2024q1 第 15 週測驗題

目的: 檢驗學員對並行和多執行緒程式設計的認知

作答表單

測驗 1

考慮我們嘗試建構 lock-free 的 MPMC broadcast queue、依循 Publish–subscribe 模式，程式碼可見 broadcast，其中 pool.[ch] 是 lock-free memory pool。

編譯方式:

$ gcc -Wall -O2 -D_GNU_SOURCE \
                -o stress \
                stress.c \
                broadcast.c \
                pool.c \
                -lpthread

參考執行輸出:

Test: 1pub0sub
  Pub Thread 0 | n_msgs:  100000 n_drops:       0 | 169 ns/msg
Test: 2pub0sub
  Pub Thread 0 | n_msgs:  100000 n_drops:       0 | 519 ns/msg
  Pub Thread 1 | n_msgs:  100000 n_drops:       0 | 416 ns/msg
Test: 4pub0sub
  Pub Thread 0 | n_msgs:  100000 n_drops:       0 | 945 ns/msg
  Pub Thread 1 | n_msgs:  100000 n_drops:       0 | 965 ns/msg
  Pub Thread 2 | n_msgs:  100000 n_drops:       0 | 952 ns/msg
  Pub Thread 3 | n_msgs:  100000 n_drops:       0 | 967 ns/msg
Test: 4pub0sub
  Pub Thread 0 | n_msgs:  100000 n_drops:       0 | 2800 ns/msg
  Pub Thread 1 | n_msgs:  100000 n_drops:       0 | 3015 ns/msg
  Pub Thread 2 | n_msgs:  100000 n_drops:       0 | 3065 ns/msg
  Pub Thread 3 | n_msgs:  100000 n_drops:       0 | 3060 ns/msg
  Pub Thread 4 | n_msgs:  100000 n_drops:       0 | 3062 ns/msg
  Pub Thread 5 | n_msgs:  100000 n_drops:       0 | 3033 ns/msg
  Pub Thread 6 | n_msgs:  100000 n_drops:       0 | 3021 ns/msg
  Pub Thread 7 | n_msgs:  100000 n_drops:       0 | 3043 ns/msg

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