fpmas::synchro Namespace Reference

Namespaces
namespace	ghost
namespace	hard

Classes
class	AcquireGuard
struct	DataUpdate
struct	DataUpdate< api::model::AgentPtr >
struct	DataUpdatePack
class	Guard
class	LockGuard
struct	NodeUpdatePack
class	ReadGuard
class	SharedLockGuard

Typedefs
template<typename T >
using	GhostMode = ghost::GhostMode< T, ghost::GhostMutex >
template<typename T >
using	GlobalGhostMode = ghost::GhostMode< T, ghost::GlobalGhostMutex >
template<typename T >
using	HardSyncMode = hard::hard_link::HardSyncMode< T >
template<typename T >
using	HardSyncModeWithGhostLink = hard::ghost_link::HardSyncMode< T >

Detailed Description

fpmas::api::synchro implementations.

Typedef Documentation

GhostMode

template<typename T >

using fpmas::synchro::GhostMode = typedef ghost::GhostMode<T, ghost::GhostMutex>

Regular GhostMode implementation, based on the GhostMutex.

Data synchronization can be described as follows:

• LOCAL nodes: read and acquires are performed directly on the local data
• DISTANT nodes: read and acquires are performed on a local copy, imported from the origin process at each DataSync::synchronize() call. Local modifications are overridden at each synchronization.

In the Agent context, this means that modifications on LOCAL agents are immediately perceived by LOCAL agents, even if they are only exported at the end of the time step to distant processes.

Since modifications on DISTANT agents are erased at each synchronization, modifications between agents is likely to produce unexpected behaviors in this mode. However, each LOCAL agent is allowed to modify its own state.

In consequence, even in a read-only model, the state of perceived agents depends on the execution order and on the LOCAL or DISTANT state of each agent:

• the state of a LOCAL agent not executed yet corresponds to its state at the previous time step
• the state of an already executed LOCAL agent corresponds to its state at the current time step
• the state of a DISTANT agent always corresponds to its state at the previous time step

The results of a read-only model is hence reproducible only considering that the agents execution order and distribution are the same.

Note

The fpmas::seed() method can be used to enforce those constraints.

A more consistent and reproducible behavior can be obtained using the fpmas::synchro::GlobalGhostMode.

This synchronization policy is inspired from RepastHPC.

See also

fpmas::synchro::GlobalGhostMode

fpmas::synchro::HardSyncMode

GlobalGhostMode

template<typename T >

using fpmas::synchro::GlobalGhostMode = typedef ghost::GhostMode<T, ghost::GlobalGhostMutex>

Strict GhostMode implementation, based on the GlobalGhostMutex.

read and acquire operations, on LOCAL or DISTANT nodes, are always performed on a temporary ghost copy. The copy is updated at each DataSync::synchronize() call from the state of the original data.

In the Agent context, this means that modifications on LOCAL agents are only perceived after the next synchronization.

Since modifications on DISTANT agents are erased at each synchronization, modifications between agents is likely to produce unexpected behaviors in this mode. However, each LOCAL agent is allowed to modify its own state.

In consequence, when an agent modifies its own state, modifications are not perceived yet by other LOCAL agent who still see the ghost copy.

This ensures that LOCAL agents always perceive the state of other LOCAL or DISTANT agents at the previous time step. In the case of a properly implemented read-only model, the execution does not depends on the order of execution of agents nor on their LOCAL or DISTANT state. In consequence, this mode implements the strongest reproducibility requirements.

This synchronization policy is inspired from D-MASON.

See also

fpmas::synchro::GhostMode

fpmas::synchro::HardSyncMode

HardSyncMode

template<typename T >

using fpmas::synchro::HardSyncMode = typedef hard::hard_link::HardSyncMode<T>

Default HardSyncMode.

HardSyncModeWithGhostLink

template<typename T >

using fpmas::synchro::HardSyncModeWithGhostLink = typedef hard::ghost_link::HardSyncMode<T>

HardSyncMode but link operations are managed as in GhostMode.