net.corda.core.flows

Class FlowLogic<T>

net.corda.core.flows.FlowLogic<T>

Direct Known Subclasses:

AbstractCashFlow, AbstractStateReplacementFlow.Acceptor, ContractUpgradeFlow.Authorise, TwoPartyTradeFlow.Buyer, CashExitResponderFlow, CashPaymentReceiverFlow, CollectSignatureFlow, CollectSignaturesFlow, DataVendingFlow, ContractUpgradeFlow.Deauthorise, FinalityFlow, AbstractStateReplacementFlow.Instigator, TwoPartyDealFlow.Primary, ReceiveFinalityFlow, ReceiveStateAndRefFlow, ReceiveTransactionFlow, TwoPartyDealFlow.Secondary, TwoPartyTradeFlow.Seller, SignTransactionFlow, WithReferencedStatesFlow

public class FlowLogic<T>

A sub-class of class FlowLogic implements a flow using direct, straight line blocking code. Thus you can write complex flow logic in an ordinary fashion, without having to think about callbacks, restarting after a node crash, how many instances of your flow there are running and so on.

Invoking the network will cause the call stack to be suspended onto the heap and then serialized to a database using the Quasar fibers framework. Because of this, if you need access to data that might change over time, you should request it just-in-time via the FlowLogic.getServiceHub property which is provided. Don't try and keep data you got from a service across calls to send/receive/sendAndReceive because the world might change in arbitrary ways out from underneath you, for instance, if the node is restarted or reconfigured!

Additionally, be aware of what data you pin either via the stack or in your class FlowLogic implementation. Very large objects or datasets will hurt performance by increasing the amount of data stored in each checkpoint.

If you'd like to use another FlowLogic class as a component of your own, construct it on the fly and then pass it to the FlowLogic.subFlow method. It will return the result of that flow when it completes.

If your flow (whether it's a top-level flow or a subflow) is supposed to initiate a session with the counterparty and request they start their counterpart flow, then make sure it's annotated with interface InitiatingFlow. This annotation also has a version property to allow you to version your flow and enables a node to restrict support for the flow to that particular version.

Functions that suspend the flow (including all functions on class FlowSession) accept a maySkipCheckpoint parameter defaulting to false, false meaning a checkpoint should always be created on suspend. This parameter may be set to true which allows the implementation to potentially optimise away the checkpoint, saving a roundtrip to the database.

This option however comes with a big warning sign: Setting the parameter to true requires the flow's code to be replayable from the previous checkpoint (or start of flow) up until the next checkpoint (or end of flow) in order to prepare for hard failures. As suspending functions always commit the flow's database transaction regardless of this parameter the flow must be prepared for scenarios where a previous running of the flow already committed itsrelevant database transactions. Only set this option to true if you know what you're doing.

See Also:

class FlowLogic, FlowLogic.getServiceHub, class FlowLogic, FlowLogic.subFlow, interface InitiatingFlow, class FlowSession

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	FlowLogic.Companion

Field Summary

Fields

Modifier and Type	Field and Description
static FlowLogic.Companion	Companion

Constructor Summary

Constructors

Constructor and Description
FlowLogic() A sub-class of class FlowLogic implements a flow using direct, straight line blocking code. Thus you can write complex flow logic in an ordinary fashion, without having to think about callbacks, restarting after a node crash, how many instances of your flow there are running and so on.

