Intel(R) Threading Building Blocks Doxygen Documentation  version 4.2.3
tbb::spin_mutex Class Reference

A lock that occupies a single byte. More...

#include <spin_mutex.h>

Inheritance diagram for tbb::spin_mutex:
Collaboration diagram for tbb::spin_mutex:

Classes

class  scoped_lock
 Represents acquisition of a mutex. More...
 

Public Member Functions

 spin_mutex ()
 Construct unacquired lock. More...
 
void __TBB_EXPORTED_METHOD internal_construct ()
 Internal constructor with ITT instrumentation. More...
 
void lock ()
 Acquire lock. More...
 
bool try_lock ()
 Try acquiring lock (non-blocking) More...
 
void unlock ()
 Release lock. More...
 

Static Public Attributes

static const bool is_rw_mutex = false
 
static const bool is_recursive_mutex = false
 
static const bool is_fair_mutex = false
 

Private Attributes

__TBB_atomic_flag flag
 0 if lock is released, 1 if lock is acquired. More...
 

Friends

class scoped_lock
 

Detailed Description

A lock that occupies a single byte.

A spin_mutex is a spin mutex that fits in a single byte. It should be used only for locking short critical sections (typically less than 20 instructions) when fairness is not an issue. If zero-initialized, the mutex is considered unheld.

Definition at line 36 of file spin_mutex.h.

Constructor & Destructor Documentation

◆ spin_mutex()

tbb::spin_mutex::spin_mutex ( )
inline

Construct unacquired lock.

Equivalent to zero-initialization of *this.

Definition at line 43 of file spin_mutex.h.

References internal_construct().

43  : flag(0) {
44 #if TBB_USE_THREADING_TOOLS
46 #endif
47  }
__TBB_atomic_flag flag
0 if lock is released, 1 if lock is acquired.
Definition: spin_mutex.h:38
void __TBB_EXPORTED_METHOD internal_construct()
Internal constructor with ITT instrumentation.
Definition: spin_mutex.cpp:50
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Member Function Documentation

◆ internal_construct()

void tbb::spin_mutex::internal_construct ( )

Internal constructor with ITT instrumentation.

Definition at line 50 of file spin_mutex.cpp.

References _T, and ITT_SYNC_CREATE.

Referenced by spin_mutex(), and tbb::spin_mutex::scoped_lock::~scoped_lock().

50  {
51  ITT_SYNC_CREATE(this, _T("tbb::spin_mutex"), _T(""));
52 }
#define ITT_SYNC_CREATE(obj, type, name)
Definition: itt_notify.h:119
#define _T(string_literal)
Standard Windows style macro to markup the string literals.
Definition: itt_notify.h:62
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◆ lock()

void tbb::spin_mutex::lock ( )
inline

Acquire lock.

Definition at line 144 of file spin_mutex.h.

References __TBB_LockByte(), tbb::aligned_space< T, N >::begin(), and tbb::spin_mutex::scoped_lock::scoped_lock().

144  {
145 #if TBB_USE_THREADING_TOOLS
146  aligned_space<scoped_lock> tmp;
147  new(tmp.begin()) scoped_lock(*this);
148 #else
150 #endif /* TBB_USE_THREADING_TOOLS*/
151  }
__TBB_atomic_flag flag
0 if lock is released, 1 if lock is acquired.
Definition: spin_mutex.h:38
__TBB_Flag __TBB_LockByte(__TBB_atomic_flag &flag)
Definition: tbb_machine.h:922
friend class scoped_lock
Definition: spin_mutex.h:176
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◆ try_lock()

bool tbb::spin_mutex::try_lock ( )
inline

Try acquiring lock (non-blocking)

Return true if lock acquired; false otherwise.

Definition at line 155 of file spin_mutex.h.

References __TBB_TryLockByte(), and tbb::aligned_space< T, N >::begin().

155  {
156 #if TBB_USE_THREADING_TOOLS
157  aligned_space<scoped_lock> tmp;
158  return (new(tmp.begin()) scoped_lock)->internal_try_acquire(*this);
159 #else
160  return __TBB_TryLockByte(flag);
161 #endif /* TBB_USE_THREADING_TOOLS*/
162  }
bool __TBB_TryLockByte(__TBB_atomic_flag &flag)
Definition: tbb_machine.h:916
__TBB_atomic_flag flag
0 if lock is released, 1 if lock is acquired.
Definition: spin_mutex.h:38
friend class scoped_lock
Definition: spin_mutex.h:176
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◆ unlock()

void tbb::spin_mutex::unlock ( )
inline

Release lock.

Definition at line 165 of file spin_mutex.h.

References __TBB_UnlockByte, tbb::aligned_space< T, N >::begin(), tbb::spin_mutex::scoped_lock::internal_release(), tbb::spin_mutex::scoped_lock::my_mutex, and s.

165  {
166 #if TBB_USE_THREADING_TOOLS
167  aligned_space<scoped_lock> tmp;
168  scoped_lock& s = *tmp.begin();
169  s.my_mutex = this;
170  s.internal_release();
171 #else
173 #endif /* TBB_USE_THREADING_TOOLS */
174  }
void const char const char int ITT_FORMAT __itt_group_sync s
__TBB_atomic_flag flag
0 if lock is released, 1 if lock is acquired.
Definition: spin_mutex.h:38
#define __TBB_UnlockByte
Definition: gcc_generic.h:211
friend class scoped_lock
Definition: spin_mutex.h:176
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Friends And Related Function Documentation

◆ scoped_lock

Member Data Documentation

◆ flag

◆ is_fair_mutex

const bool tbb::spin_mutex::is_fair_mutex = false
static

Definition at line 139 of file spin_mutex.h.

◆ is_recursive_mutex

const bool tbb::spin_mutex::is_recursive_mutex = false
static

Definition at line 138 of file spin_mutex.h.

◆ is_rw_mutex

const bool tbb::spin_mutex::is_rw_mutex = false
static

Definition at line 137 of file spin_mutex.h.


The documentation for this class was generated from the following files:

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