392 lines
19 KiB
HTML
392 lines
19 KiB
HTML
|
<html>
|
||
|
|
<head>
|
||
|
|
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
|
||
|
|
<title>deadline_timer</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="../reference.html" title="Reference">
|
||
|
|
<link rel="prev" href="coroutine/is_parent.html" title="coroutine::is_parent">
|
||
|
|
<link rel="next" href="default_completion_token.html" title="default_completion_token">
|
||
|
|
<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="coroutine/is_parent.html"><img src="../../prev.png" alt="Prev"></a><a accesskey="u" href="../reference.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="default_completion_token.html"><img src="../../next.png" alt="Next"></a>
|
||
|
|
</div>
|
||
|
|
<div class="section">
|
||
|
|
<div class="titlepage"><div><div><h3 class="title">
|
||
|
|
<a name="asio.reference.deadline_timer"></a><a class="link" href="deadline_timer.html" title="deadline_timer">deadline_timer</a>
|
||
|
|
</h3></div></div></div>
|
||
|
|
<p>
|
||
|
|
<a class="indexterm" name="asio.indexterm.deadline_timer"></a>
|
||
|
|
</p>
|
||
|
|
<p>
|
||
|
|
Typedef for the typical usage of timer. Uses a UTC clock.
|
||
|
|
</p>
|
||
|
|
<pre class="programlisting"><span class="keyword">typedef</span> <span class="identifier">basic_deadline_timer</span><span class="special"><</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">posix_time</span><span class="special">::</span><span class="identifier">ptime</span> <span class="special">></span> <span class="identifier">deadline_timer</span><span class="special">;</span>
|
||
|
|
</pre>
|
||
|
|
<h5>
|
||
|
|
<a name="asio.reference.deadline_timer.h0"></a>
|
||
|
|
<span><a name="asio.reference.deadline_timer.types"></a></span><a class="link" href="deadline_timer.html#asio.reference.deadline_timer.types">Types</a>
|
||
|
|
</h5>
|
||
|
|
<div class="informaltable"><table class="table">
|
||
|
|
<colgroup>
|
||
|
|
<col>
|
||
|
|
<col>
|
||
|
|
</colgroup>
|
||
|
|
<thead><tr>
|
||
|
|
<th>
|
||
|
|
<p>
|
||
|
|
Name
|
||
|
|
</p>
|
||
|
|
</th>
|
||
|
|
<th>
|
||
|
|
<p>
|
||
|
|
Description
|
||
|
|
</p>
|
||
|
|
</th>
|
||
|
|
</tr></thead>
|
||
|
|
<tbody>
|
||
|
|
<tr>
|
||
|
|
<td>
|
||
|
|
<p>
|
||
|
|
<a class="link" href="basic_deadline_timer__rebind_executor.html" title="basic_deadline_timer::rebind_executor"><span class="bold"><strong>rebind_executor</strong></span></a>
|
||
|
|
</p>
|
||
|
|
</td>
|
||
|
|
<td>
|
||
|
|
<p>
|
||
|
|
Rebinds the timer type to another executor.
|
||
|
|
</p>
|
||
|
|
</td>
|
||
|
|
</tr>
|
||
|
|
<tr>
|
||
|
|
<td>
|
||
|
|
<p>
|
||
|
|
<a class="link" href="basic_deadline_timer/duration_type.html" title="basic_deadline_timer::duration_type"><span class="bold"><strong>duration_type</strong></span></a>
|
||
|
|
</p>
|
||
|
|
</td>
|
||
|
|
<td>
|
||
|
|
<p>
|
||
|
|
The duration type.
|
||
|
|
</p>
|
||
|
|
</td>
|
||
|
|
</tr>
|
||
|
|
<tr>
|
||
|
|
<td>
|
||
|
|
<p>
|
||
|
|
<a class="link" href="basic_deadline_timer/executor_type.html" title="basic_deadline_timer::executor_type"><span class="bold"><strong>executor_type</strong></span></a>
|
||
|
|
</p>
|
||
|
|
</td>
|
||
|
|
<td>
|
||
|
|
<p>
|
||
|
|
The type of the executor associated with the object.
|
||
|
|
</p>
|
||
|
|
</td>
|
||
|
|
</tr>
|
||
|
|
<tr>
|
||
|
|
<td>
|
||
|
|
<p>
|
||
|
|
<a class="link" href="basic_deadline_timer/time_type.html" title="basic_deadline_timer::time_type"><span class="bold"><strong>time_type</strong></span></a>
|
||
|
|
</p>
|
||
|
|
</td>
|
||
|
|
<td>
|
||
|
|
<p>
|
||
|
|
The time type.
