5,321
edits
Python: Difference between revisions
→concurrrency
| Line 337: | Line 337: | ||
executor = ThreadPoolExecutor(max_workers=2 * os.cpu_count()) | executor = ThreadPoolExecutor(max_workers=2 * os.cpu_count()) | ||
thread_lock = threading.Lock() | |||
sum = 0 | |||
def do_something(a, b): | def do_something(a, b): | ||
with thread_lock: | |||
sum += a + b | |||
return sum | |||
futures = [] | futures = [] | ||
| Line 354: | Line 359: | ||
* Starting in Python 3.5, if <code>max_workers</code> is none, it defaults to <code>5 * os.cpu_count()</code>. | * Starting in Python 3.5, if <code>max_workers</code> is none, it defaults to <code>5 * os.cpu_count()</code>. | ||
* <code>executor.shutdown()</code> will wait for all jobs to finish but you cannot submit any additional jobs from other threads, after calling shutdown. | * <code>executor.shutdown()</code> will wait for all jobs to finish but you cannot submit any additional jobs from other threads, after calling shutdown. | ||
* List operations are thread-safe but most other operations will require using a thread lock or semaphore. | |||
==Data Structures== | ==Data Structures== | ||