From 5911a732d643327419746cf87c2dda447fe195a2 Mon Sep 17 00:00:00 2001
From: Marko Luukkainen <marko.luukkainen@semantum.fi>
Date: Fri, 7 Feb 2020 12:15:49 +0200
Subject: [PATCH] SCL threads support

gitlab #22


Change-Id: I18e2cf1b2f7d45624362bd0712964e6ed5b08a94
---
 .../META-INF/MANIFEST.MF                      |  3 +-
 .../scl/Interop/Threads.scl                   | 15 +++
 .../org/simantics/interop/scl/Threads.java    | 93 +++++++++++++++++++
 3 files changed, 110 insertions(+), 1 deletion(-)
 create mode 100644 org.simantics.interop.scl/scl/Interop/Threads.scl
 create mode 100644 org.simantics.interop.scl/src/org/simantics/interop/scl/Threads.java

diff --git a/org.simantics.interop.scl/META-INF/MANIFEST.MF b/org.simantics.interop.scl/META-INF/MANIFEST.MF
index 008487b..93c3c68 100644
--- a/org.simantics.interop.scl/META-INF/MANIFEST.MF
+++ b/org.simantics.interop.scl/META-INF/MANIFEST.MF
@@ -11,4 +11,5 @@ Require-Bundle: org.simantics.scl.data;bundle-version="1.0.0",
  org.simantics.scl.osgi;bundle-version="1.0.4",
  org.simantics.scl.reflection;bundle-version="1.0.0",
  org.simantics.scl.runtime;bundle-version="0.4.0",
- org.simantics.utils.datastructures;bundle-version="1.1.0"
+ org.simantics.utils.datastructures;bundle-version="1.1.0",
+ org.simantics.utils.thread;bundle-version="1.1.0"
diff --git a/org.simantics.interop.scl/scl/Interop/Threads.scl b/org.simantics.interop.scl/scl/Interop/Threads.scl
new file mode 100644
index 0000000..84cb606
--- /dev/null
+++ b/org.simantics.interop.scl/scl/Interop/Threads.scl
@@ -0,0 +1,15 @@
+importJava "org.simantics.interop.scl.Threads" where
+  
+  runAsync :: (<Proc>()) -> <Proc> SCLThread
+  
+  setMaximumPoolSize :: Integer -> <Proc> ()
+
+importJava "org.simantics.interop.scl.Threads$SCLThread" where
+  data SCLThread
+  
+  isRunning :: SCLThread -> <Proc> Boolean
+  isCompleted :: SCLThread -> <Proc> Boolean
+  hasErrors :: SCLThread -> <Proc> Boolean
+  getReturnValue :: SCLThread -> <Proc> Maybe a
+  
+  
\ No newline at end of file
diff --git a/org.simantics.interop.scl/src/org/simantics/interop/scl/Threads.java b/org.simantics.interop.scl/src/org/simantics/interop/scl/Threads.java
new file mode 100644
index 0000000..f077492
--- /dev/null
+++ b/org.simantics.interop.scl/src/org/simantics/interop/scl/Threads.java
@@ -0,0 +1,93 @@
+package org.simantics.interop.scl;
+
+import java.util.concurrent.ScheduledThreadPoolExecutor;
+import java.util.concurrent.ThreadFactory;
+import java.util.concurrent.atomic.AtomicInteger;
+
+import org.simantics.scl.runtime.SCLContext;
+import org.simantics.scl.runtime.function.Function;
+import org.simantics.scl.runtime.tuple.Tuple0;
+
+public class Threads {
+	
+	private static final AtomicInteger threadCount = new AtomicInteger(0);
+	
+    private static final ThreadFactory threadFactory = r -> {
+	        Thread t = new Thread(r, "scl-interop-thread-" + threadCount.incrementAndGet());
+	        t.setDaemon(true);
+	        return t;
+	    };
+
+
+	private static final ScheduledThreadPoolExecutor scheduledExecutor;
+	   
+	static {
+		scheduledExecutor = new ScheduledThreadPoolExecutor(2, threadFactory);
+		scheduledExecutor.setMaximumPoolSize(2);
+	}
+	
+	public static void setMaximumPoolSize(int size) {
+		if (size < 2)
+			return;
+		scheduledExecutor.setMaximumPoolSize(size);
+	}
+	
+    @SuppressWarnings({ "rawtypes", "unchecked" })
+    public static SCLThread runAsync(Function f) {
+        SCLContext context = SCLContext.createDerivedContext();
+        SCLThread t = new SCLThread(context,f);
+        scheduledExecutor.submit(t);
+        return t;
+    }
+	
+	public static class SCLThread implements Runnable {
+		SCLContext context;
+		Function f;
+		boolean running = false;
+		boolean completed = false;
+		Object returnValue = null;
+		Throwable error;
+		
+		public SCLThread(SCLContext context, Function f) {
+			this.context = context;
+			this.f = f;
+		}
+		
+		@Override
+		public void run() {
+			SCLContext.push(context);
+			running = true;
+			try {
+				returnValue = f.apply(Tuple0.INSTANCE);
+			} catch (Throwable t) {
+				error = t;
+			} finally {
+                SCLContext.pop();
+            }
+			running = false;
+			completed = true;
+		}
+		
+		public boolean isRunning() {
+			return running;
+		}
+		
+		public boolean isCompleted() {
+			return completed;
+		}
+		
+		public boolean hasErrors() {
+			return error != null;
+		}
+		
+		public Object getReturnValue() {
+			return returnValue;
+		}
+		
+		public Throwable getError() {
+			return error;
+		}
+		
+	}
+
+}
-- 
2.43.2