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tinyos中文手册,是根据tinyos系统自带手册翻译过来的,虽然质量不好,但是对英文不强的人还是有用的

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	      <code>
		<pre>
call settimer0(10);
	      </pre>
	      </code>
	    </td></tr>
	</table>
      </center>

      This will start firing Timer0 at 1Hz, or once per second. Hit
      <b>Inject</b>. You should see the LEDs start ticking.</p>

    <p>
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	  <td width="100%"><nobr> <b>
		<font face="arial,helvetica">TinyScript</font>
	      </b></td> </tr>
      </table>
    </p>

    <p>TinyScript programs have two sections. The first is the
    variable declaration region. In the Timer handler above, this was
    the <code>private counter;</code> statement. All variables must be
    declared before any statements. There are three kinds of
    variables: <code>private</code>, which only that handler can
    access, <code>shared</code>, which all handlers can access, and
    <code>buffer</code> variables, which are shared. For example, this
    program declares a shared variable, a private variable, a buffer,
    and turns on the red LED:
      

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	      <code>
		<pre>
shared data;
private value;
buffer cache;

call led(1); ! Turn on red led
	      </pre>
	      </code>
	    </td></tr>
	</table>
      </center>

      Comments can be entered with <code>!</code>, which comments out
      everything until the end of line.</p>

    <p>Private and shared valuables can be either sensor readings,
    generated by primitives such as <code>temp</code> or
    <code>light</code>, or integers. Sensor readings are immutable;
    trying to modify them will result in a run-time error. You also
    cannot compare with with anything except sensor values of the same
    type (e.g., light with light). For example:

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	      <code>
		<pre>
private cond;
shared value;

cond = call rand() & 1;
if (cond) then
  value = call light();
else
  value = 20;
end if

value = value / 2;  ! This will fail if value is a light reading
	      </pre>
	      </code>
	    </td></tr>
	</table>
      </center> 

      If you need to modify sensor readings, say, for averaging, then
      you can cast them to integers with the <code>cast</code>
      primitive. This is a version of the above program that will execute
      without a run-time error:

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	      <code>
		<pre>
private cond;
shared value;

cond = call rand() & 1;
if (cond) then
  value = call cast(call light());
else
  value = 20;
end if

value = value / 2;  ! Now it works
	      </pre>
	      </code>
	    </td></tr>
	</table>
      </center>
      </p>

    <p>Buffers are indexed with <code>[]</code>; by default, they have
    ten elements. An empty index implies the tail of the buffer;
    <code>call cast(buf[]);</code> will return an integer value of the
    end of the buffer, while <code>buf[] = 0;</code> will append to a
    buffer.</p>

    <p>Buffers are typed. An empty buffer has no type. The
    <code>bclear</code> primitive empties a buffer. A buffer takes the
    type of the first element put into it (integer, light reading,
    etc.), and a run-time error occurs if any other type is put into
    it. Here is a program that sends a light reading over a tree-based
    ad-hoc collection routing protocol:
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	      <code>
		<pre>
buffer buf;

call bclear(buf);
buf[] = call light();
call send(buf);
	      </pre>
	      </code>
	    </td></tr>
	</table>
      </center>
      </p>
    
    <p>TinyScript supports basic arithmetic operations, such as
    addition (<code>+</code>), multiplication (<code>*</code>),
      division (<code>/</code>), modulus (<code>%</code>), as well as
      boolean operations such as and (<code>AND</code>) as well as or
      (<code>OR</code>), as well as their binary (logical) equivalents
    (<code>&</code>, <code>|</code>).</p>

    <p>Primitives are invoked with the <code>call</code> keyword
    (e.g., <code>call led(1);</code>). If the primitive has a return
    value (check its documentation), it must be stored. For example,
    <code>rand()</code> returns a random value. <code>call
    random();</code> will cause a compile error, while <code>rval =
    call random();</code> will not.</p>

    <p>Control structures include <code>if ... then</code> as shown
    above, as well as loops. For example, to put ten successive light
    values into a buffer:

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	      <code>
		<pre>
buffer buf;
private i;

call bclear(buf);

for i=0 to 9 
  buf[] = call light();
next i

call send(buf);
	      </pre>
	      </code>
	    </td></tr>
	</table>
      </center>
    </p>

    <p>There are a limited number of buffers and variables. By
    default, there are 16 shared variables, eight private variables
    (per handler), and eight buffers.</p>
    
    <p>A full <A HREF="../mate-manual.pdf">reference</A> for
    TinyScript can be found in the standard documentation
    directory. This tutorial only covers a few major points.</p>

