[Experimental] Quasi-static scheduler

org.lflang/src/org/lflang/TargetProperty.java

@@ -1363,6 +1363,7 @@ public String getcMakeName() {
     /**
      * Supported schedulers.
      * @author{Soroush Bateni <[email protected]>}
+     * @author{Shaokai Lin <[email protected]>}
      */
     public enum SchedulerOption {
         NP(false),         // Non-preemptive
@@ -1373,8 +1374,9 @@ public enum SchedulerOption {
             Path.of("data_collection.h")
         )),
         GEDF_NP(true),    // Global EDF non-preemptive
-        GEDF_NP_CI(true); // Global EDF non-preemptive with chain ID
+        GEDF_NP_CI(true), // Global EDF non-preemptive with chain ID
         // PEDF_NP(true);    // Partitioned EDF non-preemptive (FIXME: To be re-added in a future PR)
+        QS(false);          // Quasi-static
 
         /**
          * Indicate whether or not the scheduler prioritizes reactions by deadline.

org.lflang/src/org/lflang/generator/ReactionInstance.java

@@ -202,6 +202,8 @@ public ReactionInstance(
      * If left at the default, parallel execution will be based purely
      * on levels.
      */
+    //TODO:
+    public long reactionid ;
     public long chainID = 1L;
 
     /**
@@ -535,10 +537,20 @@ public class Runtime {
         /** ID ranging from 0 to parent.getTotalWidth() - 1. */
         public int id = 0;
         public int level = 0;
+        public int reactionID = 0; // Reaction Runtime ID
 
         public ReactionInstance getReaction() {
             return ReactionInstance.this;
         }
+
+        public long getReactionID() {
+            return this.reactionID;
+        }
+
+        public String getFullName() {
+            return ReactionInstance.this.toString();
+        }
+
         @Override
         public String toString() {
             String result = ReactionInstance.this + "(level: " + level;

org.lflang/src/org/lflang/generator/ReactionInstanceGraph.java

@@ -31,10 +31,11 @@ STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 import java.util.List;
 import java.util.Set;
 
+import org.eclipse.xtext.xbase.lib.Exceptions;
+
 import org.lflang.generator.ReactionInstance.Runtime;
 import org.lflang.graph.PrecedenceGraph;
 import org.lflang.lf.Variable;
-
 /**
  * This class analyzes the dependencies between reaction runtime instances.
  * For each ReactionInstance, there may be more than one runtime instance because
@@ -60,18 +61,23 @@ public class ReactionInstanceGraph extends PrecedenceGraph<ReactionInstance.Runt
      * Create a new graph by traversing the maps in the named instances 
      * embedded in the hierarchy of the program. 
      */
-    public ReactionInstanceGraph(ReactorInstance main) {
+    public ReactionInstanceGraph(ReactorInstance main, boolean detectCycles) {
         this.main = main;
+        this.detectCycles = detectCycles;
         rebuild();
     }
 
     ///////////////////////////////////////////////////////////
     //// Public fields
 
-    /**
-     * The main reactor instance that this graph is associated with.
-     */
+    /** The main reactor instance that this graph is associated with. */
     public final ReactorInstance main;
+
+    /** 
+     * Whether this ReactionInstanceGraph is built for detecting cycles,
+     * which involves removing nodes from the graph.
+     */
+    public final boolean detectCycles;
 
     ///////////////////////////////////////////////////////////
     //// Public methods
@@ -83,14 +89,16 @@ public ReactionInstanceGraph(ReactorInstance main) {
     public void rebuild() {
         this.clear();
         addNodesAndEdges(main);
-        // Assign a level to each reaction. 
-        // If there are cycles present in the graph, it will be detected here.
-        assignLevels();
-        if (nodeCount() != 0) {
-            // The graph has cycles.
-            // main.reporter.reportError("Reactions form a cycle! " + toString());
-            // Do not throw an exception so that cycle visualization can proceed.
-            // throw new InvalidSourceException("Reactions form a cycle!");
+        if (this.detectCycles) { 
+            // Assign a level to each reaction. 
+            // If there are cycles present in the graph, it will be detected here.
+            assignLevels();
+            if (nodeCount() != 0) {
+                // The graph has cycles.
+                // main.reporter.reportError("Reactions form a cycle! " + toString());
+                // Do not throw an exception so that cycle visualization can proceed.
+                // throw new InvalidSourceException("Reactions form a cycle!");
+            }
         }
     }
 
@@ -115,6 +123,19 @@ public int getBreadth() {
         return maxBreadth;
     }
 
+    /*
+     * Get a reaction in the dependency graph based on a reaction ID.
+     */
+    public Runtime getReactionByID(long reactionID) {
+        for (var node : this.nodes()) {
+            if (node.getReactionID() == reactionID)
+                return node;
+        }
+        Exceptions.sneakyThrow(
+            new Exception("Reaction with ID " + reactionID + " not found."));
+        return null;
+    }
+
     ///////////////////////////////////////////////////////////
     //// Protected methods
 
@@ -291,7 +312,7 @@ private void assignLevels() {
                 }
             }
 
