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
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
|
//===- Unix/MappedFile.cpp - Unix MappedFile Implementation -----*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file provides the generic Unix implementation of the MappedFile concept.
//
//===----------------------------------------------------------------------===//
//===----------------------------------------------------------------------===//
//=== WARNING: Implementation here must contain only generic UNIX code that
//=== is guaranteed to work on *all* UNIX variants.
//===----------------------------------------------------------------------===//
#include "Unix.h"
#include "llvm/System/Process.h"
#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif
#ifdef HAVE_SYS_MMAN_H
#include <sys/mman.h>
#endif
#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
using namespace llvm;
using namespace sys;
namespace llvm {
namespace sys {
struct MappedFileInfo {
int FD;
off_t Size;
};
}
}
bool MappedFile::initialize(std::string* ErrMsg) {
int mode = 0;
if (Options & READ_ACCESS)
if (Options & WRITE_ACCESS)
mode = O_RDWR;
else
mode = O_RDONLY;
else if (Options & WRITE_ACCESS)
mode = O_WRONLY;
int FD = ::open(Path.c_str(), mode);
if (FD < 0) {
MakeErrMsg(ErrMsg, "can't open file '" + Path.toString() + "'");
return true;
}
const FileStatus *Status = Path.getFileStatus(false, ErrMsg);
if (!Status) {
::close(FD);
return true;
}
MapInfo = new MappedFileInfo();
MapInfo->FD = FD;
MapInfo->Size = Status->getSize();
return false;
}
void MappedFile::terminate() {
assert(MapInfo && "MappedFile not initialized");
::close(MapInfo->FD);
delete MapInfo;
MapInfo = 0;
}
void MappedFile::unmap() {
assert(MapInfo && "MappedFile not initialized");
if (!isMapped()) return;
if (Options & WRITE_ACCESS)
::msync(BasePtr, MapInfo->Size, MS_SYNC);
::munmap(BasePtr, MapInfo->Size);
BasePtr = 0; // Mark this as non-mapped.
}
void* MappedFile::map(std::string* ErrMsg) {
assert(MapInfo && "MappedFile not initialized");
if (isMapped()) return BasePtr;
int prot = PROT_NONE;
int flags = 0;
#ifdef MAP_FILE
flags |= MAP_FILE;
#endif
if (Options == 0) {
prot = PROT_READ;
flags = MAP_PRIVATE;
} else {
if (Options & READ_ACCESS)
prot |= PROT_READ;
if (Options & WRITE_ACCESS)
prot |= PROT_WRITE;
if (Options & EXEC_ACCESS)
prot |= PROT_EXEC;
if (Options & SHARED_MAPPING)
flags |= MAP_SHARED;
else
flags |= MAP_PRIVATE;
}
size_t map_size = ((MapInfo->Size / Process::GetPageSize())+1) *
Process::GetPageSize();
BasePtr = ::mmap(0, map_size, prot, flags, MapInfo->FD, 0);
if (BasePtr == MAP_FAILED) {
MakeErrMsg(ErrMsg, "Can't map file:" + Path.toString());
return 0;
}
return BasePtr;
}
size_t MappedFile::size() const {
assert(MapInfo && "MappedFile not initialized");
return MapInfo->Size;
}
bool MappedFile::resize(size_t new_size, std::string* ErrMsg) {
assert(MapInfo && "MappedFile not initialized");
// Take the mapping out of memory
unmap();
// Adjust the current size to a page boundary
size_t cur_size = ((MapInfo->Size / Process::GetPageSize())+1) *
Process::GetPageSize();
// Adjust the new_size to a page boundary
new_size = ((new_size / Process::GetPageSize())+1) *
Process::GetPageSize();
// If the file needs to be extended
if (new_size > cur_size) {
// Ensure we can allocate at least the idodes necessary to handle the
// file size requested.
if ((off_t)-1 == ::lseek(MapInfo->FD, new_size, SEEK_SET))
return MakeErrMsg(ErrMsg, "Can't lseek: ");
if (-1 == ::write(MapInfo->FD, "\0", 1))
return MakeErrMsg(ErrMsg, "Can't write: ");
}
// Put the mapping back into memory.
return map(ErrMsg);
}
|
