PTimedMutex Class Reference

This class defines a thread mutual exclusion object. More...

#include <mutex.h>

Inheritance diagram for PTimedMutex:

Collaboration diagram for PTimedMutex:

Public Types
enum	DeadlockStackWalkModes { DeadlockStackWalkDisabled, DeadlockStackWalkEnabled, DeadlockStackWalkOnPhantomRelease, DeadlockStackWalkNoSymbols }
Public Types inherited from PObject
enum	Comparison { LessThan = -1, EqualTo = 0, GreaterThan = 1 }
	Result of the comparison operation performed by the Compare() function. More...

Public Member Functions
	PTimedMutex ()
	PTimedMutex (const PDebugLocation &location, unsigned timeout=0)
	PTimedMutex (const PTimedMutex &mutex)
	Copy constructor is allowed but does not copy, allocating a new mutex. More...
PTimedMutex &	operator= (const PTimedMutex &)
	Assignment operator is allowed but does nothing. More...
	~PTimedMutex ()
	Destruction. More...
virtual void	Wait ()
	Block until the synchronisation object is available. More...
virtual PBoolean	Wait (const PTimeInterval &timeout)
	Block, for a time, until the synchronisation object is available. More...
virtual void	Signal ()
	Signal that the synchronisation object is available. More...
PINLINE bool	Try ()
	Try to enter the critical section for exlusive access. More...
virtual void	PrintOn (ostream &strm) const
	Output the contents of the object to the stream. More...
Public Member Functions inherited from PSync
	PSync ()
virtual bool	InstrumentedWait (const PTimeInterval &timeout, const PDebugLocation &)
	As for Wait() but with location of call for instrumentation. Mostly used internally. More...
virtual void	InstrumentedSignal (const PDebugLocation &)
	As for Signal() but with location of call for instrumentation. Mostly used internally. More...
Public Member Functions inherited from PObject
__inline unsigned	GetTraceContextIdentifier () const
	Get PTRACE context identifier. More...
__inline void	SetTraceContextIdentifier (unsigned id)
__inline void	SetTraceContextIdentifier (const PObject &obj)
__inline void	SetTraceContextIdentifier (const PObject *obj)
__inline void	CopyTraceContextIdentifier (PObject &obj) const
__inline void	CopyTraceContextIdentifier (PObject *obj) const
virtual	~PObject ()
__inline const char *	GetClass () const
__inline bool	IsClass (const char *name) const
__inline const PObject *	PTraceObjectInstance () const
virtual PObject *	Clone () const
	Create a copy of the class on the heap. More...
template<class CLS >
CLS *	CloneAs () const
	As for Clone() but converts to specified type. More...
virtual PINDEX	HashFunction () const
	This function yields a hash value required by the PDictionary class. More...
virtual Comparison	Compare (const PObject &obj) const
	Compare the two objects and return their relative rank. More...
virtual Comparison	CompareObjectMemoryDirect (const PObject &obj) const
	Determine the byte wise comparison of two objects. More...
bool	operator== (const PObject &obj) const
	Compare the two objects. More...
bool	operator!= (const PObject &obj) const
	Compare the two objects. More...
bool	operator< (const PObject &obj) const
	Compare the two objects. More...
bool	operator> (const PObject &obj) const
	Compare the two objects. More...
bool	operator<= (const PObject &obj) const
	Compare the two objects. More...
bool	operator>= (const PObject &obj) const
	Compare the two objects. More...
virtual void	ReadFrom (istream &strm)
	Input the contents of the object from the stream. More...
Public Member Functions inherited from PMutexExcessiveLockInfo
void	SetLocationName (const char *name)

Static Public Attributes
static unsigned	ExcessiveLockWaitTime
static DeadlockStackWalkModes	DeadlockStackWalkMode

Protected Member Functions
void	Construct ()
void	PlatformConstruct ()
bool	PlatformWait (const PTimeInterval &timeout)
void	PlatformSignal (const PDebugLocation *location)
void	InternalWait (const PDebugLocation *location)
void	InternalWaitComplete (uint64_t startWaitCycle, const PDebugLocation *location)
bool	InternalSignal (const PDebugLocation *location)
Protected Member Functions inherited from PObject
	PObject ()
	Constructor for PObject, made protected so cannot ever create one on its own. More...
Protected Member Functions inherited from PMutexExcessiveLockInfo
	PMutexExcessiveLockInfo ()
	PMutexExcessiveLockInfo (const PDebugLocation &location, unsigned timeout)
	PMutexExcessiveLockInfo (const PMutexExcessiveLockInfo &other)
virtual	~PMutexExcessiveLockInfo ()
void	Construct (unsigned timeout)
void	PrintOn (ostream &strm) const
void	ExcessiveLockPhantom (const PObject &mutex) const
virtual void	AcquiredLock (uint64_t startWaitCycle, bool readOnly, const PDebugLocation &location)
virtual void	ReleasedLock (const PObject &mutex, uint64_t startHeldSamplePoint, bool readOnly, const PDebugLocation &location)

Protected Attributes
PThreadIdentifier	m_lockerId
PThreadIdentifier	m_lastLockerId
PUniqueThreadIdentifier	m_lastUniqueId
unsigned	m_lockCount
Protected Attributes inherited from PObject
unsigned	m_traceContextIdentifier
Protected Attributes inherited from PMutexExcessiveLockInfo
PDebugLocation	m_location
unsigned	m_excessiveLockTimeout
atomic< bool >	m_excessiveLockActive
uint64_t	m_startHeldSamplePoint

