1 /* Copyright (c) 2006-2014. The SimGrid Team.
2 * All rights reserved. */
4 /* This program is free software; you can redistribute it and/or modify it
5 * under the terms of the license (GNU LGPL) which comes with this package. */
7 package org.simgrid.msg;
9 import java.util.Arrays;
10 import java.util.ArrayList;
13 * A process may be defined as a code, with some private data, executing
14 * in a location (host). All the process used by your simulation must be
15 * declared in the deployment file (XML format).
16 * To create your own process you must inherit your own process from this
17 * class and override the method "main()". For example if you want to use
18 * a process named Slave proceed as it :
20 * (1) import the class Process of the package simgrid.msg
21 * import simgrid.msg.Process;
23 * public class Slave extends simgrid.msg.Process {
25 * (2) Override the method function
28 * public void main(String[] args) {
29 * System.out.println("Hello MSG");
33 * The name of your process must be declared in the deployment file of your simulation.
34 * For the example, for the previous process Slave this file must contains a line :
35 * <process host="Maxims" function="Slave"/>, where Maxims is the host of the process
36 * Slave. All the process of your simulation are automatically launched and managed by Msg.
37 * A process use tasks to simulate communications or computations with another process.
38 * For more information see Task. For more information on host concept
43 public abstract class Process implements Runnable {
45 * This attribute represents a bind between a java process object and
46 * a native process. Even if this attribute is public you must never
47 * access to it. It is set automatically during the build of the object.
49 private long bind = 0;
50 /** Indicates if the process is started */
52 * Even if this attribute is public you must never access to it.
53 * It is used to compute the id of an MSG process.
55 private static long nextProcessId = 0;
58 * Even if this attribute is public you must never access to it.
59 * It is compute automatically during the creation of the object.
60 * The native functions use this identifier to synchronize the process.
64 /** Time at which the process should be created */
65 protected double startTime = 0;
66 /** Time at which the process should be killed.
68 * Set at creation, and used internally by SimGrid
70 private double killTime = -1;
72 private String name = null;
75 private int ppid = -1;
76 private Host host = null;
78 /** The arguments of the method function of the process. */
79 private ArrayList<String> args = new ArrayList<>();
82 * Constructs a new process from the name of a host and his name. The method
83 * function of the process doesn't have argument.
85 * @param hostname Where to create the process.
86 * @param name The name of the process.
88 * @exception HostNotFoundException if no host with this name exists.
92 public Process(String hostname, String name) throws HostNotFoundException {
93 this(Host.getByName(hostname), name, null);
96 * Constructs a new process from the name of a host and his name. The arguments
97 * of the method function of the process are specified by the parameter args.
99 * @param hostname Where to create the process.
100 * @param name The name of the process.
101 * @param args The arguments of the main function of the process.
103 * @exception HostNotFoundException if no host with this name exists.
106 public Process(String hostname, String name, String[] args) throws HostNotFoundException {
107 this(Host.getByName(hostname), name, args);
110 * Constructs a new process from a host and his name. The method function of the
111 * process doesn't have argument.
113 * @param host Where to create the process.
114 * @param name The name of the process.
117 public Process(Host host, String name) {
118 this(host, name, null);
121 * Constructs a new process from a host and his name, the arguments of here method function are
122 * specified by the parameter args.
124 * @param host Where to create the process.
125 * @param name The name of the process.
126 * @param args The arguments of main method of the process.
128 public Process(Host host, String name, String[]args)
131 throw new NullPointerException("Cannot create a process on the null host");
133 throw new NullPointerException("Process name cannot be null");
135 this.id = nextProcessId++;
139 this.args = new ArrayList<>();
141 this.args.addAll(Arrays.asList(args));
144 * Constructs a new process from a host and his name, the arguments of here method function are
145 * specified by the parameter args.
147 * @param host Where to create the process.
148 * @param name The name of the process.
149 * @param args The arguments of main method of the process.
150 * @param startTime Start time of the process
151 * @param killTime Kill time of the process
154 public Process(Host host, String name, String[]args, double startTime, double killTime) {
155 this(host, name, args);
156 this.startTime = startTime;
157 this.killTime = killTime;
160 * The natively implemented method to create an MSG process.
