1*699cd480SApple OSS Distributions<h2>thread_suspend</h2> 2*699cd480SApple OSS Distributions<hr> 3*699cd480SApple OSS Distributions<p> 4*699cd480SApple OSS Distributions<strong>Function</strong> - Suspend a thread. 5*699cd480SApple OSS Distributions<h3>SYNOPSIS</h3> 6*699cd480SApple OSS Distributions<pre> 7*699cd480SApple OSS Distributions<strong>kern_return_t thread_suspend</strong> 8*699cd480SApple OSS Distributions <strong>(thread_act_t</strong> <var>target_thread</var><strong>);</strong> 9*699cd480SApple OSS Distributions</pre> 10*699cd480SApple OSS Distributions<h3>PARAMETERS</h3> 11*699cd480SApple OSS Distributions<dl> 12*699cd480SApple OSS Distributions<p> 13*699cd480SApple OSS Distributions<dt> <var>target_thread</var> 14*699cd480SApple OSS Distributions<dd> 15*699cd480SApple OSS Distributions[in thread send right] 16*699cd480SApple OSS DistributionsThe thread to be suspended. 17*699cd480SApple OSS Distributions</dl> 18*699cd480SApple OSS Distributions<h3>DESCRIPTION</h3> 19*699cd480SApple OSS Distributions<p> 20*699cd480SApple OSS DistributionsThe <strong>thread_suspend</strong> function increments the suspend 21*699cd480SApple OSS Distributionscount for <var>target_thread</var> 22*699cd480SApple OSS Distributionsand prevents the thread from executing any more user-level instructions. 23*699cd480SApple OSS Distributions<p> 24*699cd480SApple OSS DistributionsIn this context, a user-level instruction can be either a machine instruction 25*699cd480SApple OSS Distributionsexecuted in user mode or a system trap instruction, including 26*699cd480SApple OSS Distributionsa page fault. If a 27*699cd480SApple OSS Distributionsthread is currently executing within a system trap, the kernel 28*699cd480SApple OSS Distributionscode may continue 29*699cd480SApple OSS Distributionsto execute until it reaches the system return code or it may 30*699cd480SApple OSS Distributionssuspend within the 31*699cd480SApple OSS Distributionskernel code. In either case, the system trap returns when the thread resumes. 32*699cd480SApple OSS Distributions<p> 33*699cd480SApple OSS DistributionsTo resume a suspended thread, use <strong>thread_resume</strong>. If 34*699cd480SApple OSS Distributionsthe suspend count is 35*699cd480SApple OSS Distributionsgreater than one, <strong>thread_resume</strong> must be repeated that 36*699cd480SApple OSS Distributionsnumber of times. 37*699cd480SApple OSS Distributions<h3>CAUTIONS</h3> 38*699cd480SApple OSS Distributions<p> 39*699cd480SApple OSS DistributionsUnpredictable results may occur if a program suspends a thread and alters its 40*699cd480SApple OSS Distributionsuser state so that its direction is changed upon resuming. Note that the 41*699cd480SApple OSS Distributions<strong>thread_abort</strong> function allows a system call to be aborted 42*699cd480SApple OSS Distributionsonly if it is progressing in a 43*699cd480SApple OSS Distributionspredictable way. 44*699cd480SApple OSS Distributions<h3>RETURN VALUES</h3> 45*699cd480SApple OSS Distributions<p> 46*699cd480SApple OSS DistributionsOnly generic errors apply. 47*699cd480SApple OSS Distributions<h3>RELATED INFORMATION</h3> 48*699cd480SApple OSS Distributions<p> 49*699cd480SApple OSS DistributionsFunctions: 50*699cd480SApple OSS Distributions<a href="task_resume.html"><strong>task_resume</strong></a>, 51*699cd480SApple OSS Distributions<a href="task_suspend.html"><strong>task_suspend</strong></a>, 52*699cd480SApple OSS Distributions<a href="thread_abort.html"><strong>thread_abort</strong></a>, 53*699cd480SApple OSS Distributions<a href="thread_get_state.html"><strong>thread_get_state</strong></a>, 54*699cd480SApple OSS Distributions<a href="thread_info.html"><strong>thread_info</strong></a>, 55*699cd480SApple OSS Distributions<a href="thread_resume.html"><strong>thread_resume</strong></a>, 56*699cd480SApple OSS Distributions<a href="thread_set_state.html"><strong>thread_set_state</strong></a>, 57*699cd480SApple OSS Distributions<a href="thread_terminate.html"><strong>thread_terminate</strong></a>. 58