Editing Netscape Portable Runtime

{{Short description|C programming language library}}
{{Multiple issues|
{{Primary sources|date=January 2024}}
{{Notability|date=January 2024}}
}}
{{Infobox software
| name = Netscape Portable Runtime
| caption = 
| latest release version = {{wikidata|property|reference|edit|P348}}
| latest release date = {{release date and age|{{wikidata|qualifier|P348|P577}}}}
| programming language = [[C (programming language)|C]]
| developer = [[Mozilla Foundation]] / [[Mozilla Corporation]]
| operating system = [[Cross-platform]]
| genre = [[Library (computer science)|Software library]]
| license = [[Mozilla Public License|MPL]]
| website = {{URL|https://firefox-source-docs.mozilla.org/nspr/index.html}}
}}

The '''Netscape Portable Runtime''', or '''NSPR''', is a cross-platform [[abstraction layer]] library for the [[C programming language]]. It provides a uniform [[API]] for various operating system functions.<ref name="nspr-index">{{cite web |url=https://firefox-source-docs.mozilla.org/nspr/ |title=NSPR |website=Firefox Source Docs |publisher=Mozilla |access-date=2024-01-27}}</ref>

== History ==
NSPR was originally designed to provide a base for the [[Java virtual machine]] in [[Netscape 5]]. Over time it was extended to allow support for additional functionality used for Netscape's server and client software.<ref name="nspr-about">{{cite web |url=https://firefox-source-docs.mozilla.org/nspr/about_nspr.html |title=About NSPR |author=Larry H. |website=Firefox Source Docs |publisher=Mozilla |access-date=2024-01-27}}</ref> NSPR continues to be used today by Firefox as well as many of Oracle and Red Hat's server products.<ref name="nspr-index" />

== Features ==

=== Threads ===
NSPR provides a [[Thread (computer science)|thread]] API. It uses the OS's threading capabilities where possible. It also provides support for sharing memory between threads, as well as creating and using thread pools.
[[Lock (computer science)|Locks]], [[Linearizability#Primitive_atomic_instructions|atomics]], [[Semaphore_(programming)|semaphores]], and both cached and uncached [[Monitor (synchronization)|monitors]] are provided.<ref name="nspr-api">{{cite web |url=https://firefox-source-docs.mozilla.org/nspr/reference/index.html |title=NSPR API Reference |website=Firefox Source Docs |publisher=Mozilla |access-date=2024-01-27}}</ref>

=== I/O ===
NSPR provides functions for working with files, directories, [[Anonymous pipe|anonymous pipes]] and [[Network socket|network sockets]].<ref name="nspr-api" />

=== Network addresses ===
NSPR defines an [[Internet Protocol|IP]]-centric network address object. Functions are provided to translate [[ASCII]] strings ([[Domain Name System|DNS]] names) into NSPR's network address structures, regardless of whether the addressing technology uses IPv4 or IPv6.<ref name="nspr-about" /><ref name="nspr-api" />

=== Time ===
NSPR makes timing facilities available in two forms: interval timing and calendar functions.

Interval timers are based on a free running 32-bit resolution timer. Their [[epoch]] and interval can be set as needed.

Calendar times are represented using 64-bit signed [[Unix time]]. NSPR provides functions for manipulating and converting timestamps.<ref name="nspr-about" /><ref name="nspr-api" />

=== Memory management ===
NSPR provides API to perform the basic [[malloc]], [[calloc]], [[realloc]] and [[free (programming)|free]] functions. Depending on the platform, the functions may be implemented almost entirely in the NSPR runtime or simply [[shim (computing)|shims]] that call immediately into the host operating system's offerings.<ref name="nspr-about" /><ref name="nspr-api" />

=== Linking ===
Support for linking ([[shared library]] loading and unloading) forms part of NSPR's feature set. In most cases this is simply a smoothing over of the facilities offered by the various platform providers.<ref name="nspr-about" /><ref name="nspr-api" />

=== Data structures ===
NSPR provides implementations of a [[Linked_list#Circular_linked_list|circular linked list]] and a [[hash table]].<ref name="nspr-api" />

== See also ==
{{Portal|Free and open-source software}}
* [[Apache Portable Runtime]]
* [[Adaptive Communication Environment]]
* [[Cross-platform support middleware]]

==References==
{{Reflist}}

==External links==
* [https://developer.mozilla.org/docs/NSPR/ Official website]
* [https://ftp.mozilla.org/pub/mozilla.org/nspr/releases/ NSPR source code]

{{Mozilla projects}}

[[Category:Application programming interfaces]]
[[Category:Mozilla]]
[[Category:Netscape]]