1*c54f35caSApple OSS Distributions<h2>device_write_async</h2> 2*c54f35caSApple OSS Distributions<hr> 3*c54f35caSApple OSS Distributions<p> 4*c54f35caSApple OSS Distributions<strong>System Trap</strong> - Write a sequence of bytes to a device object. 5*c54f35caSApple OSS Distributions<h3>SYNOPSIS</h3> 6*c54f35caSApple OSS Distributions<pre> 7*c54f35caSApple OSS Distributions<strong>kern_return_t device_write_async</strong> 8*c54f35caSApple OSS Distributions <strong>(mach_port_t</strong> <var>device</var>, 9*c54f35caSApple OSS Distributions <strong>mach_port_t</strong> <var>queue</var>, 10*c54f35caSApple OSS Distributions <strong>mach_port_t</strong> <var>request_id</var>, 11*c54f35caSApple OSS Distributions <strong>dev_mode_t</strong> <var>mode</var>, 12*c54f35caSApple OSS Distributions <strong>recnum_t</strong> <var>recnum</var>, 13*c54f35caSApple OSS Distributions <strong>io_buf_ptr_t</strong> <var>data</var>, 14*c54f35caSApple OSS Distributions <strong>io_buf_len_t</strong> <var>bytes_wanted</var><strong>);</strong> 15*c54f35caSApple OSS Distributions</pre> 16*c54f35caSApple OSS Distributions<h3>PARAMETERS</h3> 17*c54f35caSApple OSS Distributions<dl> 18*c54f35caSApple OSS Distributions<p> 19*c54f35caSApple OSS Distributions<dt> <var>device</var> 20*c54f35caSApple OSS Distributions<dd> 21*c54f35caSApple OSS Distributions[in device send right] A device port to the device to be read. 22*c54f35caSApple OSS Distributions<p> 23*c54f35caSApple OSS Distributions<dt> <var>queue</var> 24*c54f35caSApple OSS Distributions<dd> 25*c54f35caSApple OSS Distributions[in io_done queue send right] The port returned from 26*c54f35caSApple OSS Distributionsio_done_queue_create. 27*c54f35caSApple OSS Distributions<p> 28*c54f35caSApple OSS Distributions<dt> <var>request_id</var> 29*c54f35caSApple OSS Distributions<dd> 30*c54f35caSApple OSS Distributions[in send right] An unique request identifier that will be passed back as 31*c54f35caSApple OSS Distributionspart of the io_done_result structure. 32*c54f35caSApple OSS Distributions<p> 33*c54f35caSApple OSS Distributions<dt> <var>mode</var> 34*c54f35caSApple OSS Distributions<dd> 35*c54f35caSApple OSS Distributions[in scalar] I/O mode value. Meaningful options are: 36*c54f35caSApple OSS Distributions<p> 37*c54f35caSApple OSS Distributions <dl> 38*c54f35caSApple OSS Distributions<dt> <strong>D_NOWAIT</strong> 39*c54f35caSApple OSS Distributions<dd> 40*c54f35caSApple OSS DistributionsDo not wait if data is unavailable. 41*c54f35caSApple OSS Distributions </dl> 42*c54f35caSApple OSS Distributions<p> 43*c54f35caSApple OSS Distributions<dt> <var>recnum</var> 44*c54f35caSApple OSS Distributions<dd> 45*c54f35caSApple OSS Distributions[in scalar] Record number to be read. 46*c54f35caSApple OSS Distributions<p> 47*c54f35caSApple OSS Distributions<dt> <var>data</var> 48*c54f35caSApple OSS Distributions<dd> 49*c54f35caSApple OSS Distributions[pointer to in array of bytes] Data bytes to be written. 50*c54f35caSApple OSS Distributions<p> 51*c54f35caSApple OSS Distributions<dt> <var>bytes_wanted</var> 52*c54f35caSApple OSS Distributions<dd> 53*c54f35caSApple OSS Distributions[in scalar] Size of data transfer. 54*c54f35caSApple OSS Distributions</dl> 55*c54f35caSApple OSS Distributions<h3>DESCRIPTION</h3> 56*c54f35caSApple OSS Distributions<p> 57*c54f35caSApple OSS DistributionsThe <strong>device_write_async</strong> function enqueues a write operation for a 58*c54f35caSApple OSS Distributionssequence of bytes to a device object. The meaning of recnum as well as 59*c54f35caSApple OSS Distributionsthe specific operation performed is device dependent. 60*c54f35caSApple OSS Distributions<h3>RETURN VALUES</h3> 61*c54f35caSApple OSS Distributions<p> 62*c54f35caSApple OSS Distributions<strong>device_write_async</strong> returns only invalid parameter errors. 63*c54f35caSApple OSS Distributions<h3>RELATED INFORMATION</h3> 64*c54f35caSApple OSS Distributions<p> 65*c54f35caSApple OSS DistributionsFunctions: 66*c54f35caSApple OSS Distributions<a href="device_read_async_inband.html"><strong>device_read_async_inband</strong></a>, 67*c54f35caSApple OSS Distributions<a href="DR_overwrite_async.html"><strong>device_read_overwrite_async</strong></a>, 68*c54f35caSApple OSS Distributions<a href="device_write_async_inband.html"><strong>device_write_async_inband</strong></a>, 69*c54f35caSApple OSS Distributions<a href="io_done_queue_create.html"><strong>io_done_queue_create</strong></a>. 70