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// locks.h - Thread synchronization primitives. Alpha implementation.
/* Copyright (C) 2002 Free Software Foundation
This file is part of libgcj.
This software is copyrighted work licensed under the terms of the
Libgcj License. Please consult the file "LIBGCJ_LICENSE" for
details. */
#ifndef __SYSDEP_LOCKS_H__
#define __SYSDEP_LOCKS_H__
typedef size_t obj_addr_t; /* Integer type big enough for object */
/* address. */
inline static bool
compare_and_swap(volatile obj_addr_t *addr,
obj_addr_t old,
obj_addr_t new_val)
{
unsigned long oldval;
char result;
__asm__ __volatile__(
"1:ldq_l %0, %1\n\t" \
"cmpeq %0, %5, %2\n\t" \
"beq %2, 2f\n\t" \
"mov %3, %0\n\t" \
"stq_c %0, %1\n\t" \
"bne %0, 2f\n\t" \
"br 1b\n\t" \
"2:mb"
: "=&r"(oldval), "=m"(*addr), "=&r"(result)
: "r" (new_val), "m"(*addr), "r"(old) : "memory");
return (bool) result;
}
inline static void
release_set(volatile obj_addr_t *addr, obj_addr_t new_val)
{
__asm__ __volatile__("mb" : : : "memory");
*(addr) = new_val;
}
inline static bool
compare_and_swap_release(volatile obj_addr_t *addr,
obj_addr_t old,
obj_addr_t new_val)
{
return compare_and_swap(addr, old, new_val);
}
// Ensure that subsequent instructions do not execute on stale
// data that was loaded from memory before the barrier.
inline static void
read_barrier()
{
__asm__ __volatile__("mb" : : : "memory");
}
// Ensure that prior stores to memory are completed with respect to other
// processors.
inline static void
write_barrier()
{
__asm__ __volatile__("wmb" : : : "memory");
}
#endif
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