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| author | Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com> | 2021-10-17 16:43:10 -0700 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2021-10-17 18:43:10 -0500 |
| commit | 7082abf53db0ce599eb7347bd7efab0a647efb18 (patch) | |
| tree | 4dbefea14e9ca44318a38c1f2d8c10950eeab24c | |
| parent | 65c1db794e0484e18142658c691141387c1dc2e4 (diff) | |
| download | cpython-git-7082abf53db0ce599eb7347bd7efab0a647efb18.tar.gz | |
Improve multiserver queue recipe (GH-29012) (GH-29013)
| -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 e924127d8b..b9c33af59c 100644 --- a/Doc/library/random.rst +++ b/Doc/library/random.rst @@ -512,7 +512,7 @@ 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, quantiles @@ -524,14 +524,15 @@ 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} Max wait: {max(waits):.1f}') print('Quartiles:', [round(q, 1) for q in quantiles(waits)]) |