| // locks.h - Thread synchronization primitives. SuperH 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. */ |
| |
| static unsigned char __cas_lock = 0; |
| |
| inline static void |
| __cas_start_atomic (void) |
| { |
| unsigned int val; |
| |
| do |
| __asm__ __volatile__ ("tas.b @%1; movt %0" |
| : "=r" (val) |
| : "r" (&__cas_lock) |
| : "memory"); |
| while (val == 0); |
| } |
| |
| inline static void |
| __cas_end_atomic (void) |
| { |
| __asm__ __volatile__ (" " : : : "memory"); |
| __cas_lock = 0; |
| } |
| |
| inline static bool |
| compare_and_swap (volatile obj_addr_t *addr, obj_addr_t old, |
| obj_addr_t new_val) |
| { |
| bool ret; |
| |
| __cas_start_atomic (); |
| if (*addr != old) |
| ret = false; |
| else |
| { |
| *addr = new_val; |
| ret = true; |
| } |
| __cas_end_atomic (); |
| |
| return ret; |
| } |
| |
| inline static void |
| release_set (volatile obj_addr_t *addr, obj_addr_t new_val) |
| { |
| __asm__ __volatile__ (" " : : : "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); |
| } |
| |
| #endif /* ! __SYSDEP_LOCKS_H__ */ |