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<div class="subTitle">org.apache.ignite</div>
<h2 title="Interface IgniteSemaphore" class="title">Interface IgniteSemaphore</h2>
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<dt>All Superinterfaces:</dt>
<dd><a href="http://docs.oracle.com/javase/7/docs/api/java/lang/AutoCloseable.html?is-external=true" title="class or interface in java.lang">AutoCloseable</a>, <a href="http://docs.oracle.com/javase/7/docs/api/java/io/Closeable.html?is-external=true" title="class or interface in java.io">Closeable</a></dd>
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<pre>public interface <span class="strong">IgniteSemaphore</span>
extends <a href="http://docs.oracle.com/javase/7/docs/api/java/io/Closeable.html?is-external=true" title="class or interface in java.io">Closeable</a></pre>
<div class="block">This interface provides a rich API for working with distributed semaphore.
<p>
<h1 class="header">Functionality</h1>
Distributed semaphore provides functionality similar to <code>java.util.concurrent.Semaphore</code>.
<h1 class="header">Creating Distributed Semaphore</h1>
Instance of cache semaphore can be created by calling the following method:
<a href="../../../org/apache/ignite/Ignite.html#semaphore(java.lang.String,%20int,%20boolean,%20boolean)"><code>Ignite.semaphore(String, int, boolean, boolean)</code></a>.</div>
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<h3>Method Summary</h3>
<table class="overviewSummary" border="0" cellpadding="3" cellspacing="0" summary="Method Summary table, listing methods, and an explanation">
<caption><span>Methods</span><span class="tabEnd">&nbsp;</span></caption>
<tr>
<th class="colFirst" scope="col">Modifier and Type</th>
<th class="colLast" scope="col">Method and Description</th>
</tr>
<tr class="altColor">
<td class="colFirst"><code>void</code></td>
<td class="colLast"><code><strong><a href="../../../org/apache/ignite/IgniteSemaphore.html#acquire()">acquire</a></strong>()</code>
<div class="block">Acquires a permit from this semaphore, blocking until one is available, or the thread is <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/Thread.html?is-external=true#interrupt()" title="class or interface in java.lang">interrupted</a>.</div>
</td>
</tr>
<tr class="rowColor">
<td class="colFirst"><code>void</code></td>
<td class="colLast"><code><strong><a href="../../../org/apache/ignite/IgniteSemaphore.html#acquire(int)">acquire</a></strong>(int&nbsp;permits)</code>
<div class="block">Acquires the given number of permits from this semaphore, blocking until all are available, or the thread is
<a href="http://docs.oracle.com/javase/7/docs/api/java/lang/Thread.html?is-external=true#interrupt()" title="class or interface in java.lang">interrupted</a>.</div>
</td>
</tr>
<tr class="altColor">
<td class="colFirst"><code>void</code></td>
<td class="colLast"><code><strong><a href="../../../org/apache/ignite/IgniteSemaphore.html#acquireUninterruptibly()">acquireUninterruptibly</a></strong>()</code>
<div class="block">Acquires a permit from this semaphore, blocking until one is available.</div>
</td>
</tr>
<tr class="rowColor">
<td class="colFirst"><code>void</code></td>
<td class="colLast"><code><strong><a href="../../../org/apache/ignite/IgniteSemaphore.html#acquireUninterruptibly(int)">acquireUninterruptibly</a></strong>(int&nbsp;permits)</code>
<div class="block">Acquires the given number of permits from this semaphore, blocking until all are available.</div>
</td>
</tr>
<tr class="altColor">
<td class="colFirst"><code>int</code></td>
<td class="colLast"><code><strong><a href="../../../org/apache/ignite/IgniteSemaphore.html#availablePermits()">availablePermits</a></strong>()</code>
<div class="block">Returns the current number of permits available in this semaphore.</div>
</td>
</tr>
<tr class="rowColor">
<td class="colFirst"><code>void</code></td>
<td class="colLast"><code><strong><a href="../../../org/apache/ignite/IgniteSemaphore.html#close()">close</a></strong>()</code>
<div class="block">Removes this semaphore.</div>
</td>
</tr>
<tr class="altColor">
<td class="colFirst"><code>int</code></td>
<td class="colLast"><code><strong><a href="../../../org/apache/ignite/IgniteSemaphore.html#drainPermits()">drainPermits</a></strong>()</code>
<div class="block">Acquires and returns all permits that are immediately available.</div>
</td>
</tr>
<tr class="rowColor">
<td class="colFirst"><code>int</code></td>
<td class="colLast"><code><strong><a href="../../../org/apache/ignite/IgniteSemaphore.html#getQueueLength()">getQueueLength</a></strong>()</code>
