dotMemory Unit 2.3 Help

Working with Object Sets

Object set is a number of objects selected by specific condition. To ease the understanding, think of an object set as of the result of some query, like "Select all objects of the string type promoted to Gen 2", or "Select all objects retained in memory by the instance A", and so on. An ObjectSet instance is returned as a result of the ObjectSet.GetObjects and ObjectSet.GetExclusivelyRetainedObjects methods.

To slice data by a number of conditions, you can build chains of GetObjects calls. The ObjectSet type has two properties that you can use in test assertions: ObjectsCount and SizeInBytes.

Example

For example, the following code asserts that there are no string and Foo objects in the Large Object Heap:

dotMemory.Check(memory => { Assert.That(memory.GetObjects(where => where.Type.Is(typeof(string), typeof(Foo))) .GetObjects(where => where.Generation.Is(Generation.LOH)).ObjectsCount, Is.EqualTo(0)); });

dotMemory Unit also provides alternative syntax for object set queries. You can use the == , &, and | logic operators to combine a number of queries. For example:

Assert.That(memory.GetObjects(where => where.Type == (typeof(string)) & where.Generation == Generation.LOH).ObjectsCount, Is.EqualTo(0));

ObjectSet Class

Represents a set of objects in memory.

ObjectSet Methods

NameDescription
GetObjects(Func<ObjectProperty, Query> query): ObjectSet Gets a subset of objects by a specific condition. The condition is defined by a Query that should be returned by a lambda expression. The ObjectProperty object passed to the lambda allows creating queries that select objects by type, interface, and other parameters.
Returns an instance of the ObjectSet type.
GetObjects(ObjectSetQuery objectSetQuery): ObjectSet Gets a subset of objects by a specific condition. The condition is defined by a reusable query - an instance of the ObjectSetQuery type. See QueryBuilder for details.
Returns an instance of the ObjectSet type.
GetExclusivelyRetainedObjects(): ObjectSet Gets a set of objects that are exclusively retained (dominated) by the current object set.
Returns an instance of the ObjectSet type.

ObjectSet Properties

NameTypeDescription
ObjectsCount int Total number of objects in the set.
SizeInBytes long Total size of objects in the set in bytes.

ObjectProperty Class

Selects objects in a set by a specific condition: type, interface, and others.

ObjectProperty Methods

NameDescription
LeakedOnEventHandler(): Query Creates the "Select all objects that cause the event handlers leak" query. Learn more.
Returns Query that can be used by the GetObjects method.
IsNotDominated(): Query Creates the query "Select all objects that are not exclusively retained in memory (in other words, objects that are retained by more than one object)".
Returns Query that can be used by the GetObjects method.

ObjectProperty Properties

NameTypeDescription
Type TypeProperty Allows selecting objects by type.
Interface InterfaceProperty Allows selecting objects by interface.
Namespace NamespaceProperty Allows selecting objects by namespace.
Assembly AssemblyProperty Allows selecting objects by assembly.
Generation GenerationProperty Allows selecting objects by generation.

TypeProperty Class

TypeProperty is used to create "select objects by type" queries.

TypeProperty Methods

NameDescription
Is(params Type[] typeList): Query Creates the "Select all objects of particular types" query. The list of types is passed in a Type array. Open generic types are also supported.
Returns Query that can be used by the GetObjects method.
Is<T>: Query Creates the "Select all objects of a particular type" query. Open generic types are also supported.
Returns Query that can be used by the GetObjects method.
IsNot(params Type[] typeList): Query Creates the "Select all objects that do not belong to particular types" query. The list of types is passed in a Type array. Open generic types are also supported.
Returns Query that can be used by the GetObjects method.
IsNot<T>: Query Creates the "Select all objects that do not belong to a particular type" query. Open generic types are also supported.
Returns Query that can be used by the GetObjects method.
Like(params string[] typeWildcard): Query Creates the "Select all objects of particular types" query. The list of types is passed in a string array. Asterisk (*) wildcards are allowed.
Returns Query that can be used by the GetObjects method.
NotLike(params string[] typeWildcard): Query Creates the "Select all objects that do not belong to particular types" query. The list of types is passed in a string array. Asterisk (*) wildcards are allowed.
Returns Query that can be used by the GetObjects method.

