$NetBSD: fork1.9,v 1.3 1999/03/16 00:40:47 garbled Exp $
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.Dd $Mdocdate: February 12 2017 $ .Dt THREAD_FORK 9 .Os .Sh NAME .Nm thread_fork .Nd create a new thread inside a process .Sh SYNOPSIS n sys/types.h n sys/proc.h .Ft int .Fo thread_fork .Fa "struct proc *p1" .Fa "void *stack" .Fa "void *tcb" .Fa "pid_t *tidptr" .Fa "register_t *retval" .Fc .Sh DESCRIPTION .Fn thread_fork creates a new thread out of .Ar p1 , which should be the current thread. This function is used to implement the .Xr __tfork 3 system call.
p .Fa stack , which must not be .Dv NULL , will be used as the initial value of the new thread's stack pointer.
p If .Fa tcb is not .Dv NULL , it will be used as the initial address of the new thread's TCB (thread control block).
p If .Fa tidptr is not .Dv NULL , the TID of the new thread will be copied out there on success. This is guaranteed to be done before the new thread is started.
p On successful completion the TID of the new thread will be stored in .Fa *retval . .Sh RETURN VALUES Upon successful completion of the operation, .Fn thread_fork returns 0. Otherwise, the following error values are returned: l -tag -width [EAGAIN] t Bq Er EAGAIN The system limit on the total number of threads would be exceeded. t Bq Er ENOMEM There is insufficient swap space for the new thread. t Bq Er EINVAL The .Fa stack argument was .Dv NULL . .El .Sh SEE ALSO .Xr __get_tcb 2 , .Xr fork 2 , .Xr __tfork 3 , .Xr tfind 9 .Sh HISTORY The .Fn thread_fork function appeared in .Ox 6.1 .