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 #include <android-base/logging.h>
18 #include <condition_variable>
19 #include <memory>
20 #include <mutex>
21 #include <queue>
22 #include <unistd.h>
23 
24 #include "PosixAsyncIO.h"
25 
26 namespace {
27 
read_func(struct aiocb * aiocbp)28 void read_func(struct aiocb *aiocbp) {
29     aiocbp->ret = TEMP_FAILURE_RETRY(pread(aiocbp->aio_fildes,
30                 aiocbp->aio_buf, aiocbp->aio_nbytes, aiocbp->aio_offset));
31     if (aiocbp->ret == -1) aiocbp->error = errno;
32 }
33 
write_func(struct aiocb * aiocbp)34 void write_func(struct aiocb *aiocbp) {
35     aiocbp->ret = TEMP_FAILURE_RETRY(pwrite(aiocbp->aio_fildes,
36                 aiocbp->aio_buf, aiocbp->aio_nbytes, aiocbp->aio_offset));
37     if (aiocbp->ret == -1) aiocbp->error = errno;
38 }
39 
40 } // end anonymous namespace
41 
~aiocb()42 aiocb::~aiocb() {
43     CHECK(!thread.joinable());
44 }
45 
aio_read(struct aiocb * aiocbp)46 int aio_read(struct aiocb *aiocbp) {
47     aiocbp->thread = std::thread(read_func, aiocbp);
48     return 0;
49 }
50 
aio_write(struct aiocb * aiocbp)51 int aio_write(struct aiocb *aiocbp) {
52     aiocbp->thread = std::thread(write_func, aiocbp);
53     return 0;
54 }
55 
aio_error(const struct aiocb * aiocbp)56 int aio_error(const struct aiocb *aiocbp) {
57     return aiocbp->error;
58 }
59 
aio_return(struct aiocb * aiocbp)60 ssize_t aio_return(struct aiocb *aiocbp) {
61     return aiocbp->ret;
62 }
63 
aio_suspend(struct aiocb * aiocbp[],int n,const struct timespec *)64 int aio_suspend(struct aiocb *aiocbp[], int n,
65         const struct timespec *) {
66     for (int i = 0; i < n; i++) {
67         aiocbp[i]->thread.join();
68     }
69     return 0;
70 }
71 
aio_prepare(struct aiocb * aiocbp,void * buf,size_t count,off_t offset)72 void aio_prepare(struct aiocb *aiocbp, void* buf, size_t count, off_t offset) {
73     aiocbp->aio_buf = buf;
74     aiocbp->aio_offset = offset;
75     aiocbp->aio_nbytes = count;
76 }
77