1 /* Copyright (c) 2006-2019. The SimGrid Team. All rights reserved. */
3 /* This program is free software; you can redistribute it and/or modify it
4 * under the terms of the license (GNU LGPL) which comes with this package. */
6 package org.simgrid.msg;
8 import java.util.ArrayList;
9 import java.util.Arrays;
12 * A process may be defined as a code, with some private data, executing
13 * in a location (host). All the process used by your simulation must be
14 * declared in the deployment file (XML format).
15 * To create your own process you must inherit your own process from this
16 * class and override the method "main()". For example if you want to use
17 * a process named Slave proceed as it :
19 * (1) import the class Process of the package simgrid.msg
20 * import simgrid.msg.Process;
22 * public class Slave extends simgrid.msg.Process {
24 * (2) Override the method function
27 * public void main(String[] args) {
28 * System.out.println("Hello MSG");
32 * The name of your process must be declared in the deployment file of your simulation.
33 * For the example, for the previous process Slave this file must contains a line :
34 * <process host="Maxims" function="Slave"/>, where Maxims is the host of the process
35 * Slave. All the process of your simulation are automatically launched and managed by Msg.
36 * A process use tasks to simulate communications or computations with another process.
37 * For more information see Task. For more information on host concept
42 public abstract class Process implements Runnable {
44 * This attribute represents a bind between a java process object and
45 * a native process. Even if this attribute is public you must never
46 * access to it. It is set automatically during the build of the object.
48 private long bind = 0;
49 /** Indicates if the process is started */
51 /** Time at which the process should be created */
52 protected double startTime = 0;
53 /** Time at which the process should be killed */
54 private double killTime = -1; // Used from the C world
56 private String name = null;
59 private int ppid = -1;
60 private Host host = null;
62 /** The arguments of the method function of the process. */
63 private ArrayList<String> args = new ArrayList<>();
66 * Constructs a new process from the name of a host and his name. The method
67 * function of the process doesn't have argument.
69 * @param hostname Where to create the process.
70 * @param name The name of the process.
72 * @exception HostNotFoundException if no host with this name exists.
76 public Process(String hostname, String name) throws HostNotFoundException {
77 this(Host.getByName(hostname), name, null);
80 * Constructs a new process from the name of a host and his name. The arguments
81 * of the method function of the process are specified by the parameter args.
83 * @param hostname Where to create the process.
84 * @param name The name of the process.
85 * @param args The arguments of the main function of the process.
87 * @exception HostNotFoundException if no host with this name exists.
90 public Process(String hostname, String name, String[] args) throws HostNotFoundException {
91 this(Host.getByName(hostname), name, args);
94 * Constructs a new process from a host and his name. The method function of the
95 * process doesn't have argument.
97 * @param host Where to create the process.
98 * @param name The name of the process.
101 public Process(Host host, String name) {
102 this(host, name, null);
105 * Constructs a new process from a host and his name, the arguments of here method function are
106 * specified by the parameter args.
108 * @param host Where to create the process.
109 * @param name The name of the process.
110 * @param argsParam The arguments of main method of the process.
112 public Process(Host host, String name, String[]argsParam)
115 throw new IllegalArgumentException("Cannot create a process on the null host");
117 throw new IllegalArgumentException("Process name cannot be null");
122 this.args = new ArrayList<>();
123 if (null != argsParam)
124 this.args.addAll(Arrays.asList(argsParam));
127 * Constructs a new process from a host and his name, the arguments of here method function are
128 * specified by the parameter args.
130 * @param host Where to create the process.
131 * @param name The name of the process.
132 * @param args The arguments of main method of the process.
133 * @param startTime Start time of the process
134 * @param killTime Kill time of the process
137 public Process(Host host, String name, String[]args, double startTime, double killTime) {
138 this(host, name, args);
139 this.startTime = startTime;
140 this.killTime = killTime;
143 * The native method to create an MSG process.
144 * @param host where to create the process.
146 protected native void create(Host host);
149 * This method kills all running process of the simulation.
151 public static native void killAll();
153 /** Simply kills the receiving process.
155 * SimGrid sometimes have issues when you kill processes that are currently communicating and such. We are working on it to fix the issues.