Method Summary

Modifier and Type	Method and Description
T	call() This is where you fill out your business logic.
void	checkFlowPermission(java.lang.String permissionName, java.util.Map<java.lang.String,java.lang.String> extraAuditData) Flows can call this method to ensure that the active FlowInitiator is authorised for a particular action. This provides fine grained control over application level permissions, when RPC control over starting the flow is insufficient, or the permission is runtime dependent upon the choices made inside long lived flow code. For example some users may have restricted limits on how much cash they can transfer, or whether they can change certain fields. An audit event is always recorded whenever this method is used. If the permission is not granted for the FlowInitiator a FlowException is thrown.
FlowStackSnapshot	flowStackSnapshot() Returns a shallow copy of the Quasar stack frames at the time of call to FlowLogic.flowStackSnapshot. Use this to inspect what objects would be serialised at the time of call to a suspending action (e.g. send/receive). Note: This logic is only available during tests and is not meant to be used during the production deployment. Therefore the default implementation does nothing.
static FlowLogic<?>	getCurrentTopLevel() Return the outermost class FlowLogic instance, or null if not in a flow.
FlowInfo	getFlowInfo(Party otherParty) Deprecated.
org.slf4j.Logger	getLogger() This is where you should log things to.
Party	getOurIdentity() Specifies the identity to use for this flow. This will be one of the multiple identities that belong to this node. This is the same as calling ourIdentityAndCert.party.
PartyAndCertificate	getOurIdentityAndCert() Specifies the identity, with certificate, to use for this flow. This will be one of the multiple identities that belong to this node.
ProgressTracker	getProgressTracker() Override this to provide a class ProgressTracker. If one is provided and stepped, the framework will do something helpful with the progress reports e.g record to the audit service. If this flow is invoked as a subflow of another, then the tracker will be made a child of the current step in the parent. If it's null, this flow doesn't track progress.
StateMachineRunId	getRunId() Returns a wrapped java.util.UUID object that identifies this state machine run (i.e. subflows have the same identifier as their parents).
ServiceHub	getServiceHub() Provides access to big, heavy classes that may be reconstructed from time to time, e.g. across restarts. It is only available once the flow has started, which means it cannot be accessed in the constructor. Either access this lazily or from inside FlowLogic.call.
FlowSession	initiateFlow(Destination destination) Creates a communication session with destination. Subsequently you may send/receive using this session object. How the messaging is routed depends on the interface Destination type, including whether this call does any initial communication.
FlowSession	initiateFlow(Party party) Creates a communication session with party. Subsequently you may send/receive using this session object. Note that this function does not communicate in itself, the counter-flow will be kicked off by the first send/receive.
void	persistFlowStackSnapshot() Persists a shallow copy of the Quasar stack frames at the time of call to FlowLogic.persistFlowStackSnapshot. Use this to track the monitor evolution of the quasar stack values during the flow execution. The flow stack snapshot is stored in a file located in {baseDir}/flowStackSnapshots/YYYY-MM-DD/{flowId}/ where baseDir is the node running directory and flowId is the flow unique identifier generated by the platform.
<R> UntrustworthyData<R>	receive(java.lang.Class<R> receiveType, Party otherParty) Deprecated.
<R> java.util.List<net.corda.core.utilities.UntrustworthyData>	receiveAll(java.lang.Class<R> receiveType, java.util.List<? extends net.corda.core.flows.FlowSession> sessions, boolean maySkipCheckpoint) Suspends until a message has been received for each session in the specified sessions.
<R> java.util.List<net.corda.core.utilities.UntrustworthyData>	receiveAll(java.lang.Class<R> receiveType, java.util.List<? extends net.corda.core.flows.FlowSession> sessions) Suspends until a message has been received for each session in the specified sessions.
java.util.Map<net.corda.core.flows.FlowSession,net.corda.core.utilities.UntrustworthyData>	receiveAllMap(java.util.Map<net.corda.core.flows.FlowSession,? extends java.lang.Class<? extends java.lang.Object>> sessions, boolean maySkipCheckpoint) Suspends until a message has been received for each session in the specified sessions.
java.util.Map<net.corda.core.flows.FlowSession,net.corda.core.utilities.UntrustworthyData>	receiveAllMap(java.util.Map<net.corda.core.flows.FlowSession,? extends java.lang.Class<? extends java.lang.Object>> sessions) Suspends until a message has been received for each session in the specified sessions.
void	recordAuditEvent(java.lang.String eventType, java.lang.String comment, java.util.Map<java.lang.String,java.lang.String> extraAuditData) Flows can call this method to record application level flow audit events
void	send(Party otherParty, java.lang.Object payload) Deprecated.
<R> UntrustworthyData<R>	sendAndReceive(java.lang.Class<R> receiveType, Party otherParty, java.lang.Object payload) Deprecated.
static void	sleep(java.time.Duration duration, boolean maySkipCheckpoint) If on a flow, suspends the flow and only wakes it up after at least duration time has passed. Otherwise, just sleep for duration. This sleep function is not designed to aid scheduling, for which you should consider using interface SchedulableState. It is designed to aid with managing contention for which you have not managed via another means.
static void	sleep(java.time.Duration duration) If on a flow, suspends the flow and only wakes it up after at least duration time has passed. Otherwise, just sleep for duration. This sleep function is not designed to aid scheduling, for which you should consider using interface SchedulableState. It is designed to aid with managing contention for which you have not managed via another means.
<R> R	subFlow(FlowLogic<? extends R> subLogic) Invokes the given subflow. This function returns once the subflow completes successfully with the result returned by that subflow's FlowLogic.call method. If the subflow has a progress tracker, it is attached to the current step in this flow's progress tracker.
DataFeed<java.lang.String,java.lang.String>	track() Returns a pair of the current progress step, as a string, and an observable of stringified changes to the FlowLogic.getProgressTracker.
DataFeed<java.util.List,java.util.List>	trackStepsTree() Returns a pair of the current steps tree of current FlowLogic.getProgressTracker as pairs of zero-based depth and stringified step label and observable of upcoming changes to the structure.
DataFeed<java.lang.Integer,java.lang.Integer>	trackStepsTreeIndex() Returns a pair of the current progress step index (as integer) in steps tree of current FlowLogic.getProgressTracker, and an observable of its upcoming changes.
SignedTransaction	waitForLedgerCommit(SecureHash hash, boolean maySkipCheckpoint) Suspends the flow until the transaction with the specified ID is received, successfully verified and sent to the vault for processing. Note that this call suspends until the transaction is considered valid by the local node, but that doesn't imply the vault will consider it relevant.
SignedTransaction	waitForLedgerCommit(SecureHash hash) Suspends the flow until the transaction with the specified ID is received, successfully verified and sent to the vault for processing. Note that this call suspends until the transaction is considered valid by the local node, but that doesn't imply the vault will consider it relevant.
void	waitForStateConsumption(java.util.Set<net.corda.core.contracts.StateRef> stateRefs) Suspends the current flow until all the provided class StateRefs have been consumed.

