Data commit

Task/Metered-concurrency/Python/metered-concurrency.py

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+import time
+import threading
+
+# Only 4 workers can run in the same time
+sem = threading.Semaphore(4)
+
+workers = []
+running = 1
+
+
+def worker():
+    me = threading.currentThread()
+    while 1:
+        sem.acquire()
+        try:
+            if not running:
+                break
+            print '%s acquired semaphore' % me.getName()
+            time.sleep(2.0)
+        finally:
+            sem.release()
+        time.sleep(0.01) # Let others acquire
+
+# Start 10 workers
+for i in range(10):
+    t = threading.Thread(name=str(i), target=worker)
+    workers.append(t)
+    t.start()
+
+# Main loop
+try:
+    while 1:
+        time.sleep(0.1)
+except KeyboardInterrupt:
+    running = 0
+    for t in workers:
+        t.join()