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<h2>
<a name="1242681"> </a><font color="#003366" face="Verdana, Arial, Helvetica, sans-serif">task_suspend</font>
</h2><hr>
<p>
<a name="1242682"> </a><font size=2 face="Verdana, Arial, Helvetica, sans-serif">Suspend a specified task</font>
</p>
<h3>
<a name="1242683"> </a><font color="#003366" face="Verdana, Arial, Helvetica, sans-serif">Synopsis</font>
</h3>
<a name="1209699"> </a><font size=2 face=Courier><strong>#include <task.h><br></strong></font>
<a name="1209700"> </a><font size=2 face=Courier><strong>int task_suspend( task_t* <font size=2 face=Courier><strong><em>Task</em></strong></font> );<br></strong></font>
<h3>
<a name="1209701"> </a><font color="#003366" face="Verdana, Arial, Helvetica, sans-serif">Arguments</font>
</h3>
<p>
<a name="1234326"> </a><font size=2 face="Verdana, Arial, Helvetica, sans-serif"><b><font size=2 face=Courier><strong>task_t* </strong></font><font size=2 face=Courier><strong><em>Task</em></strong></font></b></font>
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<dl><dl> <dl>
<dt> <a name="1234328"> </a><font size=2 face="Verdana, Arial, Helvetica, sans-serif">Pointer to the task structure</font>
</dl>
</dl></dl>
<h3>
<a name="1209704"> </a><font color="#003366" face="Verdana, Arial, Helvetica, sans-serif">Results</font>
</h3>
<p>
<a name="1209705"> </a><font size=2 face="Verdana, Arial, Helvetica, sans-serif">Returns <font size=2 face=Courier><strong>0</strong></font> if the task was successfully suspended, or <font size=2 face=Courier><strong>-1</strong></font> if it could not be suspended.</font>
</p>
<h3>
<a name="1209706"> </a><font color="#003366" face="Verdana, Arial, Helvetica, sans-serif">Errors</font>
</h3>
<p>
<a name="1209707"> </a><font size=2 face="Verdana, Arial, Helvetica, sans-serif">If the task has been deleted then the call fails.</font>
</p>
<h3>
<a name="1209708"> </a><font color="#003366" face="Verdana, Arial, Helvetica, sans-serif">Description</font>
</h3>
<p>
<a name="1209709"> </a><font size=2 face="Verdana, Arial, Helvetica, sans-serif">This function suspends the specified task. If <font size=2 face=Courier><strong><em>Task</em></strong></font> is <font size=2 face=Courier><strong>NULL</strong></font> then this suspends the current task.</font>
</p>
<p>
<a name="1209710"> </a><font size=2 face="Verdana, Arial, Helvetica, sans-serif"><font size=2 face=Courier><strong>task_suspend</strong></font> stops the task from executing immediately, until it is resumed using <font size=2 face=Courier><strong>task_resume</strong></font>.</font>
</p>
<p>
<a name="1209711"> </a><font size=2 face="Verdana, Arial, Helvetica, sans-serif">On ST20C2 cores <font size=2 face=Courier><strong>task_suspend</strong></font> cannot be used on a high priority process.</font>
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<p>
<a name="1269929"> </a><font size=2 face="Verdana, Arial, Helvetica, sans-serif"><b>Caution:</b></font>
<br>
<dl><dl> <dl>
<dt> <a name="1209712"> </a><font size=2 face="Verdana, Arial, Helvetica, sans-serif"><font size=2 face=Courier><strong>task_suspend()</strong></font> is an inherently dangerous API when applied to any task except the caller, because it takes no account of the state of the specified task.</font>
<dt> <a name="1269983"> </a><font size=2 face="Verdana, Arial, Helvetica, sans-serif">If the suspended task holds any semaphores or other locks, these locks will not be released until the task is resumed.</font>
<dt> <a name="1269984"> </a><font size=2 face="Verdana, Arial, Helvetica, sans-serif">Similarly, if the suspended task is waiting for a lock, the fact that the task is suspended does not prevent the lock being assigned to the task.</font>
<dt> <a name="1269985"> </a><font size=2 face="Verdana, Arial, Helvetica, sans-serif">Both these situations make deadlock highly likely.</font>
<dt> <a name="1269976"> </a><font size=2 face="Verdana, Arial, Helvetica, sans-serif"><font size=2 face=Courier><strong>task_suspend()</strong></font> can be used for interactive debug/test tools but should not be used as a general syncronization mechanism.</font>
</dl>
</dl></dl>
<h3>
<a name="1269954"> </a><font color="#003366" face="Verdana, Arial, Helvetica, sans-serif">Callable from</font>
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<p>
<a name="1209713"> </a><font size=2 face="Verdana, Arial, Helvetica, sans-serif">Tasks only</font>
</p>
<h3>
<a name="1209714"> </a><font color="#003366" face="Verdana, Arial, Helvetica, sans-serif">See also</font>
</h3>
<p>
<a name="1209715"> </a><font size=2 face="Verdana, Arial, Helvetica, sans-serif"><a href="libs131.htm#1242668"><font color="#0000ff" face="Verdana, Arial, Helvetica, sans-serif"><i>task_resume</i></font></a></font>
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