add more concurrent examples

Concurrence_examples/concurrent_tasks_with_math.py

@@ -0,0 +1,47 @@
+import os
+import time
+import threading
+import multiprocessing
+
+NUM_WORKERS = 4
+
+def run_numbers():
+    print("PID: %s, Process Name: %s, Thread Name: %s" % (
+        os.getpid(),
+        multiprocessing.current_process().name,
+        threading.current_thread().name)
+    )
+    x = 0
+    while x < 10000000:
+        x += 1
+
+start_time = time.time()
+
+for _ in range(NUM_WORKERS):
+    run_numbers()
+
+end_time = time.time()
+ 
+print("Serial time=", end_time - start_time)
+ 
+
+start_time = time.time()
+
+threads = [threading.Thread(target=run_numbers) for _ in range(NUM_WORKERS)]
+[thread.start() for thread in threads]
+[thread.join() for thread in threads]
+
+end_time = time.time()
+ 
+print("Threads time=", end_time - start_time)
+ 
+ 
+start_time = time.time()
+
+processes = [multiprocessing.Process(target=run_numbers) for _ in range(NUM_WORKERS)]
+[process.start() for process in processes]
+[process.join() for process in processes]
+end_time = time.time()
+
+ 
+print("Parallel time=", end_time - start_time)

Concurrence_examples/getenv_example.py

@@ -0,0 +1,23 @@
+import time
+from gevent.pool import Pool
+from gevent import monkey
+ 
+# Note that you can spawn many workers with gevent since the cost of creating and switching is very low
+NUM_WORKERS = 4
+ 
+# Monkey-Patch socket module for HTTP requests
+monkey.patch_socket()
+ 
+start_time = time.time()
+ 
+pool = Pool(NUM_WORKERS)
+for address in WEBSITE_LIST:
+    pool.spawn(check_website, address)
+ 
+# Wait for stuff to finish
+pool.join()
+         
+end_time = time.time()        
+ 
+print("Time for GreenSquirrel: %ssecs" % (end_time - start_time))
+g

Concurrence_examples/threads_with_queues.py

@@ -0,0 +1,34 @@
+import time
+from queue import Queue
+from threading import Thread
+ 
+NUM_WORKERS = 4
+task_queue = Queue()
+ 
+def worker():
+    # Constantly check the queue for addresses
+    while True:
+        address = task_queue.get()
+        run_function(address)
+         
+        # Mark the processed task as done
+        task_queue.task_done()
+ 
+start_time = time.time()
+         
+# Create the worker threads
+threads = [Thread(target=worker) for _ in range(NUM_WORKERS)]
+ 
+# Add the websites to the task queue
+[task_queue.put(item) for item in SOME_LIST]
+ 
+# Start all the workers
+[thread.start() for thread in threads]
+ 
+# Wait for all the tasks in the queue to be processed
+task_queue.join()
+ 
+         
+end_time = time.time()        
+ 
+print("Time: %ssecs" % (end_time - start_time))