Refactored Mtp driver interface into multiple classes.
Added new interface for FunctionFS. This allows most of
the driver code to exist in userspace. The driver will
automatically use FunctionFS if it is enabled for that
device, otherwise it will default to the kernel driver.
The intention is to eventually deprecate the kernel driver.
Bug: 30976142
Change-Id: I36b8d16ca254fddd995b3ea1bd3d37b0ff4a28f7
Test: New automated tests for MtpFfsHandle, AsyncIO.
Manual testing on each device.
diff --git a/media/mtp/AsyncIO.h b/media/mtp/AsyncIO.h
new file mode 100644
index 0000000..f7515a2
--- /dev/null
+++ b/media/mtp/AsyncIO.h
@@ -0,0 +1,77 @@
+/*
+ * Copyright (C) 2016 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 _ASYNCIO_H
+#define _ASYNCIO_H
+
+#include <fcntl.h>
+#include <linux/aio_abi.h>
+#include <memory>
+#include <signal.h>
+#include <sys/cdefs.h>
+#include <sys/types.h>
+#include <time.h>
+#include <thread>
+#include <unistd.h>
+
+/**
+ * Provides a subset of POSIX aio operations, as well
+ * as similar operations with splice and threadpools.
+ */
+
+struct aiocb {
+ int aio_fildes; // Assumed to be the source for splices
+ void *aio_buf; // Unused for splices
+
+ // Used for threadpool operations only, freed automatically
+ std::unique_ptr<char[]> aio_pool_buf;
+
+ off_t aio_offset;
+ size_t aio_nbytes;
+
+ int aio_sink; // Unused for non splice r/w
+
+ // Used internally
+ std::thread thread;
+ ssize_t ret;
+ int error;
+};
+
+// Submit a request for IO to be completed
+int aio_read(struct aiocb *);
+int aio_write(struct aiocb *);
+int aio_splice_read(struct aiocb *);
+int aio_splice_write(struct aiocb *);
+
+// Suspend current thread until given IO is complete, at which point
+// its return value and any errors can be accessed
+int aio_suspend(struct aiocb *[], int, const struct timespec *);
+int aio_error(const struct aiocb *);
+ssize_t aio_return(struct aiocb *);
+int aio_cancel(int, struct aiocb *);
+
+// Initialize a threadpool to perform IO. Only one pool can be
+// running at a time.
+void aio_pool_write_init();
+void aio_pool_splice_init();
+// Suspend current thread until all queued work is complete, then ends the threadpool
+void aio_pool_end();
+// Submit IO work for the threadpool to complete. Memory associated with the work is
+// freed automatically when the work is complete.
+int aio_pool_write(struct aiocb *);
+
+#endif // ASYNCIO_H
+