[apple/xnu.git] / osfmk / man / memory_object_synchronize.html

<h2>memory_object_synchronize</h2>\r<hr>\r<p>\r<strong>Server Interface</strong> - Forward a client's request to synchronize data with its image in backing store.\r<h3>SYNOPSIS</h3>\r<pre>\r<strong>kern_return_t   memory_object_synchronize</strong>\r                <strong>(memory_object_t</strong>                  <var>memory_object</var>,\r                 <strong>memory_object_control_t</strong>         <var>memory_control</var>,\r                 <strong>vm_offset_t</strong>                             <var>offset</var>,\r                 <strong>vm_offset_t</strong>                             <var>length</var>,\r                 <strong>memory_object</strong>                       <var>sync_flags</var><strong>);</strong>\r\r\r<strong>kern_return_t   seqnos_memory_object_synchronize</strong>\r                <strong>(memory_object_t</strong>                  <var>memory_object</var>,\r                 <strong>mach_port_seqno_t</strong>                        <var>seqno</var>,\r                 <strong>memory_object_control_t</strong>         <var>memory_control</var>,\r                 <strong>vm_offset_t</strong>                             <var>offset</var>,\r                 <strong>vm_offset_t</strong>                             <var>length</var>,\r                 <strong>memory_object</strong>                       <var>sync_flags</var><strong>);</strong>\r</pre>\r<h3>PARAMETERS</h3>\r<dl>\r<p>\r<dt> <var>memory_object</var> \r<dd>\r[in abstract-memory-object (receive) right]\rThe abstract memory\robject port that represents the memory object data.\r<p>\r<dt> <var>seqno</var> \r<dd>\r[in scalar]\rThe sequence number of this message relative to the abstract \rmemory object port.\r<p>\r<dt> <var>memory_control</var> \r<dd>\r[in memory-cache-control send right]\rThe memory cache control port \rto be used for a response by the memory manager.  If the memory\robject has been supplied to more than one kernel, this parameter\ridentifies the kernel that is making the call.\r<p>\r<dt> <var>offset</var> \r<dd>\r[in scalar]\rThe offset within the memory object.\r<p>\r<dt> <var>length</var> \r<dd>\r[in scalar]\rThe number of bytes cleaned or flushed, starting at <var>offset</var>. \rThe number converts to an integral number of virtual pages.\r<p>\r<dt> <var>sync_flags</var> \r<dd>\r[in scalar]\rThe bit-wise OR of flags affecting the synchronization.\r<dl>\r<p>\r<dt> <strong>VM_SYNC_INVALIDATE</strong>\r<dd>\rFlushes pages in the range.  Only precious pages are returned \rto the memory manager.\r<p>\r<dt> <strong>VM_SYNC_SYNCHRONOUS</strong>\r<dd>\rWrites dirty and precious pages back to the memory manager, \rwaits for pages to reach backing storage.\r<p>\r<dt> <strong>VM_SYNC_ASYNCHRONOUS</strong>\r<dd>\rWrites dirty and precious pages back to the memory manager, \rreturns without waiting for pages to reach backing storage.\r</dl>\r</dl>\r<h3>DESCRIPTION</h3>\r<p>\rA <strong>memory_object_synchronize</strong> function is called as the\rresult of a kernel\rmessage indicating that a client wishes to synchronize the contents\rof a range of a \rmemory object with its backing storage image.  This message would have been \rpreceded by <strong>memory_object_data_return</strong> messages cleaning\ror flushing the \rspecified range.\r<p>\rDepending on the client's supplied <var>sync_flags</var>, the manager waits \rfor the pages \rto reach the desired state and then replies with\r<strong>memory_object_synchronize_completed</strong> at which time the\rclient returns from its <strong>vm_msync</strong> call.  Multiple \rsynchronize requests may be outstanding at a time but they will not overlap.\r<h3>RETURN VALUES</h3>\r<p>\rOnly generic errors apply.\r<h3>RELATED INFORMATION</h3>\r<p>\rFunctions:\r<a href="vm_msync.html"><strong>vm_msync</strong></a>,\r<a href="MO_SY_completed.html"><strong>memory_object_synchronize_completed</strong></a>,\r<a href="memory_object_data_return.html"><strong>memory_object_data_return</strong></a>,\r<a href="memory_object_server.html"><strong>memory_object_server</strong></a>,\r<a href="SMO_server.html"><strong>seqnos_memory_object_server</strong></a>.\r