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
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
|
//file_allocator.h
/* Copyright 2009 10gen Inc.
*
* 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 "../stdafx.h"
#include <fcntl.h>
#include <errno.h>
#if defined(__freebsd__)
#include <sys/stat.h>
#endif
#ifndef O_NOATIME
#define O_NOATIME 0
#endif
namespace mongo {
/* Handles allocation of contiguous files on disk. Allocation may be
requested asynchronously or synchronously.
*/
class FileAllocator {
/* The public functions may not be called concurrently. The allocation
functions may be called multiple times per file, but only the first
size specified per file will be used.
*/
public:
#if !defined(_WIN32)
FileAllocator() : failed_() {}
#endif
void start() {
#if !defined(_WIN32)
Runner r( *this );
boost::thread t( r );
#endif
}
// May be called if file exists. If file exists, or its allocation has
// been requested, size is updated to match existing file size.
void requestAllocation( const string &name, long &size ) {
#if !defined(_WIN32)
boostlock lk( pendingMutex_ );
long oldSize = prevSize( name );
if ( oldSize != -1 ) {
size = oldSize;
return;
}
pending_.push_back( name );
pendingSize_[ name ] = size;
pendingUpdated_.notify_all();
#endif
}
// Returns when file has been allocated. If file exists, size is
// updated to match existing file size.
void allocateAsap( const string &name, long &size ) {
#if !defined(_WIN32)
boostlock lk( pendingMutex_ );
long oldSize = prevSize( name );
if ( oldSize != -1 ) {
size = oldSize;
if ( !inProgress( name ) )
return;
}
pendingSize_[ name ] = size;
if ( pending_.size() == 0 )
pending_.push_back( name );
else if ( pending_.front() != name ) {
pending_.remove( name );
list< string >::iterator i = pending_.begin();
++i;
pending_.insert( i, name );
}
pendingUpdated_.notify_all();
while( inProgress( name ) )
pendingUpdated_.wait( lk );
#endif
}
void waitUntilFinished() const {
#if !defined(_WIN32)
if ( failed_ )
return;
boostlock lk( pendingMutex_ );
while( pending_.size() != 0 )
pendingUpdated_.wait( lk );
#endif
}
private:
#if !defined(_WIN32)
// caller must hold pendingMutex_ lock. Returns size if allocated or
// allocation requested, -1 otherwise.
long prevSize( const string &name ) const {
if ( pendingSize_.count( name ) > 0 )
return pendingSize_[ name ];
if ( boost::filesystem::exists( name ) )
return boost::filesystem::file_size( name );
return -1;
}
// caller must hold pendingMutex_ lock.
bool inProgress( const string &name ) const {
for( list< string >::const_iterator i = pending_.begin(); i != pending_.end(); ++i )
if ( *i == name )
return true;
return false;
}
mutable boost::mutex pendingMutex_;
mutable boost::condition pendingUpdated_;
list< string > pending_;
mutable map< string, long > pendingSize_;
bool failed_;
struct Runner {
Runner( FileAllocator &allocator ) : a_( allocator ) {}
FileAllocator &a_;
void operator()() {
while( 1 ) {
{
boostlock lk( a_.pendingMutex_ );
if ( a_.pending_.size() == 0 )
a_.pendingUpdated_.wait( lk );
}
while( 1 ) {
string name;
long size;
{
boostlock lk( a_.pendingMutex_ );
if ( a_.pending_.size() == 0 )
break;
name = a_.pending_.front();
size = a_.pendingSize_[ name ];
}
try {
long fd = open(name.c_str(), O_CREAT | O_RDWR | O_NOATIME, S_IRUSR | S_IWUSR);
if ( fd <= 0 ) {
stringstream ss;
ss << "couldn't open " << name << ' ' << errno;
massert( ss.str(), fd <= 0 );
}
#if defined(POSIX_FADV_DONTNEED)
if( posix_fadvise(fd, 0, size, POSIX_FADV_DONTNEED) ) {
log() << "warning: posix_fadvise fails " << name << ' ' << errno << endl;
}
#endif
/* make sure the file is the full desired length */
off_t filelen = lseek(fd, 0, SEEK_END);
if ( filelen < size ) {
massert( "failure creating new datafile", filelen == 0 );
// Check for end of disk.
massert( "Unable to allocate file of desired size",
size - 1 == lseek(fd, size - 1, SEEK_SET) );
massert( "Unable to allocate file of desired size",
1 == write(fd, "", 1) );
lseek(fd, 0, SEEK_SET);
log() << "allocating new datafile " << name << ", filling with zeroes..." << endl;
Timer t;
long z = 256 * 1024;
char buf[z];
memset(buf, 0, z);
long left = size;
while ( 1 ) {
if ( left <= z ) {
massert( "write failed", left == write(fd, buf, left) );
break;
}
massert( "write failed", z == write(fd, buf, z) );
left -= z;
}
log() << "done allocating datafile " << name << ", size: " << size/1024/1024 << "MB, took " << ((double)t.millis())/1000.0 << " secs" << endl;
}
close( fd );
} catch ( ... ) {
problem() << "Failed to allocate new file: " << name
<< ", size: " << size << ", aborting." << endl;
try {
BOOST_CHECK_EXCEPTION( boost::filesystem::remove( name ) );
} catch ( ... ) {
}
a_.failed_ = true;
dbexit( EXIT_FS );
}
{
boostlock lk( a_.pendingMutex_ );
a_.pendingSize_.erase( name );
a_.pending_.pop_front();
a_.pendingUpdated_.notify_all();
}
}
}
}
};
#endif
};
FileAllocator &theFileAllocator();
} // namespace mongo
|
