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-rw-r--r--atomic/unix/mutex.c206
1 files changed, 206 insertions, 0 deletions
diff --git a/atomic/unix/mutex.c b/atomic/unix/mutex.c
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+++ b/atomic/unix/mutex.c
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+/* 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 */