Lock

class Lock

Functions

Name	Description
Lock	Create a lock on a device.
Lock	Copy construction is disabled other : Move construction will invalidate the lock being moved. other :
~Lock	The destructor unlocks the device the lock is held on if the lock is valid.
lock	Reacquire a lock if this lock was previously unlocked recursive: : allow recursive locking if true
unlock	Unlock this lock
valid	Returns if this lock is currently valid.
lock_impl	Perform locking.
unlock_impl	Simply calls the clearLock slot on the locked device if we are the lock-holder

Function Details

Lock

Lock(std::weak_ptr<karabo::xms::SignalSlotable> sigSlot, const std::string& deviceId, bool recursive = false)

Create a lock on a device. Throws a karabo::util::LockException if the lock cannot be acquired

sigSlot: : a SignalSlotable instance to use for locking the remote device

deviceId: : the deviceId of the device to lock

recursive: : allow recursive locking if true

Lock(Lock&& other)

Copy construction is disabled

other : Move construction will invalidate the lock being moved.

other :

lock

void lock(bool recursive = false) const

Reacquire a lock if this lock was previously unlocked

recursive: : allow recursive locking if true

lock_impl

void lock_impl(bool recursive) const

Perform locking. Calling this function leads to the following remote calls:

1) check if we are allowed to lock: the lockedBy field on the remote device is either empty, or if recursive == true contains the lock requestor's device id

2) request locking, e.g. set the lockedBy field. This can still fail if another device locked in between

3) check if we are the lock holder: lockedBy should now contain our device id

recursive: : allow recursive locking if true

unlock

void unlock() const

Unlock this lock

unlock_impl

void unlock_impl() const

Simply calls the clearLock slot on the locked device if we are the lock-holder

valid

bool valid() const

Returns if this lock is currently valid. Note that the locked device will be queried through the distributed system when asking for lock validity.

~Lock

virtual ~Lock()

The destructor unlocks the device the lock is held on if the lock is valid. It is called explictly if the lock was stolen and will then throw a karabo::util::LockException