Field Detail

Companion

public static FlowLogic.Companion Companion

Constructor Detail

FlowLogic

public FlowLogic()

A sub-class of class FlowLogic implements a flow using direct, straight line blocking code. Thus you can write complex flow logic in an ordinary fashion, without having to think about callbacks, restarting after a node crash, how many instances of your flow there are running and so on.

Invoking the network will cause the call stack to be suspended onto the heap and then serialized to a database using the Quasar fibers framework. Because of this, if you need access to data that might change over time, you should request it just-in-time via the FlowLogic.getServiceHub property which is provided. Don't try and keep data you got from a service across calls to send/receive/sendAndReceive because the world might change in arbitrary ways out from underneath you, for instance, if the node is restarted or reconfigured!

Additionally, be aware of what data you pin either via the stack or in your class FlowLogic implementation. Very large objects or datasets will hurt performance by increasing the amount of data stored in each checkpoint.

If you'd like to use another FlowLogic class as a component of your own, construct it on the fly and then pass it to the FlowLogic.subFlow method. It will return the result of that flow when it completes.

If your flow (whether it's a top-level flow or a subflow) is supposed to initiate a session with the counterparty and request they start their counterpart flow, then make sure it's annotated with interface InitiatingFlow. This annotation also has a version property to allow you to version your flow and enables a node to restrict support for the flow to that particular version.

Functions that suspend the flow (including all functions on class FlowSession) accept a maySkipCheckpoint parameter defaulting to false, false meaning a checkpoint should always be created on suspend. This parameter may be set to true which allows the implementation to potentially optimise away the checkpoint, saving a roundtrip to the database.

This option however comes with a big warning sign: Setting the parameter to true requires the flow's code to be replayable from the previous checkpoint (or start of flow) up until the next checkpoint (or end of flow) in order to prepare for hard failures. As suspending functions always commit the flow's database transaction regardless of this parameter the flow must be prepared for scenarios where a previous running of the flow already committed itsrelevant database transactions. Only set this option to true if you know what you're doing.

See Also:

class FlowLogic, FlowLogic.getServiceHub, class FlowLogic, FlowLogic.subFlow, interface InitiatingFlow, class FlowSession

Method Detail

getLogger

public org.slf4j.Logger getLogger()

This is where you should log things to.

getRunId

public StateMachineRunId getRunId()

Returns a wrapped java.util.UUID object that identifies this state machine run (i.e. subflows have the same identifier as their parents).

See Also:

java.util.UUID

getServiceHub

public ServiceHub getServiceHub()

Provides access to big, heavy classes that may be reconstructed from time to time, e.g. across restarts. It is only available once the flow has started, which means it cannot be accessed in the constructor. Either access this lazily or from inside FlowLogic.call.

