PCL
Mutex.h
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7 // pcl/Mutex.h - Released 2019-11-07T10:59:34Z
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50 // ----------------------------------------------------------------------------
51 
52 #ifndef __PCL_Mutex_h
53 #define __PCL_Mutex_h
54 
56 
57 #include <pcl/Defs.h>
58 #include <pcl/Diagnostics.h>
59 
60 #include <pcl/Utility.h>
61 
62 #ifdef __PCL_UNIX
63 # include <pcl/Atomic.h>
64 # include <stdio.h>
65 # include <pthread.h>
66 #endif
67 
68 #ifdef __PCL_WINDOWS
69 # include <windows.h>
70 #endif
71 
72 namespace pcl
73 {
74 
75 // ----------------------------------------------------------------------------
76 
208 class PCL_CLASS Mutex
209 {
210 public:
211 
222  Mutex( int spin = 512 ) :
223  m_spinCount( Max( 0, spin ) )
224  {
225 #ifdef __PCL_WINDOWS
226  (void)InitializeCriticalSectionAndSpinCount( &criticalSection, DWORD( m_spinCount ) );
227 #else
228  (void)PThreadInitMutex();
229 #endif
230  }
231 
239  virtual ~Mutex()
240  {
241 #ifdef __PCL_WINDOWS
242  DeleteCriticalSection( &criticalSection );
243 #else
244  (void)PThreadDestroyMutex();
245 #endif
246  }
247 
252  Mutex( const Mutex& ) = delete;
253 
258  Mutex& operator =( const Mutex& ) = delete;
259 
279  void Lock()
280  {
281 #ifdef __PCL_WINDOWS
282  EnterCriticalSection( &criticalSection );
283 #else
284  for ( int spin = m_spinCount; ; )
285  {
286  // Is the mutex free? If so, get it now and don't look back!
287  if ( m_lockState.TestAndSet( 0, 1 ) )
288  {
289  (void)PThreadLockMutex();
290  break;
291  }
292 
293  if ( --spin < 0 )
294  {
295  // Either no spinning, or spinned to no avail...
296  // Block thread until we can get this mutex. This is expensive.
297  (void)PThreadLockMutex();
298  m_lockState.Store( 1 );
299  break;
300  }
301  }
302 #endif
303  }
304 
310  void Unlock()
311  {
312 #ifdef __PCL_WINDOWS
313  LeaveCriticalSection( &criticalSection );
314 #else
315  m_lockState.Store( 0 );
316  (void)PThreadUnlockMutex();
317 #endif
318  }
319 
347  void operator ()( bool lock = true )
348  {
349  if ( lock )
350  Lock();
351  else
352  Unlock();
353  }
354 
362  bool TryLock()
363  {
364 #ifdef __PCL_WINDOWS
365  return TryEnterCriticalSection( &criticalSection ) != FALSE;
366 #else
367  // ### N.B.: This code is performance and stability critical. DO NOT
368  // modify it unless you are absolutely sure of what you are doing.
369  return m_lockState == 0 && m_lockState.TestAndSet( 0, 1 ) && PThreadLockMutex();
370 #endif
371  }
372 
380  int SpinCount() const
381  {
382  return m_spinCount;
383  }
384 
385 private:
386 
387 #ifdef __PCL_WINDOWS
388 
389  CRITICAL_SECTION criticalSection;
390 
391 #else // Linux/UNIX
392 
393  AtomicInt m_lockState; // 0=unlocked, 1=acquired
394  pthread_mutex_t m_mutex;
395 
396  bool PThreadInitMutex()
397  {
398  return PThreadCheckError( pthread_mutex_init( &m_mutex, 0 ), "pthread_mutex_init" );
399  }
400 
401  bool PThreadDestroyMutex()
402  {
403  return PThreadCheckError( pthread_mutex_destroy( &m_mutex ), "pthread_mutex_destroy" );
404  }
405 
406  bool PThreadLockMutex()
407  {
408  return PThreadCheckError( pthread_mutex_lock( &m_mutex ), "pthread_mutex_lock" );
409  }
410 
411  bool PThreadUnlockMutex()
412  {
413  return PThreadCheckError( pthread_mutex_unlock( &m_mutex ), "pthread_mutex_unlock" );
414  }
415 
416  static bool PThreadCheckError( int errorCode, const char* funcName )
417  {
418  if ( errorCode == 0 )
419  return true;
420  fprintf( stderr, "%s() failed. Error code: %d\n", funcName, errorCode );
421  return false;
422  }
423 
424 #endif // __PCL_WINDOWS
425 
426  int m_spinCount = 512;
427 };
428 
429 // ----------------------------------------------------------------------------
430 
431 } // pcl
432 
433 #endif // __PCL_Mutex_h
434 
435 // ----------------------------------------------------------------------------
436 // EOF pcl/Mutex.h - Released 2019-11-07T10:59:34Z
Mutex(int spin=512)
Definition: Mutex.h:222
void Lock()
Definition: Mutex.h:279
Adaptive mutual exclusion lock variable.
Definition: Mutex.h:208
Atomic operations on integers.
Definition: Atomic.h:94
PCL root namespace.
Definition: AbstractImage.h:76
virtual ~Mutex()
Definition: Mutex.h:239
constexpr const T & Max(const T &a, const T &b)
Definition: Utility.h:119
bool TryLock()
Definition: Mutex.h:362
int SpinCount() const
Definition: Mutex.h:380
void Unlock()
Definition: Mutex.h:310