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-rw-r--r--linuxthreads/sysdeps/i386/i686/pt-machine.h79
1 files changed, 79 insertions, 0 deletions
diff --git a/linuxthreads/sysdeps/i386/i686/pt-machine.h b/linuxthreads/sysdeps/i386/i686/pt-machine.h
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+++ b/linuxthreads/sysdeps/i386/i686/pt-machine.h
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+/* Machine-dependent pthreads configuration and inline functions.
+   i686 version.
+   Copyright (C) 1996-2001, 2002, 2003 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 Lesser General Public License as
+   published by the Free Software Foundation; either version 2.1 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser 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.  */
+
+#ifndef _PT_MACHINE_H
+#define _PT_MACHINE_H	1
+
+#ifndef PT_EI
+# define PT_EI extern inline __attribute__ ((always_inline))
+#endif
+#include "kernel-features.h"
+
+#ifndef __ASSEMBLER__
+extern long int testandset (int *spinlock);
+extern int __compare_and_swap (long int *p, long int oldval, long int newval);
+
+/* 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  __builtin_frame_address (0)
+
+
+/* Spinlock implementation; required.  */
+PT_EI long int
+testandset (int *spinlock)
+{
+  long int ret;
+
+  __asm__ __volatile__ (
+	"xchgl %0, %1"
+	: "=r" (ret), "=m" (*spinlock)
+	: "0" (1), "m" (*spinlock)
+	: "memory");
+
+  return ret;
+}
+
+
+/* Compare-and-swap for semaphores.  It's always available on i686.  */
+#define HAS_COMPARE_AND_SWAP
+
+PT_EI 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)
+			: "memory");
+  return ret;
+}
+#endif
+
+#if __ASSUME_LDT_WORKS > 0
+#include "../useldt.h"
+#endif
+
+/* The P4 and above really want some help to prevent overheating.  */
+#define BUSY_WAIT_NOP	__asm__ ("rep; nop")
+
+#endif /* pt-machine.h */