4.2. Locks

There are several locking mechanisms available in Daslang, designed to ensure the runtime safety of the code.

4.2.1. Context locks

A Context can be locked and unlocked via the lock and unlock functions from the C++ side. When locked, a Context cannot be restarted. tryRestartAndLock restarts the context if it is not locked, and then locks it regardless. The main reason to lock a context is when data on the heap is accessed externally. Heap collection is safe to perform on a locked context.

4.2.2. Array and Table locks

An Array or Table can be locked and unlocked explicitly. When locked, they cannot be modified. Calling resize, reserve, push, emplace, erase, etc. on a locked Array will cause a panic. Accessing a locked Table’s elements via the [] operator will also cause a panic.

Arrays are locked when iterated over, preventing modification during iteration. The keys and values iterators lock a Table as well. Tables are also locked during find* operations.

The following operations perform lock checks on data structures:

* a <- b
* return <- a
* resize
* reserve
* push
* push_clone
* emplace
* pop
* erase
* clear
* insert
* for the ``Table``

See also

Arrays and Tables for the container types that support locking, Iterators for iteration patterns that lock containers, Contexts for context-level locking.