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File: [cvs.NetBSD.org] / src / lib / libc / arch / i386 / gen / _lwp.c (download)

Revision 1.7, Thu Feb 24 04:28:42 2011 UTC (13 years, 1 month ago) by joerg
Branch: MAIN
CVS Tags: yamt-pagecache-base5, yamt-pagecache-base4, yamt-pagecache-base3, yamt-pagecache-base2, yamt-pagecache-base, netbsd-6-base, netbsd-6-1-RELEASE, netbsd-6-1-RC4, netbsd-6-1-RC3, netbsd-6-1-RC2, netbsd-6-1-RC1, netbsd-6-1-5-RELEASE, netbsd-6-1-4-RELEASE, netbsd-6-1-3-RELEASE, netbsd-6-1-2-RELEASE, netbsd-6-1-1-RELEASE, netbsd-6-1, netbsd-6-0-RELEASE, netbsd-6-0-RC2, netbsd-6-0-RC1, netbsd-6-0-6-RELEASE, netbsd-6-0-5-RELEASE, netbsd-6-0-4-RELEASE, netbsd-6-0-3-RELEASE, netbsd-6-0-2-RELEASE, netbsd-6-0-1-RELEASE, netbsd-6-0, netbsd-6, matt-nb6-plus-nbase, matt-nb6-plus-base, matt-nb6-plus, cherry-xenmp-base, cherry-xenmp, bouyer-quota2-nbase
Branch point for: yamt-pagecache
Changes since 1.6: +4 -3 lines

Allow storing and receiving the LWP private pointer via ucontext_t
on all platforms except VAX and IA64. Add fast access via register for
AMD64, i386 and SH3 ports. Use this fast access in libpthread to replace
the stack based pthread_self(). Implement skeleton support for Alpha,
HPPA, PowerPC, SPARC and SPARC64, but leave it disabled.

Ports that support this feature provide __HAVE____LWP_GETPRIVATE_FAST in
machine/types.h and a corresponding __lwp_getprivate_fast in
machine/mcontext.h.

This material is based upon work partially supported by
The NetBSD Foundation under a contract with Joerg Sonnenberger.

/*	$NetBSD: _lwp.c,v 1.7 2011/02/24 04:28:42 joerg Exp $	*/

/*-
 * Copyright (c) 2001 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Nathan J. Williams.
 *
 * 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>
#if defined(LIBC_SCCS) && !defined(lint)
__RCSID("$NetBSD: _lwp.c,v 1.7 2011/02/24 04:28:42 joerg Exp $");
#endif /* LIBC_SCCS and not lint */

#include "namespace.h"
#include <sys/types.h>
#include <inttypes.h>
#include <ucontext.h>
#include <lwp.h>
#include <stdlib.h>

void
_lwp_makecontext(ucontext_t *u, void (*start)(void *),
    void *arg, void *private, caddr_t stack_base, size_t stack_size)
{
	void **sp;

	getcontext(u);
	u->uc_link = NULL;

	u->uc_stack.ss_sp = stack_base;
	u->uc_stack.ss_size = stack_size;

	/* LINTED uintptr_t is safe */
	u->uc_mcontext.__gregs[_REG_EIP] = (uintptr_t)start;
	
	/* Align to a word */
	/* LINTED uintptr_t is safe */
	sp = (void **) ((uintptr_t)(stack_base + stack_size) & ~0x3);
	
	*--sp = arg;
	*--sp = (void *) _lwp_exit;
	
	/* LINTED uintptr_t is safe */
	u->uc_mcontext.__gregs[_REG_UESP] = (uintptr_t) sp;

	u->uc_mcontext._mc_tlsbase = (uintptr_t)private;
	u->uc_flags |= _UC_TLSBASE;
}