File: [cvs.NetBSD.org] / src / lib / libpthread / pthread_makelwp_netbsd.c (download)
Revision 1.1, Tue Dec 16 20:05:54 2014 UTC (9 years, 3 months ago) by pooka
Branch: MAIN
Allow for arbitrary MI scheduler implementations.
A concrete result is enabling unpatched libpthread to run on the
rumprun stacks (e.g. Xen and bare metal) with a non-NetBSD scheduler.
Those schedulers hook into the existing _lwp_frobnitz() NetBSD syscall
interfaces (well, "syscall" interfaces in that scenario ;)
More specifically about the change itself:
1) instead of calling _lwp_makecontext() followed by _lwp_create()
and passing the entry point in ucontext_t (MD) through the calls, roll
the calls into pthread__makelwp() and allow alternate implementations
for that MI interface.
2) allow compile-time overriding of __lwp_gettcb_fast() or
__lwp_getprivate_fast, which are inline and leak MD scheduler/thread
details into libpthread
Additionally, two small nits:
I) define LIB=pthread before including mk.conf so that it's possible
to test for LIB==pthread in mk.conf
II) make it possible to leave out pthread_cancelstub.c. This is required
by the current implementation of rumprun-posix (i.e. rumprun on
POSIX hosts) due to symbol collisions. It needs to be fixed properly
some day, but for now allows an almost-correct libpthread to run.
I am sure @justin will be happy to explain the details ;)
no change to NetBSD
tested: anita+atf
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/* $NetBSD: pthread_makelwp_netbsd.c,v 1.1 2014/12/16 20:05:54 pooka Exp $ */
/*-
* Copyright (c) 2001, 2002, 2003, 2006, 2007, 2008 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Nathan J. Williams and Andrew Doran.
*
* 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.
*/
#include <sys/cdefs.h>
__RCSID("$NetBSD: pthread_makelwp_netbsd.c,v 1.1 2014/12/16 20:05:54 pooka Exp $");
#include <sys/param.h>
#include <lwp.h>
#include <pthread.h>
#include "pthread_int.h"
#include "pthread_makelwp.h"
int
pthread__makelwp(void (*start_routine)(void *), void *arg, void *priv,
void *stack_base, size_t stack_size,
unsigned long flag, lwpid_t *newlid)
{
ucontext_t uc;
/*
* XXX: most of the following chunk is these days
* performed also by _lwp_makecontext(), but there may
* be MD differences, so lug everything along for now.
*/
memset(&uc, 0, sizeof(uc));
_INITCONTEXT_U(&uc);
uc.uc_stack.ss_sp = stack_base;
uc.uc_stack.ss_size = stack_size;
uc.uc_stack.ss_flags = 0;
uc.uc_link = NULL;
_lwp_makecontext(&uc, start_routine, arg, priv, stack_base, stack_size);
return _lwp_create(&uc, flag, newlid);
}