Typically when you execute a cell the kernel will wait for the cell thread to finish before displaying its output and allowing you to execute another cell. This is synchronous execution and it is the default. Jodin also supports asynchronous execution where you can execute a cell and leave its thread running for as long as it wants to or until you terminate it from another cell.
To make a cell execute asynchronously, add the #+async directive at the top. To prevent race-conditions, this cell won’t be allowed to access external variables in its root scope, and any variables declared there will not be exported to other cells.
#+async
…
In order for this cell to interact with other cells, you need to declare at least one scope with the sync label.
#+async
…
sync: {
…
}
…
Every Jodin session has a Ticket_Mutex called __data_mutex__, which is acquired at the beginning of the cell and released at the end, to allow the synchonous cells to share the same memory as asynchronous cells. In asynchronous cells the __data_mutex__ is acquired at the beginning of every sync scope and released at it’s end.
So if an asynchronous cell with a sync loop is running, and you execute a synchronous cell, the asynchronous cell will halt at the end of the current iteration until the synchronous cell is executed.
There are several notebooks in the examples folder of the Jodin repository which show how this feature can be used for live coding.
glfw.ipynb notebook shows how you can update the contents of a GLFW window live.miniaudio.ipynb notebook shows how you can live-program sound.