|
||
|
|
</p>
|
||
|
|
</td>
|
||
|
|
</tr>
|
||
|
|
<tr>
|
||
|
|
<td>
|
||
|
|
<p>
|
||
|
|
<a class="link" href="basic_deadline_timer/traits_type.html" title="basic_deadline_timer::traits_type"><span class="bold"><strong>traits_type</strong></span></a>
|
||
|
|
</p>
|
||
|
|
</td>
|
||
|
|
<td>
|
||
|
|
<p>
|
||
|
|
The time traits type.
|
||
|
|
</p>
|
||
|
|
</td>
|
||
|
|
</tr>
|
||
|
|
</tbody>
|
||
|
|
</table></div>
|
||
|
|
<h5>
|
||
|
|
<a name="asio.reference.deadline_timer.h1"></a>
|
||
|
|
<span><a name="asio.reference.deadline_timer.member_functions"></a></span><a class="link" href="deadline_timer.html#asio.reference.deadline_timer.member_functions">Member
|
||
|
|
Functions</a>
|
||
|
|
</h5>
|
||
|
|
<div class="informaltable"><table class="table">
|
||
|
|
<colgroup>
|
||
|
|
<col>
|
||
|
|
<col>
|
||
|
|
</colgroup>
|
||
|
|
<thead><tr>
|
||
|
|
<th>
|
||
|
|
<p>
|
||
|
|
Name
|
||
|
|
</p>
|
||
|
|
</th>
|
||
|
|
<th>
|
||
|
|
<p>
|
||
|
|
Description
|
||
|
|
</p>
|
||
|
|
</th>
|
||
|
|
</tr></thead>
|
||
|
|
<tbody>
|
||
|
|
<tr>
|
||
|
|
<td>
|
||
|
|
<p>
|
||
|
|
<a class="link" href="basic_deadline_timer/async_wait.html" title="basic_deadline_timer::async_wait"><span class="bold"><strong>async_wait</strong></span></a>
|
||
|
|
</p>
|
||
|
|
</td>
|
||
|
|
<td>
|
||
|
|
<p>
|
||
|
|
Start an asynchronous wait on the timer.
|
||
|
|
</p>
|
||
|
|
</td>
|
||
|
|
</tr>
|
||
|
|
<tr>
|
||
|
|
<td>
|
||
|
|
<p>
|
||
|
|
<a class="link" href="basic_deadline_timer/basic_deadline_timer.html" title="basic_deadline_timer::basic_deadline_timer"><span class="bold"><strong>basic_deadline_timer</strong></span></a> <span class="silver">[constructor]</span>
|
||
|
|
</p>
|
||
|
|
</td>
|
||
|
|
<td>
|
||
|
|
<p>
|
||
|
|
Constructor. <br> <span class="silver"> —</span><br> Constructor to set a particular expiry
|
||
|
|
time as an absolute time. <br> <span class="silver"> —</span><br> Constructor to set a particular
|
||
|
|
expiry time relative to now. <br> <span class="silver"> —</span><br> Move-construct a basic_deadline_timer
|
||
|
|
from another.
|
||
|
|
</p>
|
||
|
|
</td>
|
||
|
|
</tr>
|
||
|
|
<tr>
|
||
|
|
<td>
|
||
|
|
<p>
|
||
|
|
<a class="link" href="basic_deadline_timer/cancel.html" title="basic_deadline_timer::cancel"><span class="bold"><strong>cancel</strong></span></a>
|
||
|
|
</p>
|
||
|
|
</td>
|
||
|
|
<td>
|
||
|
|
<p>
|
||
|
|
Cancel any asynchronous operations that are waiting on the timer.
|
||
|
|
</p>
|
||
|
|
</td>
|
||
|
|
</tr>
|
||
|
|
<tr>
|
||
|
|
<td>
|
||
|
|
<p>
|
||
|
|
<a class="link" href="basic_deadline_timer/cancel_one.html" title="basic_deadline_timer::cancel_one"><span class="bold"><strong>cancel_one</strong></span></a>
|
||
|
|
</p>
|
||
|
|
</td>
|
||
|
|
<td>
|
||
|
|
<p>
|
||
|
|
Cancels one asynchronous operation that is waiting on the timer.