<div class="block">Returns an estimate of the number of nodes waiting to acquire.</div>
</td>
</tr>
<tr class="altColor">
<td class="colFirst"><code>boolean</code></td>
<td class="colLast"><code><strong><a href="../../../org/apache/ignite/IgniteSemaphore.html#hasQueuedThreads()">hasQueuedThreads</a></strong>()</code>
<div class="block">Queries whether any threads are waiting to acquire.</div>
</td>
</tr>
<tr class="rowColor">
<td class="colFirst"><code>boolean</code></td>
<td class="colLast"><code><strong><a href="../../../org/apache/ignite/IgniteSemaphore.html#isBroken()">isBroken</a></strong>()</code>
<div class="block">Gets <code>broken</code> status of the semaphore.</div>
</td>
</tr>
<tr class="altColor">
<td class="colFirst"><code>boolean</code></td>
<td class="colLast"><code><strong><a href="../../../org/apache/ignite/IgniteSemaphore.html#isFailoverSafe()">isFailoverSafe</a></strong>()</code>
<div class="block">Returns <code>true</code> if this semaphore is safe to use after node failure.</div>
</td>
</tr>
<tr class="rowColor">
<td class="colFirst"><code><a href="http://docs.oracle.com/javase/7/docs/api/java/lang/String.html?is-external=true" title="class or interface in java.lang">String</a></code></td>
<td class="colLast"><code><strong><a href="../../../org/apache/ignite/IgniteSemaphore.html#name()">name</a></strong>()</code>
<div class="block">Gets name of the semaphore.</div>
</td>
</tr>
<tr class="altColor">
<td class="colFirst"><code>void</code></td>
<td class="colLast"><code><strong><a href="../../../org/apache/ignite/IgniteSemaphore.html#release()">release</a></strong>()</code>
<div class="block">Releases a permit, returning it to the semaphore.</div>
</td>
</tr>
<tr class="rowColor">
<td class="colFirst"><code>void</code></td>
<td class="colLast"><code><strong><a href="../../../org/apache/ignite/IgniteSemaphore.html#release(int)">release</a></strong>(int&nbsp;permits)</code>
<div class="block">Releases the given number of permits, returning them to the semaphore.</div>
</td>
</tr>
<tr class="altColor">
<td class="colFirst"><code>boolean</code></td>
<td class="colLast"><code><strong><a href="../../../org/apache/ignite/IgniteSemaphore.html#removed()">removed</a></strong>()</code>
<div class="block">Gets <code>removed</code> status of the semaphore.</div>
</td>
</tr>
<tr class="rowColor">
<td class="colFirst"><code>boolean</code></td>
<td class="colLast"><code><strong><a href="../../../org/apache/ignite/IgniteSemaphore.html#tryAcquire()">tryAcquire</a></strong>()</code>
<div class="block">Acquires a permit from this semaphore, only if one is available at the time of invocation.</div>
</td>
</tr>
<tr class="altColor">
<td class="colFirst"><code>boolean</code></td>
<td class="colLast"><code><strong><a href="../../../org/apache/ignite/IgniteSemaphore.html#tryAcquire(int)">tryAcquire</a></strong>(int&nbsp;permits)</code>
<div class="block">Acquires the given number of permits from this semaphore, only if all are available at the time of invocation.</div>
</td>
</tr>
<tr class="rowColor">
<td class="colFirst"><code>boolean</code></td>
<td class="colLast"><code><strong><a href="../../../org/apache/ignite/IgniteSemaphore.html#tryAcquire(int,%20long,%20java.util.concurrent.TimeUnit)">tryAcquire</a></strong>(int&nbsp;permits,
long&nbsp;timeout,
<a href="http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/TimeUnit.html?is-external=true" title="class or interface in java.util.concurrent">TimeUnit</a>&nbsp;unit)</code>
<div class="block">Acquires the given number of permits from this semaphore, if all become available within the given waiting time
and the current thread has not been <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/Thread.html?is-external=true#interrupt()" title="class or interface in java.lang">interrupted</a>.</div>
</td>
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<td class="colFirst"><code>boolean</code></td>
<td class="colLast"><code><strong><a href="../../../org/apache/ignite/IgniteSemaphore.html#tryAcquire(long,%20java.util.concurrent.TimeUnit)">tryAcquire</a></strong>(long&nbsp;timeout,
<a href="http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/TimeUnit.html?is-external=true" title="class or interface in java.util.concurrent">TimeUnit</a>&nbsp;unit)</code>
<div class="block">Acquires a permit from this semaphore, if one becomes available within the given waiting time and the current
thread has not been <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/Thread.html?is-external=true#interrupt()" title="class or interface in java.lang">interrupted</a>.</div>
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<h4>name</h4>
