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    <![endif]--><meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /><meta name="keywords" content="Access, BeOS, BeBook, API" /><link rel="start" href="index.html" title="The Be Book" /><link rel="up" href="TheKernelKit.html" title="The Kernel Kit" /><link rel="prev" href="TheKernelKit_SystemInfo.html" title="System Information" /><link rel="next" href="TheMailKit.html" title="The Mail Kit" /></head><body><div id="header"><div id="headerT"><div id="headerTL"><a accesskey="p" href="TheKernelKit_SystemInfo.html" title="System Information"><img src="./images/navigation/prev.png" alt="Prev" /></a> <a accesskey="u" href="TheKernelKit.html" title="The Kernel Kit"><img src="./images/navigation/up.png" alt="Up" /></a> <a accesskey="n" href="TheMailKit.html" title="The Mail Kit"><img src="./images/navigation/next.png" alt="Next" /></a></div><div id="headerTR"><div id="navigpeople"><a href="http://www.haiku-os.org"><img src="./images/People_24.png" alt="haiku-os.org" title="Visit The Haiku Website" /></a></div><div class="navighome" title="Home"><a accesskey="h" href="index.html"><img src="./images/navigation/home.png" alt="Home" /></a></div><div class="navigboxed" id="navigindex"><a accesskey="i" href="ClassIndex.html" title="Index">I</a></div><div class="navigboxed" id="naviglang" title="English">en</div></div><div id="headerTC">The Be Book - Classes And Methods - The Kernel Kit</div></div><div id="headerB">Prev: <a href="TheKernelKit_SystemInfo.html">System Information</a>  Up: <a href="TheKernelKit.html">The Kernel Kit</a>  Next: <a href="TheMailKit.html">The Mail Kit</a></div><hr /></div><div class="section"><div xmlns="" xmlns:d="http://docbook.org/ns/docbook" class="titlepage"><div><div xmlns:d="http://docbook.org/ns/docbook"><h2 xmlns="http://www.w3.org/1999/xhtml" class="title"><a id="TheKernelKit_Miscellaneous"></a>Miscellaneous Functions And Constants</h2></div></div></div><div class="informaltable"><table border="0"><colgroup><col /><col /></colgroup><tbody><tr><td>Declared in:</td><td><code class="filename">kernel/OS.h</code></td></tr><tr><td>Library:</td><td><code class="filename">libroot.so</code></td></tr></tbody></table></div><div class="section"><div xmlns="" xmlns:d="http://docbook.org/ns/docbook" class="titlepage"><div><hr /><div xmlns:d="http://docbook.org/ns/docbook"><h3 xmlns="http://www.w3.org/1999/xhtml" class="title"><a id="Miscellaneous_Functions"></a>Functions</h3></div></div></div><div class="section"><div xmlns="" xmlns:d="http://docbook.org/ns/docbook" class="titlepage"><div><div xmlns:d="http://docbook.org/ns/docbook"><h4 xmlns="http://www.w3.org/1999/xhtml" class="title"><a id="clear_caches"></a>clear_caches()</h4></div></div></div><a id="id1114057" class="indexterm"></a><code class="methodsynopsis c"><span class="type">void </span><span class="methodname">clear_caches</span>(<span class="methodparam"><span class="type">void* </span><span class="parameter">addr</span></span>,<br />                  <span class="methodparam"><span class="type">size_t </span><span class="parameter">len</span></span>,<br />                  <span class="methodparam"><span class="type">uint32 </span><span class="parameter">flags</span></span>);</code><p>Declared in: <code class="filename">kernel/image.h</code></p><p>This function clears or invalidates the instruction and data caches. You
should only need this function if you're generating code on the fly, or
if you're performing a timing loop and you want to start with fresh
caches (to get a "worst case" estimate).</p><p>The parameters are:</p><table class="variablelist parameters"><thead><tr><th>Parameter</th><th>Description</th></tr></thead><tbody><tr><td><p><span class="term"><code class="parameter">addr</code></span></p></td><td><p>Is the starting address of a section of memory that corresponds
to a section of one of the caches.</p></td></tr><tr><td><p><span class="term"><code class="parameter">len</code></span></p></td><td><p>Is the length, in bytes, of the instruction or data segment that
you want to clear or invalidate.</p></td></tr><tr><td><p><span class="term"><code class="parameter">flags</code></span></p></td><td><p>Is one or both of <code class="constant">B_INVALIDATE_ICACHE</code>
and <code class="constant">B_FLUSH_DCACHE</code>.</p></td></tr></tbody></table><p>By invalidating a section of the instruction cache, you cause the
instructions in that section to be reloaded next time they're needed.
