Change the way the threads are launched: they are now launched as

[simgrid.git] / org / simgrid / msg / Process.java

diff --git a/org/simgrid/msg/Process.java b/org/simgrid/msg/Process.java
index bb9f963..85d822f 100644 (file)
--- a/org/simgrid/msg/Process.java
+++ b/org/simgrid/msg/Process.java
@@ -14,6 +14,7 @@ package org.simgrid.msg;
 import java.util.Arrays;
 import java.util.Hashtable;
 import java.util.Vector;
 import java.util.Arrays;
 import java.util.Hashtable;
 import java.util.Vector;

+import java.lang.Runnable;

 import java.util.concurrent.Semaphore;
 
 /**
 import java.util.concurrent.Semaphore;
 
 /**


@@ -47,7 +48,7 @@ import java.util.concurrent.Semaphore;
  * 
  */
 
  * 
  */
 

-public abstract class Process extends Thread {
+public abstract class Process implements Runnable {

        /**
         * This attribute represents a bind between a java process object and
         * a native process. Even if this attribute is public you must never
        /**
         * This attribute represents a bind between a java process object and
         * a native process. Even if this attribute is public you must never


@@ -92,22 +93,17 @@ public abstract class Process extends Thread {
 
        /* process synchronization tools */
        
 
        /* process synchronization tools */
        

-       /* give the full path to semaphore to ensure that our own implementation don't get selected */
-    protected java.util.concurrent.Semaphore schedBegin, schedEnd;

     private boolean nativeStop = false;
 
        /**
         * Default constructor (used in ApplicationHandler to initialize it)
         */
        protected Process() {
     private boolean nativeStop = false;
 
        /**
         * Default constructor (used in ApplicationHandler to initialize it)
         */
        protected Process() {

-               super();

                this.id = nextProcessId++;
                this.name = null;
                this.bind = 0;
                this.args = new Vector<String>();
                this.properties = null;
                this.id = nextProcessId++;
                this.name = null;
                this.bind = 0;
                this.args = new Vector<String>();
                this.properties = null;

-               schedBegin = new java.util.concurrent.Semaphore(0);
-               schedEnd = new java.util.concurrent.Semaphore(0);

        }
 
 
        }
 
 


@@ -164,7 +160,7 @@ public abstract class Process extends Thread {
        public Process(Host host, String name, String[]args) {
                /* This is the constructor called by all others */
                this();
        public Process(Host host, String name, String[]args) {
                /* This is the constructor called by all others */
                this();

-               
+               this.host = host;

                if (name == null)
                        throw new NullPointerException("Process name cannot be NULL");
                this.name = name;
                if (name == null)
                        throw new NullPointerException("Process name cannot be NULL");
                this.name = name;


@@ -172,12 +168,6 @@ public abstract class Process extends Thread {
                this.args = new Vector<String>();
                if (null != args)
                        this.args.addAll(Arrays.asList(args));
                this.args = new Vector<String>();
                if (null != args)
                        this.args.addAll(Arrays.asList(args));

-
-               try {
-                       create(host.getName());
-               } catch (HostNotFoundException e) {
-                       throw new RuntimeException("The impossible happened (yet again): the host that I have were not found",e);
-               }

                
                this.properties = new Hashtable<String,String>();
                
                
                this.properties = new Hashtable<String,String>();
                


@@ -345,22 +335,22 @@ public abstract class Process extends Thread {
      * Exit the process
      */
     public native void exit();
      * Exit the process
      */
     public native void exit();

-
+    /**
+     * This method actually creates and run the process.
+     * @throws HostNotFoundException
+     */
+    public void start() throws HostNotFoundException {
+       create(host.getName());
+    }
+    

        /**
         * This method runs the process. Il calls the method function that you must overwrite.
         */
        public void run() {
 
                String[] args = null;      /* do not fill it before the signal or this.args will be empty */
        /**
         * This method runs the process. Il calls the method function that you must overwrite.
         */
        public void run() {
 
                String[] args = null;      /* do not fill it before the signal or this.args will be empty */

-

                //waitSignal(); /* wait for other people to fill the process in */
 
                //waitSignal(); /* wait for other people to fill the process in */
 

-
-               try {
-                       schedBegin.acquire();
-               } catch(InterruptedException e) {
-               }
-

                try {
                        args = new String[this.args.size()];
                        if (this.args.size() > 0) {
                try {
                        args = new String[this.args.size()];
                        if (this.args.size() > 0) {


@@ -369,7 +359,6 @@ public abstract class Process extends Thread {
 
                        this.main(args);
                        exit();
 
                        this.main(args);
                        exit();

-                       schedEnd.release();

                } catch(MsgException e) {
                        e.printStackTrace();
                        Msg.info("Unexpected behavior. Stopping now");
                } catch(MsgException e) {
                        e.printStackTrace();
                        Msg.info("Unexpected behavior. Stopping now");


@@ -388,10 +377,9 @@ public abstract class Process extends Thread {
                                         * exception now. This should be ok since we ignore only a very specific exception 
                                         * class and not a generic (such as any RuntimeException).
                                         */
                                         * exception now. This should be ok since we ignore only a very specific exception 
                                         * class and not a generic (such as any RuntimeException).
                                         */

