1<h2>vm_deallocate</h2> 2<hr> 3<p> 4<strong>Function</strong> - Deallocate a region of virtual memory. 5<h3>SYNOPSIS</h3> 6<pre> 7<strong>kern_return_t vm_deallocate</strong> 8 <strong>(vm_task_t</strong> <var>target_task</var>, 9 <strong>vm_address_t</strong> <var>address</var>, 10 <strong>vm_size_t</strong> <var>size</var><strong>);</strong> 11</pre> 12<h3>PARAMETERS</h3> 13<dl> 14<p> 15<dt> <var>target_task</var> 16<dd> 17[in task send right] 18The port for the task in whose address space the 19region is to be deallocated. 20<p> 21<dt> <var>address</var> 22<dd> 23[in scalar] 24The starting address for the region. 25<p> 26<dt> <var>size</var> 27<dd> 28[in scalar] 29The number of bytes to deallocate. 30</dl> 31<h3>DESCRIPTION</h3> 32<p> 33The <strong>vm_deallocate</strong> function deallocates a region of 34virtual memory in the 35specified task's address space. 36The region starts at the beginning of the virtual page containing 37<var>address</var> and ends 38at the end of the virtual page containing <var>address</var> 39+ <var>size</var> - 1. Because of this 40rounding to virtual page boundaries, the amount of memory deallocated may be 41greater than <var>size</var>. Use <strong>host_page_size</strong> 42to find the current virtual page size. 43<p> 44<strong>vm_deallocate</strong> affects only <var>target_task</var>. Other tasks 45that have access to the deallocated memory can continue to reference it. 46<h3>NOTES</h3> 47<p> 48<strong>vm_deallocate</strong> can be used to deallocate memory passed 49as out-of-line data in a 50message. 51<p> 52This interface is machine word length specific because of the virtual address 53parameter. 54<h3>RETURN VALUES</h3> 55<dl> 56<p> 57<dt> <strong>KERN_INVALID_ADDRESS</strong> 58<dd> 59The address is illegal or specifies a non-allocated region. 60</dl> 61<h3>RELATED INFORMATION</h3> 62<p> 63Functions: 64<a href="mach_msg.html"><strong>mach_msg</strong></a>, 65<a href="vm_allocate.html"><strong>vm_allocate</strong></a>, 66<a href="vm_map.html"><strong>vm_map</strong></a>, 67<a href="host_page_size.html"><strong>host_page_size</strong></a>. 68