glibc/linuxthreads/sysdeps/i386/pt-machine.h
Ulrich Drepper 0ca7e46e16 Update.
1998-06-25 19:26  Ulrich Drepper  <drepper@cygnus.com>

	* Makeconfig (CPPFLAGS): Use $($(subdir)-CPPFLAGS) if defined first.
	* locale/Makefile: Define locale-CPPFLAGS instead of redefining
	CPPFLAGS.

	* libc.map: Export __sigaction.

1998-06-25  Andreas Jaeger  <aj@arthur.rhein-neckar.de>

	* sysdeps/unix/sysv/linux/bits/sched.h (CLONE_PTRACE): Add it
	(from Linux 2.1.107).

1998-06-24  Ulrich Drepper  <drepper@cygnus.com>

	* nss/nss_files/files-XXX.c (_nss_files_get,ENTNAME_r): Initialize
	position when file was opened here.
	Reported by Howard Chu <hyc@platinum.com>.

	* sysdeps/generic/glob.c: Also protect FNM_* macros from being
	undefined in a second inclusion.

1998-06-20  Mark Kettenis  <kettenis@phys.uva.nl>

	* sysdeps/mach/hurd/i386/Makefile: New file.
	* sysdeps/mach/hurd/i386/init-first.c [!PIC] (init1): Call
	__libc_init_secure.
	(_hurd_stack_setup): Renamed
	from __libc_init_first.
	(__libc_init_first): New function.
	* sysdeps/mach/hurd/i386/static-start.S: New file.

1998-05-30  Mark Kettenis  <kettenis@phys.uva.nl>

	* sysdeps/mach/hurd/i386/init-first.c

1998-06-22  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>

	* grp/initgroups.c: Use _CALL_DL_FCT.

1998-06-23  Mark Kettenis  <kettenis@phys.uva.nl>

	* elf/dl-load.c (_dl_map_object_from_fd): Add missing cast.
1998-06-25 19:44:22 +00:00

94 lines
2.6 KiB
C

/* Machine-dependent pthreads configuration and inline functions.
i386 version.
Copyright (C) 1996, 1997, 1998 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Richard Henderson <rth@tamu.edu>.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
/* Spinlock implementation; required. */
extern inline int
testandset (int *spinlock)
{
int ret;
__asm__ __volatile__("xchgl %0, %1"
: "=r"(ret), "=m"(*spinlock)
: "0"(1), "m"(*spinlock));
return ret;
}
/* Get some notion of the current stack. Need not be exactly the top
of the stack, just something somewhere in the current frame. */
#define CURRENT_STACK_FRAME stack_pointer
register char * stack_pointer __asm__ ("%esp");
/* Compare-and-swap for semaphores.
Available on the 486 and above, but not on the 386.
We test dynamically whether it's available or not. */
#define HAS_COMPARE_AND_SWAP
#define TEST_FOR_COMPARE_AND_SWAP
extern inline int
__compare_and_swap (long int *p, long int oldval, long int newval)
{
char ret;
long int readval;
__asm__ __volatile__ ("lock; cmpxchgl %3, %1; sete %0"
: "=q" (ret), "=m" (*p), "=a" (readval)
: "r" (newval), "m" (*p), "a" (oldval));
return ret;
}
extern inline int
get_eflags (void)
{
int res;
__asm__ __volatile__ ("pushfl; popl %0" : "=r" (res) : );
return res;
}
extern inline void
set_eflags (int newflags)
{
__asm__ __volatile__ ("pushl %0; popfl" : : "r" (newflags) : "cc");
}
extern inline int
compare_and_swap_is_available (void)
{
int oldflags = get_eflags ();
int changed;
/* Flip AC bit in EFLAGS. */
set_eflags (oldflags ^ 0x40000);
/* See if bit changed. */
changed = (get_eflags () ^ oldflags) & 0x40000;
/* Restore EFLAGS. */
set_eflags (oldflags);
/* If the AC flag did not change, it's a 386 and it lacks cmpxchg.
Otherwise, it's a 486 or above and it has cmpxchg. */
return changed != 0;
}