Skip to main content

Difference Between Static And Shared Libraries ?

By
Libraries are collection of precompiled functions which have been written to be reusable.

Libraries in Linux are classified into two types:

1) Static Libraries:- The collection of object files kept together. When a program needs a function, that is stored in static library, it includes the header file that declares the function. The compiler combines the program code and linker links the library into an execuatble code.

Static Libraries are also called as archives that ends with .a extension.

e.g. /usr/lib/libc.a is a standard C library.

Disadvantage of Static Libraries:- In the static libraries the function code is included in the executable. So when we run many applications that use the same function code, we end up with many copies of same functions in memory.

2) Shared Libraries:- When a program uses a function in a shared library, then that code does not get included in the execuatable. Instead it references to shared code that will be made available at run time. So when that program is loaded in memory to execute, the functions references are resolved and calls are maded to shared libraries which will be loaded into memory.

So many applications uses a single copy of shared libraries. Also shared libraries can be updated independently of the applications that rely on it.

Shared libraries has the form libname.so.N

name - name of library so - extension N - major revision number

e.g. libc.so.5

Shared libraries(.so) are just like Dynamic Link Libraries(.dll) in Windows.

Labels:

Comments

Post a Comment

Popular posts from this blog

Dotnet, .Net 3.5, 2.0, C# Interview Questions

By
Few questions on dotnet, C# 2.0, 3.5 On Object oriented concepts 1)What is inheritance with e.g 2)What is polymorphism -function overloading -Function overriding -virtual keyword use -Static keyword and use -Abstract classes -Interface -Object 3)What is threading and how do we use in realtime application(cognizant) 4)What is threadpooling, lock, monitor(write code sample) 5)Architecture of current project 6)Session state, diffrent types of state management. 7)What is Application_Start, how it works. 8)Type of authentication in asp.net 9)How to configure ASP.NET application. 10) What is Impersonation. 11) What is WebService, WSDL, UDDI, Discovery, asmx files. 12) How to implement WebService and use it. 13) When to use WebServices. 14) WPF, how to implement(BOA) 15) Testing concvepts. 16) Test attributes 17) Flow of Automation Test Method execution 18) Features of dotnet 3.5 19) CLR, garbage collection 20) Finally block 21) Manifest, Metadata, MSIL 22) Assemblies, Type of assemblies, str...
2 comments
Read more

Linux SMB write performance With Simple Tips

By
SMB write performance can be increased by Tuning the buffer cache. The secret to good performance is to keep as much of the data in memory for as long as is possible. Writing to the disk is the slowest part of any filesystem. If you know that the filesystem will be heavily used, then you can tune this process for Linux Samba. writing out dirty blocks to the disk until the filesystem buffer cache is 80 percent full (80). default is 40%, source = http://tldp.org/LDP/solrhe/Securing-Optimizing-Linux-RH-Edition-v1.3/chap29sec287.html by writing echo 80 > /proc/sys/vm/dirty_ratio I am getting around 2MB increase while write operation, tested in Xp. I have tried with this single option, as the ref source is for linux 2.2 and we are using 2.6 kernel. we can try out Linux General Optimization suggested at http://tldp.org/LDP/solrhe/Securing-Optimizing-Linux-RH-Edition-v1.3/gen-optim.html Tried with smb.conf, I am getting around 1MB gain while read and write. socket options = TCP_NODELAY I...
Post a Comment
Read more

The Linux Foundation Free Training Program at linuxfoundation

By
The Linux Foundation Training Program is: * For the Community, by the Community. The Linux Foundation is building the program with its Technical Advisory Board to ensure the content, instructors and classes are the top quality available. * Technically the most advanced. Since the Linux Foundation works directly with community developers, it can cover features and advances in Linux before commercial companies. * Connected. The Linux Foundation has unfettered access to the leading developers and companies in the Linux ecosystem and will use these connections to best position attendees for success. For example, attendees can attend the exclusive, invite-only Collaboration Summit where they can forge connections beneficial to their career. * Real World. The Linux Foundation training courses all have hands on components and a highly rigorous curriculum of programming or administration exercises. Graduates will be well equipped to master Linux programming and system administr...
Post a Comment
Read more