See Also:

FlowLogic.call

initiateFlow

public FlowSession initiateFlow(Destination destination)

Creates a communication session with destination. Subsequently you may send/receive using this session object. How the messaging is routed depends on the interface Destination type, including whether this call does any initial communication.

See Also:

interface Destination

initiateFlow

public FlowSession initiateFlow(Party party)

Creates a communication session with party. Subsequently you may send/receive using this session object. Note that this function does not communicate in itself, the counter-flow will be kicked off by the first send/receive.

getOurIdentityAndCert

public PartyAndCertificate getOurIdentityAndCert()

Specifies the identity, with certificate, to use for this flow. This will be one of the multiple identities that belong to this node.

getOurIdentity

public Party getOurIdentity()

Specifies the identity to use for this flow. This will be one of the multiple identities that belong to this node. This is the same as calling ourIdentityAndCert.party.

See Also:

NodeInfo.getLegalIdentities

getFlowInfo

public FlowInfo getFlowInfo(Party otherParty)

Deprecated.

Returns a class FlowInfo object describing the flow otherParty is using. With FlowInfo.flowVersion it provides the necessary information needed for the evolution of flows and enabling backwards compatibility.

This method can be called before any send or receive has been done with otherParty. In such a case this will force them to start their flow.

See Also:

class FlowInfo

sendAndReceive

public <R> UntrustworthyData<R> sendAndReceive(java.lang.Class<R> receiveType,
                                               Party otherParty,
                                               java.lang.Object payload)

Deprecated.

Serializes and queues the given payload object for sending to the otherParty. Suspends until a response is received, which must be of the given receiveType. Remember that when receiving data from other parties the data should not be trusted until it's been thoroughly verified for consistency and that all expectations are satisfied, as a malicious peer may send you subtly corrupted data in order to exploit your code.

Note that this function is not just a simple send+receive pair: it is more efficient and more correct to use this when you expect to do a message swap than do use FlowLogic.send and then receive in turn.

Returns:

an class UntrustworthyData wrapper around the received object.

See Also:

FlowLogic.send

receive

public <R> UntrustworthyData<R> receive(java.lang.Class<R> receiveType,
                                        Party otherParty)

Deprecated.

Suspends until the specified otherParty sends us a message of type receiveType.

Remember that when receiving data from other parties the data should not be trusted until it's been thoroughly verified for consistency and that all expectations are satisfied, as a malicious peer may send you subtly corrupted data in order to exploit your code.

Returns:

an class UntrustworthyData wrapper around the received object.

send

public void send(Party otherParty,
                 java.lang.Object payload)

Deprecated.

Queues the given payload for sending to the otherParty and continues without suspending.

Note that the other party may receive the message at some arbitrary later point or not at all: if otherParty is offline then message delivery will be retried until it comes back or until the message is older than the network's event horizon time.

receiveAllMap

public java.util.Map<net.corda.core.flows.FlowSession,net.corda.core.utilities.UntrustworthyData> receiveAllMap(java.util.Map<net.corda.core.flows.FlowSession,? extends java.lang.Class<? extends java.lang.Object>> sessions,
                                                                                                                boolean maySkipCheckpoint)

Suspends until a message has been received for each session in the specified sessions.

Consider receiveAllreceiveTypeClass,sessionsListListUntrustworthyData when the same type is expected from all sessions.

Remember that when receiving data from other parties the data should not be trusted until it's been thoroughly verified for consistency and that all expectations are satisfied, as a malicious peer may send you subtly corrupted data in order to exploit your code.

See Also:

receiveAllreceiveTypeClass,sessionsListListUntrustworthyData

receiveAllMap

public java.util.Map<net.corda.core.flows.FlowSession,net.corda.core.utilities.UntrustworthyData> receiveAllMap(java.util.Map<net.corda.core.flows.FlowSession,? extends java.lang.Class<? extends java.lang.Object>> sessions)

Suspends until a message has been received for each session in the specified sessions.

Consider receiveAllreceiveTypeClass,sessionsListListUntrustworthyData when the same type is expected from all sessions.

Remember that when receiving data from other parties the data should not be trusted until it's been thoroughly verified for consistency and that all expectations are satisfied, as a malicious peer may send you subtly corrupted data in order to exploit your code.

