MediaWiki  1.28.0
FSLockManager.php
Go to the documentation of this file.
1 <?php
36 class FSLockManager extends LockManager {
38  protected $lockTypeMap = [
39  self::LOCK_SH => self::LOCK_SH,
40  self::LOCK_UW => self::LOCK_SH,
41  self::LOCK_EX => self::LOCK_EX
42  ];
43 
45  protected $lockDir;
46 
48  protected $handles = [];
49 
51  protected $isWindows;
52 
59  function __construct( array $config ) {
60  parent::__construct( $config );
61 
62  $this->lockDir = $config['lockDirectory'];
63  $this->isWindows = ( strtoupper( substr( PHP_OS, 0, 3 ) ) === 'WIN' );
64  }
65 
72  protected function doLock( array $paths, $type ) {
74 
75  $lockedPaths = []; // files locked in this attempt
76  foreach ( $paths as $path ) {
77  $status->merge( $this->doSingleLock( $path, $type ) );
78  if ( $status->isOK() ) {
79  $lockedPaths[] = $path;
80  } else {
81  // Abort and unlock everything
82  $status->merge( $this->doUnlock( $lockedPaths, $type ) );
83 
84  return $status;
85  }
86  }
87 
88  return $status;
89  }
90 
97  protected function doUnlock( array $paths, $type ) {
99 
100  foreach ( $paths as $path ) {
101  $status->merge( $this->doSingleUnlock( $path, $type ) );
102  }
103 
104  return $status;
105  }
106 
114  protected function doSingleLock( $path, $type ) {
116 
117  if ( isset( $this->locksHeld[$path][$type] ) ) {
118  ++$this->locksHeld[$path][$type];
119  } elseif ( isset( $this->locksHeld[$path][self::LOCK_EX] ) ) {
120  $this->locksHeld[$path][$type] = 1;
121  } else {
122  if ( isset( $this->handles[$path] ) ) {
123  $handle = $this->handles[$path];
124  } else {
125  MediaWiki\suppressWarnings();
126  $handle = fopen( $this->getLockPath( $path ), 'a+' );
127  if ( !$handle ) { // lock dir missing?
128  mkdir( $this->lockDir, 0777, true );
129  $handle = fopen( $this->getLockPath( $path ), 'a+' ); // try again
130  }
131  MediaWiki\restoreWarnings();
132  }
133  if ( $handle ) {
134  // Either a shared or exclusive lock
135  $lock = ( $type == self::LOCK_SH ) ? LOCK_SH : LOCK_EX;
136  if ( flock( $handle, $lock | LOCK_NB ) ) {
137  // Record this lock as active
138  $this->locksHeld[$path][$type] = 1;
139  $this->handles[$path] = $handle;
140  } else {
141  fclose( $handle );
142  $status->fatal( 'lockmanager-fail-acquirelock', $path );
143  }
144  } else {
145  $status->fatal( 'lockmanager-fail-openlock', $path );
146  }
147  }
148 
149  return $status;
150  }
151 
159  protected function doSingleUnlock( $path, $type ) {
161 
162  if ( !isset( $this->locksHeld[$path] ) ) {
163  $status->warning( 'lockmanager-notlocked', $path );
164  } elseif ( !isset( $this->locksHeld[$path][$type] ) ) {
165  $status->warning( 'lockmanager-notlocked', $path );
166  } else {
167  $handlesToClose = [];
168  --$this->locksHeld[$path][$type];
169  if ( $this->locksHeld[$path][$type] <= 0 ) {
170  unset( $this->locksHeld[$path][$type] );
171  }
172  if ( !count( $this->locksHeld[$path] ) ) {
173  unset( $this->locksHeld[$path] ); // no locks on this path
174  if ( isset( $this->handles[$path] ) ) {
175  $handlesToClose[] = $this->handles[$path];
176  unset( $this->handles[$path] );
177  }
178  }
179  // Unlock handles to release locks and delete
180  // any lock files that end up with no locks on them...