-            // Remove visited origin.
+            // (IMPORTANT) Remove visited origin.
             removeNode(origin);
 
             // Update numReactionsPerLevel info

org.lflang/src/org/lflang/generator/ReactorInstance.java

@@ -185,7 +185,8 @@ public ReactorInstance(Reactor reactor, ReactorInstance parent, ErrorReporter re
     public ReactionInstanceGraph assignLevels() {
         if (depth != 0) return root().assignLevels();
         if (cachedReactionLoopGraph == null) {
-            cachedReactionLoopGraph = new ReactionInstanceGraph(this);
+            // The 2nd param, `true`, enables cycle detection.
+            cachedReactionLoopGraph = new ReactionInstanceGraph(this, true);
         }
         return cachedReactionLoopGraph;
     }

org.lflang/src/org/lflang/generator/c/CCmakeGenerator.java

@@ -33,6 +33,7 @@
 import org.lflang.FileConfig;
 import org.lflang.TargetConfig;
 import org.lflang.TargetProperty.Platform;
+import org.lflang.TargetProperty.SchedulerOption;
 import org.lflang.generator.CodeBuilder;
 import org.lflang.util.FileUtil;
 
@@ -231,8 +232,7 @@ CodeBuilder generateCMakeCode(
                     cMakeCode.pr("add_link_options( "+compilerFlag+")");
             }
         }
-        cMakeCode.newLine();
-
+
         // Add the install option
         cMakeCode.pr("install(");
         cMakeCode.indent();

org.lflang/src/org/lflang/generator/c/CCoreFilesUtils.java

@@ -1,6 +1,7 @@
 package org.lflang.generator.c;
 import java.nio.file.Path;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;

org.lflang/src/org/lflang/generator/c/CGenerator.java

@@ -65,6 +65,7 @@ STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 import org.lflang.TargetProperty.ClockSyncMode;
 import org.lflang.TargetProperty.CoordinationType;
 import org.lflang.TargetProperty.Platform;
+import org.lflang.TargetProperty.SchedulerOption;
 import org.lflang.TimeValue;
 import org.lflang.federated.FedFileConfig;
 import org.lflang.federated.FederateInstance;
@@ -87,6 +88,7 @@ STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 import org.lflang.generator.TargetTypes;
 import org.lflang.generator.TimerInstance;
 import org.lflang.generator.TriggerInstance;
+import org.lflang.generator.uclid.UclidScheduleGenerator;
 import org.lflang.lf.Action;
 import org.lflang.lf.ActionOrigin;
 import org.lflang.lf.Expression;
@@ -579,6 +581,11 @@ public void doGenerate(Resource resource, LFGeneratorContext context) {
                 Exceptions.sneakyThrow(e);
             }
 
+            // Generate scheduler-specific code. In the case of the QS scheduler,
+            // a schedule.h is generated. This is separated from the logic in
+            // pickScheduler(), since pickScheduler() does not generate new code.
+            generateCodeForScheduler();
+
             // Create docker file.
             if (targetConfig.dockerOptions != null && mainDef != null) {
                 dockerGenerator.addFile(
@@ -882,6 +889,25 @@ private void generateCodeForCurrentFederate(
         }
     }
 
+    /**
+     * Generate scheduler-specific code. In the case of the QS scheduler,
+     * a schedule.h is generated. This is separated from the logic in
+     * pickScheduler(), since pickScheduler() does not generate new code.
+     */
+    private void generateCodeForScheduler() {
+        // Generate schedule.h if QS scheduler is used.
+        if (targetConfig.schedulerType == SchedulerOption.QS) {
+            var scheduleGenerator = new UclidScheduleGenerator(fileConfig, errorReporter, main, targetConfig);
+            var scheduleFile = fileConfig.getSrcGenPath() + File.separator + "schedule.h";
+            var scheduleCode = scheduleGenerator.generateScheduleCode();
+            try {
+                scheduleCode.writeToFile(scheduleFile);
+            } catch (IOException e) {
+                Exceptions.sneakyThrow(e);
+            }
+        }
+    }
+
     protected CDockerGenerator getDockerGenerator() {
         return new CDockerGenerator(isFederated, CCppMode, targetConfig);
     }
@@ -924,6 +950,22 @@ private void pickScheduler() {
         targetConfig.compileAdditionalSources.add(
             "core" + File.separator + "utils" + File.separator + "semaphore.c"
         );
+
+        // Perform a set of QS scheduler-specific operations.
+        if (targetConfig.schedulerType == SchedulerOption.QS) {
+            // Define a macro in CMake.
+            targetConfig.compileDefinitions.put("SCHEDULER_QS", "");
+            // Copy an additional header file for QS.
+            try {
+                FileUtil.copyFilesFromClassPath(
+                    "/lib/c/reactor-c/core",
+                    fileConfig.getSrcGenPath().resolve("core"),
+                    List.of("threaded/scheduler_QS.h")
+                );
+            } catch (IOException e) {
+                Exceptions.sneakyThrow(e);
+            }
+        }            
     }
 
     private boolean hasDeadlines(List<Reactor> reactors) {