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_LWP_CREATE(2)                System Calls Manual               _LWP_CREATE(2)

     _lwp_create - create a new light-weight process

     Standard C Library (libc, -lc)

     #include <lwp.h>

     _lwp_create(ucontext_t *context, unsigned long flags, lwpid_t *new_lwp);

     _lwp_create() causes creation of a new light-weight process, or LWP, and
     adds it to the current process.  The context argument specifies the
     initial execution context for the new LWP including signal mask, stack,
     and machine registers.  The signal stack of the newly created light-
     weight process is reset to disabled.  If this context specifies invalid
     register values (for example privilege escalation by setting machine
     dependent bits forbidden 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

     Upon successful completion, _lwp_create() returns a value of 0.
     Otherwise, a value of -1 is returned and errno is set to one of the
     values documented below.

     _lwp_create() will fail and no LWP will be created if:

     [EAGAIN]    The system-imposed limit on the total number of LWPs under
                 execution would be exceeded.  This limit is configuration-

     [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.

     [ENOMEM]    There is insufficient swap space for the new LWP.

     _lwp_continue(2), _lwp_exit(2), _lwp_wait(2), _lwp_makecontext(3)

     The _lwp_create() system call first appeared in NetBSD 2.0.

NetBSD 9.99                     April 21, 2017                     NetBSD 9.99