|
||
|
|
</p>
|
||
|
|
</td>
|
||
|
|
</tr>
|
||
|
|
<tr>
|
||
|
|
<td>
|
||
|
|
<p>
|
||
|
|
<a class="link" href="basic_deadline_timer/expires_at.html" title="basic_deadline_timer::expires_at"><span class="bold"><strong>expires_at</strong></span></a>
|
||
|
|
</p>
|
||
|
|
</td>
|
||
|
|
<td>
|
||
|
|
<p>
|
||
|
|
Get the timer's expiry time as an absolute time. <br> <span class="silver"> —</span><br>
|
||
|
|
Set the timer's expiry time as an absolute time.
|
||
|
|
</p>
|
||
|
|
</td>
|
||
|
|
</tr>
|
||
|
|
<tr>
|
||
|
|
<td>
|
||
|
|
<p>
|
||
|
|
<a class="link" href="basic_deadline_timer/expires_from_now.html" title="basic_deadline_timer::expires_from_now"><span class="bold"><strong>expires_from_now</strong></span></a>
|
||
|
|
</p>
|
||
|
|
</td>
|
||
|
|
<td>
|
||
|
|
<p>
|
||
|
|
Get the timer's expiry time relative to now. <br> <span class="silver"> —</span><br> Set
|
||
|
|
the timer's expiry time relative to now.
|
||
|
|
</p>
|
||
|
|
</td>
|
||
|
|
</tr>
|
||
|
|
<tr>
|
||
|
|
<td>
|
||
|
|
<p>
|
||
|
|
<a class="link" href="basic_deadline_timer/get_executor.html" title="basic_deadline_timer::get_executor"><span class="bold"><strong>get_executor</strong></span></a>
|
||
|
|
</p>
|
||
|
|
</td>
|
||
|
|
<td>
|
||
|
|
<p>
|
||
|
|
Get the executor associated with the object.
|
||
|
|
</p>
|
||
|
|
</td>
|
||
|
|
</tr>
|
||
|
|
<tr>
|
||
|
|
<td>
|
||
|
|
<p>
|
||
|
|
<a class="link" href="basic_deadline_timer/operator_eq_.html" title="basic_deadline_timer::operator="><span class="bold"><strong>operator=</strong></span></a>
|
||
|
|
</p>
|
||
|
|
</td>
|
||
|
|
<td>
|
||
|
|
<p>
|
||
|
|
Move-assign a basic_deadline_timer from another.
|
||
|
|
</p>
|
||
|
|
</td>
|
||
|
|
</tr>
|
||
|
|
<tr>
|
||
|
|
<td>
|
||
|
|
<p>
|
||
|
|
<a class="link" href="basic_deadline_timer/wait.html" title="basic_deadline_timer::wait"><span class="bold"><strong>wait</strong></span></a>
|
||
|
|
</p>
|
||
|
|
</td>
|
||
|
|
<td>
|
||
|
|
<p>
|
||
|
|
Perform a blocking wait on the timer.
|
||
|
|
</p>
|
||
|
|
</td>
|
||
|
|
</tr>
|
||
|
|
<tr>
|
||
|
|
<td>
|
||
|
|
<p>
|
||
|
|
<a class="link" href="basic_deadline_timer/_basic_deadline_timer.html" title="basic_deadline_timer::~basic_deadline_timer"><span class="bold"><strong>~basic_deadline_timer</strong></span></a> <span class="silver">[destructor]</span>
|
||
|
|
</p>
|
||
|
|
</td>
|
||
|
|
<td>
|
||
|
|
<p>
|
||
|
|
Destroys the timer.
|
||
|
|
</p>
|
||
|
|
</td>
|
||
|
|
</tr>
|
||
|
|
</tbody>
|
||
|
|
</table></div>
|
||
|
|
<p>
|
||
|
|
The <a class="link" href="basic_deadline_timer.html" title="basic_deadline_timer"><code class="computeroutput"><span class="identifier">basic_deadline_timer</span></code></a>
|
||
|
|
class template provides the ability to perform a blocking or asynchronous
|
||
|
|
wait for a timer to expire.
|
||
|
|
</p>
|
||
|
|
<p>
|
||
|
|
A deadline timer is always in one of two states: "expired" or "not
|
||
|
|
expired". If the <code class="computeroutput"><span class="identifier">wait</span><span class="special">()</span></code> or <code class="computeroutput"><span class="identifier">async_wait</span><span class="special">()</span></code> function is called on an expired timer,
|
||
|
|
the wait operation will complete immediately.
|
||
|
|
</p>
|
||
|
|
<p>
|
||
|
|
Most applications will use the <a class="link" href="deadline_timer.html" title="deadline_timer"><code class="computeroutput"><span class="identifier">deadline_timer</span></code></a> typedef.
