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Diffstat (limited to 'atomic/unix/mutex.c')
| -rw-r--r-- | atomic/unix/mutex.c | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/atomic/unix/mutex.c b/atomic/unix/mutex.c new file mode 100644 index 0000000..45bc5e2 --- /dev/null +++ b/atomic/unix/mutex.c @@ -0,0 +1,206 @@ +/* Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include "apr_arch_atomic.h" +#include "apr_thread_mutex.h" + +#ifdef USE_ATOMICS_GENERIC + +#include <stdlib.h> + +#if APR_HAS_THREADS +# define DECLARE_MUTEX_LOCKED(name, mem) \ + apr_thread_mutex_t *name = mutex_hash(mem) +# define MUTEX_UNLOCK(name) \ + do { \ + if (apr_thread_mutex_unlock(name) != APR_SUCCESS) \ + abort(); \ + } while (0) +#else +# define DECLARE_MUTEX_LOCKED(name, mem) +# define MUTEX_UNLOCK(name) +# warning Be warned: using stubs for all atomic operations +#endif + +#if APR_HAS_THREADS + +static apr_thread_mutex_t **hash_mutex; + +#define NUM_ATOMIC_HASH 7 +/* shift by 2 to get rid of alignment issues */ +#define ATOMIC_HASH(x) (unsigned int)(((unsigned long)(x)>>2)%(unsigned int)NUM_ATOMIC_HASH) + +static apr_status_t atomic_cleanup(void *data) +{ + if (hash_mutex == data) + hash_mutex = NULL; + + return APR_SUCCESS; +} + +APR_DECLARE(apr_status_t) apr_atomic_init(apr_pool_t *p) +{ + int i; + apr_status_t rv; + + if (hash_mutex != NULL) + return APR_SUCCESS; + + hash_mutex = apr_palloc(p, sizeof(apr_thread_mutex_t*) * NUM_ATOMIC_HASH); + apr_pool_cleanup_register(p, hash_mutex, atomic_cleanup, + apr_pool_cleanup_null); + + for (i = 0; i < NUM_ATOMIC_HASH; i++) { + rv = apr_thread_mutex_create(&(hash_mutex[i]), + APR_THREAD_MUTEX_DEFAULT, p); + if (rv != APR_SUCCESS) { + return rv; + } + } + + return apr__atomic_generic64_init(p); +} + +static APR_INLINE apr_thread_mutex_t *mutex_hash(volatile apr_uint32_t *mem) +{ + apr_thread_mutex_t *mutex = hash_mutex[ATOMIC_HASH(mem)]; + + if (apr_thread_mutex_lock(mutex) != APR_SUCCESS) { + abort(); + } + + return mutex; +} + +#else + +APR_DECLARE(apr_status_t) apr_atomic_init(apr_pool_t *p) +{ + return apr__atomic_generic64_init(p); +} + +#endif /* APR_HAS_THREADS */ + +APR_DECLARE(apr_uint32_t) apr_atomic_read32(volatile apr_uint32_t *mem) +{ + return *mem; +} + +APR_DECLARE(void) apr_atomic_set32(volatile apr_uint32_t *mem, apr_uint32_t val) +{ + DECLARE_MUTEX_LOCKED(mutex, mem); + + *mem = val; + + MUTEX_UNLOCK(mutex); +} + +APR_DECLARE(apr_uint32_t) apr_atomic_add32(volatile apr_uint32_t *mem, apr_uint32_t val) +{ + apr_uint32_t old_value; + DECLARE_MUTEX_LOCKED(mutex, mem); + + old_value = *mem; + *mem += val; + + MUTEX_UNLOCK(mutex); + + return old_value; +} + +APR_DECLARE(void) apr_atomic_sub32(volatile apr_uint32_t *mem, apr_uint32_t val) +{ + DECLARE_MUTEX_LOCKED(mutex, mem); + *mem -= val; + MUTEX_UNLOCK(mutex); +} + +APR_DECLARE(apr_uint32_t) apr_atomic_inc32(volatile apr_uint32_t *mem) +{ + return apr_atomic_add32(mem, 1); +} + +APR_DECLARE(int) apr_atomic_dec32(volatile apr_uint32_t *mem) +{ + apr_uint32_t new; + DECLARE_MUTEX_LOCKED(mutex, mem); + + (*mem)--; + new = *mem; + + MUTEX_UNLOCK(mutex); + + return new; +} + +APR_DECLARE(apr_uint32_t) apr_atomic_cas32(volatile apr_uint32_t *mem, apr_uint32_t with, + apr_uint32_t cmp) +{ + apr_uint32_t prev; + DECLARE_MUTEX_LOCKED(mutex, mem); + + prev = *mem; + if (prev == cmp) { + *mem = with; + } + + MUTEX_UNLOCK(mutex); + + return prev; +} + +APR_DECLARE(apr_uint32_t) apr_atomic_xchg32(volatile apr_uint32_t *mem, apr_uint32_t val) +{ + apr_uint32_t prev; + DECLARE_MUTEX_LOCKED(mutex, mem); + + prev = *mem; + *mem = val; + + MUTEX_UNLOCK(mutex); + + return prev; +} + +APR_DECLARE(void*) apr_atomic_casptr(volatile void **mem, void *with, const void *cmp) +{ + void *prev; + DECLARE_MUTEX_LOCKED(mutex, *mem); + + prev = *(void **)mem; + if (prev == cmp) { + *mem = with; + } + + MUTEX_UNLOCK(mutex); + + return prev; +} + +APR_DECLARE(void*) apr_atomic_xchgptr(volatile void **mem, void *with) +{ + void *prev; + DECLARE_MUTEX_LOCKED(mutex, *mem); + + prev = *(void **)mem; + *mem = with; + + MUTEX_UNLOCK(mutex); + + return prev; +} + +#endif /* USE_ATOMICS_GENERIC */ |