ON_Lock Class Reference

ON_Lock is a thread safe lock semephore. It is implemented using platform specfic compare and set functions. More...

#include <opennurbs_lock.h>

Public Types
enum	: int { UnlockedValue = 0, DefaultLockedValue = 1, InvalidLockValue = -1 }
	ON_Lock::InvalidLockValue (= -1) may never be used as a lock value. More...

Public Member Functions
	ON_Lock ()=default
	ON_Lock (const ON_Lock &)=default
	~ON_Lock ()=default
int	BreakLock ()
	Unconditionally sets the lock value to ON_Lock::UnlockedValue. More...
bool	GetDefaultLock ()
	Calls GetLock(ON_Lock::DefaultLockedValue); More...
bool	GetLock (int lock_value)
int	IsLocked ()
ON_Lock &	operator= (const ON_Lock &)=default
bool	ReturnDefaultLock ()
	Calls ReturnLock(ON_Lock::DefaultLockedValue); More...
bool	ReturnLock (int lock_value)

Detailed Description

ON_Lock is a thread safe lock semephore. It is implemented using platform specfic compare and set functions.

Member Enumeration Documentation

anonymous enum

anonymous enum : int

ON_Lock::InvalidLockValue (= -1) may never be used as a lock value.

Enumerator
UnlockedValue
DefaultLockedValue
InvalidLockValue

Constructor & Destructor Documentation

ON_Lock() [1/2]

ON_Lock::ON_Lock ( )

default

~ON_Lock()

ON_Lock::~ON_Lock ( )

default

ON_Lock() [2/2]

ON_Lock::ON_Lock ( const ON_Lock &  )

default

Member Function Documentation

BreakLock()

int ON_Lock::BreakLock

(

)

Unconditionally sets the lock value to ON_Lock::UnlockedValue.

Returns

previous value of the lock. ON_Lock::UnlockedValue indicates the lock was available otherwise the lock passed to GetLock() is returned

GetDefaultLock()

bool ON_Lock::GetDefaultLock

(

)

Calls GetLock(ON_Lock::DefaultLockedValue);

Returns

True if the lock state was unlocked and the current lock value was changed from ON_Lock::UnlockedValue to ON_Lock::DefaultLockedValue. False otherwise.

GetLock()

bool ON_Lock::GetLock

(

int

lock_value

)

Parameters

lock_value

[in] any value except ON_Lock::UnlockedValue or ON_Lock::InvalidLockValue. Typically ON_Lock::DefaultLockedValue is used.

Returns

True if the lock_value parameter was valid and the current lock value was changed from ON_Lock::UnlockedValue to lock_value. False otherwise.

IsLocked()

int ON_Lock::IsLocked

(

)

Returns

Current lock value ON_Lock::UnlockedValue indicates the the resource protected by the lock is available.

operator=()

ON_Lock& ON_Lock::operator= ( const ON_Lock &  )

default

ReturnDefaultLock()

bool ON_Lock::ReturnDefaultLock

(

)

Calls ReturnLock(ON_Lock::DefaultLockedValue);

Returns

True if the lock state was locked with a locak value = ON_Lock::DefaultLockedValue and the current lock value was changed from ON_Lock::DefaultLockedValue to ON_Lock::UnlockedValue. False otherwise.

ReturnLock()

bool ON_Lock::ReturnLock

(

int

lock_value

)

Parameters

lock_value

[in] any value except ON_Lock::UnlockedValue or ON_Lock::InvalidLockValue. Typically this is the value that was passed to GetLock().

Returns

True if the lock_value parameter was valid and the current lock value was changed from that value to zero. False otherwise.