1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
|
/*
* Copyright (C) 2019 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.
*/
#include <procinfo/process_map.h>
#include <fcntl.h>
#include <string.h>
#include <unistd.h>
#include <procinfo/process.h>
namespace android {
namespace procinfo {
bool ReadMapFileAsyncSafe(const char* map_file, void* buffer, size_t buffer_size,
const std::function<void(uint64_t, uint64_t, uint16_t, uint64_t, ino_t,
const char*)>& callback) {
if (buffer == nullptr || buffer_size == 0) {
return false;
}
int fd = open(map_file, O_RDONLY | O_CLOEXEC);
if (fd == -1) {
return false;
}
char* char_buffer = reinterpret_cast<char*>(buffer);
size_t start = 0;
size_t read_bytes = 0;
char* line = nullptr;
bool read_complete = false;
while (true) {
ssize_t bytes =
TEMP_FAILURE_RETRY(read(fd, char_buffer + read_bytes, buffer_size - read_bytes - 1));
if (bytes <= 0) {
if (read_bytes == 0) {
close(fd);
return bytes == 0;
}
// Treat the last piece of data as the last line.
char_buffer[start + read_bytes] = '\n';
bytes = 1;
read_complete = true;
}
read_bytes += bytes;
while (read_bytes > 0) {
char* newline = reinterpret_cast<char*>(memchr(&char_buffer[start], '\n', read_bytes));
if (newline == nullptr) {
break;
}
*newline = '\0';
line = &char_buffer[start];
start = newline - char_buffer + 1;
read_bytes -= newline - line + 1;
// Ignore the return code, errors are okay.
ReadMapFileContent(line, callback);
}
if (read_complete) {
close(fd);
return true;
}
if (start == 0 && read_bytes == buffer_size - 1) {
// The buffer provided is too small to contain this line, give up
// and indicate failure.
close(fd);
return false;
}
// Copy any leftover data to the front of the buffer.
if (start > 0) {
if (read_bytes > 0) {
memmove(char_buffer, &char_buffer[start], read_bytes);
}
start = 0;
}
}
}
} /* namespace procinfo */
} /* namespace android */
|
