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Diffstat (limited to 'erts/include/internal/sparc32/spinlock.h')
-rw-r--r-- | erts/include/internal/sparc32/spinlock.h | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/erts/include/internal/sparc32/spinlock.h b/erts/include/internal/sparc32/spinlock.h new file mode 100644 index 0000000000..b4fe48b714 --- /dev/null +++ b/erts/include/internal/sparc32/spinlock.h @@ -0,0 +1,81 @@ +/* + * %CopyrightBegin% + * + * Copyright Ericsson AB 2005-2009. All Rights Reserved. + * + * The contents of this file are subject to the Erlang Public License, + * Version 1.1, (the "License"); you may not use this file except in + * compliance with the License. You should have received a copy of the + * Erlang Public License along with this software. If not, it can be + * retrieved online at http://www.erlang.org/. + * + * Software distributed under the License is distributed on an "AS IS" + * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See + * the License for the specific language governing rights and limitations + * under the License. + * + * %CopyrightEnd% + */ + +/* + * Native ethread spinlocks on SPARC V9. + * Author: Mikael Pettersson. + */ +#ifndef ETHR_SPARC32_SPINLOCK_H +#define ETHR_SPARC32_SPINLOCK_H + +/* Locked with ldstub, so unlocked when 0 and locked when non-zero. */ +typedef struct { + volatile unsigned char lock; +} ethr_native_spinlock_t; + +#ifdef ETHR_TRY_INLINE_FUNCS + +static ETHR_INLINE void +ethr_native_spinlock_init(ethr_native_spinlock_t *lock) +{ + lock->lock = 0; +} + +static ETHR_INLINE void +ethr_native_spin_unlock(ethr_native_spinlock_t *lock) +{ + __asm__ __volatile__("membar #LoadStore|#StoreStore"); + lock->lock = 0; +} + +static ETHR_INLINE int +ethr_native_spin_trylock(ethr_native_spinlock_t *lock) +{ + unsigned int prev; + + __asm__ __volatile__( + "ldstub [%1], %0\n\t" + "membar #StoreLoad|#StoreStore" + : "=r"(prev) + : "r"(&lock->lock) + : "memory"); + return prev == 0; +} + +static ETHR_INLINE int +ethr_native_spin_is_locked(ethr_native_spinlock_t *lock) +{ + return lock->lock != 0; +} + +static ETHR_INLINE void +ethr_native_spin_lock(ethr_native_spinlock_t *lock) +{ + for(;;) { + if (__builtin_expect(ethr_native_spin_trylock(lock) != 0, 1)) + break; + do { + __asm__ __volatile__("membar #LoadLoad"); + } while (ethr_native_spin_is_locked(lock)); + } +} + +#endif /* ETHR_TRY_INLINE_FUNCS */ + +#endif /* ETHR_SPARC32_SPINLOCK_H */ |