Editing Shared library (section)

==Optimizations==
Since shared libraries on most systems do not change often, systems can compute a likely load address for each shared library on the system before it is needed and store that information in the libraries and executables. If every shared library that is loaded has undergone this process, then each will load at its predetermined address, which speeds up the process of dynamic linking. This optimization is known as [[prebinding|prebinding or prelinking]] on macOS and Linux, respectively. IBM [[z/VM]] uses a similar technique, called "Discontinuous Saved Segments" (DCSS).<ref>{{cite book |last1=IBM Corporation |title=Saved Segments Planning and Administration |date=2011 |url=http://publibfp.boulder.ibm.com/epubs/pdf/hcsg4c10.pdf |access-date=Jan 29, 2022}}</ref> Disadvantages of this technique include the time required to precompute these addresses every time the shared libraries change, the inability to use [[address space layout randomization]], and the requirement of sufficient virtual address space for use (a problem that will be alleviated by the adoption of [[64-bit]] architectures, at least for the time being).