See Also:

receiveAllreceiveTypeClass,sessionsListListUntrustworthyData

receiveAll

public <R> java.util.List<net.corda.core.utilities.UntrustworthyData> receiveAll(java.lang.Class<R> receiveType,
                                                                                 java.util.List<? extends net.corda.core.flows.FlowSession> sessions,
                                                                                 boolean maySkipCheckpoint)

Suspends until a message has been received for each session in the specified sessions.

Consider sessionsMapFlowSession,ClassMapFlowSession,UntrustworthyData when sessions are expected to receive different types.

Remember that when receiving data from other parties the data should not be trusted until it's been thoroughly verified for consistency and that all expectations are satisfied, as a malicious peer may send you subtly corrupted data in order to exploit your code.

See Also:

sessionsMapFlowSession,ClassMapFlowSession,UntrustworthyData

receiveAll

public <R> java.util.List<net.corda.core.utilities.UntrustworthyData> receiveAll(java.lang.Class<R> receiveType,
                                                                                 java.util.List<? extends net.corda.core.flows.FlowSession> sessions)

Suspends until a message has been received for each session in the specified sessions.

Consider sessionsMapFlowSession,ClassMapFlowSession,UntrustworthyData when sessions are expected to receive different types.

Remember that when receiving data from other parties the data should not be trusted until it's been thoroughly verified for consistency and that all expectations are satisfied, as a malicious peer may send you subtly corrupted data in order to exploit your code.

See Also:

sessionsMapFlowSession,ClassMapFlowSession,UntrustworthyData

subFlow

public <R> R subFlow(FlowLogic<? extends R> subLogic)

Invokes the given subflow. This function returns once the subflow completes successfully with the result returned by that subflow's FlowLogic.call method. If the subflow has a progress tracker, it is attached to the current step in this flow's progress tracker.

If the subflow is not an initiating flow (i.e. not annotated with interface InitiatingFlow) then it will continue to use the existing sessions this flow has created with its counterparties. This allows for subflows which can act as building blocks for other flows, for example removing the boilerplate of common sequences of sends and receives.

Throws:

- This is either thrown by subLogic itself or propagated from any of the remote class FlowLogics it communicated with. The subflow can be retried by catching this exception.

See Also:

FlowLogic.call, interface InitiatingFlow

checkFlowPermission

public void checkFlowPermission(java.lang.String permissionName,
                                java.util.Map<java.lang.String,java.lang.String> extraAuditData)

Flows can call this method to ensure that the active FlowInitiator is authorised for a particular action. This provides fine grained control over application level permissions, when RPC control over starting the flow is insufficient, or the permission is runtime dependent upon the choices made inside long lived flow code. For example some users may have restricted limits on how much cash they can transfer, or whether they can change certain fields. An audit event is always recorded whenever this method is used. If the permission is not granted for the FlowInitiator a FlowException is thrown.

Parameters:

permissionName - is a string representing the desired permission. Each flow is given a distinct namespace for these permissions.

extraAuditData - in the audit log for this permission check these extra key value pairs will be recorded.

recordAuditEvent

public void recordAuditEvent(java.lang.String eventType,
                             java.lang.String comment,
                             java.util.Map<java.lang.String,java.lang.String> extraAuditData)

Flows can call this method to record application level flow audit events

Parameters:

eventType - is a string representing the type of event. Each flow is given a distinct namespace for these names.

comment - a general human readable summary of the event.

extraAuditData - in the audit log for this permission check these extra key value pairs will be recorded.

getProgressTracker

public ProgressTracker getProgressTracker()

Override this to provide a class ProgressTracker. If one is provided and stepped, the framework will do something helpful with the progress reports e.g record to the audit service. If this flow is invoked as a subflow of another, then the tracker will be made a child of the current step in the parent. If it's null, this flow doesn't track progress.

Note that this has to return a tracker before the flow is invoked. You can't change your mind half way through.

See Also:

class ProgressTracker

call

public T call()

This is where you fill out your business logic.

track

public DataFeed<java.lang.String,java.lang.String> track()

Returns a pair of the current progress step, as a string, and an observable of stringified changes to the FlowLogic.getProgressTracker.

Returns:

Returns null if this flow has no progress tracker.

