthread_mutex_t *restrict, const struct timespec *restrict);
int   pthread_cond_wait(pthread_cond_t *restrict,
          pthread_mutex_t *restrict);
int   pthread_condattr_destroy(pthread_condattr_t *);
int   pthread_condattr_getclock(const pthread_condattr_t *restrict,
          clockid_t *restrict);
int   pthread_condattr_getpshared(const pthread_condattr_t *restrict,
          int *restrict);
int   pthread_condattr_init(pthread_condattr_t *);
int   pthread_condattr_setclock(pthread_condattr_t *, clockid_t);
int   pthread_condattr_setpshared(pthread_condattr_t *, int);
int   pthread_create(pthread_t *restrict, const pthread_attr_t *restrict,
          void *(*)(void*), void *restrict);
int   pthread_detach(pthread_t);
int   pthread_equal(pthread_t, pthread_t);
void  pthread_exit(void *);
int   pthread_getconcurrency(void);
int   pthread_getcpuclockid(pthread_t, clockid_t *);
int   pthread_getschedparam(pthread_t, int *restrict,
          struct sched_param *restrict);
void *pthread_getspecific(pthread_key_t);
int   pthread_join(pthread_t, void **);
int   pthread_key_create(pthread_key_t *, void (*)(void*));
int   pthread_key_delete(pthread_key_t);
int   pthread_mutex_consistent(pthread_mutex_t *);
int   pthread_mutex_destroy(pthread_mutex_t *);
int   pthread_mutex_getprioceiling(const pthread_mutex_t *restrict,
          int *restrict);
int   pthread_mutex_init(pthread_mutex_t *restrict,
          const pthread_mutexattr_t *restrict);
int   pthread_mutex_lock(pthread_mutex_t *);
int   pthread_mutex_setprioceiling(pthread_mutex_t *restrict, int,
          int *restrict);
int   pthread_mutex_timedlock(pthread_mutex_t *restrict,
          const struct timespec *restrict);
int   pthread_mutex_trylock(pthread_mutex_t *);
int   pthread_mutex_unlock(pthread_mutex_t *);
int   pthread_mutexattr_destroy(pthread_mutexattr_t *);
int   pthread_mutexattr_getprioceiling(
          const pthread_mutexattr_t *restrict, int *restrict);
int   pthread_mutexattr_getprotocol(const pthread_mutexattr_t *restrict,
          int *restrict);
int   pthread_mutexattr_getpshared(const pthread_mutexattr_t *restrict,
          int *restrict);
int   pthread_mutexattr_getrobust(const pthread_mutexattr_t *restrict,
          int *restrict);
int   pthread_mutexattr_gettype(const pthread_mutexattr_t *restrict,
          int *restrict);
int   pthread_mutexattr_init(pthread_mutexattr_t *);
int   pthread_mutexattr_setprioceiling(pthread_mutexattr_t *, int);
int   pthread_mutexattr_setprotocol(pthread_mutexattr_t *, int);
int   pthread_mutexattr_setpshared(pthread_mutexattr_t *, int);
int   pthread_mutexattr_setrobust(pthread_mutexattr_t *, int);
int   pthread_mutexattr_settype(pthread_mutexattr_t *, int);
int   pthread_once(pthread_once_t *, void (*)(void));
int   pthread_rwlock_destroy(pthread_rwlock_t *);
int   pthread_rwlock_init(pthread_rwlock_t *restrict,
          const pthread_rwlockattr_t *restrict);
int   pthread_rwlock_rdlock(pthread_rwlock_t *);
int   pthread_rwlock_timedrdlock(pthread_rwlock_t *restrict,
          const struct timespec *restrict);
int   pthread_rwlock_timedwrlock(pthread_rwlock_t *restrict,
          const struct timespec *restrict);
int   pthread_rwlock_tryrdlock(pthread_rwlock_t *);
int   pthread_rwlock_trywrlock(pthread_rwlock_t *);
int   pthread_rwlock_unlock(pthread_rwlock_t *);
int   pthread_rwlock_wrlock(pthread_rwlock_t *);
int   pthread_rwlockattr_destroy(pthread_rwlockattr_t *);
int   pthread_rwlockattr_getpshared(
          const pthread_rwlockattr_t *restrict, int *restrict);
int   pthread_rwlockattr_init(pthread_rwlockattr_t *);
int   pthread_rwlockattr_setpshared(pthread_rwlockattr_t *, int);
pthread_t
      pthread_self(void);
int   pthread_setcancelstate(int, int *);
int   pthread_setcanceltype(int, int *);
int   pthread_setconcurrency(int);
int   pthread_setschedparam(pthread_t, int,
          const struct sched_param *);
int   pthread_setschedprio(pthread_t, int);
int   pthread_setspecific(pthread_key_t, const void *);
int   pthread_spin_destroy(pthread_spinlock_t *);
int   pthread_spin_init(pthread_spinlock_t *, int);
int   pthread_spin_lock(pthread_spinlock_t *);
int   pthread_spin_trylock(pthread_spinlock_t *);
int   pthread_spin_unlock(pthread_spinlock_t *);
void  pthread_testcancel(void);

