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1 /*
2  * Copyright (C) 2016 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef _POSIXASYNCIO_H
18 #define _POSIXASYNCIO_H
19 
20 #include <condition_variable>
21 #include <mutex>
22 #include <sys/cdefs.h>
23 #include <sys/types.h>
24 #include <time.h>
25 #include <unistd.h>
26 
27 /**
28  * Provides a subset of POSIX aio operations.
29  */
30 
31 struct aiocb {
32     int aio_fildes;
33     void *aio_buf;
34 
35     off_t aio_offset;
36     size_t aio_nbytes;
37 
38     // Used internally
39     bool read;
40     bool queued;
41     ssize_t ret;
42     int error;
43 
44     std::mutex lock;
45     std::condition_variable cv;
46 
47     aiocb();
48     ~aiocb();
49 };
50 
51 // Submit a request for IO to be completed
52 int aio_read(struct aiocb *);
53 int aio_write(struct aiocb *);
54 
55 // Suspend current thread until given IO is complete, at which point
56 // its return value and any errors can be accessed
57 // All submitted requests must have a corresponding suspend.
58 // aiocb->aio_buf must refer to valid memory until after the suspend call
59 int aio_suspend(struct aiocb *[], int, const struct timespec *);
60 int aio_error(const struct aiocb *);
61 ssize_t aio_return(struct aiocb *);
62 
63 // Helper method for setting aiocb members
64 void aio_prepare(struct aiocb *, void*, size_t, off_t);
65 
66 #endif // POSIXASYNCIO_H
67 
68