.\" $NetBSD: pthread.3,v 1.17 2017/02/08 03:44:41 kamil Exp $ .\" .\" Copyright (c) 2003, 2007, 2009 The NetBSD Foundation, Inc. .\" All rights reserved. .\" .\" This code is derived from software contributed to The NetBSD Foundation .\" by Hubert Feyrer and Thomas Klausner . .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" .\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS .\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED .\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR .\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS .\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR .\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF .\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS .\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN .\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE .\" POSSIBILITY OF SUCH DAMAGE. .\" .Dd November 22, 2016 .Dt PTHREAD 3 .Os .Sh NAME .Nm pthread .Nd POSIX Threads Library .Sh LIBRARY .Lb libpthread .Sh SYNOPSIS .In pthread.h .Pp .Nm cc .Op Ar flags .Ar files .Fl lpthread .Op Ar libraries .Sh DESCRIPTION The .Nm library provides an implementation of the standard .Tn POSIX threads library. .Pp The .Nx implementation is based on 1:1 thread model, therefore each .Nm has a kernel thread, called a light-weight process (LWP). .Pp Note that the system private thread interfaces upon which the .Nm library is built are subject to change without notice. In order to remain compatible with future .Nx releases, programs must be linked against the dynamic version of the thread library. Statically linked programs using the .Tn POSIX threads framework may not work when run on a future version of the system. .Sh FUNCTIONS The following functions comprise the core of the .Nm library: .Bl -column -offset indent "pthread_barrier_destroy(3)" "XXX" .It Sy Function Ta Sy Description .It Xr pthread_attr 3 Ta thread attribute operations .It Xr pthread_barrier_destroy 3 Ta destroy a barrier .It Xr pthread_barrier_init 3 Ta create a barrier .It Xr pthread_barrier_wait 3 Ta wait for a barrier .It Xr pthread_barrierattr 3 Ta barrier attribute operations .It Xr pthread_cancel 3 Ta cancel the execution of a thread .It Xr pthread_cleanup_push 3 Ta add or remove cleanup functions .It Xr pthread_cond_broadcast 3 Ta unblock one or more threads .It Xr pthread_cond_destroy 3 Ta destroy a condition variable .It Xr pthread_cond_init 3 Ta create a condition variable .It Xr pthread_cond_wait 3 Ta wait for a condition variable .It Xr pthread_condattr 3 Ta condition attribute operations .It Xr pthread_create 3 Ta create a new thread .It Xr pthread_detach 3 Ta detach a thread .It Xr pthread_equal 3 Ta compare thread identifiers .It Xr pthread_exit 3 Ta terminate the calling thread .It Xr pthread_getspecific 3 Ta get a thread-specific data value .It Xr pthread_join 3 Ta wait for thread termination .It Xr pthread_key_create 3 Ta thread-specific data key creation .It Xr pthread_key_delete 3 Ta delete a thread-specific data key .It Xr pthread_kill 3 Ta send a signal to a specific thread .It Xr pthread_mutex_destroy 3 Ta free a mutex .It Xr pthread_mutex_init 3 Ta create a mutex .It Xr pthread_mutex_lock 3 Ta acquire a lock on a mutex .It Xr pthread_mutex_unlock 3 Ta unlock a mutex .It Xr pthread_mutexattr 3 Ta mutex attribute operations .It Xr pthread_once 3 Ta dynamic package initialization .It Xr pthread_rwlock_destroy 3 Ta destroy a read/write lock .It Xr pthread_rwlock_init 3 Ta initialize a read/write lock .It Xr pthread_rwlock_rdlock 3 Ta acquire a read/write lock for reading .It Xr pthread_rwlock_unlock 3 Ta release a read/write lock .It Xr pthread_rwlock_wrlock 3 Ta acquire a read/write lock for writing .It Xr pthread_rwlockattr 3 Ta read/write lock attribute operations .It Xr pthread_schedparam 3 Ta thread scheduling manipulation .It Xr pthread_self 3 Ta get the ID of the calling thread .It Xr pthread_setspecific 3 Ta get a thread-specific data value .It Xr pthread_sigmask 3 Ta manipulate a thread's signal mask .It Xr pthread_spin_destroy 3 Ta destroy a spin lock .It Xr pthread_spin_init 3 Ta initialize a spin lock .It Xr pthread_spin_lock 3 Ta acquire a spin lock .It Xr pthread_spin_unlock 3 Ta release a spin lock .It Xr pthread_testcancel 3 Ta set cancelability state .El .Sh ENVIRONMENT The following environment variables affect the behavior of the library: .Bl -tag -width "XXX" .It Ev PTHREAD_DIAGASSERT Possible values are any combinations of: .Pp .Bl -tag -width "X " -offset 1n -compact .It Em A Report errors to application by error return, but do not abort. .It Em a Abort on errors, creating a core dump for further debugging. .It Em E Do not log errors to stdout. .It Em e Log errors to stdout. .It Em L Do not log errors via .Xr syslogd 8 . .It Em l Log errors via .Xr syslogd 8 . .El .Pp If not set in the environment, the .Nm library behaves as if .Em AEL has been specified. .It Ev PTHREAD_STACKSIZE Integer value giving the stack size in kilobytes. This allows to set a smaller stack size than the default stack size. The default stack size is the current limit on the stack size as set with the shell's command to change limits .Ic ( limit for .Xr csh 1 , or .Ic ulimit for .Xr sh 1 ) . .El .Sh SEE ALSO .Rs .%A David R. Butenhof .%T Programming with POSIX(R) Threads .%D 1997 .%I Addison-Wesley .Re .Sh STANDARDS The .Nm library conforms to .St -p1003.1-2001 . .Sh CAVEATS Due to limitations in the current pthread implementation, .Xr makecontext 3 and .Xr sigaltstack 2 should not be used in programs which link against the .Nm library (whether threads are used or not).