<pre><a href="http://docs.oracle.com/javase/7/docs/api/java/lang/String.html?is-external=true" title="class or interface in java.lang">String</a>&nbsp;name()</pre>
<div class="block">Gets name of the semaphore.</div>
<dl><dt><span class="strong">Returns:</span></dt><dd>Name of the semaphore.</dd></dl>
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<pre>void&nbsp;acquire()
throws <a href="../../../org/apache/ignite/IgniteInterruptedException.html" title="class in org.apache.ignite">IgniteInterruptedException</a></pre>
<div class="block">Acquires a permit from this semaphore, blocking until one is available, or the thread is <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/Thread.html?is-external=true#interrupt()" title="class or interface in java.lang">interrupted</a>.
<p>Acquires a permit, if one is available and returns immediately, reducing the number of available permits by
one.
<p>If no permit is available then the current thread becomes disabled for thread scheduling purposes and lies
dormant until one of two things happens: <ul> <li>Some other thread invokes the <a href="../../../org/apache/ignite/IgniteSemaphore.html#release()"><code>release()</code></a> method for this
semaphore and the current thread is next to be assigned a permit; or <li>Some other thread <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/Thread.html?is-external=true#interrupt()" title="class or interface in java.lang">interrupts</a> the current thread. </ul>
<p>If the current thread: <ul> <li>has its interrupted status set on entry to this method; or <li>is <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/Thread.html?is-external=true#interrupt()" title="class or interface in java.lang">interrupted</a> while waiting for a permit, </ul> then <a href="../../../org/apache/ignite/IgniteInterruptedException.html" title="class in org.apache.ignite"><code>IgniteInterruptedException</code></a> is thrown
and the current thread's interrupted status is cleared.</div>
<dl><dt><span class="strong">Throws:</span></dt>
<dd><code><a href="../../../org/apache/ignite/IgniteInterruptedException.html" title="class in org.apache.ignite">IgniteInterruptedException</a></code> - if the current thread is interrupted</dd></dl>
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<pre>void&nbsp;acquireUninterruptibly()</pre>
<div class="block">Acquires a permit from this semaphore, blocking until one is available.
<p>Acquires a permit, if one is available and returns immediately, reducing the number of available permits by
one.
<p>If no permit is available then the current thread becomes disabled for thread scheduling purposes and lies
dormant until some other thread invokes the <a href="../../../org/apache/ignite/IgniteSemaphore.html#release()"><code>release()</code></a> method for this semaphore and the current thread is
next to be assigned a permit.
<p>If the current thread is <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/Thread.html?is-external=true#interrupt()" title="class or interface in java.lang">interrupted</a> while waiting for a permit then it will
continue to wait, but the time at which the thread is assigned a permit may change compared to the time it would
have received the permit had no interruption occurred. When the thread does return from this method its
interrupt status will be set.</div>
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<pre>boolean&nbsp;tryAcquire()</pre>
<div class="block">Acquires a permit from this semaphore, only if one is available at the time of invocation.
<p>Acquires a permit, if one is available and returns immediately, with the value <code>true</code>, reducing the
number of available permits by one.
<p>If no permit is available then this method will return immediately with the value <code>false</code>.</div>
<dl><dt><span class="strong">Returns:</span></dt><dd><code>true</code> if a permit was acquired and <code>false</code> otherwise</dd></dl>
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<pre>boolean&nbsp;tryAcquire(long&nbsp;timeout,
<a href="http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/TimeUnit.html?is-external=true" title="class or interface in java.util.concurrent">TimeUnit</a>&nbsp;unit)
throws <a href="../../../org/apache/ignite/IgniteInterruptedException.html" title="class in org.apache.ignite">IgniteInterruptedException</a></pre>
<div class="block">Acquires a permit from this semaphore, if one becomes available within the given waiting time and the current
thread has not been <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/Thread.html?is-external=true#interrupt()" title="class or interface in java.lang">interrupted</a>.
