1*e13b1fa5SApple OSS Distributions<h2>thread_suspend</h2> 2*e13b1fa5SApple OSS Distributions<hr> 3*e13b1fa5SApple OSS Distributions<p> 4*e13b1fa5SApple OSS Distributions<strong>Function</strong> - Suspend a thread. 5*e13b1fa5SApple OSS Distributions<h3>SYNOPSIS</h3> 6*e13b1fa5SApple OSS Distributions<pre> 7*e13b1fa5SApple OSS Distributions<strong>kern_return_t thread_suspend</strong> 8*e13b1fa5SApple OSS Distributions <strong>(thread_act_t</strong> <var>target_thread</var><strong>);</strong> 9*e13b1fa5SApple OSS Distributions</pre> 10*e13b1fa5SApple OSS Distributions<h3>PARAMETERS</h3> 11*e13b1fa5SApple OSS Distributions<dl> 12*e13b1fa5SApple OSS Distributions<p> 13*e13b1fa5SApple OSS Distributions<dt> <var>target_thread</var> 14*e13b1fa5SApple OSS Distributions<dd> 15*e13b1fa5SApple OSS Distributions[in thread send right] 16*e13b1fa5SApple OSS DistributionsThe thread to be suspended. 17*e13b1fa5SApple OSS Distributions</dl> 18*e13b1fa5SApple OSS Distributions<h3>DESCRIPTION</h3> 19*e13b1fa5SApple OSS Distributions<p> 20*e13b1fa5SApple OSS DistributionsThe <strong>thread_suspend</strong> function increments the suspend 21*e13b1fa5SApple OSS Distributionscount for <var>target_thread</var> 22*e13b1fa5SApple OSS Distributionsand prevents the thread from executing any more user-level instructions. 23*e13b1fa5SApple OSS Distributions<p> 24*e13b1fa5SApple OSS DistributionsIn this context, a user-level instruction can be either a machine instruction 25*e13b1fa5SApple OSS Distributionsexecuted in user mode or a system trap instruction, including 26*e13b1fa5SApple OSS Distributionsa page fault. If a 27*e13b1fa5SApple OSS Distributionsthread is currently executing within a system trap, the kernel 28*e13b1fa5SApple OSS Distributionscode may continue 29*e13b1fa5SApple OSS Distributionsto execute until it reaches the system return code or it may 30*e13b1fa5SApple OSS Distributionssuspend within the 31*e13b1fa5SApple OSS Distributionskernel code. In either case, the system trap returns when the thread resumes. 32*e13b1fa5SApple OSS Distributions<p> 33*e13b1fa5SApple OSS DistributionsTo resume a suspended thread, use <strong>thread_resume</strong>. If 34*e13b1fa5SApple OSS Distributionsthe suspend count is 35*e13b1fa5SApple OSS Distributionsgreater than one, <strong>thread_resume</strong> must be repeated that 36*e13b1fa5SApple OSS Distributionsnumber of times. 37*e13b1fa5SApple OSS Distributions<h3>CAUTIONS</h3> 38*e13b1fa5SApple OSS Distributions<p> 39*e13b1fa5SApple OSS DistributionsUnpredictable results may occur if a program suspends a thread and alters its 40*e13b1fa5SApple OSS Distributionsuser state so that its direction is changed upon resuming. Note that the 41*e13b1fa5SApple OSS Distributions<strong>thread_abort</strong> function allows a system call to be aborted 42*e13b1fa5SApple OSS Distributionsonly if it is progressing in a 43*e13b1fa5SApple OSS Distributionspredictable way. 44*e13b1fa5SApple OSS Distributions<h3>RETURN VALUES</h3> 45*e13b1fa5SApple OSS Distributions<p> 46*e13b1fa5SApple OSS DistributionsOnly generic errors apply. 47*e13b1fa5SApple OSS Distributions<h3>RELATED INFORMATION</h3> 48*e13b1fa5SApple OSS Distributions<p> 49*e13b1fa5SApple OSS DistributionsFunctions: 50*e13b1fa5SApple OSS Distributions<a href="task_resume.html"><strong>task_resume</strong></a>, 51*e13b1fa5SApple OSS Distributions<a href="task_suspend.html"><strong>task_suspend</strong></a>, 52*e13b1fa5SApple OSS Distributions<a href="thread_abort.html"><strong>thread_abort</strong></a>, 53*e13b1fa5SApple OSS Distributions<a href="thread_get_state.html"><strong>thread_get_state</strong></a>, 54*e13b1fa5SApple OSS Distributions<a href="thread_info.html"><strong>thread_info</strong></a>, 55*e13b1fa5SApple OSS Distributions<a href="thread_resume.html"><strong>thread_resume</strong></a>, 56*e13b1fa5SApple OSS Distributions<a href="thread_set_state.html"><strong>thread_set_state</strong></a>, 57*e13b1fa5SApple OSS Distributions<a href="thread_terminate.html"><strong>thread_terminate</strong></a>. 58