Merge Android R (rvc-dev-plus-aosp-without-vendor@6692709)

Bug: 166295507
Merged-In: I3d92a6de21a938f6b352ec26dc23420c0fe02b27
Change-Id: Ifdb80563ef042738778ebb8a7581a97c4e3d96e2

1 files changed, 83 insertions, 0 deletions

diff --git a/libs/hwui/jni/android_nio_utils.h b/libs/hwui/jni/android_nio_utils.h
new file mode 100644
index 000000000000..4760d9ca8107
--- /dev/null
+++ b/libs/hwui/jni/android_nio_utils.h
@@ -0,0 +1,83 @@
+/*
+ * Copyright (C) 2008 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 _ANDROID_NIO_UTILS_H_
+#define _ANDROID_NIO_UTILS_H_
+
+#include <jni.h>
+
+#include <cstddef>
+
+namespace android {
+
+/**
+ * Class providing scoped access to the memory backing a java.nio.Buffer instance.
+ *
+ * Instances of this class should only be allocated on the stack as heap allocation is not
+ * supported.
+ *
+ * Instances of this class do not create any global references for performance reasons.
+ */
+class AutoBufferPointer final {
+public:
+    /** Constructor for an AutoBufferPointer instance.
+     *
+     * @param env          The current JNI env
+     * @param nioBuffer    Instance of a java.nio.Buffer whose memory will be accessed.
+     * @param commit       JNI_TRUE if the underlying memory will be updated and should be
+     *                     copied back to the managed heap. JNI_FALSE if the data will
+     *                     not be modified or the modifications may be discarded.
+     *
+     * The commit parameter is only applicable if the buffer is backed by a managed heap
+     * array and the runtime had to provide a copy of the data rather than the original data.
+     */
+    AutoBufferPointer(JNIEnv* env, jobject nioBuffer, jboolean commit);
+
+    /** Destructor for an AutoBufferPointer instance.
+     *
+     * Releases critical managed heap array pointer if acquired.
+     */
+    ~AutoBufferPointer();
+
+    /**
+     * Returns a pointer to the current position of the buffer provided to the constructor.  This
+     * pointer is only valid whilst the AutoBufferPointer instance remains in scope.
+     */
+    void* pointer() const { return fPointer; }
+
+private:
+    JNIEnv* const fEnv;
+    void* fPointer;   // Pointer to current buffer position when constructed.
+    void* fElements;  // Pointer to array element 0 (null if buffer is direct, may be
+                      // within fArray or point to a copy of the array).
+    jarray fArray;    // Pointer to array on managed heap.
+    const jboolean fCommit;  // Flag to commit data to source (when fElements is a copy of fArray).
+
+    // Unsupported constructors and operators.
+    AutoBufferPointer() = delete;
+    AutoBufferPointer(AutoBufferPointer&) = delete;
+    AutoBufferPointer& operator=(AutoBufferPointer&) = delete;
+    static void* operator new(size_t);
+    static void* operator new[](size_t);
+    static void* operator new(size_t, void*);
+    static void* operator new[](size_t, void*);
+    static void operator delete(void*, size_t);
+    static void operator delete[](void*, size_t);
+};
+
+}   /* namespace android */
+
+#endif  // _ANDROID_NIO_UTILS_H_