157 public native void kill();
158 public static void kill(Process p) {
162 /** Suspends the process. See {@link #resume()} to resume it afterward */
163 public native void suspend();
164 /** Resume a process that was suspended by {@link #suspend()}. */
165 public native void resume();
166 /** Tests if a process is suspended.
171 public native boolean isSuspended();
173 /** Yield the current process. All other processes that are ready at the same timestamp will be executed first */
174 public static native void yield();
177 * Specify whether the process should restart when its host restarts after a failure
179 * A process naturally stops when its host stops. It starts again only if autoRestart is set to true.
180 * Otherwise, it just disappears when the host stops.
182 public native void setAutoRestart(boolean autoRestart);
183 /** Restarts the process from the beginning */
184 public native void restart();
186 * Returns the name of the process
188 public String getName() {
192 * Returns the host of the process.
193 * @return The host instance of the process.
195 public Host getHost() {
199 * This static method gets a process from a PID.
201 * @param pid The process identifier of the process to get.
203 * @return The process with the specified PID.
205 public static native Process fromPID(int pid);
207 * This method returns the PID of the process.
209 * @return The PID of the process.
212 public int getPID() {
213 if (pid == -1) // Don't traverse the JNI barrier if you already have the answer
214 pid = nativeGetPID();
217 // This should not be used: the PID is supposed to be initialized from the C directly when the actor is created,
218 // but this sometimes fail, so let's play nasty but safe here.
219 private native int nativeGetPID();
221 * This method returns the PID of the parent of a process.
223 * @return The PID of the parent of the process.
226 public int getPPID() {
230 * Returns the value of a given process property.
232 public native String getProperty(String name);
235 * Set the kill time of the process
236 * @param killTime the time when the process is killed
238 public native void setKillTime(double killTime);
241 * This static method returns the currently running process.
243 * @return The current process.
246 public static native Process getCurrentProcess();
248 * Migrates a process to another host.
250 * @param host The host where to migrate the process.
253 public native void migrate(Host host);
255 * Makes the current process sleep until millis milliseconds have elapsed.
256 * You should note that unlike "waitFor" which takes seconds (as usual in SimGrid), this method takes milliseconds (as usual for sleep() in Java).
258 * @param millis the length of time to sleep in milliseconds.
260 public static void sleep(long millis) throws HostFailureException {
264 * Makes the current process sleep until millis milliseconds and nanos nanoseconds
266 * Unlike {@link #waitFor(double)} which takes seconds, this method takes
267 * milliseconds and nanoseconds.
268 * Overloads Thread.sleep.
269 * @param millis the length of time to sleep in milliseconds.
270 * @param nanos additional nanoseconds to sleep.
272 public static native void sleep(long millis, int nanos) throws HostFailureException;
274 * Makes the current process sleep until time seconds have elapsed.
275 * @param seconds The time the current process must sleep.
277 public native void waitFor(double seconds) throws HostFailureException;
279 * This method actually creates and run the process.
280 * It is a noop if the process is already launched.
282 public final void start() {
287 /** This method runs the process. It calls the method function that you must overwrite. */
292 String[] argsArray = new String[this.args.size()];
293 this.args.toArray(argsArray);
295 this.main(argsArray);
297 catch(MsgException e) {
299 Msg.info("Unexpected behavior. Stopping now");
302 /* Let the ProcessKilledError (that we'd get if the process is forcefully killed) flow back to the caller */
306 * The main function of the process (to implement by the user).
309 * @throws MsgException
311 public abstract void main(String[]args) throws MsgException;
313 /** Stops the execution of the current actor */
318 * Class initializer, to initialize various JNI stuff
320 private static native void nativeInit();
322 org.simgrid.NativeLib.nativeInit();
326 * This static method returns the current amount of processes running
328 * @return The count of the running processes
330 public static native int getCount();
332 public static void debugAllThreads() {
333 // Search remaining threads that are not main nor daemon
334 for (Thread t : Thread.getAllStackTraces().keySet())
335 if (! t.isDaemon() && !t.getName().equals("main"))
336 System.err.println("Thread "+t.getName()+" is still running! Please report that bug");