Enum ProcessAction 

pub enum ProcessAction {
    WriteDbLink {
        link_field: &'static str,
        value: EpicsValue,
    },
    ReadDbLink {
        link_field: &'static str,
        target_field: &'static str,
    },
    ReprocessAfter(Duration),
    DeviceCommand {
        command: &'static str,
        args: Vec<EpicsValue>,
    },
    WriteDbLinkNotify {
        link_field: &'static str,
        value: EpicsValue,
    },
    CancelReprocess,
}

Side-effect actions that a record requests from the processing framework.

Records return these from process() via ProcessOutcome::actions. The framework executes them at the appropriate point in the processing cycle, keeping records as pure state machines without direct DB access.

Variants

WriteDbLink

Write a value to a DB link. The framework reads link_field from the record to get the target PV name, then writes value to that PV.

Executed after alarm/snapshot, before FLNK. Example: scaler writes CNT to COUT/COUTP links.

Fields

link_field: &'static str

value: EpicsValue

ReadDbLink

Read a value from a DB link into a record field. The framework reads link_field from the record to get the source PV name, reads that PV, and writes the result into target_field via an internal put that bypasses read-only checks.

The value delivered is the link target’s native EpicsValue — it is NOT coerced to a numeric type on the way in. The record coerces (or preserves) it at its own put_field/put_field_internal boundary, so a string-class source can reach a string field byte-exact (the sseq DOLn→STRn path, C sseqRecord.c:643-705). Records whose target_field is numeric simply convert there, exactly as before.

Pre-process action: executed BEFORE the next process() cycle so the value is immediately available. This matches C EPICS dbGetLink() which is synchronous/immediate.

Example: throttle reads SINP into VAL when SYNC is triggered.

Fields

link_field: &'static str

target_field: &'static str

ReprocessAfter(Duration)

Schedule a re-process of this record after the given duration. The framework spawns tokio::spawn(sleep(d) + process_record(name)). The current cycle’s OUT/FLNK/notify proceed normally.

Equivalent to C EPICS callbackRequestDelayed() + scanOnce().

DeviceCommand

Send a named command to the device support driver. The framework calls DeviceSupport::handle_command() with this data. Used by scaler to request reset/arm/write_preset operations without the record holding a direct driver reference.

Fields

command: &'static str

args: Vec<EpicsValue>

WriteDbLinkNotify

Write a value to a DB link as a put-with-completion, then re-enter THIS record’s process() when the downstream operation completes.

The framework arms a put-notify wait-set (C dbProcessNotify), writes link_field’s target through it, releases the initiator’s own count, and wires the completion to an async re-entry of this record (mint_async_token + reprocess_on_notify). The record returns RecordProcessResult::AsyncPending alongside this action and is re-entered once the downstream record (and its FLNK/OUT chain) finishes — the synApps sseq WAITn “wait for the put callback” dependency (sseqRecord.c::processNextLink, dbCaPutLinkCallback). Built on the same new_put_notify + reprocess_on_notify primitive an out-of-band crate::server::database::AsyncDbHandle caller uses.

Executed before FLNK, like Self::WriteDbLink.

Fields

link_field: &'static str

value: EpicsValue

CancelReprocess

Cancel this record’s outstanding async re-entry (C callbackCancelDelayed): the framework advances the record’s re-entry generation so any pending ReprocessAfter timer or WriteDbLinkNotify completion re-entry becomes a structural no-op (the AsyncToken gate), with no runtime “is-aborted” check on the re-entry path. Used by sseq ABORT to drop a pending DLYn delay or WAITn wait; the record resets its own sequence state in the same process() cycle that emits this.

Trait Implementations

impl Clone for ProcessAction

fn clone(&self) -> ProcessAction

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ProcessAction

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq for ProcessAction

fn eq(&self, other: &ProcessAction) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for ProcessAction