Implement basic flow control: sending a message costs reductions equa…

…l to the size of the target queue. Also, minor updates to debug messages.
trifork · Mar 18, 2010 · 3cde8cd · 3cde8cd · jlouis · Mar 18, 2010
1 parent 6c40220
commit 3cde8cd
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Showing 6 changed files with 32 additions and 8 deletions.
diff --git a/erl.sh b/erl.sh
@@ -4,8 +4,8 @@ if [ "x${OTPROOT}" == "x" ]; then
   OTPROOT=/sw/lib/erlang
 fi
 
-java -ea -cp erjang-0.1.jar \
-    -Derj.threads=1 \
+java -server -ea -cp erjang-0.1.jar \
+    -Derj.threads=2 \
     -Derjpath=$OTPROOT/lib/erts-5.7.3/ebin erjang.OTPMain \
     -root $OTPROOT \
     -progname erl \

diff --git a/lib/kilim-0.6-krab.jar b/lib/kilim-0.6-krab.jar
diff --git a/src/main/java/erjang/EHandle.java b/src/main/java/erjang/EHandle.java
@@ -20,6 +20,7 @@
 package erjang;
 
 import kilim.Pausable;
+import kilim.Task;
 
 /**
  * An EHandle is either an EPort or an EPID.  EHandles can be sent messages
@@ -51,6 +52,13 @@ public boolean exists() {
 	public void send(EObject msg) throws Pausable {
 		ETask<?> task = task();
 		if (task != null) {
+
+			task.reds += task.mbox.size();
+			if (task.reds > 1000) {
+				task.reds = 0;
+				Task.yield();
+			}
+
 			task.mbox_send(msg);
 		}
 	}

diff --git a/src/main/java/erjang/EInternalPID.java b/src/main/java/erjang/EInternalPID.java
@@ -20,6 +20,7 @@
 package erjang;
 
 import kilim.Pausable;
+import kilim.Task;
 
 /**
  * This is a PID on this node
@@ -63,6 +64,13 @@ EProc task() {
 	public void send(EObject msg) throws Pausable {
 		EProc task = this.task;
 		if (task != null) {
+
+			task.reds += task.mbox.size();
+			if (task.reds > 1000) {
+				task.reds = 0;
+				Task.yield();
+			}
+
 			task.mbox.put(msg);
 		}
 	}

diff --git a/src/main/java/erjang/ERT.java b/src/main/java/erjang/ERT.java
@@ -458,6 +458,8 @@ public static EObject send(EProc proc, EObject pid, EObject msg)
 			throws Pausable {
 		// TODO handle ports also?
 		proc.check_exit();
+
+		//System.out.println(""+proc+" :: "+pid+" ! "+msg);
 
 		EHandle p;
 		if ((p = pid.testHandle()) != null) {
@@ -711,7 +713,9 @@ public static void run(Task task) {
 
 	/** peek mbox at current index (proc.midx), which is 0 upon entry to the loop. */
 	public static EObject loop_rec(EProc proc) {
-		EObject msg = proc.mbox.peek(proc.midx);		
+		int idx = proc.midx;
+		EObject msg = proc.mbox.peek(idx);		
+		if (DEBUG_WAIT) System.err.println("WAIT| entered loop #"+idx+" message="+msg);
 		return msg;
 	}
 
@@ -748,13 +752,15 @@ public static boolean wait_timeout(EProc proc, EObject howlong)
 
 	/** wait forever, for one more message to be available */
 	public static void wait(EProc proc) throws Pausable {
-		if (DEBUG_WAIT) System.err.println("WAIT| "+proc+" waits for messages");
-		proc.mbox.untilHasMessages(proc.midx + 1);
-		if (DEBUG_WAIT) System.err.println("WAIT| "+proc+" wakes up after timeout");
+		int idx = proc.midx + 1;
+		if (DEBUG_WAIT) System.err.println("WAIT| "+proc+" waits for "+idx+" messages");
+		proc.mbox.untilHasMessages(idx);
+		if (DEBUG_WAIT) System.err.println("WAIT| "+proc+" wakes up after timeout; now has "+(idx));
 	}
 
 	/** message reception timed out, reset message index */
 	public static void timeout(EProc proc) {
+		if (DEBUG_WAIT) System.err.println("WAIT| "+proc+" timed out");
 		proc.midx = 0;
 	}
 

diff --git a/src/main/java/erjang/ETask.java b/src/main/java/erjang/ETask.java
@@ -129,8 +129,8 @@ public void remove_monitor(ERef r, boolean flush) {
 	}
 
 
-
-	protected Mailbox<EObject> mbox = new Mailbox<EObject>(10, 1000);
+	static final int MAX_MAILBOX_SIZE = 1000;
+	protected Mailbox<EObject> mbox = new Mailbox<EObject>(10, MAX_MAILBOX_SIZE);
 
 	protected static enum State {
 		INIT, // has not started yet
@@ -144,6 +144,8 @@ protected static enum State {
 	protected State pstate = State.INIT;
 	protected EObject exit_reason;
 
+	public int reds;
+
 	/**
 	 * @throws Pausable
 	 *