src/edu/berkeley/fleet/interpreter/Outbox.java

   1 package edu.berkeley.fleet.interpreter;
   2 import edu.berkeley.sbp.util.ANSI;
   3 import edu.berkeley.fleet.api.*;
   4 import edu.berkeley.fleet.ies44.*;
   5 import edu.berkeley.fleet.util.*;
   6 import edu.berkeley.fleet.api.Instruction;
   7
   8 public class Outbox extends InstructionPump {
   9
  10     /** are we ready to accept another item from the ship? */
  11     private boolean readyForDataFromShip = false;
  12     private boolean haveDataFromShip     = false;
  13
  14     /** data which has been presented by the ship and is waiting to depart */
  15     private long    itemPresentedByShip;
  16
  17     /** number of tokens queued on the trigger input */
  18     private int     triggersReceived = 0;
  19
  20     /** the latched value */
  21     private long register;
  22
  23     public boolean isInbox() { return false; }
  24     public boolean isOutbox() { return true; }
  25     public Outbox(InterpreterShip ship, String name) { this(ship, name, new String[] { "" }); }
  26     public Outbox(InterpreterShip ship, String name, String[] ports) { super(ship, name, ports); }
  27
  28     protected final boolean service(Instruction.Executable instruction) {
  29
  30         // if no instruction waiting, do nothing
  31         if (instruction == null) return false;
  32
  33         // check firing conditions
  34         if (instruction.tokenIn && triggersReceived <= 0) return false;
  35         if (instruction.dataIn) {
  36             if (!haveDataFromShip) { readyForDataFromShip = true; return false; }
  37         }
  38
  39         // consume trigger
  40         if (instruction.tokenIn) triggersReceived--;
  41
  42         // consume item
  43         if (instruction.dataIn) {
  44             haveDataFromShip = false;
  45             if (instruction.latch)
  46                 register = itemPresentedByShip;
  47         }
  48
  49         if (instruction.dataOut) {
  50
  51             // if item to be transmitted, send it
  52             InterpreterDestination dest = (InterpreterDestination)instruction.dest;
  53             if (instruction.dataOutDest) {
  54                 // FIXME
  55                 long bits = BitManipulations.getField(InstructionEncoder.WIDTH_WORD-1,
  56                                                       InstructionEncoder.WIDTH_WORD-InstructionEncoder.WIDTH_DEST_ADDR,
  57                                                       register);
  58                 dest = (InterpreterDestination)(((Interpreter)getInterpreter()).iie.getDestByAddr(bits));
  59                 throw new RuntimeException();
  60             }
  61             new Packet(getInterpreter(), this, register, dest).send();
  62             if (instruction.tokenOut)
  63                 throw new RuntimeException("outboxes may not send acks!");
  64
  65         } else if (instruction.tokenOut) {
  66
  67             // if no item was sent, we might still send an ack
  68             new Packet(getInterpreter(), this, 0, (InterpreterDestination)instruction.dest).send();
  69         }
  70
  71         return true;
  72     }
  73
  74     public final boolean readyForDataFromShip() { return readyForDataFromShip; }
  75     public       void addDataFromShip(long data) { addItemFromShip(data); }
  76     public       void addDataFromFabric(Packet packet) { triggersReceived++; }
  77
  78     /** subclass invokes this to add an item from the ship */
  79     protected final void addItemFromShip(long data) {
  80         if (!readyForDataFromShip)
  81             throw new RuntimeException("tried to add an item to an outbox which was not ready!  you have a buggy ship!");
  82         readyForDataFromShip = false;
  83         haveDataFromShip = true;
  84         itemPresentedByShip = data;
  85     }
  86
  87     void shutdown() {
  88         if (haveDataFromShip)
  89             Log.println(ANSI.red(" WARNING: you left a value ("+itemPresentedByShip+") on outbox port " + this));
  90         if (triggersReceived > 0)
  91             Log.println(ANSI.red(" WARNING: you left a token on the trigger input to port " + this));
  92         super.shutdown(false);
  93     }
  94
  95 }