95 lines
5.2 KiB
HTML
95 lines
5.2 KiB
HTML
|
<html>
|
||
|
|
<head>
|
||
|
|
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
|
||
|
|
<title>Rationale</title>
|
||
|
|
<link rel="stylesheet" href="../../boostbook.css" type="text/css">
|
||
|
|
<meta name="generator" content="DocBook XSL Stylesheets V1.75.2">
|
||
|
|
<link rel="home" href="../../index.html" title="Asio">
|
||
|
|
<link rel="up" href="../overview.html" title="Overview">
|
||
|
|
<link rel="prev" href="../overview.html" title="Overview">
|
||
|
|
<link rel="next" href="basics.html" title="Basic Asio Anatomy">
|
||
|
|
<meta name="viewport" content="width=device-width, initial-scale=1">
|
||
|
|
</head>
|
||
|
|
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
|
||
|
|
<table cellpadding="2" width="100%"><tr><td valign="top"><img alt="asio C++ library" width="250" height="60" src="../../asio.png"></td></tr></table>
|
||
|
|
<hr>
|
||
|
|
<div class="spirit-nav">
|
||
|
|
<a accesskey="p" href="../overview.html"><img src="../../prev.png" alt="Prev"></a><a accesskey="u" href="../overview.html"><img src="../../up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../home.png" alt="Home"></a><a accesskey="n" href="basics.html"><img src="../../next.png" alt="Next"></a>
|
||
|
|
</div>
|
||
|
|
<div class="section">
|
||
|
|
<div class="titlepage"><div><div><h3 class="title">
|
||
|
|
<a name="asio.overview.rationale"></a><a class="link" href="rationale.html" title="Rationale">Rationale</a>
|
||
|
|
</h3></div></div></div>
|
||
|
|
<p>
|
||
|
|
Most programs interact with the outside world in some way, whether it be
|
||
|
|
via a file, a network, a serial cable, or the console. Sometimes, as is the
|
||
|
|
case with networking, individual I/O operations can take a long time to complete.
|
||
|
|
This poses particular challenges to application development.
|
||
|
|
</p>
|
||
|
|
<p>
|
||
|
|
Asio provides the tools to manage these long running operations, without
|
||
|
|
requiring programs to use concurrency models based on threads and explicit
|
||
|
|
locking.
|
||
|
|
</p>
|
||
|
|
<p>
|
||
|
|
The Asio library is intended for programmers using C++ for systems programming,
|
||
|
|
where access to operating system functionality such as networking is often
|
||
|
|
required. In particular, Asio addresses the following goals:
|
||
|
|
</p>
|
||
|
|
<div class="itemizedlist"><ul class="itemizedlist" type="disc">
|
||
|
|
<li class="listitem">
|
||
|
|
<span class="bold"><strong>Portability.</strong></span> The library should support
|
||
|
|
a range of commonly used operating systems, and provide consistent behaviour
|
||
|
|
across these operating systems.
|
||
|
|
</li>
|
||
|
|
<li class="listitem">
|
||
|
|
<span class="bold"><strong>Scalability.</strong></span> The library should facilitate
|
||
|
|
the development of network applications that scale to thousands of concurrent
|
||
|
|
connections. The library implementation for each operating system should
|
||
|
|
use the mechanism that best enables this scalability.
|
||
|
|
</li>
|
||
|
|
<li class="listitem">
|
||
|
|
<span class="bold"><strong>Efficiency.</strong></span> The library should support
|
||
|
|
techniques such as scatter-gather I/O, and allow programs to minimise
|
||
|
|
data copying.
|
||
|
|
</li>
|
||
|
|
<li class="listitem">
|
||
|
|
<span class="bold"><strong>Model concepts from established APIs, such as BSD
|
||
|
|
sockets.</strong></span> The BSD socket API is widely implemented and understood,
|
||
|
|
and is covered in much literature. Other programming languages often
|
||
|
|
use a similar interface for networking APIs. As far as is reasonable,
|
||
|
|
Asio should leverage existing practice.
|
||
|
|
</li>
|
||
|
|
<li class="listitem">
|
||
|
|
<span class="bold"><strong>Ease of use.</strong></span> The library should provide
|
||
|
|
a lower entry barrier for new users by taking a toolkit, rather than
|
||
|
|
framework, approach. That is, it should try to minimise the up-front
|
||
|
|
investment in time to just learning a few basic rules and guidelines.
|
||
|
|
After that, a library user should only need to understand the specific
|
||
|
|
functions that are being used.
|
||
|
|
</li>
|
||
|
|
<li class="listitem">
|
||
|
|
<span class="bold"><strong>Basis for further abstraction.</strong></span> The library
|
||
|
|
should permit the development of other libraries that provide higher
|
||
|
|
levels of abstraction. For example, implementations of commonly used
|
||
|
|
protocols such as HTTP.
|
||
|
|
</li>
|
||
|
|
</ul></div>
|
||
|
|
<p>
|
||
|
|
Although Asio started life focused primarily on networking, its concepts
|
||
|
|
of asynchronous I/O have been extended to include other operating system
|
||
|
|
resources such as serial ports, file descriptors, and so on.
|
||
|
|
</p>
|
||
|
|
</div>
|
||
|
|
<div class="copyright-footer">Copyright © 2003-2023 Christopher M. Kohlhoff<p>
|
||
|
|
Distributed under the Boost Software License, Version 1.0. (See accompanying
|
||
|
|
file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
|
||
|
|
</p>
|
||
|
|
</div>
|
||
|
|
<hr>
|
||
|
|
<div class="spirit-nav">
|
||
|
|
<a accesskey="p" href="../overview.html"><img src="../../prev.png" alt="Prev"></a><a accesskey="u" href="../overview.html"><img src="../../up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../home.png" alt="Home"></a><a accesskey="n" href="basics.html"><img src="../../next.png" alt="Next"></a>
|
||
|
|
</div>
|
||
|
|
</body>
|
||
|
|
</html>
|