Merge "Fix SharedBuffer. Remove aref."
diff --git a/include/cutils/aref.h b/include/cutils/aref.h
deleted file mode 100644
index 3bd36ea..0000000
--- a/include/cutils/aref.h
+++ /dev/null
@@ -1,58 +0,0 @@
-/*
- * Copyright (C) 2013 The Android Open Source Project
- *
- * Licensed 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 _CUTILS_AREF_H_
-#define _CUTILS_AREF_H_
-
-#include <stddef.h>
-#include <sys/cdefs.h>
-
-#include <cutils/atomic.h>
-
-__BEGIN_DECLS
-
-#define AREF_TO_ITEM(aref, container, member) \
- (container *) (((char*) (aref)) - offsetof(container, member))
-
-struct aref
-{
- volatile int32_t count;
-};
-
-static inline void aref_init(struct aref *r)
-{
- r->count = 1;
-}
-
-static inline int32_t aref_count(struct aref *r)
-{
- return r->count;
-}
-
-static inline void aref_get(struct aref *r)
-{
- android_atomic_inc(&r->count);
-}
-
-static inline void aref_put(struct aref *r, void (*release)(struct aref *))
-{
- if (android_atomic_dec(&r->count) == 1)
- release(r);
-}
-
-__END_DECLS
-
-#endif // _CUTILS_AREF_H_
diff --git a/libutils/SharedBuffer.cpp b/libutils/SharedBuffer.cpp
index c7dd1ab..f3d6d8f 100644
--- a/libutils/SharedBuffer.cpp
+++ b/libutils/SharedBuffer.cpp
@@ -20,7 +20,6 @@
#include <string.h>
#include <log/log.h>
-#include <utils/Atomic.h>
#include "SharedBuffer.h"
@@ -37,18 +36,19 @@
SharedBuffer* sb = static_cast<SharedBuffer *>(malloc(sizeof(SharedBuffer) + size));
if (sb) {
- sb->mRefs = 1;
+ // Should be std::atomic_init(&sb->mRefs, 1);
+ // But that generates a warning with some compilers.
+ // The following is OK on Android-supported platforms.
+ sb->mRefs.store(1, std::memory_order_relaxed);
sb->mSize = size;
}
return sb;
}
-ssize_t SharedBuffer::dealloc(const SharedBuffer* released)
+void SharedBuffer::dealloc(const SharedBuffer* released)
{
- if (released->mRefs != 0) return -1; // XXX: invalid operation
free(const_cast<SharedBuffer*>(released));
- return 0;
}
SharedBuffer* SharedBuffer::edit() const
@@ -108,14 +108,15 @@
}
void SharedBuffer::acquire() const {
- android_atomic_inc(&mRefs);
+ mRefs.fetch_add(1, std::memory_order_relaxed);
}
int32_t SharedBuffer::release(uint32_t flags) const
{
int32_t prev = 1;
- if (onlyOwner() || ((prev = android_atomic_dec(&mRefs)) == 1)) {
- mRefs = 0;
+ if (onlyOwner() || ((prev = mRefs.fetch_sub(1, std::memory_order_release) == 1)
+ && (atomic_thread_fence(std::memory_order_acquire), true))) {
+ mRefs.store(0, std::memory_order_relaxed);
if ((flags & eKeepStorage) == 0) {
free(const_cast<SharedBuffer*>(this));
}
diff --git a/libutils/SharedBuffer.h b/libutils/SharedBuffer.h
index b670953..48358cd 100644
--- a/libutils/SharedBuffer.h
+++ b/libutils/SharedBuffer.h
@@ -14,9 +14,14 @@
* limitations under the License.
*/
+/*
+ * DEPRECATED. DO NOT USE FOR NEW CODE.
+ */
+
#ifndef ANDROID_SHARED_BUFFER_H
#define ANDROID_SHARED_BUFFER_H
+#include <atomic>
#include <stdint.h>
#include <sys/types.h>
@@ -43,7 +48,7 @@
* In other words, the buffer must have been release by all its
* users.
*/
- static ssize_t dealloc(const SharedBuffer* released);
+ static void dealloc(const SharedBuffer* released);
//! access the data for read
inline const void* data() const;
@@ -94,12 +99,16 @@
SharedBuffer(const SharedBuffer&);
SharedBuffer& operator = (const SharedBuffer&);
- // 16 bytes. must be sized to preserve correct alignment.
- mutable int32_t mRefs;
- size_t mSize;
- uint32_t mReserved[2];
+ // Must be sized to preserve correct alignment.
+ mutable std::atomic<int32_t> mRefs;
+ size_t mSize;
+ uint32_t mReserved[2];
};
+static_assert(sizeof(SharedBuffer) % 8 == 0
+ && (sizeof(size_t) > 4 || sizeof(SharedBuffer) == 16),
+ "SharedBuffer has unexpected size");
+
// ---------------------------------------------------------------------------
const void* SharedBuffer::data() const {
@@ -127,7 +136,7 @@
}
bool SharedBuffer::onlyOwner() const {
- return (mRefs == 1);
+ return (mRefs.load(std::memory_order_acquire) == 1);
}
}; // namespace android