Program lifecycle phase
A program lifecycle phase is a distinct period of time that is relevant to the operation of a computer program as it transitions from development to execution. Any distinct period in a program's life cycle in which the operational state of the program changes can be identified as a time. For example, compile time is when a program is compiled and link time is when a program is linked. Also, phases can often be divided into component phases. For example, build time might be divided into compile and link times, compile time into parse and code-generation times, and run time into initialization and normal-operation times.
A program tends to transition through phases in sequences, but often not from first to last and sometimes some are skipped. For example, when programming, a developer may repeatedly edit, build, and run a program without distributing or installing it. After programming is complete, then it may be distributed to and installed by a user.
Even though the term program lifecycle phase is less than notable, the times (phases) are well-known, commonly-used and notable. The collective term is used for this article for lack of a better term.
Examples
[edit]The operational phases of a program vary by its development technology. For example, a compiled program involves compile and link phases, but an interpreted program has no such phases – is distributed as source code. Even for compiled programs, the phases vary. For example, some runtimes (such as for .Net and Java) include a just-in-time compilation phase, yet more traditional runtimes (such as for C) do not.
The phases for a program that is compiled to a host-native executable typically include:
- Design time (a.k.a. edit time)
- When the program source code is being authored. This includes initial coding as well as bug fixes, new features, and refactoring.[1]
- Compile time
- When source code is compiled to object code – machine code plus information for linking.[2]
- Link time
- When object code and external libraries are linked – combined to form an executable. Functions and data from a library are linked either via static linking (performed at link time) or dynamic linking (performed at load time).[3]
- Distribution time
- When the program is transferring to a user – often downloaded from the Internet or via physical media such as a USB flash drive.[4]
- Installation time
- When the program is installed. The executable and related files are stored such that the host computer can readily run the program.[5]
- Load time
- When the program is loaded – including copying the machine code into executable memory and resolving dynamic linkages.[6][7]
- Run time
- When the program is running. The central processing unit executes the program's machine code instructions.[8][9]
Use
[edit]Describe binding time
[edit]Binding time describes whether an association between entities is fixed either before (early) or after (late) the program starts running. The phases described here provide a way to describe when the binding occurs more precisely. For example, an early binding might be made at design, compile or link time.
Parallel computing
[edit]One of the key functions of parallel computing development is specializing the code to the host runtime environment.[10][11] Such specialization cannot be performed before that environment is known. If the desire is for the same code to run on a variety of hardware platforms, then such specialization cannot happen during edit or compile phases. The earliest phase would be the distribution phase,[12] if a system were put in place that gathers hardware information, then chooses an executable that is already specialized to that hardware or substantially similar hardware, or generates a specialized binary on the fly. Likewise, specialization could be performed at load time,[13] by invoking a binary rewriting tool [14] in combination with a tool that uses the control flow structure to generate a specialized form.
References
[edit]- ^ Franchitti, Jean-Claude (13 November 2024). "4.2 Building C Programs". Introduction to Computer Science. OpenStax. Retrieved 12 November 2025.
- ^ Aho, Alfred V.; Lam, Monica S.; Sethi, Ravi; Ullman, Jeffrey D. (2006). Compilers: Principles, Techniques, and Tools (2nd ed.). Addison-Wesley. ISBN 978-0321486813.
- ^ Levine, John R. (1999). Linkers and Loaders. Morgan Kaufmann. ISBN 978-1558604964.
- ^ "Software Distribution – an overview". ScienceDirect Topics. Elsevier. Retrieved 12 November 2025.
- ^ "Overview of Windows Installer". Microsoft Learn. Microsoft. 7 January 2021. Retrieved 12 November 2025.
- ^ "ld.so(8) — dynamic linker/loader". man7.org Linux man-pages. Michael Kerrisk. Retrieved 12 November 2025.
- ^ "Linking (CS:APP lecture slides) — load-time vs run-time dynamic linking" (PDF). Carnegie Mellon University. 26 October 2023. Retrieved 12 November 2025.
- ^ "execve(2) — execute program". man7.org Linux man-pages. Michael Kerrisk. Retrieved 12 November 2025.
- ^ "Linking (CS:APP lecture slides) — run-time dynamic linking (dlopen)" (PDF). Carnegie Mellon University. 26 October 2023. Retrieved 12 November 2025.
- ^ Midkiff, Samuel P. (2012). Automatic Parallelization: An Overview of Fundamental Compiler Techniques (PDF). Synthesis Lectures on Computer Architecture. Morgan & Claypool. ISBN 978-1608458103. Retrieved 12 November 2025.
- ^ "Device targeting (beta)". Android Developers. Google. 21 July 2025. Retrieved 12 November 2025.
- ^ "LTO (Link Time Optimization)". GCC Internals Manual. Free Software Foundation. Retrieved 12 November 2025.
- ^ Panchenko, Maksim; Fedorov, Andrey; Ottoni, Guilherme; Condon, Rodrigo (2019). BOLT: A Practical Binary Optimizer for Data Centers and Beyond. IEEE. pp. 2–14. doi:10.1109/CGO.2019.8661187. Retrieved 12 November 2025.