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<h2>
<span class="refentrytitle">stack</span>
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<p>stack —
Initializes the stack.
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<div class="refsect1" title="Description">
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<h2>Description</h2>
<p>
Initializes and sets the size of the global stack.
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<div class="refsect1" title="Syntax">
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<h2>Syntax</h2>
<pre class="synopsis"><span class="command"><strong>stack</strong></span> iStackSize</pre>
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<div class="refsect1" title="Initialization">
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<h2>Initialization</h2>
<p>
<span class="emphasis"><em>iStackSize</em></span> - size of the stack in bytes.
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<div class="refsect1" title="Performance">
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<h2>Performance</h2>
<p>
Csound implements a single global stack. Initializing the stack with the <span class="emphasis"><em>stack</em></span> opcode is not required - it is optional, and if not done, the first use of <a class="link" href="push.html" title="push"><em class="citetitle">push</em></a> or <a class="link" href="push_f.html" title="push_f"><em class="citetitle">push_f</em></a> will automatically create a stack of 32768 bytes. Otherwise, <span class="emphasis"><em>stack</em></span> is normally called from the orchestra header, and takes a stack size parameter in bytes (there is an upper limit of about 16 MB). Once set, the stack size is fixed and cannot be changed during performance.
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<p>
The global stack works in LIFO order: after multiple <a class="link" href="push.html" title="push"><em class="citetitle">push</em></a> calls, <a class="link" href="pop.html" title="pop"><em class="citetitle">pop</em></a> should be used in reverse order.
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<p>
Each <a class="link" href="push.html" title="push"><em class="citetitle">push</em></a> or <a class="link" href="pop.html" title="pop"><em class="citetitle">pop</em></a> operation can work on a "bundle" of multiple variables. When using <a class="link" href="pop.html" title="pop"><em class="citetitle">pop</em></a>, the number, type, and order of items must match those used by the corresponding <a class="link" href="push.html" title="push"><em class="citetitle">push</em></a>. That is, after a 'push Sfoo, ibar', you must call something like 'pop Sbar, ifoo', and not e.g. two separate 'pop' statements.
</p>
<p>
<a class="link" href="push.html" title="push"><em class="citetitle">push</em></a> and <a class="link" href="pop.html" title="pop"><em class="citetitle">pop</em></a> opcodes can take variables of any type (i-, k-, a- and strings). Variables of type 'a' and 'k' are passed at performance time only, while 'i' and 'S' are passed at init time only.
</p>
<p>
push/pop for a, k, i, and S types copy data by value. By contrast, <a class="link" href="push_f.html" title="push_f"><em class="citetitle">push_f</em></a> only pushes a "reference" to the f-signal, and then the corresponding <a class="link" href="pop_f.html" title="pop_f"><em class="citetitle">pop_f</em></a> will copy directly from the original variable to its output signal. For this reason, changing the source f-signal of <a class="link" href="push_f.html" title="push_f"><em class="citetitle">push_f</em></a> before <a class="link" href="pop_f.html" title="pop_f"><em class="citetitle">pop_f</em></a> is called is not recommended, and if the instrument instance owning the variable that was passed by push_f is deactivated before pop_f is called, undefined behavior may occur.
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<p>
Any stack errors (trying to push when there is no more space, or pop from an empty stack, inconsistent number or type of arguments, etc.) are fatal and terminate performance.
</p>
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<div class="refsect1" title="See also">
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<h2>See also</h2>
<p>
<a class="link" href="pop.html" title="pop"><em class="citetitle">pop</em></a>,
<a class="link" href="push.html" title="push"><em class="citetitle">push</em></a>,
<a class="link" href="pop_f.html" title="pop_f"><em class="citetitle">pop_f</em></a> and
<a class="link" href="push_f.html" title="push_f"><em class="citetitle">push_f</em></a>.
</p>
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<div class="refsect1" title="Credits">
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<h2>Credits</h2>
<p>By: Istvan Varga.</p>
<p>2006</p>
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