_LWP_CREATE(2) BSD System Calls Manual _LWP_CREATE(2)NAME_lwp_create — create a new light-weight process
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <lwp.h>
int
_lwp_create(ucontext_t *context, unsigned long flags, lwpid_t *new_lwp);
DESCRIPTION_lwp_create() causes creation of a new light-weight process, or LWP, and
adds it to the current process. The context argument specifies the ini‐
tial execution context for the new LWP including signal mask, stack, and
machine registers. If this context specifies invalid register values
(for example priviledge escalation by setting machine dependend bits for‐
bidden for user processes), or does not specify cpu register values
(uc_flags does not have the _UC_CPU bit set), the call will fail and
errno will be set to EINVAL.
The following flags affect the creation of the new LWP:
LWP_DETACHED The LWP is created detached. The resources associated
with a detached LWP will be automatically reclaimed by the
system when the LWP exits. Otherwise, a terminated LWP's
resources will not be reclaimed until its status is
reported to another LWP via _lwp_wait(2).
LWP_SUSPENDED The LWP is created suspended, and will not begin execution
until it is resumed by another LWP via _lwp_continue(2).
The LWP ID of the new LWP is stored in the location pointed to by
new_lwp.
RETURN VALUES
Upon successful completion, _lwp_create() returns a value of 0. Other‐
wise, a value of -1 is returned and errno is set to one of the values
documented below.
ERRORS_lwp_create() will fail and no LWP will be created if:
[EAGAIN] The system-imposed limit on the total number of LWPs under exe‐
cution would be exceeded. This limit is configuration-depen‐
dent.
[ENOMEM] There is insufficient swap space for the new LWP.
[EFAULT] The address pointed to by context or new_lwp is outside the
process's allocated address space.
[EINVAL] The ucontext_t passed is invalid.
SEE ALSO_lwp_continue(2), _lwp_exit(2), _lwp_wait(2), _lwp_makecontext(3)HISTORY
The _lwp_create() system call first appeared in NetBSD 2.0.
BSD January 13, 2003 BSD