161 * @param hostName A valid (bound) host where create the process.
163 protected native void create(String hostName) throws HostNotFoundException;
165 * This method kills all running process of the simulation.
167 * @param resetPID Should we reset the PID numbers. A negative number means no reset
168 * and a positive number will be used to set the PID of the next newly
171 * @return The function returns the PID of the next created process.
174 public static native int killAll(int resetPID);
176 /** Simply kills the receiving process.
178 * SimGrid sometimes have issues when you kill processes that are currently communicating and such. We are working on it to fix the issues.
180 public native void kill();
181 public static void kill(Process p) {
185 /** Suspends the process. See {@link #resume()} to resume it afterward */
186 public native void suspend();
187 /** Resume a process that was suspended by {@link #suspend()}. */
188 public native void resume();
189 /** Tests if a process is suspended.
194 public native boolean isSuspended();
196 /** Yield the current process. All other processes that are ready at the same timestamp will be executed first */
197 public static native void yield();
200 * Specify whether the process should restart when its host restarts after a failure
202 * A process naturally stops when its host stops. It starts again only if autoRestart is set to true.
203 * Otherwise, it just disappears when the host stops.
205 public native void setAutoRestart(boolean autoRestart);
206 /** Restarts the process from the beginning */
207 public native void restart();
209 * Returns the name of the process
211 public String getName() {
215 * Returns the host of the process.
216 * @return The host instance of the process.
218 public Host getHost() {
222 * This static method gets a process from a PID.
224 * @param pid The process identifier of the process to get.
226 * @return The process with the specified PID.
228 public static native Process fromPID(int pid);
230 * This method returns the PID of the process.
232 * @return The PID of the process.
235 public int getPID() {
239 * This method returns the PID of the parent of a process.
241 * @return The PID of the parent of the process.
244 public int getPPID() {
248 * Returns the value of a given process property.
250 public native String getProperty(String name);
253 * Set the kill time of the process
254 * @param killTime the time when the process is killed
256 public native void setKillTime(double killTime);
259 * This static method returns the currently running process.
261 * @return The current process.
264 public static native Process getCurrentProcess();
266 * Migrates a process to another host.
268 * @param host The host where to migrate the process.
271 public native void migrate(Host host);
273 * Makes the current process sleep until millis milliseconds have elapsed.
274 * You should note that unlike "waitFor" which takes seconds, this method takes milliseconds.
275 * FIXME: Not optimal, maybe we should have two native functions.
276 * @param millis the length of time to sleep in milliseconds.
278 public static void sleep(long millis) throws HostFailureException {
282 * Makes the current process sleep until millis milliseconds and nanos nanoseconds
284 * Unlike {@link #waitFor(double)} which takes seconds, this method takes
285 * milliseconds and nanoseconds.
286 * Overloads Thread.sleep.
287 * @param millis the length of time to sleep in milliseconds.
288 * @param nanos additional nanoseconds to sleep.
290 public static native void sleep(long millis, int nanos) throws HostFailureException;
292 * Makes the current process sleep until time seconds have elapsed.
293 * @param seconds The time the current process must sleep.
295 public native void waitFor(double seconds) throws HostFailureException;
297 * This method actually creates and run the process.
298 * It is a noop if the process is already launched.
299 * @throws HostNotFoundException
301 public final void start() throws HostNotFoundException {
303 create(host.getName());
306 /** This method runs the process. It calls the method function that you must overwrite. */
310 String[] args = null; /* do not fill it before the signal or this.args will be empty */
313 args = new String[this.args.size()];
314 if (!this.args.isEmpty()) {
315 this.args.toArray(args);
320 catch(MsgException e) {
322 Msg.info("Unexpected behavior. Stopping now");
325 catch(ProcessKilledError pk) {
326 /* The process was killed before its end. With a kill() or something. */
331 * The main function of the process (to implement).
334 * @throws MsgException
336 public abstract void main(String[]args) throws MsgException;
338 /** Stops the execution of the current actor */
343 * Class initializer, to initialize various JNI stuff
345 private static native void nativeInit();
347 org.simgrid.NativeLib.nativeInit();
351 * This static method returns the current amount of processes running
353 * @return The count of the running processes
355 public static native int getCount();