<p>Acquires a permit, if one is available and returns immediately, with the value <code>true</code>, reducing the
number of available permits by one.
<p>If no permit is available then the current thread becomes disabled for thread scheduling purposes and lies
dormant until one of three things happens: <ul> <li>Some other thread invokes the <a href="../../../org/apache/ignite/IgniteSemaphore.html#release()"><code>release()</code></a> method for
this semaphore and the current thread is next to be assigned a permit; or <li>Some other thread <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/Thread.html?is-external=true#interrupt()" title="class or interface in java.lang">interrupts</a> the current thread; or <li>The specified waiting time elapses. </ul>
<p>If a permit is acquired then the value <code>true</code> is returned.
<p>If the current thread: <ul> <li>has its interrupted status set on entry to this method; or <li>is <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/Thread.html?is-external=true#interrupt()" title="class or interface in java.lang">interrupted</a> while waiting to acquire a permit, </ul> then <a href="../../../org/apache/ignite/IgniteInterruptedException.html" title="class in org.apache.ignite"><code>IgniteInterruptedException</code></a> is
thrown and the current thread's interrupted status is cleared.
<p>If the specified waiting time elapses then the value <code>false</code> is returned. If the time is less than or
equal to zero, the method will not wait at all.</div>
<dl><dt><span class="strong">Parameters:</span></dt><dd><code>timeout</code> - the maximum time to wait for a permit</dd><dd><code>unit</code> - the time unit of the <code>timeout</code> argument</dd>
<dt><span class="strong">Returns:</span></dt><dd><code>true</code> if a permit was acquired and <code>false</code> if the waiting time elapsed before a permit was
acquired</dd>
<dt><span class="strong">Throws:</span></dt>
<dd><code><a href="../../../org/apache/ignite/IgniteInterruptedException.html" title="class in org.apache.ignite">IgniteInterruptedException</a></code> - if the current thread is interrupted</dd></dl>
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<pre>void&nbsp;acquireUninterruptibly(int&nbsp;permits)</pre>
<div class="block">Acquires the given number of permits from this semaphore, blocking until all are available.
<p>Acquires the given number of permits, if they are available, and returns immediately, reducing the number of
available permits by the given amount.
<p>If insufficient permits are available then the current thread becomes disabled for thread scheduling purposes
and lies dormant until some other thread invokes one of the <a href="../../../org/apache/ignite/IgniteSemaphore.html#release()"><code>release</code></a> methods for this
semaphore, the current thread is next to be assigned permits and the number of available permits satisfies this
request.
<p>If the current thread is <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/Thread.html?is-external=true#interrupt()" title="class or interface in java.lang">interrupted</a> while waiting for permits then it will
continue to wait and its position in the queue is not affected. When the thread does return from this method its
interrupt status will be set.</div>
<dl><dt><span class="strong">Parameters:</span></dt><dd><code>permits</code> - the number of permits to acquire</dd>
<dt><span class="strong">Throws:</span></dt>
<dd><code><a href="http://docs.oracle.com/javase/7/docs/api/java/lang/IllegalArgumentException.html?is-external=true" title="class or interface in java.lang">IllegalArgumentException</a></code> - if <code>permits</code> is negative</dd></dl>
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<pre>int&nbsp;availablePermits()</pre>
<div class="block">Returns the current number of permits available in this semaphore.
<p>This method is typically used for debugging and testing purposes.</div>
<dl><dt><span class="strong">Returns:</span></dt><dd>the number of permits available in this semaphore</dd></dl>
</li>
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<pre>int&nbsp;drainPermits()</pre>
<div class="block">Acquires and returns all permits that are immediately available.</div>
<dl><dt><span class="strong">Returns:</span></dt><dd>the number of permits acquired</dd></dl>
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<h4>release</h4>
<pre>void&nbsp;release()</pre>
<div class="block">Releases a permit, returning it to the semaphore.
<p>Releases a permit, increasing the number of available permits by one. If any threads are trying to acquire a
permit, then one is selected and given the permit that was just released. That thread is (re)enabled for thread
scheduling purposes.
