Cooperative concurrency

The cooperative gate enables go statements, channels, select, synchronization, and cancellation. Source tasks run on a deterministic cooperative scheduler. Host workers can perform native operations; only the scheduler owner mutates source state.

Enable the gate

goalchemy check -gate cooperative .
goalchemy run -gate cooperative -target python .

For multi-target builds, set gate: cooperative in goalchemy.yaml. A go statement under the default sequential gate is rejected.

Pass a value through a channel

package main

func main() {
    values := make(chan int, 1)
    go func() {
        values <- 42
    }()
    println(<-values)
}

Tasks yield at defined scheduler operations. Cooperative execution does not provide source-visible parallel Go threads. Do not rely on host thread scheduling or use a busy loop to wait for another task.

Use mapped synchronization and contexts

Use the Goalchemy packages for synchronization, contexts, virtual time, and structured waiting. The pipeline example combines worker channels with per-job deadlines.

Distinguish virtual and host time

Deterministic fixtures use virtual time. Host-driven execution uses monotonic time for pending native I/O and deadlines; wall-clock observations remain a separate capability. Generated executable entries select the appropriate driver based on their linked capabilities.

Cancellation signals native work and retires operations only after required cleanup. See host operations and each target’s implementation details before integrating callbacks or driving a library from a host application.

The language specification defines scheduling and source behavior. Commands and output documents the supported forms and HTTP options.