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Posted to commits@apr.apache.org by da...@apache.org on 2007/07/04 20:17:22 UTC

svn commit: r553289 - in /apr/apr/trunk: atomic/unix/apr_atomic.c atomic/unix/mutex.c configure.in include/arch/unix/apr_arch_atomic.h

Author: davi
Date: Wed Jul  4 11:17:21 2007
New Revision: 553289

URL: http://svn.apache.org/viewvc?view=rev&rev=553289
Log:
This patch tries to address some of the apr_atomic problems by reorganizing
the various backends. The generic implementation is used when no specialized
implementation fits the defined criterias, or when the user forces the choice.

PR: 42806

Added:
    apr/apr/trunk/atomic/unix/mutex.c
    apr/apr/trunk/include/arch/unix/apr_arch_atomic.h
Removed:
    apr/apr/trunk/atomic/unix/apr_atomic.c
Modified:
    apr/apr/trunk/configure.in

Added: apr/apr/trunk/atomic/unix/mutex.c
URL: http://svn.apache.org/viewvc/apr/apr/trunk/atomic/unix/mutex.c?view=auto&rev=553289
==============================================================================
--- apr/apr/trunk/atomic/unix/mutex.c (added)
+++ apr/apr/trunk/atomic/unix/mutex.c Wed Jul  4 11:17:21 2007
@@ -0,0 +1,192 @@
+/* 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"
+
+#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_SUCCESS;
+}
+
+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_SUCCESS;
+}
+
+#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;
+}
+
+#endif /* USE_ATOMICS_GENERIC */

Modified: apr/apr/trunk/configure.in
URL: http://svn.apache.org/viewvc/apr/apr/trunk/configure.in?view=diff&rev=553289&r1=553288&r2=553289
==============================================================================
--- apr/apr/trunk/configure.in (original)
+++ apr/apr/trunk/configure.in Wed Jul  4 11:17:21 2007
@@ -495,7 +495,7 @@
 ])
 
 if test $force_generic_atomics = yes; then
-   AC_DEFINE([USE_GENERIC_ATOMICS], 1,
+   AC_DEFINE([USE_ATOMICS_GENERIC], 1,
              [Define if use of generic atomics is requested])
 fi
 

Added: apr/apr/trunk/include/arch/unix/apr_arch_atomic.h
URL: http://svn.apache.org/viewvc/apr/apr/trunk/include/arch/unix/apr_arch_atomic.h?view=auto&rev=553289
==============================================================================
--- apr/apr/trunk/include/arch/unix/apr_arch_atomic.h (added)
+++ apr/apr/trunk/include/arch/unix/apr_arch_atomic.h Wed Jul  4 11:17:21 2007
@@ -0,0 +1,35 @@
+/* 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.
+ */
+
+#ifndef ATOMIC_H
+#define ATOMIC_H
+
+#include "apr.h"
+#include "apr_private.h"
+#include "apr_atomic.h"
+#include "apr_thread_mutex.h"
+
+#if defined(USE_ATOMICS_GENERIC)
+/* noop */
+#elif defined(__GNUC__) && defined(__STRICT_ANSI__)
+/* force use of generic atomics if building e.g. with -std=c89, which
+ * doesn't allow inline asm */
+#   define USE_ATOMICS_GENERIC
+#else
+#   define USE_ATOMICS_GENERIC
+#endif
+
+#endif /* ATOMIC_H */