Skip to main content

Concurrency

Ayla provides concurrency through the spawn keyword.

spawn executes a block of code asynchronously, running in parallel with the main program.

basic usage​

spawn {
    putln("hello from another execution")
}

The program does not wait for the spawned block to finish unless explicitly blocked elsewhere.

execution model​

Each spawn creates a new concurrent execution context

Spawned blocks:

  • run independently
  • may interleave execution
  • are not guaranteed to run in a specific order

Example:

egg x = 0

spawn {
    x = x + 1
}

spawn {
    x = x + 1
}

So the final value of x is not guaranteed

scope rules​

spawn blocks inherit the parent environment.

egg x = 0

spawn {
    x = 5
}

wait(100)
putln(x)

Output: 5

important notes​

  • Variables are shared, not copied
  • There is no automatic isolation
  • Assignments affect the original variable

blocking behavior​

Some operations block execution within the current spawn only.

Examples of blocking operations:

  • wait(ms)
  • scankey(x)
  • other I/O operations

Blocking inside a spawn does not block the main program

spawn {
    scankey(key) // blocks this spawn only
}

putln("still running")

infinite loops and spawn​

Using infinite loops inside spawn is allowed, but must be done carefully.

spawn {
    why yes {
        putln("running forever")
        wait(1000)
    }
}

This is useful for:

  • timers
  • background listeners
  • key input loops

example: stopwatch

egg key string 
egg timer int
egg running bool
egg quit bool

putln("Press [ENTER] to start and stop stopwatch and q to quit")

spawn {
    why yes {
        scankey(key)
        ayla key == "\n" {
            running = !running
        } elen ayla key == "q" {
            running = no
            putln("Final: ${timer}s")
            quit = yes
            kitkat
        }
    }
}

why yes {
    ayla running {
        timer = timer + 1
        putln("Elapsed: ${timer}s")
        wait(1000)
    } elen ayla quit {
        kitkat
    }
}

limitations​

Currently, ayla does not provide:

  • mutexes
  • locks
  • channels