Help/Scheduling/Condition.html

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  27 <p class="p1"><span class="s1"><b>Condition</b></span><span class="s2"><span class="Apple-tab-span">    </span><span class="Apple-tab-span">    </span><span class="Apple-tab-span">    </span></span><b>block execution of a thread</b></p>
  28 <p class="p2"><br></p>
  29 <p class="p2"><br></p>
  30 <p class="p1">superclass: Object</p>
  31 <p class="p2"><br></p>
  32 <p class="p2"><br></p>
  33 <p class="p1"><b><span class="Apple-tab-span">  </span>*new(test)<span class="Apple-tab-span">  </span></b>create a new instance, set the <b>test</b> variable.</p>
  34 <p class="p2"><b><span class="Apple-tab-span">  </span></b></p>
  35 <p class="p1"><b><span class="Apple-tab-span">  </span>test<span class="Apple-tab-span">        </span><span class="Apple-tab-span">    </span><span class="Apple-tab-span">    </span></b>return the test variable (boolean)</p>
  36 <p class="p2"><b><span class="Apple-tab-span">  </span></b></p>
  37 <p class="p1"><b><span class="Apple-tab-span">  </span>wait<span class="Apple-tab-span">        </span><span class="Apple-tab-span">    </span><span class="Apple-tab-span">    </span></b>wait until the condition is true and signalled</p>
  38 <p class="p2"><b><span class="Apple-tab-span">  </span></b></p>
  39 <p class="p1"><b><span class="Apple-tab-span">  </span>hang(val)<span class="Apple-tab-span">   </span><span class="Apple-tab-span">    </span></b>wait for <b>val</b> time, regardless of test</p>
  40 <p class="p2"><b><span class="Apple-tab-span">  </span></b></p>
  41 <p class="p1"><b><span class="Apple-tab-span">  </span>signal<span class="Apple-tab-span">      </span><span class="Apple-tab-span">    </span></b>if <b>test</b> is true, reschedule blocked threads</p>
  42 <p class="p2"><b><span class="Apple-tab-span">  </span></b></p>
  43 <p class="p1"><b><span class="Apple-tab-span">  </span>unhang<span class="Apple-tab-span">      </span><span class="Apple-tab-span">    </span></b>resume threads</p>
  44 <p class="p3"><br></p>
  45 <p class="p3"><br></p>
  46 <p class="p3"><br></p>
  47 <p class="p3"><br></p>
  48 <p class="p4">// example</p>
  49 <p class="p5"><br></p>
  50 <p class="p3"><br></p>
  51 <p class="p6">(</p>
  52 <p class="p7"><span class="s3">c = </span>Condition<span class="s3">.new(</span>false<span class="s3">);</span></p>
  53 <p class="p3"><br></p>
  54 <p class="p7">Routine<span class="s3"> {</span></p>
  55 <p class="p6"><span class="Apple-tab-span">     </span>1.wait;</p>
  56 <p class="p8"><span class="s3"><span class="Apple-tab-span">    </span></span>"waited for 1 second"<span class="s3">.postln;</span></p>
  57 <p class="p6"><span class="Apple-tab-span">     </span>1.wait;</p>
  58 <p class="p8"><span class="s3"><span class="Apple-tab-span">    </span></span>"waited for another second, now waiting for you ... "<span class="s3">.postln;</span></p>
  59 <p class="p6"><span class="Apple-tab-span">     </span>c.wait;</p>
  60 <p class="p8"><span class="s3"><span class="Apple-tab-span">    </span></span>"the condition has stopped waiting."<span class="s3">.postln;</span></p>
  61 <p class="p6"><span class="Apple-tab-span">     </span>1.wait;</p>
  62 <p class="p8"><span class="s3"><span class="Apple-tab-span">    </span></span>"waited for another second"<span class="s3">.postln;</span></p>
