added semaphore solution for dining philosopher

Author: Rakibul73

README.md

@@ -34,8 +34,8 @@ py -3.11 -m pip install numpy
  [Python File](./same_python_file/semaphore_producer_consumer.py)    /    [Python File Alternative](./same_python_file/semaphore_producer_consumer_alternative.py)
 
 ### Lab - 4 == Semaphore Solution in Process-Synchronization (Dining Philosopher Problem)
- [jupyter File](./exponential_distribution.ipynb)     <br/>
- [Python File](./same_python_file/exponential_distribution.py)
+ [jupyter File](./semaphore_dining_philosopher.ipynb)     <br/>
+ [Python File](./same_python_file/semaphore_dining_philosopher.py)
 
 ### Lab - 5 == Banker’s Algorithm (Deadlock Avoidance)
  [jupyter File](./bankers_algorithm.ipynb)     <br/>

same_python_file/semaphore_dining_philosopher.py

@@ -0,0 +1,45 @@
+import threading
+import time
+import random
+
+NUM_PHILOSOPHERS = 5
+chopsticks = [threading.Semaphore(1) for _ in range(NUM_PHILOSOPHERS)]
+
+def philosopher(philosopher_id):
+    # Get the left and right chopsticks for the philosopher
+    left_chopstick = chopsticks[philosopher_id]
+    right_chopstick = chopsticks[(philosopher_id + 1) % NUM_PHILOSOPHERS]
+
+    while True:
+        # Thinking
+        print(f"Philosopher {philosopher_id} is thinking.")
+        time.sleep(random.random())
+
+        # Pick up left chopstick
+        left_chopstick.acquire()
+        print(f"Philosopher {philosopher_id} picked up the left chopstick.")
+
+        # Try to pick up right chopstick without blocking
+        if right_chopstick.acquire(blocking=False):
+            # Pick up right chopstick and start eating
+            print(f"Philosopher {philosopher_id} picked up the right chopstick.")
+            print(f"Philosopher {philosopher_id} is eating.")
+            time.sleep(random.random())
+
+            # Release right chopstick after eating
+            right_chopstick.release()
+            print(f"Philosopher {philosopher_id} put down the right chopstick.")
+        
+        # Release left chopstick after eating or if right chopstick is not available
+        left_chopstick.release()
+        print(f"Philosopher {philosopher_id} put down the left chopstick.")
+
+if __name__ == "__main__":
+    # Create philosopher threads and start them
+    philosophers = [threading.Thread(target=philosopher, args=(i,)) for i in range(NUM_PHILOSOPHERS)]
+    for p in philosophers:
+        p.start()
+
+    # Wait for all philosopher threads to complete
+    for p in philosophers:
+        p.join()

semaphore_dining_philosopher.ipynb

@@ -0,0 +1,79 @@
+{
+ "cells": [
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "import threading\n",
+    "import time\n",
+    "import random\n",
+    "\n",
+    "NUM_PHILOSOPHERS = 5\n",
+    "chopsticks = [threading.Semaphore(1) for _ in range(NUM_PHILOSOPHERS)]\n",
+    "\n",
+    "def philosopher(philosopher_id):\n",
+    "    # Get the left and right chopsticks for the philosopher\n",
+    "    left_chopstick = chopsticks[philosopher_id]\n",
+    "    right_chopstick = chopsticks[(philosopher_id + 1) % NUM_PHILOSOPHERS]\n",
+    "\n",
+    "    while True:\n",
+    "        # Thinking\n",
+    "        print(f\"Philosopher {philosopher_id} is thinking.\")\n",
+    "        time.sleep(random.random())\n",
+    "\n",
+    "        # Pick up left chopstick\n",
+    "        left_chopstick.acquire()\n",
+    "        print(f\"Philosopher {philosopher_id} picked up the left chopstick.\")\n",
+    "\n",
+    "        # Try to pick up right chopstick without blocking\n",
+    "        if right_chopstick.acquire(blocking=False):\n",
+    "            # Pick up right chopstick and start eating\n",
+    "            print(f\"Philosopher {philosopher_id} picked up the right chopstick.\")\n",
+    "            print(f\"Philosopher {philosopher_id} is eating.\")\n",
+    "            time.sleep(random.random())\n",
+    "\n",
+    "            # Release right chopstick after eating\n",
+    "            right_chopstick.release()\n",
+    "            print(f\"Philosopher {philosopher_id} put down the right chopstick.\")\n",
+    "        \n",
+    "        # Release left chopstick after eating or if right chopstick is not available\n",
+    "        left_chopstick.release()\n",
+    "        print(f\"Philosopher {philosopher_id} put down the left chopstick.\")\n",
+    "\n",
+    "if __name__ == \"__main__\":\n",
+    "    # Create philosopher threads and start them\n",
+    "    philosophers = [threading.Thread(target=philosopher, args=(i,)) for i in range(NUM_PHILOSOPHERS)]\n",
+    "    for p in philosophers:\n",
+    "        p.start()\n",
+    "\n",
+    "    # Wait for all philosopher threads to complete\n",
+    "    for p in philosophers:\n",
+    "        p.join()\n"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.11.0"
+  },
+  "orig_nbformat": 4
+ },
+ "nbformat": 4,
+ "nbformat_minor": 2
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