Flushing the data cache causes the in-memory copy of the data to be
written out to the cache.</p></div><div class="section"><div xmlns="" xmlns:d="http://docbook.org/ns/docbook" class="titlepage"><div><div xmlns:d="http://docbook.org/ns/docbook"><h4 xmlns="http://www.w3.org/1999/xhtml" class="title"><a id="debugger"></a>debugger()</h4></div></div></div><a id="id1114207" class="indexterm"></a><code class="methodsynopsis c"><span class="type">void </span><span class="methodname">debugger</span>(<span class="methodparam"><span class="type">const char* </span><span class="parameter">string</span></span>);</code><p>Throws the calling thread into the debugger. The <code class="parameter">string</code> argument becomes
the debugger's first utterance.</p></div><div class="section"><div xmlns="" xmlns:d="http://docbook.org/ns/docbook" class="titlepage"><div><div xmlns:d="http://docbook.org/ns/docbook"><h4 xmlns="http://www.w3.org/1999/xhtml" class="title"><a id="disable_debugger"></a>disable_debugger()</h4></div></div></div><a id="id1114255" class="indexterm"></a><code class="methodsynopsis c"><span class="type">int </span><span class="methodname">disable_debugger</span>(<span class="methodparam"><span class="type">int </span><span class="parameter">state</span></span>);</code><p>Instructs the kernel to send a signal for all exceptions, even those that
don't normally trigger the debugger. If the application doesn't have a
handler installed for the exception, the team dies without triggering the
debugger. <code class="parameter">state</code> should be nonzero to turn on this functionality or 0 to
turn it off.</p></div><div class="section"><div xmlns="" xmlns:d="http://docbook.org/ns/docbook" class="titlepage"><div><div xmlns:d="http://docbook.org/ns/docbook"><h4 xmlns="http://www.w3.org/1999/xhtml" class="title"><a id="set_alarm"></a>set_alarm()</h4></div></div></div><a id="id1114306" class="indexterm"></a><code class="methodsynopsis c"><span class="type">bigtime_t </span><span class="methodname">set_alarm</span>(<span class="methodparam"><span class="type">bigtime_t </span><span class="parameter">time</span></span>,<br />                    <span class="methodparam"><span class="type">uint32 </span><span class="parameter">mode</span></span>);</code><p>Tells the kernel to send the <span class="signal">SIGALRM</span>
signal at some point in the future,
as defined by the arguments:</p><ul class="itemizedlist"><li><p>If <code class="parameter">mode</code> is <code class="constant">B_PERIODIC_ALARM</code>,
the signal is sent every <code class="parameter">time</code> microseconds,
starting as soon as <code class="function">set_alarm()</code> function returns.</p></li><li><p>If <code class="parameter">mode</code> is <code class="constant">B_ONE_SHOT_ABOLUTE_ALARM</code>, the signal is sent once (only)
after <code class="parameter">time</code> microseconds have elapsed measured from the time the system
was booted. If that point has already passed, the signal is sent
immediately.</p></li><li><p>If <code class="parameter">mode</code> is <code class="constant">B_ONE_SHOT_RELATIVE_ALARM</code>,
the signal is sent once (only) after <code class="parameter">time</code> microseconds
have elapsed from the time <code class="function">set_alarm()</code> returns.</p></li></ul><p>When the signal is sent, the <span class="signal">SIGALRM</span>
handler is called (you set the
handler through the normal means, by calling the Posix <code class="function">signal()</code>
function). The handler runs in the thread that set the alarm.</p><div class="admonition warning"><div class="title">Warning</div><div class="graphic"><img class="icon" alt="Warning" width="32" src="./images/admonitions/Stop_32.png" /><div class="text"><p>From within the SIGALRM handler, you mustn't call anything that would
cause the kernel scheduler to run. Just about the only safe call you can
make from your signal handler is
<a class="link" href="TheKernelKit_Semaphores.html#release_sem" title="release_sem(), release_sem_etc()"><code class="function">release_sem()</code></a>.</p></div></div></div><p>The most recent alarm requested cancels any previous request. For
example, in this sequence…</p><pre class="programlisting example c"><span class="comment">/* Ask for an alarm ten seconds from now. */</span>
<code class="function">set_alarm</code>(10e6, <code class="constant">B_ONE_SHOT_RELATIVE_ALARM</code>);

<span class="comment">/* Ask for an alarm one second from now. */</span>
<code class="function">set_alarm</code>(10e5, <code class="constant">B_ONE_SHOT_RELATIVE_ALARM</code>);</pre><p>…only the second alarm request will be fulfilled the first