181  if ( $this->isWindows ) {
182  // Windows: for any process, including this one,
183  // calling unlink() on a locked file will fail
184  $status->merge( $this->closeLockHandles( $path, $handlesToClose ) );
185  $status->merge( $this->pruneKeyLockFiles( $path ) );
186  } else {
187  // Unix: unlink() can be used on files currently open by this
188  // process and we must do so in order to avoid race conditions
189  $status->merge( $this->pruneKeyLockFiles( $path ) );
190  $status->merge( $this->closeLockHandles( $path, $handlesToClose ) );
191  }
192  }
193 
194  return $status;
195  }
196 
202  private function closeLockHandles( $path, array $handlesToClose ) {
204  foreach ( $handlesToClose as $handle ) {
205  if ( !flock( $handle, LOCK_UN ) ) {
206  $status->fatal( 'lockmanager-fail-releaselock', $path );
207  }
208  if ( !fclose( $handle ) ) {
209  $status->warning( 'lockmanager-fail-closelock', $path );
210  }
211  }
212 
213  return $status;
214  }
215 
220  private function pruneKeyLockFiles( $path ) {
222  if ( !isset( $this->locksHeld[$path] ) ) {
223  # No locks are held for the lock file anymore
224  if ( !unlink( $this->getLockPath( $path ) ) ) {
225  $status->warning( 'lockmanager-fail-deletelock', $path );
226  }
227  unset( $this->handles[$path] );
228  }
229 
230  return $status;
231  }
232 
238  protected function getLockPath( $path ) {
239  return "{$this->lockDir}/{$this->sha1Base36Absolute( $path )}.lock";
240  }
241 
245  function __destruct() {
246  while ( count( $this->locksHeld ) ) {
247  foreach ( $this->locksHeld as $path => $locks ) {
248  $this->doSingleUnlock( $path, self::LOCK_EX );
249  $this->doSingleUnlock( $path, self::LOCK_SH );
250  }
251  }
252  }
253 }
the array() calling protocol came about after MediaWiki 1.4rc1.
pruneKeyLockFiles($path)
closeLockHandles($path, array $handlesToClose)
__construct(array $config)
Construct a new instance from configuration.
getLockPath($path)
Get the path to the lock file for a key.
array $lockTypeMap
Mapping of lock types to the type actually used.
const LOCK_EX
Definition: LockManager.php:70
__destruct()
Make sure remaining locks get cleared for sanity.
string $lockDir
Global dir for all servers.
const LOCK_SH
Lock types; stronger locks have higher values.
Definition: LockManager.php:68
static newGood($value=null)
Factory function for good results.
Definition: StatusValue.php:76
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Definition: distributors.txt:9
injection txt This is an overview of how MediaWiki makes use of dependency injection The design described here grew from the discussion of RFC T384 The term dependency this means that anything an object needs to operate should be injected from the the object itself should only know narrow no concrete implementation of the logic it relies on The requirement to inject everything typically results in an architecture that based on two main types of and essentially stateless service objects that use other service objects to operate on the value objects As of the beginning MediaWiki is only starting to use the DI approach Much of the code still relies on global state or direct resulting in a highly cyclical dependency which acts as the top level factory for services in MediaWiki which can be used to gain access to default instances of various services MediaWikiServices however also allows new services to be defined and default services to be redefined Services are defined or redefined by providing a callback the instantiator that will return a new instance of the service When it will create an instance of MediaWikiServices and populate it with the services defined in the files listed by thereby bootstrapping the DI framework Per $wgServiceWiringFiles lists includes ServiceWiring php
Definition: injection.txt:35
doUnlock(array $paths, $type)
Class for handling resource locking.
Definition: LockManager.php:47
doSingleUnlock($path, $type)
Unlock a single resource key.
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Definition: hooks.txt:1046
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Definition: hooks.txt:2491
Simple version of LockManager based on using FS lock files.
doLock(array $paths, $type)
doSingleLock($path, $type)
Lock a single resource key.
array $handles
Map of (locked key => lock file handle)