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POIs it okay to use "delete this;" on an object that inherits from a Thread class?
 

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  1. POIs it okay to use "delete this;" on an object that inherits from a Thread class?
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    <p>In general, if you have a class that inherits from a <code>Thread</code> class, and you want instances of that class to automatically deallocate after they are finished running, is it okay to <code>delete this</code>?</p> <p>Specific Example:</p> <p>In my application I have a <code>Timer</code> class with one <code>static</code> method called <code>schedule</code>. Users call it like so:</p> <pre><code>Timer::schedule((void*)obj, &amp;callbackFunction, 15); // call callbackFunction(obj) in 15 seconds </code></pre> <p>The <code>schedule</code> method creates a <code>Task</code> object (which is similar in purpose to a Java TimerTask object). The <code>Task</code> class is <code>private</code> to the <code>Timer</code> class and inherits from the <code>Thread</code> class (which is implemented with pthreads). So the <code>schedule</code> method does this:</p> <pre><code>Task *task = new Task(obj, callback, seconds); task-&gt;start(); // fork a thread, and call the task's run method </code></pre> <p>The <code>Task</code> constructor saves the arguments for use in the new thread. In the new thread, the task's <code>run</code> method is called, which looks like this:</p> <pre><code>void Timer::Task::run() { Thread::sleep(this-&gt;seconds); this-&gt;callback(this-&gt;obj); delete this; } </code></pre> <p>Note that I can't make the <code>task</code> object a stack allocated object because the new thread needs it. Also, I've made the <code>Task</code> class <code>private</code> to the <code>Timer</code> class to prevent others from using it.</p> <p>I am particularly worried because deleting the <code>Task</code> object means deleting the underlying <code>Thread</code> object. The only state in the <code>Thread</code> object is a <code>pthread_t</code> variable. Is there any way this could come back to bite me? Keep in mind that I do not use the <code>pthread_t</code> variable after the <code>run</code> method finishes.</p> <p>I could bypass calling <code>delete this</code> by introducing some sort of state (either through an argument to the <code>Thread::start</code> method or something in the <code>Thread</code> constructor) signifying that the method that is forked to should <code>delete</code> the object that it is calling the <code>run</code> method on. However, the code seems to work as is.</p> <p>Any thoughts?</p>
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