Additional Inherited Members
Static Public Member Functions inherited from PObject
static __inline void	CopyTraceContextIdentifier (PObject &to, const PObject &from)
static __inline void	CopyTraceContextIdentifier (PObject &to, const PObject *from)
static __inline void	CopyTraceContextIdentifier (PObject *to, const PObject &from)
static __inline void	CopyTraceContextIdentifier (PObject *to, const PObject *from)
static __inline const char *	Class ()
static __inline const PObject *	PTraceObjectInstance (const char *)
static __inline const PObject *	PTraceObjectInstance (const PObject *obj)
template<typename T >
static Comparison	Compare2 (T v1, T v2)
	Compare two types, returning Comparison type. More...
static Comparison	InternalCompareObjectMemoryDirect (const PObject *obj1, const PObject *obj2, PINDEX size)
	Internal function caled from CompareObjectMemoryDirect() More...
Static Protected Member Functions inherited from PMutexExcessiveLockInfo
static unsigned	MinDeadlockTime (unsigned waitTime)

Detailed Description

This class defines a thread mutual exclusion object.

A mutex is where a piece of code or data cannot be accessed by more than one thread at a time. To prevent this the PMutex is used in the following manner:

      PMutex mutex;

      ...

      mutex.Wait();

      ... critical section - only one thread at a time here.

      mutex.Signal();

      ...

The first thread will pass through the Wait() function, a second thread will block on that function until the first calls the Signal() function, releasing the second thread.

Member Enumeration Documentation

enum PTimedMutex::DeadlockStackWalkModes

Enumerator
DeadlockStackWalkDisabled
DeadlockStackWalkEnabled
DeadlockStackWalkOnPhantomRelease
DeadlockStackWalkNoSymbols

Constructor & Destructor Documentation

PTimedMutex::PTimedMutex ( )

explicit

PTimedMutex::PTimedMutex ( const PDebugLocation &  location, unsigned  timeout = 0  )

explicit

Parameters

location	Source file/line of mutex definition
timeout	Timeout in ms, before declaring a possible deadlock. Zero uses default.

PTimedMutex::PTimedMutex

(

const PTimedMutex &

mutex

)

Copy constructor is allowed but does not copy, allocating a new mutex.

Two copies of the same mutex information would be very bad.

PTimedMutex::~PTimedMutex

(

)

Destruction.

Member Function Documentation

void PTimedMutex::Construct ( )

protected

bool PTimedMutex::InternalSignal ( const PDebugLocation *  location )

protected

void PTimedMutex::InternalWait ( const PDebugLocation *  location )

protected

void PTimedMutex::InternalWaitComplete ( uint64_t  startWaitCycle, const PDebugLocation *  location  )

protected

PTimedMutex& PTimedMutex::operator= ( const PTimedMutex &  )

inline

Assignment operator is allowed but does nothing.

Overwriting the old mutex information would be very bad.

void PTimedMutex::PlatformConstruct ( )

protected

void PTimedMutex::PlatformSignal ( const PDebugLocation *  location )

protected

bool PTimedMutex::PlatformWait ( const PTimeInterval &  timeout )

protected

virtual void PTimedMutex::PrintOn ( ostream &  strm ) const

virtual

Output the contents of the object to the stream.

The exact output is dependent on the exact semantics of the descendent class. This is primarily used by the standard operator<< function.

The default behaviour is to print the class name.

Reimplemented from PObject.

Reimplemented in PIntCondMutex.

virtual void PTimedMutex::Signal ( )

virtual

Signal that the synchronisation object is available.

Implements PSync.

Reimplemented in PCondMutex.

Referenced by PSafeDictionaryBase< PDictionary< K, D >, K, D >::Find(), PSafeDictionaryBase< PDictionary< K, D >, K, D >::FindIterator(), PSafeColl< PArray< Base >, Base >::FindWithLock(), PSafeDictionaryBase< PDictionary< K, D >, K, D >::GetKeys(), and PSafeDictionaryBase< PDictionary< K, D >, K, D >::SetAt().

PINLINE bool PTimedMutex::Try ( )

inline

Try to enter the critical section for exlusive access.

Does not wait.

Returns

true if cirical section entered, leave/Signal must be called.

References Wait().

virtual void PTimedMutex::Wait ( )

virtual

Block until the synchronisation object is available.

Implements PSync.

Referenced by PSafeDictionaryBase< PDictionary< K, D >, K, D >::Find(), PSafeDictionaryBase< PDictionary< K, D >, K, D >::FindIterator(), PSafeColl< PArray< Base >, Base >::FindWithLock(), PSafeDictionaryBase< PDictionary< K, D >, K, D >::GetKeys(), PSafePtrMultiThreaded::LockPtr(), PSafeDictionaryBase< PDictionary< K, D >, K, D >::SetAt(), and Try().

virtual PBoolean PTimedMutex::Wait ( const PTimeInterval &  timeout )

virtual

Block, for a time, until the synchronisation object is available.

Returns

true if lock is acquired, false if timed out

Implements PSync.

Member Data Documentation

DeadlockStackWalkModes PTimedMutex::DeadlockStackWalkMode

static

unsigned PTimedMutex::ExcessiveLockWaitTime

static

PThreadIdentifier PTimedMutex::m_lastLockerId

protected

PUniqueThreadIdentifier PTimedMutex::m_lastUniqueId

protected

unsigned PTimedMutex::m_lockCount

protected

PThreadIdentifier PTimedMutex::m_lockerId

protected

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

• mutex.h