Libc-763.13.tar.gz

[apple/libc.git] / pthreads / pthread_create.3

.\" Copyright (c) 1996 John Birrell <jb@cimlogic.com.au>.
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.\" $FreeBSD: src/lib/libc_r/man/pthread_create.3,v 1.9.2.4 2001/08/17 15:42:51 ru Exp $
.\"
.Dd April 4, 1996
.Dt PTHREAD_CREATE 3
.Os
.Sh NAME
.Nm pthread_create
.Nd create a new thread
.Sh SYNOPSIS
.Fd #include <pthread.h>
.Ft int
.Fo pthread_create
.Fa "pthread_t *restrict thread"
.Fa "const pthread_attr_t *restrict attr"
.Fa "void *(*start_routine)(void *)"
.Fa "void *restrict arg"
.Fc
.Sh DESCRIPTION
The
.Fn pthread_create
function is used to create a new thread, with attributes specified by
.Fa attr ,
within a process.
If
.Fa attr
is NULL, the default attributes are used.
If the attributes specified by
.Fa attr
are modified later, the thread's attributes are not affected.
Upon successful completion,
.Fn pthread_create
will store the ID of the created thread in the location specified by
.Fa thread .
.Pp
Upon its creation, the thread executes
.Fa start_routine ,
with
.Fa arg
as its sole argument.
If
.Fa start_routine
returns, the effect is as if there was an implicit call to
.Fn pthread_exit ,
using the return value of
.Fa start_routine
as the exit status.
Note that the thread in which
.Fn main
was originally invoked differs from this.
When it returns from
.Fn main ,
the effect is as if there was an implicit call to
.Fn exit ,
using the return value of
.Fn main
as the exit status.
.Pp
The signal state of the new thread is initialized as:
.Bl -bullet -offset indent
.It
The signal mask is inherited from the creating thread.
.It
The set of signals pending for the new thread is empty.
.El
.Sh RETURN VALUES
If successful,  the
.Fn pthread_create
function will return zero.
Otherwise, an error number will be returned to
indicate the error.
.Sh ERRORS
.Fn pthread_create
will fail if:
.Bl -tag -width Er
.It Bq Er EAGAIN
The system lacked the necessary resources to create another thread, or
the system-imposed limit on the total number of threads in a process
[PTHREAD_THREADS_MAX] would be exceeded.
.It Bq Er EINVAL
The value specified by
.Fa attr
is invalid.
.El
.Sh SEE ALSO
.Xr fork 2 ,
.Xr pthread_cleanup_pop 3 ,
.Xr pthread_cleanup_push 3 ,
.Xr pthread_exit 3 ,
.Xr pthread_join 3
.Sh STANDARDS
.Fn pthread_create
conforms to
.St -p1003.1-96 .