        <p>
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	<tr bgcolor="#e0e0ff">
	  <td width="100%"><nobr> <b> <font
	  face="arial,helvetica">Errors</font> </b></td> </tr> </table></p>
    

    
      <p>When Mat&eacute; encounters an error in a program
      (e.g. trying to add a light and temperture value), it enters an
      error state. In this error state, it stops running
      capsules. Instead, it periodically toggles all of the LEDs (all
      of them blinking on and off is an indication something has gone
      wrong) and sends a packet over the UART. The packet is a
      Mat&eacute;ErrorMsg and contains information on the cause of the
      error.</p>



        <p>
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	<tr bgcolor="#e0e0ff">
	  <td width="100%"><nobr> <b> <font
	  face="arial,helvetica">A Simple Program</font> </b></td> </tr> </table></p>

    <p>Here is a simple program, where each mote will periodically
    (one every ten seconds) sample its temperature and light sensors,
    but those values into a buffer, and route those to a base
    station. Note that, for this to work, there must be a routing base
    station (a node with ID 0).</p>

    <p>If Timer0 is running from the earlier part of the tutorial,
    stop it with the Once handler by <code>call
    settimer0(0);</code>. Then, install this as Timer0:

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	      <code>
		<pre>
buffer buf;
private counter;

counter = counter + 1;
if (counter >= 10) then
  call bclear(buf);
  buf[] = call cast(call light());
  buf[] = call cast(call temp());
  counter = 0;
  call send(buf);
end if
	      </pre>
	      </code>
	    </td></tr>
	</table>
      </center>
      </p>

    followed by this as Once:

    
    <center>
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	<tr bgcolor="#e0e0e0">
	  <td width="100%">
	    <code>
	      <pre>
call settimer0(10);
	      </pre>
	      </code>
	    </td></tr>
	</table>
      </center>

    Alternatively, instead of maintaining the counter value, you could
    <code>call settimer0(100);</code>.</p>
    
    <table border=0 hspace=4 cellspacing=2 width="100%" cellpadding=3>
      <tr bgcolor="#e0e0ff">
	<td width="100%"><nobr> <b> <font face="arial,helvetica">Data
	Consistency</font> </b></td> </tr> </table></p>
    

    
    <p>By default, multiple Mat&eacute; handlers can run concurrently;
    the VM interleaves their execution at instruction-level
    granularity. When there are shared variables (and buffers), this
    can lead to possible race conditions. Using installation-time
    program analysis, Mat&eacute; ensures race-free, deadlock-free
    execution of handlers. If two handlers can safely run concurrently
    (they share no variables), then the scheduler lets them do so.</p>
    
    <p>This can fail due to handler installation. Notably, as
      handlers are installed immediately upon reception, a context
      can be in the midst of a computation when it is halted due to
      new code being installed.</p>
    
    <p>This means that to ensure perfect data consistency, the
      values of shared variables cannot be transferred from one
      version of a handler to the next. For example, before
      installing a new version of the clock handler, one could
      install a clock handler that clears out the shared variables,
      restoring them to a consistent state.</p>
    
    <p>We are currently working on a handler installation
      mechanism that will preserve execution atomicity; this
      understandably becomes difficult in the presence of buggy
      handlers that do not halt.</p>
    
    
    <table border=0 hspace=4 cellspacing=2 width="100%" cellpadding=3>
      <tr bgcolor="#e0e0ff">
	<td width="100%"><nobr> <b> <font face="arial,helvetica">Further Use
	</font> </b></td> </tr> </table></p>

    <p>This document just touches on Mat&eacute; and some simple
    programs that you can write with the example Bombilla
    VM. Mat&eacute; allows you to build customized VMs, with
    user-specified event handlers and primitives. For example, you can
    build a scripting environment that receives and sends packets,
    reacts to target detection, or acts as a data aggregation engine.
    For more information, please refer to the <A
    HREF="../mate-manual.pdf">Mat&eacute; manual</A></p>

    <p>Mat&eacute; is in active development. If you find bugs, please
    enter them in the <A HREF="http://sourceforge.net/tracker/?group_id=28656&atid=393934">TinyOS bug tracker</A> on
    Sourceforge. Feature requests and questions should be sent to the
    standard TinyOS users list,
    <code>[e-mail]</code>. You can sign up
    <A
    HREF="http://webs.cs.berkeley.edu/tos/support.html#lists">here</A>.
    <p>
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