Net Framework Part - II - Created By: Asst. Prof. Ashish Shah, J.M.Patel College of Commerce
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.Net
Net Framework
Part - II
Created By: Asst. Prof. Ashish Shah, J.M.Patel
College of Commerce 1Benefits of .Net
Simplify
p y the application
pp development
p :
There are several limitation with current developments
tools and techs that reduce developers productivity.
Development should become easier because the
.NET Framework provides a new set of tools, including
a large set of object oriented, extensible system-level
system level
classes.
The .NET framework brings the power of the os.
Whi h iis much
Which h closer
l tto th
the d
developer,
l th
through
h a rich
i h
set of classes and services that are more easily
accessible than anyy pprevious windows-based set of
APIs.
Created By: Asst. Prof. Ashish Shah, J.M.Patel
College of Commerce 2Benefits of .Net
The .Net framework simplifies development in the
long term.
Application Development are subject to the familiar
headaches of “DLL hell” that arise when component
registrations get corrupted or type library versions
get mixed upup.
The .net Framework overcomes these deployment
limitations by making components self-describing
self describing
through metadata, so removing the need for GUID-
based registration.
Created By: Asst. Prof. Ashish Shah, J.M.Patel
College of Commerce 3Benefits of .Net
XML Everywhere
y : .Net framework introduces XML
into every aspect of software development.
XML is common communication technology in
information in .net.
net
It is used as basis for a number of xml based
grammars that describe the limitation in the .net .
g
A grammar refers to a collection of fixed tags that
combine to describe a specific object or entity.
S XML provides
So id a unified
ifi d system
t ffor sharing
h i d data
t
within the .Net framework and between components
built using
g .net.
Created By: Asst. Prof. Ashish Shah, J.M.Patel
College of Commerce 4Benefits of .Net
UDA : It stands for Universal Data Access
Access.
In case of .Net UDA means that ability to
access data anytime
anytime, anywhere
anywhere, regardless
of what device is used.
Created By: Asst. Prof. Ashish Shah, J.M.Patel
College of Commerce 5Highlights of .Net Framework
The .Net Framework is made of layered,
y constituent
parts that provide the services, classes and tools that
work together to provide the .Net development
p
platform.
The high-level layers of .net framework are :
1) CLR : It provides reliable, secure execution envt and
supports multiple programming langs
langs.
2) Class Library : It provides set of factored, extensible
classes that area are used across all .Net complaint
langs.
3) Lang. and development tools : familiar langs. Such as
c++, vb and jjavascript
p are overhauled in .Net feature
sets are greatly.
Created By: Asst. Prof. Ashish Shah, J.M.Patel
College of Commerce 6Highlights of .Net Framework
The .Net
Net frame work is layered into
increasingly abstracted levels of functionality.
At the base of the framework CLR is present
provides the core managed execution envt.
that runs all .Net assembly code.
Next comes the class libraries which abstract
system level functionality into a set of
extensible classes the implement the
pp
application code.
Created By: Asst. Prof. Ashish Shah, J.M.Patel
College of Commerce 7Highlights of .Net Framework
Class Libraries :
1) The .net framework classes are similar in
concept to MFC namely they provide
developers with access to a wide range of
system services without having to do a lot
coding.
2) The framework classes are organized into
namespaces, which organize classes into
hierarchical structure of related groups.
g p
Created By: Asst. Prof. Ashish Shah, J.M.Patel
College of Commerce 8Highlights of .Net Framework
Framework classes save developers time
and effort, bcoz they provide an excellent
level of encapsulation
p support
pp for windows
system functionally.
The .Net framework provides classes at
different levels of abstraction.
At the lowest level,
level the base class library
provides a set of classes that give easy
access to windows API functionalilty.y
Created By: Asst. Prof. Ashish Shah, J.M.Patel
College of Commerce 9Compilers of .NET FRAMEWORK
There are 2 types of compilers:
1) JIT compiler : it is known as just in time compile. It
is an optimized compilers that analyzes MSIL and
convert it to native code as needed.
2) Traditional Compiler : The assembly is entirely
converted
t d into
i t native
ti code
d and d lloads
d single
i l
instruction set. Traditional compilers are less
optimized than JIT compilers, bcoz, they must be
compiling an entire assembly all at once, rather
than the parts that executed.
Created By: Asst. Prof. Ashish Shah, J.M.Patel
College of Commerce 10Primitive Data Types in .Net :
Primitive Data Types supported by compiler
and are located in the root system
namespace.
p
The table below shows a selection of the
most common primitive types.
Created By: Asst. Prof. Ashish Shah, J.M.Patel
College of Commerce 11Name in CLS Type Name in Description
MSIL Class
Assembler Library
(CTS) (
(SYSTEM.)
)
BOOL Yes Bool True/false
value
Char Yes Char Unicode 16
bit char
Class Yes Object Object string
Float32 Yes Single 32 bit float
Float64 Yes Double 64 bit float
Int8 No SByte Signed 8 bit
integer
Created By: Asst. Prof. Ashish Shah, J.M.Patel
College of Commerce 12Int16 Yes Int16 Signed 16
bit iinteger
t
Typedref No TypedRefer- Pointer +
ence runtime type
Unsigned int8 Yes Byte Unsigned 8
bit integer
Unsigned Yes Uint16 Unsigned 16
int16 bit integer
Created By: Asst. Prof. Ashish Shah, J.M.Patel
College of Commerce 13Garbage collection Algo.