  63 <p class="p8"><span class="s3"><span class="Apple-tab-span">    </span></span>"waiting for you ... "<span class="s3">.postln;</span></p>
  64 <p class="p6"><span class="Apple-tab-span">     </span><span class="Apple-tab-span">    </span>c.test = <span class="s4">false</span>;</p>
  65 <p class="p6"><span class="Apple-tab-span">     </span><span class="Apple-tab-span">    </span>c.wait;</p>
  66 <p class="p8"><span class="s3"><span class="Apple-tab-span">    </span></span>"the condition has stopped waiting."<span class="s3">.postln;</span></p>
  67 <p class="p6"><span class="Apple-tab-span">     </span>1.wait;</p>
  68 <p class="p6"><span class="Apple-tab-span">     </span><span class="s5">"the end"</span>.postln;</p>
  69 <p class="p6">}.play;<span class="Apple-converted-space"> </span></p>
  70 <p class="p6">)</p>
  71 <p class="p3"><br></p>
  72 <p class="p4">// continue</p>
  73 <p class="p6">(</p>
  74 <p class="p6">c.test = <span class="s4">true</span>;</p>
  75 <p class="p6">c.signal;</p>
  76 <p class="p6">)</p>
  77 <p class="p3"><br></p>
  78 <p class="p4">// a typical use is a routine that can pause under certin conditions:</p>
  79 <p class="p6">(</p>
  80 <p class="p6">c = <span class="s4">Condition</span>.new;</p>
  81 <p class="p6">fork { loop { 1.wait; <span class="s5">"going"</span>.postln; c.wait } };</p>
  82 <p class="p6">)</p>
  83 <p class="p6">c.test = <span class="s4">true</span>; c.signal;</p>
  84 <p class="p6">c.test = <span class="s4">false</span>;</p>
  85 <p class="p3"><br></p>
  86 <p class="p3"><br></p>
  87 <p class="p3"><br></p>
  88 <p class="p4">// the same, using hang</p>
  89 <p class="p3"><br></p>
  90 <p class="p6">(</p>
  91 <p class="p6">c = <span class="s4">Condition</span>.new;</p>
  92 <p class="p3"><br></p>
  93 <p class="p7">Routine<span class="s3"> {</span></p>
  94 <p class="p6"><span class="Apple-tab-span">     </span>1.wait;</p>
  95 <p class="p8"><span class="s3"><span class="Apple-tab-span">    </span></span>"waited for 1 second"<span class="s3">.postln;</span></p>
  96 <p class="p6"><span class="Apple-tab-span">     </span>1.wait;</p>
  97 <p class="p8"><span class="s3"><span class="Apple-tab-span">    </span></span>"waited for another second, now waiting for you ... "<span class="s3">.postln;</span></p>
  98 <p class="p6"><span class="Apple-tab-span">     </span>c.hang;</p>
  99 <p class="p8"><span class="s3"><span class="Apple-tab-span">    </span></span>"the condition has stopped waiting."<span class="s3">.postln;</span></p>
 100 <p class="p6"><span class="Apple-tab-span">     </span>1.wait;</p>
 101 <p class="p8"><span class="s3"><span class="Apple-tab-span">    </span></span>"waited for another second"<span class="s3">.postln;</span></p>
 102 <p class="p8"><span class="s3"><span class="Apple-tab-span">    </span></span>"waiting for you ... "<span class="s3">.postln;</span></p>
 103 <p class="p6"><span class="Apple-tab-span">     </span>c.hang;</p>
 104 <p class="p8"><span class="s3"><span class="Apple-tab-span">    </span></span>"the condition has stopped waiting."<span class="s3">.postln;</span></p>
 105 <p class="p6">}.play;<span class="Apple-converted-space"> </span></p>
 106 <p class="p6">)</p>
 107 <p class="p3"><br></p>
 108 <p class="p4">// continue</p>
 109 <p class="p6">c.unhang;</p>
 110 <p class="p3"><br></p>
 111 <p class="p3"><br></p>
 112 </body>
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