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Diffstat (limited to '')
-rw-r--r-- | mtp/ffs/AsyncIO.h | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/mtp/ffs/AsyncIO.h b/mtp/ffs/AsyncIO.h new file mode 100644 index 000000000..19e76179c --- /dev/null +++ b/mtp/ffs/AsyncIO.h @@ -0,0 +1,83 @@ +/* + * 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; + + ~aiocb(); +}; + +// 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 +// All submitted requests must have a corresponding suspend. +// aiocb->aio_buf must refer to valid memory until after the suspend call +int aio_suspend(struct aiocb *[], int, const struct timespec *); +int aio_error(const struct aiocb *); +ssize_t aio_return(struct aiocb *); + +// (Currently unimplemented) +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 + |