4.18. Thread::AbstractSmartLock Class

4.18. Thread::AbstractSmartLock Class
Prev	Chapter 4. System Namespaces and Class Library	Next

Note: This class is not available with the PO_NO_THREAD_CLASSES parse option.

This is an abstract class to be inherited by builtin classes that implement the internal Qore API that allows them to be used by the Condition class. Currently the RWLock and Mutex classes inherit this class.

This class cannot be instantiated directly and also cannot be directly inherited by user-defined classes.

Table 4.715. AbstractSmartLock Method Overview

Method	Except?	Description
`AbstractSmartLock::constructor()`	Y	Throws an exception if called directly; this class can only be instantiated by builtin subclasses.
`::AbstractSmartLock::destructor()`	N	Performs no action.
`AbstractSmartLock::copy()`	N	Performs no action.
`string AbstractSmartLock::getName()`	N	Returns the name of the threading class directly inheriting this class.
`bool AbstractSmartLock::lockOwner()`	N	Returns True if the calling thread owns the lock, False if not.
`int AbstractSmartLock::lockTID()`	N	Returns the TID of the thread owning the lock or -1 if the lock is currently not acquired.

4.18.1. AbstractSmartLock::constructor()

Synopsis: Throws an exception if called directly or if inherited by a user-defined class; this class can only be instantiated by builtin subclasses.

Table 4.716. Exceptions Thrown by AbstractSmartLock::constructor()

err	desc
`ABSTRACTSMARTLOCK-CONSTRUCTOR-ERROR`	This class cannot be instantiated directly or inherited by user code.

4.18.2. AbstractSmartLock::destructor()

Synopsis: Performs no action.

4.18.3. AbstractSmartLock::copy()

Synopsis: Performs no action.

4.18.4. AbstractSmartLock::getName()

Synopsis

Returns the name of the threading class directly inheriting this class.

Prototype

string AbstractSmartLock::getName()

Example

my $name = $lock.getName();

Table 4.717. Return Values for AbstractSmartLock::getName()

Return Type	Description
`string`	Returns the name of the threading class directly inheriting this class.

4.18.5. AbstractSmartLock::lockOwner()

Synopsis

Returns True if the calling thread owns the lock, False if not.

Prototype

bool AbstractSmartLock::lockOwner()

Example

# only grab and release lock if we don't already own it
if (!$lock.lockOwner())
    $lock.lock();
on_exit
    if (!$lock.lockOwner())
	$lock.unlock();

Table 4.718. Return Values for AbstractSmartLock::lockOwner()

Return Type	Description
`bool`	Returns True if the calling thread owns the lock, False if not.

4.18.6. AbstractSmartLock::lockTID()

Synopsis

Returns the TID of the thread owning the lock or -1 if the lock is currently not acquired.

This method normally not useful in practice for anything except checking that the current thread owns the lock, in which case AbstractSmartLock::lockOwner() is better, because if the lock is not owned by the current thread the lock ownership can change at any time.

Prototype

int AbstractSmartLock::lockTID()

Example

my int $tid = $lock.lockTID();

Table 4.719. Return Values for AbstractSmartLock::lockTID()

Return Type	Description
`int`	Returns the TID of the thread owning the lock or -1 if the lock is currently not acquired.

Prev	Up	Next
4.17. SQL::SQLStatement Class	Home	4.19. Thread::AutoGate Class