From 02baf6cb2819d40db95d6c27659e56807bd46072 Mon Sep 17 00:00:00 2001
From: Hannes Kuchelmeister <hannes@kuchelmeister.org>
Date: Sun, 10 Jan 2021 21:28:35 +0100
Subject: [PATCH] implement pop and push for treiber stack

---
 Assignment_3/lib/CMakeLists.txt   |  2 +-
 Assignment_3/lib/TreiberStack.cpp | 40 +++++++++++++++++++++++++++++++
 Assignment_3/lib/TreiberStack.h   | 14 +++++++++++
 3 files changed, 55 insertions(+), 1 deletion(-)
 create mode 100644 Assignment_3/lib/TreiberStack.cpp
 create mode 100644 Assignment_3/lib/TreiberStack.h

diff --git a/Assignment_3/lib/CMakeLists.txt b/Assignment_3/lib/CMakeLists.txt
index 7dd4299..38be678 100644
--- a/Assignment_3/lib/CMakeLists.txt
+++ b/Assignment_3/lib/CMakeLists.txt
@@ -1 +1 @@
-add_library(sets STATIC ADT_Stack.h ADT_Stack.cpp Node.h Node.cpp Stack.h Stack.cpp SimpleLockingStack.h SimpleLockingStack.cpp)
+add_library(sets STATIC ADT_Stack.h ADT_Stack.cpp Node.h Node.cpp Stack.h Stack.cpp SimpleLockingStack.h SimpleLockingStack.cpp TreiberStack.h TreiberStack.cpp)
diff --git a/Assignment_3/lib/TreiberStack.cpp b/Assignment_3/lib/TreiberStack.cpp
new file mode 100644
index 0000000..8715fef
--- /dev/null
+++ b/Assignment_3/lib/TreiberStack.cpp
@@ -0,0 +1,40 @@
+#include<stdexcept>
+
+#include "TreiberStack.h"
+#include "ADT_Stack.h"
+
+
+TreiberStack::TreiberStack(ADTOperationQueue * queue) : Stack(queue) { }
+
+void TreiberStack::push(int element) {
+    Node * n;
+    Node * t;
+
+    while (true) {
+        t = top.load(std::memory_order_relaxed);
+        n->next = t;
+        if (top.compare_exchange_weak(t, n)) {
+            op_queue->enqueue(create_operation(methodname::push, element));
+            return;
+        }
+    }
+    
+}
+int TreiberStack::pop() {
+    Node * n;
+    Node * t;
+
+    while (true) {
+        t = top.load(std::memory_order_relaxed);
+        if (t == NULL) {
+            throw std::invalid_argument("Invalid operation: pop on an empty stack");
+        } else if (top.compare_exchange_weak(t, t->next)) {
+            int data = t->get_data();
+            op_queue->enqueue(create_operation(methodname::pop, data));
+            return data;
+        }
+    }
+}
+int TreiberStack::size() { 
+    return 0;    
+}
\ No newline at end of file
diff --git a/Assignment_3/lib/TreiberStack.h b/Assignment_3/lib/TreiberStack.h
new file mode 100644
index 0000000..376c12b
--- /dev/null
+++ b/Assignment_3/lib/TreiberStack.h
@@ -0,0 +1,14 @@
+#include <atomic>
+
+#include "Stack.h"
+#include "Node.h"
+
+class TreiberStack:public Stack{
+    private:
+        std::atomic<Node *> top;
+    public:
+        TreiberStack(ADTOperationQueue * queue);
+        void push(int element);
+        int pop();
+        int size();
+};
\ No newline at end of file