|
||
|
|
</p>
|
||
|
|
<h5>
|
||
|
|
<a name="asio.reference.deadline_timer.h2"></a>
|
||
|
|
<span><a name="asio.reference.deadline_timer.thread_safety"></a></span><a class="link" href="deadline_timer.html#asio.reference.deadline_timer.thread_safety">Thread
|
||
|
|
Safety</a>
|
||
|
|
</h5>
|
||
|
|
<p>
|
||
|
|
<span class="emphasis"><em>Distinct</em></span> <span class="emphasis"><em>objects:</em></span> Safe.
|
||
|
|
</p>
|
||
|
|
<p>
|
||
|
|
<span class="emphasis"><em>Shared</em></span> <span class="emphasis"><em>objects:</em></span> Unsafe.
|
||
|
|
</p>
|
||
|
|
<h5>
|
||
|
|
<a name="asio.reference.deadline_timer.h3"></a>
|
||
|
|
<span><a name="asio.reference.deadline_timer.examples"></a></span><a class="link" href="deadline_timer.html#asio.reference.deadline_timer.examples">Examples</a>
|
||
|
|
</h5>
|
||
|
|
<p>
|
||
|
|
Performing a blocking wait:
|
||
|
|
</p>
|
||
|
|
<pre class="programlisting"><span class="comment">// Construct a timer without setting an expiry time.</span>
|
||
|
|
<span class="identifier">asio</span><span class="special">::</span><span class="identifier">deadline_timer</span> <span class="identifier">timer</span><span class="special">(</span><span class="identifier">my_context</span><span class="special">);</span>
|
||
|
|
|
||
|
|
<span class="comment">// Set an expiry time relative to now.</span>
|
||
|
|
<span class="identifier">timer</span><span class="special">.</span><span class="identifier">expires_from_now</span><span class="special">(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">posix_time</span><span class="special">::</span><span class="identifier">seconds</span><span class="special">(</span><span class="number">5</span><span class="special">));</span>
|
||
|
|
|
||
|
|
<span class="comment">// Wait for the timer to expire.</span>
|
||
|
|
<span class="identifier">timer</span><span class="special">.</span><span class="identifier">wait</span><span class="special">();</span>
|
||
|
|
</pre>
|
||
|
|
<p>
|
||
|
|
Performing an asynchronous wait:
|
||
|
|
</p>
|
||
|
|
<pre class="programlisting"><span class="keyword">void</span> <span class="identifier">handler</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">asio</span><span class="special">::</span><span class="identifier">error_code</span><span class="special">&</span> <span class="identifier">error</span><span class="special">)</span>
|
||
|
|
<span class="special">{</span>
|
||
|
|
<span class="keyword">if</span> <span class="special">(!</span><span class="identifier">error</span><span class="special">)</span>
|
||
|
|
<span class="special">{</span>
|
||
|
|
<span class="comment">// Timer expired.</span>
|
||
|
|
<span class="special">}</span>
|
||
|
|
<span class="special">}</span>
|
||
|
|
|
||
|
|
<span class="special">...</span>
|
||
|
|
|
||
|
|
<span class="comment">// Construct a timer with an absolute expiry time.</span>
|
||
|
|
<span class="identifier">asio</span><span class="special">::</span><span class="identifier">deadline_timer</span> <span class="identifier">timer</span><span class="special">(</span><span class="identifier">my_context</span><span class="special">,</span>
|
||
|
|
<span class="identifier">boost</span><span class="special">::</span><span class="identifier">posix_time</span><span class="special">::</span><span class="identifier">time_from_string</span><span class="special">(</span><span class="string">"2005-12-07 23:59:59.000"</span><span class="special">));</span>
|
||
|
|
|
||
|
|
<span class="comment">// Start an asynchronous wait.</span>
|
||
|
|
<span class="identifier">timer</span><span class="special">.</span><span class="identifier">async_wait</span><span class="special">(</span><span class="identifier">handler</span><span class="special">);</span>
|
||
|
|
</pre>
|
||
|
|
<h5>
|
||
|
|
<a name="asio.reference.deadline_timer.h4"></a>
|
||
|
|
<span><a name="asio.reference.deadline_timer.changing_an_active_deadline_timer_s_expiry_time"></a></span><a class="link" href="deadline_timer.html#asio.reference.deadline_timer.changing_an_active_deadline_timer_s_expiry_time">Changing
|
||
|
|
an active deadline_timer's expiry time</a>
|
||
|
|
</h5>
|
||
|
|
<p>
|
||
|
|
Changing the expiry time of a timer while there are pending asynchronous
|
||
|
|
waits causes those wait operations to be cancelled. To ensure that the action
|
||
|
|
