问jheatbugs-2001-03-28中某些代码

sybbk

HeatbugModelSwarm中buildActions部分，3个try分别是做什么？查了下refbook-java-2.2，解释太简略，还是不懂，高手指点，谢谢！代码如下：

public Object buildActions () {
, z% o, z6 r9 |4 \    super.buildActions();
# v% O, D7 l, o4 t% P( A5 O   
! U" x; @, G# H    // Create the list of simulation actions. We put these in
    // an action group, because we want these actions to be
    // executed in a specific order, but these steps should
    // take no (simulated) time. The M(foo) means "The message
    // called <foo>". You can send a message To a particular
    // object, or ForEach object in a collection.
        
    // Note we update the heatspace in two phases: first run
    // diffusion, then run "updateWorld" to actually enact the
    // changes the heatbugs have made. The ordering here is
; `1 v- R( R7 r- w; P    // significant!
        
    // Note also, that with the additional
    // `randomizeHeatbugUpdateOrder' Boolean flag we can
    // randomize the order in which the bugs actually run
    // their step rule.  This has the effect of removing any
    // systematic bias in the iteration throught the heatbug
    // list from timestep to timestep
1 S& ]5 }7 C7 n. j        
    // By default, all `createActionForEach' modelActions have
2 ?, P) Y6 m. y! h5 ~/ f    // a default order of `Sequential', which means that the
    // order of iteration through the `heatbugList' will be
1 y( o( W& ]: v    // identical (assuming the list order is not changed
    // indirectly by some other process).
   
( ~+ b/ @% r1 \2 X2 y( }$ q    modelActions = new ActionGroupImpl (getZone ());
% V$ b8 K! a0 i  G
% P0 d$ o3 m# `( _  e  M3 u    try {
3 {0 @% I& ?! m1 E3 h* [( ~      modelActions.createActionTo$message
        (heat, new Selector (heat.getClass (), "stepRule", false));
4 g) t, k, |0 L! O. E5 N    } catch (Exception e) {
      System.err.println ("Exception stepRule: " + e.getMessage ());
+ ^0 A+ e8 ^5 Q( D    }
: f  i! g0 n7 k" T
" }) V. }# T+ i9 a# s8 u2 V' {  f    try {
0 i! a; F2 r0 z  Q      Heatbug proto = (Heatbug) heatbugList.get (0);
      Selector sel =
        new Selector (proto.getClass (), "heatbugStep", false);
- I, d1 F9 e. r! `1 \6 {      actionForEach =
        modelActions.createFActionForEachHomogeneous$call
        (heatbugList,
. m) a+ y# v7 K         new FCallImpl (this, proto, sel,
                        new FArgumentsImpl (this, sel)));
; W; B" ?6 V. v3 k$ a    } catch (Exception e) {
5 k( e: Z. D& f      e.printStackTrace (System.err);
    }
" B' [- ~% }: D; H) w( b/ J   
+ \. \5 L. r+ l' n7 u    syncUpdateOrder ();
) _0 m- z8 N: ~; c0 q
    try {
      modelActions.createActionTo$message
0 n6 w/ ~* z& J) M9 b        (heat, new Selector (heat.getClass (), "updateLattice", false));
! |$ _" z0 T) u  p6 }6 N1 v    } catch (Exception e) {
      System.err.println("Exception updateLattice: " + e.getMessage ());
    }
        
    // Then we create a schedule that executes the
3 `0 N4 |4 E3 ^3 A    // modelActions. modelActions is an ActionGroup, by itself it
    // has no notion of time. In order to have it executed in
    // time, we create a Schedule that says to use the
$ x# e5 R4 ?2 g    // modelActions ActionGroup at particular times.  This
    // schedule has a repeat interval of 1, it will loop every
    // time step.  The action is executed at time 0 relative to
& a- B+ W5 y3 X$ n/ u7 r: ?6 a    // the beginning of the loop.
; r2 `  f" Y5 e- }. y
    // This is a simple schedule, with only one action that is
    // just repeated every time. See jmousetrap for more
  l8 Q* a3 b! a8 X    // complicated schedules.
! W. J( }# v  N  
    modelSchedule = new ScheduleImpl (getZone (), 1);
    modelSchedule.at$createAction (0, modelActions);
        
    return this;
  }