Program control
The Program control group changes what Velox or the host operating system does next. It includes cooperative map/flow cancellation, linked-record reprocessing, Windows process or Shell launch, thread suspension and synchronous execution of another Velox flow.
Cancellation families
The five stop/cancel names collapse to two native behaviors:
CancelExecutionandStopStepcancel all views/fields in the current map without setting the enclosing flow log to cancelled.StopAction,StopExecutionandStopFlowcancel the current map's views and also mark the enclosing action/flow log cancelled.
These calls are cooperative state changes. They do not behave like a language exit, throw an exception, undo prior work or prevent the remainder of the current script statement sequence from running. Return/exit explicitly when no later script code should execute.
External processes and waiting
ExecCmdLine... uses a Windows process command line; ExecShellCmd... uses Shell associations and can open executables, documents, folders or URLs. Inputs execute with the Velox process identity and environment. Never concatenate untrusted values into a command line, executable, argument, working directory, verb or URL.
The wait variants and Sleep block the current Velox worker thread. Their one-hour wait ceiling is not a general scheduling guarantee, and timeout does not necessarily terminate the launched process. Prefer asynchronous orchestration or bounded polling outside a mapping script where possible.
Flow and linked-record effects
ExecuteFlow synchronously checks out, loads and runs another flow. It introduces independent configuration, logging, resource, recursion and failure boundaries; it is not an in-process function call or automatic transaction continuation.
ProcessMasterRecord and ProcessGrandMasterRecord cancel the current linked view and request reprocessing at a different relationship level. They depend on active linked-data context and affect mapping iteration state rather than returning a record.
Operational safety
All effects can outlive a later script or map failure. Design idempotent retries, restrict executable/flow identifiers to configuration-owned values, bound wait durations and log only non-sensitive operational context.