The basic ggoal of g garbage
g collection is to look
for objects that are not being used by an
application.
T be
To b more technical,
h i l objects
bj that
h are not
referenced by code within the application can be
cleaned up
up.
During the cleaned up process :
* An object
object’ss finalize
a e method
et od is
s ca
called.
ed
Finalize method is written by the developer and
provides object specific cleanup code.
Created By: Asst. Prof. Ashish Shah, J.M.Patel
College of Commerce 14Garbage collection Algo.
Finalized method conti…
The memory associated with the object is
reclaimed. The trick to ggarbage
g collection is to
determine which objects are not referenced.
To determine this,, the garbage
g g collection algo
g
traverses active objects within an application.
To determine what objects are active or
referenced following rules are used :
Created By: Asst. Prof. Ashish Shah, J.M.Patel
College of Commerce 15Garbage collection Algo.
1) All object contained on a thread’s
thread s stack are
referenced, as are the objects they contain.
2)) All g
global objects
j and the object
j theyy contain
are referenced. Static object also considered
to be global and are hence part of this root.
3) All objects referred to by the cpu’s registers
are referenced, as are the objects they
contain.
i
Created By: Asst. Prof. Ashish Shah, J.M.Patel
College of Commerce 16Garbage collection Algo.
When the garbage collection process an object,
it makes sure that the object has not already
been added to the referenced list.
An object that was already traversed is skipped.
It is more efficient to skip an object that is
already referenced. This also prevents loops. If
such object were not skipped, a set of objects
implementing a circular queue would prove
“infinitely” dangerous.
Created By: Asst. Prof. Ashish Shah, J.M.Patel
College of Commerce 17Garbage collection Algo.
Once everyy referenced object
j has been added
to the graph, the garbage collection algo. Walks
up the managed heap (from bottom to top).
Regions in the heap that contained non
referenced objects are discarded and referenced
objects are moved down in the heap.
An invalid pointer now refers to each object that
is moved down the heap.
The ggarbage
g collection algorithm
g now traverse
the active objects and update the pointers
contained in each reference contained in each
reference to an object that has been moved.
Created By: Asst. Prof. Ashish Shah, J.M.Patel
College of Commerce 18Garbage collection Algo.
The final step is to reset the next object
pointer.
This is the point at which the next object is
allocated .
Created By: Asst. Prof. Ashish Shah, J.M.Patel
College of Commerce 19Managed Heap Organization..
Automatic memoryy managementg is one of the services
that the common language runtime provides during
managed execution.
Clr’s
Clr s GC manages the allocation and release of memory
for an application.
For developers, this means that they don’t have to write
code to perform memory management tasks when you
develop managed application.
Automatic Memory management can eliminate common
problems,
bl suchh as fforgetting
tti tto ffree an object
bj t and d
causing a memory leak or attempting to access memory
for an object that has already been freed.
Created By: Asst. Prof. Ashish Shah, J.M.Patel
College of Commerce 20Managed Heap Organization..
The main task in memory managed heap
organization is done by GC are :
1) Allocating Memory :
when new process is initialized, the runtime
reserves a contiguous region of address
space for the process. This reserved
address space is known as managed heap heap.
Created By: Asst. Prof. Ashish Shah, J.M.Patel
College of Commerce 21Managed Heap Organization..
The managed g heap p maintains a p pointer to the
address where next object in the heap will be
allocated. Initially this pointer is set to the
managed heap’s
heap s base address
address.
All ref. typed objects are allocated in heap.
When next object is created by application
application, the
GC allocates memory for it in the address space
immediately following the 1st object.
As long as space is available GC continues to
allocate space for new objects in this manner.
Created By: Asst. Prof. Ashish Shah, J.M.Patel
College of Commerce 22Managed Heap Organization..
Allocatingg memory y from the managed g heap p is
faster than unmanaged memory allocation.
2) Releasing Memory :
The GC’s
GC s optimizing engine determines the best
time to perform a collection based on the
allocations being made. When the garbage
collector
ll t performs
f a collection,
ll ti it releases
l th
the
memory for the objects that are no longer being
used by the application.
Every application has a set of roots. Each root
either refers to an object on the managed heap
or is set to null
null.
Created By: Asst. Prof. Ashish Shah, J.M.Patel
College of Commerce 23Managed Heap Organization..
An application
application’s s roots include global and static
object pointers, local variables and referenced
object parameters on a thread’s stack and cpu’s
registers.
The GC has access to the list of active roots that
the JIT (Just-in-Time) and the runtime maintain.
Using this list, it examines an application’s roots
and in the process it creates a graph that
contains all the objects that are reachable from
the roots
roots.
Created By: Asst. Prof. Ashish Shah, J.M.Patel
College of Commerce 24Managed Heap Organization..
Objects that are not in the graph are
unreachable from the application’s root. The
garbage
g g collector considers unreachable
objects garbage and will release the memory
allocated for them.
Created By: Asst. Prof. Ashish Shah, J.M.Patel
College of Commerce 25You can also read
