diff options
Diffstat (limited to 'www/c3ref/initialize.html')
-rw-r--r-- | www/c3ref/initialize.html | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/www/c3ref/initialize.html b/www/c3ref/initialize.html new file mode 100644 index 0000000..bfeba54 --- /dev/null +++ b/www/c3ref/initialize.html @@ -0,0 +1,205 @@ +<!DOCTYPE html> +<html><head> +<meta name="viewport" content="width=device-width, initial-scale=1.0"> +<meta http-equiv="content-type" content="text/html; charset=UTF-8"> +<link href="../sqlite.css" rel="stylesheet"> +<title>Initialize The SQLite Library</title> +<!-- path=../ --> +</head> +<body> +<div class=nosearch> +<a href="../index.html"> +<img class="logo" src="../images/sqlite370_banner.gif" alt="SQLite" border="0"> +</a> +<div><!-- IE hack to prevent disappearing logo --></div> +<div class="tagline desktoponly"> +Small. Fast. Reliable.<br>Choose any three. +</div> +<div class="menu mainmenu"> +<ul> +<li><a href="../index.html">Home</a> +<li class='mobileonly'><a href="javascript:void(0)" onclick='toggle_div("submenu")'>Menu</a> +<li class='wideonly'><a href='../about.html'>About</a> +<li class='desktoponly'><a href="../docs.html">Documentation</a> +<li class='desktoponly'><a href="../download.html">Download</a> +<li class='wideonly'><a href='../copyright.html'>License</a> +<li class='desktoponly'><a href="../support.html">Support</a> +<li class='desktoponly'><a href="../prosupport.html">Purchase</a> +<li class='search' id='search_menubutton'> +<a href="javascript:void(0)" onclick='toggle_search()'>Search</a> +</ul> +</div> +<div class="menu submenu" id="submenu"> +<ul> +<li><a href='../about.html'>About</a> +<li><a href='../docs.html'>Documentation</a> +<li><a href='../download.html'>Download</a> +<li><a href='../support.html'>Support</a> +<li><a href='../prosupport.html'>Purchase</a> +</ul> +</div> +<div class="searchmenu" id="searchmenu"> +<form method="GET" action="../search"> +<select name="s" id="searchtype"> +<option value="d">Search Documentation</option> +<option value="c">Search Changelog</option> +</select> +<input type="text" name="q" id="searchbox" value=""> +<input type="submit" value="Go"> +</form> +</div> +</div> +<script> +function toggle_div(nm) { +var w = document.getElementById(nm); +if( w.style.display=="block" ){ +w.style.display = "none"; +}else{ +w.style.display = "block"; +} +} +function toggle_search() { +var w = document.getElementById("searchmenu"); +if( w.style.display=="block" ){ +w.style.display = "none"; +} else { +w.style.display = "block"; +setTimeout(function(){ +document.getElementById("searchbox").focus() +}, 30); +} +} +function div_off(nm){document.getElementById(nm).style.display="none";} +window.onbeforeunload = function(e){div_off("submenu");} +/* Disable the Search feature if we are not operating from CGI, since */ +/* Search is accomplished using CGI and will not work without it. */ +if( !location.origin || !location.origin.match || !location.origin.match(/http/) ){ +document.getElementById("search_menubutton").style.display = "none"; +} +/* Used by the Hide/Show button beside syntax diagrams, to toggle the */ +function hideorshow(btn,obj){ +var x = document.getElementById(obj); +var b = document.getElementById(btn); +if( x.style.display!='none' ){ +x.style.display = 'none'; +b.innerHTML='show'; +}else{ +x.style.display = ''; +b.innerHTML='hide'; +} +return false; +} +var antiRobot = 0; +function antiRobotGo(){ +if( antiRobot!=3 ) return; +antiRobot = 7; +var j = document.getElementById("mtimelink"); +if(j && j.hasAttribute("data-href")) j.href=j.getAttribute("data-href"); +} +function antiRobotDefense(){ +document.body.onmousedown=function(){ +antiRobot |= 2; +antiRobotGo(); +document.body.onmousedown=null; +} +document.body.onmousemove=function(){ +antiRobot |= 2; +antiRobotGo(); +document.body.onmousemove=null; +} +setTimeout(function(){ +antiRobot |= 1; +antiRobotGo(); +}, 100) +antiRobotGo(); +} +antiRobotDefense(); +</script> +<!-- keywords: sqlite3_initialize sqlite3_os_end sqlite3_os_init sqlite3_shutdown --> +<div class=nosearch> +<a href="intro.html"><h2>SQLite C Interface</h2></a> +<h2>Initialize The SQLite Library</h2> +</div> +<blockquote><pre> +int sqlite3_initialize(void); +int sqlite3_shutdown(void); +int sqlite3_os_init(void); +int sqlite3_os_end(void); +</pre></blockquote> +<p> +The sqlite3_initialize() routine initializes the +SQLite library. The sqlite3_shutdown() routine +deallocates any resources that were allocated by sqlite3_initialize(). +These routines are designed to aid in process initialization and +shutdown on embedded systems. Workstation applications using +SQLite normally do not need to invoke either of these routines.