android.hardware.media.bufferpool@2.0 HAL
BufferPool HAL 2.0. This is identical to 1.0 HAL now.
The update will be applied afterwards.
Bug: 112203066
Change-Id: I8f5bbf979116f66357f2bc0f8114697472adf762
diff --git a/media/bufferpool/2.0/IAccessor.hal b/media/bufferpool/2.0/IAccessor.hal
new file mode 100644
index 0000000..07ea99d
--- /dev/null
+++ b/media/bufferpool/2.0/IAccessor.hal
@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) 2018 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.
+ */
+
+package android.hardware.media.bufferpool@2.0;
+
+import IConnection;
+/**
+ * IAccessor creates IConnection which is used from IClientManager in order to
+ * use functionality of the specified buffer pool.
+ */
+interface IAccessor {
+
+ /**
+ * Registers a new client and creates IConnection to the buffer pool for
+ * the client. IConnection and FMQ are used by IClientManager in order to
+ * communicate with the buffer pool. Via FMQ IClientManager sends
+ * BufferStatusMesage(s) to the buffer pool.
+ *
+ * FMQ is used to send buffer ownership status changes to a buffer pool
+ * from a buffer pool client. A buffer pool synchronizes FMQ messages when
+ * there is a hidl request from the clients. Every client has its own
+ * connection and FMQ to communicate with the buffer pool. So sending an
+ * FMQ message on behalf of other clients is not possible.
+ *
+ * FMQ messages are sent when a buffer is acquired or released. Also, FMQ
+ * messages are sent when a buffer is transferred from a client to another
+ * client. FMQ has its own ID from a buffer pool. A client is specified
+ * with the ID.
+ *
+ * To transfer a buffer, a sender must send an FMQ message. The message
+ * must include a receiver's ID and a transaction ID. A receiver must send
+ * the transaction ID to fetch a buffer from a buffer pool. Since the
+ * sender already registered the receiver via an FMQ message, The buffer
+ * pool must verify the receiver with the transaction ID. In order to
+ * prevent faking a receiver, a connection to a buffer pool from client is
+ * made and kept private. Also part of transaction ID is a sender ID in
+ * order to prevent fake transactions from other clients. This must be
+ * verified with an FMQ message from a buffer pool.
+ *
+ * @return status The status of the call.
+ * OK - A connection is made successfully.
+ * NO_MEMORY - Memory allocation failure occurred.
+ * ALREADY_EXISTS - A connection was already made.
+ * CRITICAL_ERROR - Other errors.
+ * @return connection The IConnection have interfaces
+ * to get shared buffers from the buffer pool.
+ * @return connectionId Id of IConnection. The Id identifies
+ * sender and receiver in FMQ messages during buffer transfer.
+ * @return mqDesc FMQ descriptor. The descriptor can be used to
+ * send/receive FMQ messages.
+ */
+ connect()
+ generates (ResultStatus status, IConnection connection,
+ int64_t connectionId, fmq_sync<BufferStatusMessage> mqDesc);
+};