<p>There is no requirement that a thread that releases a permit must have acquired that permit by calling <a href="../../../org/apache/ignite/IgniteSemaphore.html#acquire()"><code>acquire()</code></a>. Correct usage of a semaphore is established by programming convention in the application.</div>
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<pre>boolean&nbsp;tryAcquire(int&nbsp;permits,
long&nbsp;timeout,
<a href="http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/TimeUnit.html?is-external=true" title="class or interface in java.util.concurrent">TimeUnit</a>&nbsp;unit)
throws <a href="../../../org/apache/ignite/IgniteInterruptedException.html" title="class in org.apache.ignite">IgniteInterruptedException</a></pre>
<div class="block">Acquires the given number of permits from this semaphore, if all become available within the given waiting time
and the current thread has not been <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/Thread.html?is-external=true#interrupt()" title="class or interface in java.lang">interrupted</a>.
<p>Acquires the given number of permits, if they are available and returns immediately, with the value <code>true</code>, reducing the number of available permits by the given amount.
<p>If insufficient permits are available then the current thread becomes disabled for thread scheduling purposes
and lies dormant until one of three things happens: <ul> <li>Some other thread invokes one of the <a href="../../../org/apache/ignite/IgniteSemaphore.html#release()"><code>release</code></a> methods for this semaphore, the current thread is next to be assigned permits and the number
of available permits satisfies this request; or <li>Some other thread <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/Thread.html?is-external=true#interrupt()" title="class or interface in java.lang">interrupts</a>
the current thread; or <li>The specified waiting time elapses. </ul>
<p>If the permits are acquired then the value <code>true</code> is returned.
<p>If the current thread: <ul> <li>has its interrupted status set on entry to this method; or <li>is <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/Thread.html?is-external=true#interrupt()" title="class or interface in java.lang">interrupted</a> while waiting to acquire the permits, </ul> then <a href="../../../org/apache/ignite/IgniteInterruptedException.html" title="class in org.apache.ignite"><code>IgniteInterruptedException</code></a>
is thrown and the current thread's interrupted status is cleared. Any permits that were to be assigned to this
thread, are instead assigned to other threads trying to acquire permits, as if the permits had been made
available by a call to <a href="../../../org/apache/ignite/IgniteSemaphore.html#release()"><code>release()</code></a>.
<p>If the specified waiting time elapses then the value <code>false</code> is returned. If the time is less than or
equal to zero, the method will not wait at all. Any permits that were to be assigned to this thread, are instead
assigned to other threads trying to acquire permits, as if the permits had been made available by a call to
<a href="../../../org/apache/ignite/IgniteSemaphore.html#release()"><code>release()</code></a>.</div>
<dl><dt><span class="strong">Parameters:</span></dt><dd><code>permits</code> - the number of permits to acquire</dd><dd><code>timeout</code> - the maximum time to wait for the permits</dd><dd><code>unit</code> - the time unit of the <code>timeout</code> argument</dd>
<dt><span class="strong">Returns:</span></dt><dd><code>true</code> if all permits were acquired and <code>false</code> if the waiting time elapsed before all
permits were acquired</dd>
<dt><span class="strong">Throws:</span></dt>
<dd><code><a href="../../../org/apache/ignite/IgniteInterruptedException.html" title="class in org.apache.ignite">IgniteInterruptedException</a></code> - if the current thread is interrupted</dd>
<dd><code><a href="http://docs.oracle.com/javase/7/docs/api/java/lang/IllegalArgumentException.html?is-external=true" title="class or interface in java.lang">IllegalArgumentException</a></code> - if <code>permits</code> is negative</dd></dl>
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<h4>tryAcquire</h4>
<pre>boolean&nbsp;tryAcquire(int&nbsp;permits)</pre>
<div class="block">Acquires the given number of permits from this semaphore, only if all are available at the time of invocation.
<p>Acquires the given number of permits, if they are available, and returns immediately, with the value <code>true</code>, reducing the number of available permits by the given amount.
<p>If insufficient permits are available then this method will return immediately with the value <code>false</code>
and the number of available permits is unchanged.