requested is cancelled when the second <code class="function">set_alarm()</code> call is made. This
applies to all alarm types; for example, a one-shot alarm request will
cancel an active periodic alarm.</p><p>To explicitly cancel the previous alarm request without installing a new
alarm, do this:</p><pre class="programlisting example c"><code class="function">set_alarm</code>(<code class="constant">B_INFINITE_TIMEOUT</code>, <code class="constant">B_PERIODIC_ALARM</code>);</pre><p>This cancels the previous alarm request regardless of the type of alarm.</p></div><div class="section"><div xmlns="" xmlns:d="http://docbook.org/ns/docbook" class="titlepage"><div><div xmlns:d="http://docbook.org/ns/docbook"><h4 xmlns="http://www.w3.org/1999/xhtml" class="title"><a id="set_signal_stack"></a>set_signal_stack()</h4></div></div></div><a id="id1114550" class="indexterm"></a><code class="methodsynopsis c"><span class="type">void </span><span class="methodname">set_signal_stack</span>(<span class="methodparam"><span class="type">void* </span><span class="parameter">ptr</span></span>,<br />                      <span class="methodparam"><span class="type">size_t </span><span class="parameter">size</span></span>);</code><p>Declared in: <code class="filename">posix/signal.be.h</code></p><p>Sets the location and size of the stack that's used by the thread's
signal handlers.</p></div></div><div class="section"><div xmlns="" xmlns:d="http://docbook.org/ns/docbook" class="titlepage"><div><hr /><div xmlns:d="http://docbook.org/ns/docbook"><h3 xmlns="http://www.w3.org/1999/xhtml" class="title"><a id="Miscellaneous_Constants"></a>Constants</h3></div></div></div><div class="section"><div xmlns="" xmlns:d="http://docbook.org/ns/docbook" class="titlepage"><div><div xmlns:d="http://docbook.org/ns/docbook"><h4 xmlns="http://www.w3.org/1999/xhtml" class="title"><a id="B_INFINITE_TIMEOUT"></a>B_INFINITE_TIMEOUT</h4></div></div></div><a id="id1114623" class="indexterm"></a><pre class="programlisting c"><code class="constant">B_INFINITE_TIMEOUT</code></pre><p>The inifinite timeout value can be used to specify, to timeout-accepting
functions, that you're willing to wait forever.</p></div><div class="section"><div xmlns="" xmlns:d="http://docbook.org/ns/docbook" class="titlepage"><div><div xmlns:d="http://docbook.org/ns/docbook"><h4 xmlns="http://www.w3.org/1999/xhtml" class="title"><a id="B_OS_NAME_LENGTH"></a>B_OS_NAME_LENGTH</h4></div></div></div><a id="id1114656" class="indexterm"></a><pre class="programlisting c"><code class="constant">B_OS_NAME_LENGTH</code></pre><p>This constant gives the maximum length of the name of a thread,
semaphore, port, area, or other operating system bauble.</p></div><div class="section"><div xmlns="" xmlns:d="http://docbook.org/ns/docbook" class="titlepage"><div><div xmlns:d="http://docbook.org/ns/docbook"><h4 xmlns="http://www.w3.org/1999/xhtml" class="title"><a id="B_PAGE_SIZE"></a>B_PAGE_SIZE</h4></div></div></div><a id="id1114688" class="indexterm"></a><pre class="programlisting c"><code class="constant">B_PAGE_SIZE</code></pre><p>The <code class="constant">B_PAGE_SIZE</code> constant gives the size,
in bytes, of a page of RAM.</p></div></div></div><div id="footer"><hr /><div id="footerT">Prev: <a href="TheKernelKit_SystemInfo.html">System Information</a>  Up: <a href="TheKernelKit.html">The Kernel Kit</a>  Next: <a href="TheMailKit.html">The Mail Kit</a> </div><div id="footerB"><div id="footerBL"><a href="TheKernelKit_SystemInfo.html" title="System Information"><img src="./images/navigation/prev.png" alt="Prev" /></a> <a href="TheKernelKit.html" title="The Kernel Kit"><img src="./images/navigation/up.png" alt="Up" /></a> <a href="TheMailKit.html" title="The Mail Kit"><img src="./images/navigation/next.png" alt="Next" /></a></div><div id="footerBR"><div><a href="http://www.haiku-os.org"><img src="./images/People_24.png" alt="haiku-os.org" title="Visit The Haiku Website" /></a></div><div class="navighome" title="Home"><a accesskey="h" href="index.html"><img src="./images/navigation/home.png" alt="Home" /></a></div></div><div id="footerBC"><a href="http://www.access-company.com/home.html" title="ACCESS Co."><img alt="Access Company" src="./images/access_logo.png" /></a></div></div></div><div id="licenseFooter"><div id="licenseFooterBL"><a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/3.0/" title="Creative Commons License"><img alt="Creative Commons License" style="border-width:0" src="https://licensebuttons.net/l/by-nc-nd/3.0/88x31.png" /></a></div><div id="licenseFooterBR"><a href="./LegalNotice.html">Legal Notice</a></div><div id="licenseFooterBC"><span id="licenseText">This work is licensed under a
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