the maybe-functions, maybe-macros situation 😭

these two are special, bestie — the following may be declared as functions, or defined as macros, or honestly both. and if they are declared as functions, then function prototypes shall be provided:

  • pthread_cleanup_pop()
  • pthread_cleanup_push()

the freebie visibility perk ✨

and just so you know: including the <pthread.h> header shall make symbols defined in the headers <sched.h> and <time.h> visible. cute little bonus, we love a two-for-one. 🎀

also heads up: the following sections are informative — like, they're context, not requirements. iykyk. 👑

🎀 APPLICATION USAGE 🎀

None.

like, genuinely nothing. that's the whole section. 💀

⭐ RATIONALE ⭐

None.

again — nothing. the reasoning is between them and the standards committee. 🙈

🌈 FUTURE DIRECTIONS 🌈

None.

nothing on the horizon, bestie. it is what it is. 💖

and that's only part one of this whole saga, so don't go anywhere — more incoming 🫶

👀 SEE ALSO 👀

ok so if pthread.h was your gateway drug (as it should be 💅), here's the rest of the friend group. header besties first:

  • <sched.h>
  • <sys_types.h>
  • <time.h>

and then… the main character of this section: the System Interfaces volume of POSIX.1‐2017, which has a whole little roster of functions that lowkey all live in the same universe as this header. no cap, here's the entire cast, in order, nobody gets left out:

pthread_atfork()
pthread_attr_destroy()
pthread_attr_getdetachstate()
pthread_attr_getguardsize()
pthread_attr_getinheritsched()
pthread_attr_getschedparam()
pthread_attr_getschedpolicy()
pthread_attr_getscope()
pthread_attr_getstack()
pthread_attr_getstacksize()
pthread_barrier_destroy()
pthread_barrier_wait()
pthread_barrierattr_destroy()
pthread_barrierattr_getpshared()
pthread_cancel()
pthread_cleanup_pop()
pthread_cond_broadcast()
pthread_cond_destroy()
pthread_cond_timedwait()
pthread_condattr_destroy()
pthread_condattr_getclock()
pthread_condattr_getpshared()
pthread_create()
pthread_detach()
pthread_equal()
pthread_exit()
pthread_getconcurrency()
pthread_getcpuclockid()
pthread_getschedparam()
pthread_getspecific()
pthread_join()
pthread_key_create()
pthread_key_delete()
pthread_mutex_consistent()
pthread_mutex_destroy()
pthread_mutex_getprioceiling()
pthread_mutex_lock()
pthread_mutex_timedlock()
pthread_mutexattr_destroy()
pthread_mutexattr_getprioceiling()
pthread_mutexattr_getprotocol()
pthread_mutexattr_getpshared()
pthread_mutexattr_getrobust()
pthread_mutexattr_gettype()
pthread_once()
pthread_rwlock_destroy()
pthread_rwlock_rdlock()
pthread_rwlock_timedrdlock()
pthread_rwlock_timedwrlock()
pthread_rwlock_trywrlock()
pthread_rwlock_unlock()
pthread_rwlockattr_destroy()
pthread_rwlockattr_getpshared()
pthread_self()
pthread_setcancelstate()
pthread_setschedprio()
pthread_spin_destroy()
pthread_spin_lock()
pthread_spin_unlock()

like… that's the whole squad 🫶 go read them, they're all worth it, i promise.

ok this part is giving legal girlboss energy but bestie, we have to be accurate here, so here it is, fr fr:

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.

and listen — 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. so if anything looks off, the OG standard wins, periodt. 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 .

and that's the whole page, bestie!! 💖 we made it to the end, no skimming, no skipping, every single detail intact. icon behaviour tbh. ✨

this little masterpiece came to you from IEEE/The Open Group, dated 2017, filed under pthread.h(7POSIX) — that's the source/version/date lineup, and i'm giving it main character energy for the last time. go forth and thread safely, mwah 💅🎀🦋

📦 where this page comes from