<p>If you want to honor the failoverSafe setting, then use <a href="../../../org/apache/ignite/IgniteSemaphore.html#tryAcquire(int,%20long,%20java.util.concurrent.TimeUnit)"><code>tryAcquire(permits, 0, TimeUnit.SECONDS) </code></a> which is almost equivalent (it also detects interruption).</div>
<dl><dt><span class="strong">Parameters:</span></dt><dd><code>permits</code> - the number of permits to acquire</dd>
<dt><span class="strong">Returns:</span></dt><dd><code>true</code> if the permits were acquired and <code>false</code> otherwise</dd>
<dt><span class="strong">Throws:</span></dt>
<dd><code><a href="http://docs.oracle.com/javase/7/docs/api/java/lang/IllegalArgumentException.html?is-external=true" title="class or interface in java.lang">IllegalArgumentException</a></code> - if <code>permits</code> is negative</dd></dl>
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<h4>acquire</h4>
<pre>void&nbsp;acquire(int&nbsp;permits)
throws <a href="../../../org/apache/ignite/IgniteInterruptedException.html" title="class in org.apache.ignite">IgniteInterruptedException</a></pre>
<div class="block">Acquires the given number of permits from this semaphore, blocking until all are available, or the thread is
<a href="http://docs.oracle.com/javase/7/docs/api/java/lang/Thread.html?is-external=true#interrupt()" title="class or interface in java.lang">interrupted</a>.
<p>Acquires the given number of permits, if they are available, and returns immediately, reducing the number of
available permits by the given amount.
<p>If insufficient permits are available then the current thread becomes disabled for thread scheduling purposes
and lies dormant until one of two things happens: <ul> <li>Some other thread invokes one of the <a href="../../../org/apache/ignite/IgniteSemaphore.html#release()"><code>release</code></a> methods for this semaphore, the current thread is next to be assigned permits and the number of
available permits satisfies this request; or <li>Some other thread <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/Thread.html?is-external=true#interrupt()" title="class or interface in java.lang">interrupts</a> the
current thread. </ul>
<p>If the current thread: <ul> <li>has its interrupted status set on entry to this method; or <li>is <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/Thread.html?is-external=true#interrupt()" title="class or interface in java.lang">interrupted</a> while waiting for a permit, </ul> then <a href="../../../org/apache/ignite/IgniteInterruptedException.html" title="class in org.apache.ignite"><code>IgniteInterruptedException</code></a> is thrown
and the current thread's interrupted status is cleared. Any permits that were to be assigned to this thread are
instead assigned to other threads trying to acquire permits, as if permits had been made available by a call to
<a href="../../../org/apache/ignite/IgniteSemaphore.html#release()"><code>release()</code></a>.</div>
<dl><dt><span class="strong">Parameters:</span></dt><dd><code>permits</code> - the number of permits to acquire</dd>
<dt><span class="strong">Throws:</span></dt>
<dd><code><a href="../../../org/apache/ignite/IgniteInterruptedException.html" title="class in org.apache.ignite">IgniteInterruptedException</a></code> - if the current thread is interrupted</dd>
<dd><code><a href="http://docs.oracle.com/javase/7/docs/api/java/lang/IllegalArgumentException.html?is-external=true" title="class or interface in java.lang">IllegalArgumentException</a></code> - if <code>permits</code> is negative</dd></dl>
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<h4>release</h4>
<pre>void&nbsp;release(int&nbsp;permits)</pre>
<div class="block">Releases the given number of permits, returning them to the semaphore.
<p>Releases the given number of permits, increasing the number of available permits by that amount. If any
threads are trying to acquire permits, then one is selected and given the permits that were just released. If the
number of available permits satisfies that thread's request then that thread is (re)enabled for thread scheduling
purposes; otherwise the thread will wait until sufficient permits are available. If there are still permits
available after this thread's request has been satisfied, then those permits are assigned in turn to other
threads trying to acquire permits.
<p>There is no requirement that a thread that releases a permit must have acquired that permit by calling <a href="../../../org/apache/ignite/IgniteSemaphore.html#acquire()"><code>acquire</code></a>. Correct usage of a semaphore is established by programming convention in the
application.</div>
<dl><dt><span class="strong">Parameters:</span></dt><dd><code>permits</code> - the number of permits to release</dd>
<dt><span class="strong">Throws:</span></dt>
<dd><code><a href="http://docs.oracle.com/javase/7/docs/api/java/lang/IllegalArgumentException.html?is-external=true" title="class or interface in java.lang">IllegalArgumentException</a></code> - if <code>permits</code> is negative</dd></dl>
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<h4>isFailoverSafe</h4>
<pre>boolean&nbsp;isFailoverSafe()</pre>
<div class="block">Returns <code>true</code> if this semaphore is safe to use after node failure.
