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| author | Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com> | 2021-10-17 22:24:51 -0700 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2021-10-18 00:24:51 -0500 |
| commit | cb34c1ee1b1afe9165a26f1428362ea4bc6afe26 (patch) | |
| tree | 3af4369071e49a82e5fbe3ae8b3ab468d8788ad6 | |
| parent | 1dbf9c86b25463b9bc695e434ac034a7e313ba01 (diff) | |
| download | cpython-git-cb34c1ee1b1afe9165a26f1428362ea4bc6afe26.tar.gz | |
Improve multiserver queue recipe (GH-29012) (GH-29014)
| -rw-r--r-- | Doc/library/random.rst | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/Doc/library/random.rst b/Doc/library/random.rst index f2d6749422..758d129208 100644 --- a/Doc/library/random.rst +++ b/Doc/library/random.rst @@ -502,7 +502,7 @@ between the effects of a drug versus a placebo:: Simulation of arrival times and service deliveries for a multiserver queue:: - from heapq import heappush, heappop + from heapq import heapify, heapreplace from random import expovariate, gauss from statistics import mean, median, stdev @@ -514,14 +514,15 @@ Simulation of arrival times and service deliveries for a multiserver queue:: waits = [] arrival_time = 0.0 servers = [0.0] * num_servers # time when each server becomes available - for i in range(100_000): + heapify(servers) + for i in range(1_000_000): arrival_time += expovariate(1.0 / average_arrival_interval) - next_server_available = heappop(servers) + next_server_available = servers[0] wait = max(0.0, next_server_available - arrival_time) waits.append(wait) - service_duration = gauss(average_service_time, stdev_service_time) + service_duration = max(0.0, gauss(average_service_time, stdev_service_time)) service_completed = arrival_time + wait + service_duration - heappush(servers, service_completed) + heapreplace(servers, service_completed) print(f'Mean wait: {mean(waits):.1f}. Stdev wait: {stdev(waits):.1f}.') print(f'Median wait: {median(waits):.1f}. Max wait: {max(waits):.1f}.') |