graphlab::scope_range Struct Reference

defines the types of scope consistency guarantees provided More...

#include <iscope.hpp>

List of all members.

Public Types
enum	scope_range_enum {   NULL_CONSISTENCY = 0, VERTEX_READ_CONSISTENCY, READ_CONSISTENCY, VERTEX_CONSISTENCY,   EDGE_CONSISTENCY, FULL_CONSISTENCY, USE_DEFAULT }
	scope types More...
enum	lock_type_enum { NO_LOCK = 0, READ_LOCK = 1, WRITE_LOCK = 2 }

---

Detailed Description

defines the types of scope consistency guarantees provided

There are several choices for consistency mechanisms in the graphlab framework. Each choice determines to what extent adjacent vertices can be operated on in parallel.

• Null Consistency: provides no guarantees allowing update functions to operate on the same vertex concurrently

• Vertex Read Consistency: On ensures that that you can read from the local vertex correctly

• Vertex Consistency: Ensures that a scope is aquired by only one processor at a time

• Edge Consistency: Ensures that adjacent vertices are not updated simultaneoulsy. If the update function only modifies the data on the scope vertex and its adjacent edges then this consistency model is sufficient to guarantee sequential consistency

• Fully Consistency: This consistency models guarantees sequential consistency but may limit the available parallelism. Effectively, this consistency model ensures that overlapping scopes cannot be executed simultaneously.

The scope_range_enum is passed to the engine through the iengine interface or set using the engine factory.

Definition at line 71 of file iscope.hpp.

---

Member Enumeration Documentation

enum graphlab::scope_range::scope_range_enum

scope types

Enumerator:

NULL_CONSISTENCY	no locks
VERTEX_READ_CONSISTENCY	read only from self
READ_CONSISTENCY	read from self and adjacent structures
VERTEX_CONSISTENCY	write to self. no lock on adjacent
EDGE_CONSISTENCY	write to self, read from adjacent structures
FULL_CONSISTENCY	write to self and adjacent structures

Definition at line 73 of file iscope.hpp.

---

The documentation for this struct was generated from the following file:

• src/graphlab/scope/iscope.hpp