</p> + +<p>A call to sqlite3_initialize() is an "effective" call if it is +the first time sqlite3_initialize() is invoked during the lifetime of +the process, or if it is the first time sqlite3_initialize() is invoked +following a call to sqlite3_shutdown(). Only an effective call +of sqlite3_initialize() does any initialization. All other calls +are harmless no-ops.</p> + +<p>A call to sqlite3_shutdown() is an "effective" call if it is the first +call to sqlite3_shutdown() since the last sqlite3_initialize(). Only +an effective call to sqlite3_shutdown() does any deinitialization. +All other valid calls to sqlite3_shutdown() are harmless no-ops.</p> + +<p>The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() +is not. The sqlite3_shutdown() interface must only be called from a +single thread. All open <a href="../c3ref/sqlite3.html">database connections</a> must be closed and all +other SQLite resources must be deallocated prior to invoking +sqlite3_shutdown().</p> + +<p>Among other things, sqlite3_initialize() will invoke +sqlite3_os_init(). Similarly, sqlite3_shutdown() +will invoke sqlite3_os_end().</p> + +<p>The sqlite3_initialize() routine returns <a href="../rescode.html#ok">SQLITE_OK</a> on success. +If for some reason, sqlite3_initialize() is unable to initialize +the library (perhaps it is unable to allocate a needed resource such +as a mutex) it returns an <a href="../rescode.html">error code</a> other than <a href="../rescode.html#ok">SQLITE_OK</a>.</p> + +<p>The sqlite3_initialize() routine is called internally by many other +SQLite interfaces so that an application usually does not need to +invoke sqlite3_initialize() directly. For example, <a href="../c3ref/open.html">sqlite3_open()</a> +calls sqlite3_initialize() so the SQLite library will be automatically +initialized when <a href="../c3ref/open.html">sqlite3_open()</a> is called if it has not be initialized +already. However, if SQLite is compiled with the <a href="../compile.html#omit_autoinit">SQLITE_OMIT_AUTOINIT</a> +compile-time option, then the automatic calls to sqlite3_initialize() +are omitted and the application must call sqlite3_initialize() directly +prior to using any other SQLite interface. For maximum portability, +it is recommended that applications always invoke sqlite3_initialize() +directly prior to using any other SQLite interface. Future releases +of SQLite may require this. In other words, the behavior exhibited +when SQLite is compiled with <a href="../compile.html#omit_autoinit">SQLITE_OMIT_AUTOINIT</a> might become the +default behavior in some future release of SQLite.</p> + +<p>The sqlite3_os_init() routine does operating-system specific +initialization of the SQLite library. The sqlite3_os_end() +routine undoes the effect of sqlite3_os_init(). Typical tasks +performed by these routines include allocation or deallocation +of static resources, initialization of global variables, +setting up a default <a href="../c3ref/vfs.html">sqlite3_vfs</a> module, or setting up +a default configuration using <a href="../c3ref/config.html">sqlite3_config()</a>.</p> + +<p>The application should never invoke either sqlite3_os_init() +or sqlite3_os_end() directly. The application should only invoke +sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() +interface is called automatically by sqlite3_initialize() and +sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate +implementations for sqlite3_os_init() and sqlite3_os_end() +are built into SQLite when it is compiled for Unix, Windows, or OS/2. +When <a href="../custombuild.html">built for other platforms</a> +(using the <a href="../compile.html#os_other">SQLITE_OS_OTHER=1</a> compile-time +option) the application must supply a suitable implementation for +sqlite3_os_init() and sqlite3_os_end(). An application-supplied +implementation of sqlite3_os_init() or sqlite3_os_end() +must return <a href="../rescode.html#ok">SQLITE_OK</a> on success and some other <a href="../rescode.html">error code</a> upon +failure. +</p><p>See also lists of + <a href="objlist.html">Objects</a>, + <a href="constlist.html">Constants</a>, and + <a href="funclist.html">Functions</a>.</p> + |