From ba9469b326deef641be936b55eda72ac684a5fbd Mon Sep 17 00:00:00 2001
From: nagesh srinivas <iam.nageshbs@gmail.com>
Date: Mon, 16 Mar 2020 22:31:07 +0530
Subject: [PATCH 1/3] Create threadpool.java

---
 threadpool.java | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)
 create mode 100644 threadpool.java

diff --git a/threadpool.java b/threadpool.java
new file mode 100644
index 0000000..61e6fc3
--- /dev/null
+++ b/threadpool.java
@@ -0,0 +1,30 @@
+public class Threadpool extends Thread {
+
+    private BlockingQueue taskQueue = null;
+    private boolean       isStopped = false;
+
+    public Threadpool(BlockingQueue queue){
+        taskQueue = queue;
+    }
+
+    public void run(){
+        while(!isStopped()){
+            try{
+                Runnable runnable = (Runnable) taskQueue.dequeue();
+                runnable.run();
+            } catch(Exception e){
+                //log or otherwise report exception,
+                //but keep pool thread alive.
+            }
+        }
+    }
+
+    public synchronized void doStop(){
+        isStopped = true;
+        this.interrupt(); //break pool thread out of dequeue() call.
+    }
+
+    public synchronized boolean isStopped(){
+        return isStopped;
+    }
+}

From 7f00069abed631243d25a57c0d8a6393b1a60ad9 Mon Sep 17 00:00:00 2001
From: nagesh srinivas <iam.nageshbs@gmail.com>
Date: Mon, 16 Mar 2020 23:03:34 +0530
Subject: [PATCH 2/3] Create BlockingQueue.java

---
 BlockingQueue.java | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)
 create mode 100644 BlockingQueue.java

diff --git a/BlockingQueue.java b/BlockingQueue.java
new file mode 100644
index 0000000..73483c1
--- /dev/null
+++ b/BlockingQueue.java
@@ -0,0 +1,35 @@
+public class BlockingQueue {
+
+  private List queue = new LinkedList();
+  private int  limit = 10;
+
+  public BlockingQueue(int limit){
+    this.limit = limit;
+  }
+
+
+  public synchronized void enqueue(Object item)
+  throws InterruptedException  {
+    while(this.queue.size() == this.limit) {
+      wait();
+    }
+    this.queue.add(item);
+    if(this.queue.size() == 1) {
+      notifyAll();
+    }
+  }
+
+
+  public synchronized Object dequeue()
+  throws InterruptedException{
+    while(this.queue.size() == 0){
+      wait();
+    }
+    if(this.queue.size() == this.limit){
+      notifyAll();
+    }
+
+    return this.queue.remove(0);
+  }
+
+}

From 1258544043fa5182a86b9b105b7c2709b36a1acd Mon Sep 17 00:00:00 2001
From: nagesh srinivas <iam.nageshbs@gmail.com>
Date: Mon, 16 Mar 2020 23:40:30 +0530
Subject: [PATCH 3/3] Create executor

---
 executor | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)
 create mode 100644 executor

diff --git a/executor b/executor
new file mode 100644
index 0000000..4fdbce4
--- /dev/null
+++ b/executor
@@ -0,0 +1,31 @@
+public class Executor {
+
+    private BlockingQueue taskQueue = null;
+    private List<Threadpool> threads = new ArrayList<Threadpool>();
+    private boolean isStopped = false;
+
+    public Executor(int noOfThreads){
+        taskQueue = new BlockingQueue(noOfThreads);
+
+        for(int i=0; i<noOfThreads; i++){
+            threads.add(new Threadpool(taskQueue));
+        }
+        for(Threadpool thread : threads){
+            thread.start();
+        }
+    }
+
+    public synchronized void  execute(Runnable task) throws Exception{
+        if(this.isStopped) throw
+            new IllegalStateException("ThreadPool is stopped");
+        this.taskQueue.enqueue(task);
+    }
+
+    public synchronized void stop(){
+        this.isStopped = true;
+        for(PoolThread thread : threads){
+           thread.doStop();
+        }
+    }
+
+}