-                                       System.err.println(currentThread().getName()+": I ignore that other exception");                                        
+                                       //System.err.println(currentThread().getName()+": I ignore that other exception");                                      

                                }
                                }

-                               Msg.info(" Process " + ((Process) Thread.currentThread()).msgName() + " has been killed.");                                             
-                               schedEnd.release();                     
+                               //Msg.info(" Process " + ((Process) Thread.currentThread()).msgName() + " has been killed.");                                           

                        }
                        else {
                                pk.printStackTrace();
                        }
                        else {
                                pk.printStackTrace();


@@ -409,90 +397,6 @@ public abstract class Process extends Thread {
      */
        public abstract void main(String[]args) throws MsgException;
 
      */
        public abstract void main(String[]args) throws MsgException;
 

-
-    /** @brief Gives the control from the given user thread back to the maestro 
-     * 
-     * schedule() and unschedule() are the basis of interactions between the user threads 
-     * (executing the user code), and the maestro thread (executing the platform models to decide 
-     * which user thread should get executed when. Once it decided which user thread should be run 
-     * (because the blocking action it were blocked onto are terminated in the simulated world), the 
-     * maestro passes the control to this uthread by calling uthread.schedule() in the maestro thread 
-     * (check its code for the simple semaphore-based synchronization schema). 
-     * 
-     * The uthread executes (while the maestro is blocked), until it starts another blocking 
-     * action, such as a communication or so. In that case, uthread.unschedule() gets called from 
-     * the user thread.    
-     *
-     * As other complications, these methods are called directly by the C through a JNI upcall in 
-     * response to the JNI downcalls done by the Java code. For example, you have this (simplified) 
-     * execution path: 
-     *   - a process calls the Task.send() method in java
-     *   - this calls Java_org_simgrid_msg_MsgNative_taskSend() in C through JNI
-     *   - this ends up calling jprocess_unschedule(), still in C
-     *   - this calls the java method "org/simgrid/msg/Process/unschedule()V" through JNI
-     *   - that is to say, the unschedule() method that you are reading the documentation of.
-     *   
-     * To understand all this, you must keep in mind that there is no difference between the C thread 
-     * describing a process, and the Java thread doing the same. Most of the time, they are system 
-     * threads from the kernel anyway. In the other case (such as when using green java threads when 
-     * the OS does not provide any thread feature), I'm unsure of what happens: it's a very long time 
-     * that I didn't see any such OS. 
-     * 
-     * The synchronization itself is implemented using simple semaphores in Java, as you can see by
-     * checking the code of these functions (and run() above). That's super simple, and thus welcome
-     * given the global complexity of the synchronization architecture: getting C and Java cooperate
-     * with regard to thread handling in a portable manner is very uneasy. A simple and straightforward 
-     * implementation of each synchronization point is precious. 
-     *  
-     * But this kinda limits the system scalability. It may reveal difficult to simulate dozens of 
-     * thousands of processes this way, both for memory limitations and for hard limits pushed by the 
-     * system on the amount of threads and semaphores (we have 2 semaphores per user process).
-     * 
-     * At time of writing, the best source of information on how to simulate large systems within the 
-     * Java bindings of simgrid is here: http://tomp2p.net/dev/simgrid/
-     * 
-     */
-    public void unschedule() {
-       /* this function is called from the user thread only */
-               try {     
-                       
-                       /* unlock the maestro before going to sleep */
-                       schedEnd.release();
-                       /* Here, the user thread is locked, waiting for the semaphore, and maestro executes instead */
-                       schedBegin.acquire();
-                       /* now that the semaphore is acquired, it means that maestro gave us the control back */
-                       
-                       /* the user thread is starting again after giving the control to maestro. 
-                        * Let's check if we were asked to die in between */
-                       if ( (Thread.currentThread() instanceof Process) &&((Process) Thread.currentThread()).getNativeStop()) {                                
-                               throw new ProcessKilled();
-                       }
-                       
-               } catch (InterruptedException e) {
-                       /* ignore this exception because this is how we get killed on process.kill or end of simulation.
-                        * I don't like hiding exceptions this way, but fail to see any other solution 
-                        */
-               }
-               
-       }
-
-    /** @brief Gives the control from the maestro back to the given user thread 
-     * 
-     * Must be called from the maestro thread -- see unschedule() for details.
-     *
-     */
-    public void schedule() {
-               try {
-                       /* unlock the user thread before going to sleep */
-                       schedBegin.release();
-                       /* Here, maestro is locked, waiting for the schedEnd semaphore to get signaled by used thread, that executes instead */
-                       schedEnd.acquire();
-                       /* Maestro now has the control back and the user thread went to sleep gently */
-                       
-               } catch(InterruptedException e) {
-                       throw new RuntimeException("The impossible did happend once again: I got interrupted in schedEnd.acquire()",e);
-               }
-       }

     
        /**
         * Class initializer, to initialize various JNI stuff
     
        /**
         * Class initializer, to initialize various JNI stuff