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Diffstat (limited to 'include/exec/spinlock.h')
| -rw-r--r-- | include/exec/spinlock.h | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/include/exec/spinlock.h b/include/exec/spinlock.h new file mode 100644 index 0000000000..a72edda1d2 --- /dev/null +++ b/include/exec/spinlock.h @@ -0,0 +1,49 @@ +/* + * Copyright (c) 2003 Fabrice Bellard + * + * This 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 of the License, or (at your option) any later version. + * + * This 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 this library; if not, see <http://www.gnu.org/licenses/> + */ + +/* configure guarantees us that we have pthreads on any host except + * mingw32, which doesn't support any of the user-only targets. + * So we can simply assume we have pthread mutexes here. + */ +#if defined(CONFIG_USER_ONLY) + +#include <pthread.h> +#define spin_lock pthread_mutex_lock +#define spin_unlock pthread_mutex_unlock +#define spinlock_t pthread_mutex_t +#define SPIN_LOCK_UNLOCKED PTHREAD_MUTEX_INITIALIZER + +#else + +/* Empty implementations, on the theory that system mode emulation + * is single-threaded. This means that these functions should only + * be used from code run in the TCG cpu thread, and cannot protect + * data structures which might also be accessed from the IO thread + * or from signal handlers. + */ +typedef int spinlock_t; +#define SPIN_LOCK_UNLOCKED 0 + +static inline void spin_lock(spinlock_t *lock) +{ +} + +static inline void spin_unlock(spinlock_t *lock) +{ +} + +#endif |