InterfaceProperty Class

InterfaceProperty is used to create "select objects by interface" queries.

InterfaceProperty Methods

NameDescription
Is(params Type[] typeList): Query Creates the "Select all objects that implement particular interfaces" query. The list of interfaces is passed in a Type array. Open generic interfaces are also supported.
Returns Query that can be used by the GetObjects method.
Is<T>: Query Creates the "Select all objects that implement a particular interface" query. Open generic interfaces are also supported.
Returns Query that can be used by the GetObjects method.
IsNot(params Type[] typeList): Query Creates the "Select all objects that do not implement particular interfaces" query. The list of interfaces is passed in a Type array. Open generic interfaces are also supported.
Returns Query that can be used by the GetObjects method.
IsNot<T>: Query Creates the "Select all objects that do not implement a particular interface" query. Open generic interfaces are also supported.
Returns Query that can be used by the GetObjects method.
Like(params string[] typeWildcard): Query Creates the "Select all objects that implement particular interfaces" query. The list of interfaces is passed in a string array. Asterisk (*) wildcards are allowed.
Returns Query that can be used by the GetObjects method.
NotLike(params string[] typeWildcard): Query Creates the "Select all objects that implement particular interfaces" query. The list of interfaces is passed in a string array. Asterisk (*) wildcards are allowed.
Returns Query that can be used by the GetObjects method.

NamespaceProperty Class

NamespaceProperty is used to create "select objects by namespace" queries.

NamespaceProperty Methods

NameDescription
Like(params string[] namespaceWildcard): Query Creates the "Select all objects that belong to particular namespaces" query. The list of namespaces is passed in a string array. Asterisk (*) wildcards are allowed.
Returns Query that can be used by the GetObjects method.
NotLike(params string[] namespaceWildcard): Query Creates the "Select all objects that do not belong to particular namespaces" query. The list of namespaces is passed in a string array. Asterisk (*) wildcards are allowed.
Returns Query that can be used by the GetObjects method.

AssemblyProperty Class

AssemblyProperty is used to create "select objects by assembly" queries.

AssemblyProperty Methods

NameDescription
Is(params Assembly[] assemblies): Query Creates the "Select all objects that belong to particular assemblies" query. The list of assemblies is passed in a Assembly array.
Returns Query that can be used by the GetObjects method.
IsNot(params Assembly[] assemblies): Query Creates the "Select all objects that do not belong to particular assemblies" query. The list of assemblies is passed in a Assembly array.
Returns Query that can be used by the GetObjects method.
Like(params string[] assemblyPattern): Query Creates the "Select all objects that belong to particular assemblies" query. The list of assemblies is passed in a string array.
Returns Query that can be used by the GetObjects method.
NotLike(params string[] assemblyPattern): Query Creates the "Select all objects that do not belong to particular assemblies" query. The list of assemblies is passed in a string array.
Returns Query that can be used by the GetObjects method.

GenerationProperty Class

GenerationProperty is used to create "select objects by generation" queries.

GenerationProperty Methods

NameDescription
Is(params Generation[] generations): Query Creates the "Select all objects from particular managed heap segments" query. The list of heap segments is passed in a Generation array.
Returns Query that can be used by the GetObjects method.
IsNot(params Generation[] generations): Query Creates the "Select all objects that do not belong to particular managed heap segments" query. The list of heap segments is passed in a Generation array.
Returns Query that can be used by the GetObjects method.

Generation Enum

Represents certain managed heap segments:

ValueDescription
Gen1 Generation 1 heap segment.
Gen2 Generation 2 heap segment.
LOH Large object heap.
Last modified: 23 May 2016