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Merge pull request #1308 from cmorty/pull/safe_random

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Fix SafeRandom
This commit is contained in:
Fredrik Österlind 2015-10-15 18:53:26 +02:00
parent 6b29e4b30d f17fc20fe7
commit 0c9f11b568
1 changed files with 21 additions and 8 deletions
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29
tools/cooja/java/org/contikios/cooja/SafeRandom.java
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@ -36,26 +36,39 @@ import java.util.Random;
* This ensures that the functions of the random number generator are * This ensures that the functions of the random number generator are
* only called by the the thread initializing a simulation or the * only called by the the thread initializing a simulation or the
* simulation thread itself. * simulation thread itself.
* Rationale: By allowing another thread to use the random number * Rationale: By allowing another thread to use the random number
* generator concurrency is intruduced, thus it can not be guaranteed * generator concurrency is introduced, thus it can not be guaranteed
* that simulations are reproduceable. * that simulations are reproducible.
* *
*/ */
public class SafeRandom extends Random { public class SafeRandom extends Random {
Simulation sim = null; Simulation sim = null;
Thread initThread = null; Thread initThread = null;
Boolean simStarted = false;
private void assertSimThread() { private void assertSimThread() {
// It we are in the simulation thread everything is fine (the default)
// sim can be null, because setSeed is called by the super-constructor. // sim can be null, because setSeed is called by the super-constructor.
if(sim != null && !sim.isSimulationThread()) { if(sim == null) return;
// The thread initializing the simulation might differ from the simulation thread.
// If they are the same that is ok, too. // If we are in the simulation thread, everything is fine (the default)
if(sim.isSimulationThread()) {
simStarted = true;
return;
}
// Simulation has not started yet. Allow one initialisation thread.
if(!simStarted) {
if(initThread == null) initThread = Thread.currentThread(); if(initThread == null) initThread = Thread.currentThread();
if(Thread.currentThread() == initThread ) return; if(Thread.currentThread() == initThread ) return;
throw new RuntimeException("A random-function was not called from the simulation thread. This can break things!");
} }
//This is done via the GUI - reproducibility is lost anyway!
if(javax.swing.SwingUtilities.isEventDispatchThread()) return;
// Some other threads seems to access the PNRG. This must not happen.
throw new RuntimeException("A random-function was not called from the simulation thread. This can break things!");
} }
public SafeRandom(Simulation sim) { public SafeRandom(Simulation sim) {