See Also:

FlowLogic.getProgressTracker

trackStepsTreeIndex

public DataFeed<java.lang.Integer,java.lang.Integer> trackStepsTreeIndex()

Returns a pair of the current progress step index (as integer) in steps tree of current FlowLogic.getProgressTracker, and an observable of its upcoming changes.

Returns:

Returns null if this flow has no progress tracker.

See Also:

FlowLogic.getProgressTracker

trackStepsTree

public DataFeed<java.util.List,java.util.List> trackStepsTree()

Returns a pair of the current steps tree of current FlowLogic.getProgressTracker as pairs of zero-based depth and stringified step label and observable of upcoming changes to the structure.

Returns:

Returns null if this flow has no progress tracker.

See Also:

FlowLogic.getProgressTracker

waitForLedgerCommit

public SignedTransaction waitForLedgerCommit(SecureHash hash,
                                             boolean maySkipCheckpoint)

Suspends the flow until the transaction with the specified ID is received, successfully verified and sent to the vault for processing. Note that this call suspends until the transaction is considered valid by the local node, but that doesn't imply the vault will consider it relevant.

waitForLedgerCommit

public SignedTransaction waitForLedgerCommit(SecureHash hash)

Suspends the flow until the transaction with the specified ID is received, successfully verified and sent to the vault for processing. Note that this call suspends until the transaction is considered valid by the local node, but that doesn't imply the vault will consider it relevant.

waitForStateConsumption

public void waitForStateConsumption(java.util.Set<net.corda.core.contracts.StateRef> stateRefs)

Suspends the current flow until all the provided class StateRefs have been consumed.

WARNING! Remember that the flow which uses this async operation will NOT wake-up until all the supplied StateRefs have been consumed. If the node isn't aware of the supplied StateRefs or if the StateRefs are never consumed, then the calling flow will remain suspended FOREVER!!

Parameters:

stateRefs - the StateRefs which will be consumed in the future.

See Also:

class StateRef

flowStackSnapshot

public FlowStackSnapshot flowStackSnapshot()

Returns a shallow copy of the Quasar stack frames at the time of call to FlowLogic.flowStackSnapshot. Use this to inspect what objects would be serialised at the time of call to a suspending action (e.g. send/receive). Note: This logic is only available during tests and is not meant to be used during the production deployment. Therefore the default implementation does nothing.

See Also:

FlowLogic.flowStackSnapshot

persistFlowStackSnapshot

public void persistFlowStackSnapshot()

Persists a shallow copy of the Quasar stack frames at the time of call to FlowLogic.persistFlowStackSnapshot. Use this to track the monitor evolution of the quasar stack values during the flow execution. The flow stack snapshot is stored in a file located in {baseDir}/flowStackSnapshots/YYYY-MM-DD/{flowId}/ where baseDir is the node running directory and flowId is the flow unique identifier generated by the platform.

Note: With respect to the FlowLogic.flowStackSnapshot, the snapshot being persisted by this method is partial, meaning that only flow relevant traces and local variables are persisted. Also, this logic is only available during tests and is not meant to be used during the production deployment. Therefore the default implementation does nothing.

See Also:

FlowLogic.persistFlowStackSnapshot, FlowLogic.flowStackSnapshot

getCurrentTopLevel

public static FlowLogic<?> getCurrentTopLevel()

Return the outermost class FlowLogic instance, or null if not in a flow.

See Also:

class FlowLogic

sleep

public static void sleep(java.time.Duration duration,
                         boolean maySkipCheckpoint)

If on a flow, suspends the flow and only wakes it up after at least duration time has passed. Otherwise, just sleep for duration. This sleep function is not designed to aid scheduling, for which you should consider using interface SchedulableState. It is designed to aid with managing contention for which you have not managed via another means.

Warning: long sleeps and in general long running flows are highly discouraged, as there is currently no support for flow migration! This method will throw an exception if you attempt to sleep for longer than 5 minutes.

See Also:

interface SchedulableState

sleep

public static void sleep(java.time.Duration duration)

If on a flow, suspends the flow and only wakes it up after at least duration time has passed. Otherwise, just sleep for duration. This sleep function is not designed to aid scheduling, for which you should consider using interface SchedulableState. It is designed to aid with managing contention for which you have not managed via another means.

Warning: long sleeps and in general long running flows are highly discouraged, as there is currently no support for flow migration! This method will throw an exception if you attempt to sleep for longer than 5 minutes.

See Also:

interface SchedulableState