associated with the timer is performed only once, use something like this:
|
||
|
|
used:
|
||
|
|
</p>
|
||
|
|
<pre class="programlisting"><span class="keyword">void</span> <span class="identifier">on_some_event</span><span class="special">()</span>
|
||
|
|
<span class="special">{</span>
|
||
|
|
<span class="keyword">if</span> <span class="special">(</span><span class="identifier">my_timer</span><span class="special">.</span><span class="identifier">expires_from_now</span><span class="special">(</span><span class="identifier">seconds</span><span class="special">(</span><span class="number">5</span><span class="special">))</span> <span class="special">></span> <span class="number">0</span><span class="special">)</span>
|
||
|
|
<span class="special">{</span>
|
||
|
|
<span class="comment">// We managed to cancel the timer. Start new asynchronous wait.</span>
|
||
|
|
<span class="identifier">my_timer</span><span class="special">.</span><span class="identifier">async_wait</span><span class="special">(</span><span class="identifier">on_timeout</span><span class="special">);</span>
|
||
|
|
<span class="special">}</span>
|
||
|
|
<span class="keyword">else</span>
|
||
|
|
<span class="special">{</span>
|
||
|
|
<span class="comment">// Too late, timer has already expired!</span>
|
||
|
|
<span class="special">}</span>
|
||
|
|
<span class="special">}</span>
|
||
|
|
|
||
|
|
<span class="keyword">void</span> <span class="identifier">on_timeout</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">asio</span><span class="special">::</span><span class="identifier">error_code</span><span class="special">&</span> <span class="identifier">e</span><span class="special">)</span>
|
||
|
|
<span class="special">{</span>
|
||
|
|
<span class="keyword">if</span> <span class="special">(</span><span class="identifier">e</span> <span class="special">!=</span> <span class="identifier">asio</span><span class="special">::</span><span class="identifier">error</span><span class="special">::</span><span class="identifier">operation_aborted</span><span class="special">)</span>
|
||
|
|
<span class="special">{</span>
|
||
|
|
<span class="comment">// Timer was not cancelled, take necessary action.</span>
|
||
|
|
<span class="special">}</span>
|
||
|
|
<span class="special">}</span>
|
||
|
|
</pre>
|
||
|
|
<div class="itemizedlist"><ul class="itemizedlist" type="disc">
|
||
|
|
<li class="listitem">
|
||
|
|
The <code class="computeroutput"><span class="identifier">asio</span><span class="special">::</span><span class="identifier">basic_deadline_timer</span><span class="special">::</span><span class="identifier">expires_from_now</span><span class="special">()</span></code>
|
||
|
|
function cancels any pending asynchronous waits, and returns the number
|
||
|
|
of asynchronous waits that were cancelled. If it returns 0 then you were
|
||
|
|
too late and the wait handler has already been executed, or will soon
|
||
|
|
be executed. If it returns 1 then the wait handler was successfully cancelled.
|
||
|
|
</li>
|
||
|
|
<li class="listitem">
|
||
|
|
If a wait handler is cancelled, the <a class="link" href="error_code.html" title="error_code"><code class="computeroutput"><span class="identifier">error_code</span></code></a> passed to it contains
|
||
|
|
the value <code class="computeroutput"><span class="identifier">asio</span><span class="special">::</span><span class="identifier">error</span><span class="special">::</span><span class="identifier">operation_aborted</span></code>.
|
||
|
|
</li>
|
||
|
|
</ul></div>
|
||
|
|
<h5>
|
||
|
|
<a name="asio.reference.deadline_timer.h5"></a>
|
||
|
|
<span><a name="asio.reference.deadline_timer.requirements"></a></span><a class="link" href="deadline_timer.html#asio.reference.deadline_timer.requirements">Requirements</a>
|
||
|
|
</h5>
|
||
|
|
<p>
|
||
|
|
<span class="emphasis"><em>Header: </em></span><code class="literal">asio/deadline_timer.hpp</code>
|
||
|
|
</p>
|
||
|
|
<p>
|
||
|
|
<span class="emphasis"><em>Convenience header: </em></span><code class="literal">asio.hpp</code>
|
||
|
|
</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="coroutine/is_parent.html"><img src="../../prev.png" alt="Prev"></a><a accesskey="u" href="../reference.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="default_completion_token.html"><img src="../../next.png" alt="Next"></a>
|
||
|
|
</div>
|
||
|
|
</body>
|
||
|
|
</html>
|