Ascentis.Infrastructure 2.9.0.22

Ascentis.Infrastructure Library

This library offers a a few general purpose components:

AsyncDisposer

Use this static class to dispose of IDisposable objects using async semantics. When to use this? If you use third party software which you can't modify that has caused you trouble when disposing objects on an event which later makes software beyond your control throw exceptions because somewhere in the call stack it tries to use the diposed object. With this class you can enqueue the IDisposable instance in the AsyncDisposer queue and it will be guaranteed to stay in queue for a specified global period of time before being take for disposal. Tune the timing in a way that gives time enough for the calling procedure in the stack to complete and return to the caller.

A second class part of this package is ConcurrentObjectAccessor<>. This class allows to wrap an object within it and allow for protected access to execute functions within a readlock. This allows usage of method SwapAndExecute() which allow to swap safely the underlying reference wrapped. When to use this? When dealing with COM, COM+ or DCOM objects prone to crashing or suffering from network partitions. With this class the COM object can be isolated behing a wrapper relying on ConcurrentObjectAccessor and the low level object can be replaced transparently upon detection of partition exception.

Retrier

This class allows to wrap function or procedure calls in a try-catch block that would retry operations based on on a delegate function returning true or false. Can be combined with ConcurrentObjectAccessor to replace transparently a low level object upon certain conditions.

ConcurrentObjectAccessor

This class allows to control usage of an object reference permitting multiple concurrent threads using it for reading its value (and executing code with it), while only one thread can write to the reference at the same time. The main purpose is to replace a failing object transparently upon detection of a faulty condition. A concrete example is a COM+ object which crashed. The reference to this object is worthless until replaced by a new COM+ object instance.

SolidComPlus

This class encapsulates a COM+ object instance allowing the user to implement automatic swapping of a dead object.

BoundedParallel

Use instead of standard static Parallel class to gain control of the number of concurrent calls that be executed using Parallel static class. This allows to control the number of threads from the default .NET threadpool to avoid a runaway scenario where .NET has to keep trying to add more threads. If a high number of callers attempt multiple concurrent calls to Parallel methods it can fall into what's called "Hill Climbing" algorithm causing high contention as .NET tries to add more threads slowly

AutoInit

Small utilitarian class that allow to initialize automatically a reference to an object provided the reference, a generic type and optional constructor parameters. This class depends on GenericObjectBuilder static class.

GenericObjectBuilder

This class allows to build an object of any class provided the generic type and either parameters or an array of parameter types and parameters. This class will build expression tree based constructors and cache them based on the signature of the return type and the parameter types passed to the constructor.

Resettable

This class allows to "reset" the state of something using a small helper IDisposable interface that upon leaving the using scope it will call the a reset delegate method.

ConcurrentIncrementableResettable

Utilitarian class relying on Resettable to allow incrementing an int in a thread safe manner and automatically decrementing the value by the same amount when a helper object (Resettable) leaves the using scope.

Pool

Generalized Pool class. Will build instances lazily and wait for new objects returned to the pool when exhausted. Usage relies on simple Acquire() and Release() methods.

Conveyor

Abstraction on top of a Thread that allows for continuous processing of objects passed by calling InsertPacket method.