If not, IgniteInterruptedException is thrown on every other node after node failure.</div>
<dl><dt><span class="strong">Returns:</span></dt><dd><code>true</code> if this semaphore has failoverSafe set true</dd></dl>
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<h4>hasQueuedThreads</h4>
<pre>boolean&nbsp;hasQueuedThreads()</pre>
<div class="block">Queries whether any threads are waiting to acquire. Note that because cancellations may occur at any time, a
<code>true</code> return does not guarantee that any other thread will ever acquire. This method is designed
primarily for use in monitoring of the system state.</div>
<dl><dt><span class="strong">Returns:</span></dt><dd><code>true</code> if there may be other threads waiting to acquire the lock</dd></dl>
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<pre>int&nbsp;getQueueLength()</pre>
<div class="block">Returns an estimate of the number of nodes waiting to acquire. The value is only an estimate because the number
of nodes that are waiting may change dynamically while this method traverses internal data structures. This method is designed
for use in monitoring of the system state, not for synchronization control.</div>
<dl><dt><span class="strong">Returns:</span></dt><dd>the estimated number of nodes waiting for this lock</dd></dl>
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<pre>boolean&nbsp;isBroken()</pre>
<div class="block">Gets <code>broken</code> status of the semaphore.</div>
<dl><dt><span class="strong">Returns:</span></dt><dd><code>True</code> if a node failed on this semaphore and failoverSafe flag was set to false, <code>false</code> otherwise.</dd></dl>
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<pre>boolean&nbsp;removed()</pre>
<div class="block">Gets <code>removed</code> status of the semaphore.</div>
<dl><dt><span class="strong">Returns:</span></dt><dd><code>True</code> if semaphore was removed from cache, <code>false</code> otherwise.</dd></dl>
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<h4>close</h4>
<pre>void&nbsp;close()</pre>
<div class="block">Removes this semaphore.</div>
<dl>
<dt><strong>Specified by:</strong></dt>
<dd><code><a href="http://docs.oracle.com/javase/7/docs/api/java/lang/AutoCloseable.html?is-external=true#close()" title="class or interface in java.lang">close</a></code>&nbsp;in interface&nbsp;<code><a href="http://docs.oracle.com/javase/7/docs/api/java/lang/AutoCloseable.html?is-external=true" title="class or interface in java.lang">AutoCloseable</a></code></dd>
<dt><strong>Specified by:</strong></dt>
<dd><code><a href="http://docs.oracle.com/javase/7/docs/api/java/io/Closeable.html?is-external=true#close()" title="class or interface in java.io">close</a></code>&nbsp;in interface&nbsp;<code><a href="http://docs.oracle.com/javase/7/docs/api/java/io/Closeable.html?is-external=true" title="class or interface in java.io">Closeable</a></code></dd>
<dt><span class="strong">Throws:</span></dt>
<dd><code><a href="../../../org/apache/ignite/IgniteException.html" title="class in org.apache.ignite">IgniteException</a></code> - If operation failed.</dd></dl>
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<div class="aboutLanguage"><em>Ignite - In-Memory Data Fabric</em></div>
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<p class="legalCopy"><small><table width="100%" border="0" cellspacing=0 cellpadding=0 style="padding: 5px"> <tr> <td> <table style="padding-left: 0; margin: 0"> <tbody style="padding: 0; margin: 0"> <tr style="padding: 0; margin: 0"> <td> <a target=_blank href="https://ignite.apache.org"><nobr>2017 Copyright &#169; Apache Software Foundation</nobr></a> </td> </tr> </tbody> </table> </td> <td width="100%" align="right" valign="center"> <a href="https://twitter.com/ApacheIgnite" class="twitter-follow-button" data-show-count="false" data-size="large">Follow @ApacheIgnite</a> </td> </tr> <tr> <td colspan="2" valign="top" align="left"> <table style="padding-left: 0; margin: 0"> <tbody style="padding: 0; margin: 0"> <tr style="padding: 0; margin: 0"> <td> <b>Ignite Fabric</b> </td> <td>:&nbsp;&nbsp; ver. <strong>2.3.0</strong> </td> </tr> <tr style="padding: 0; margin: 0"> <td> <b>Release Date</b> </td> <td>:&nbsp;&nbsp; October 28 2017 </td> </tr> </tbody> </table> </td> </tr> </table></small></p>
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