play_on_spotify, play_apple_music, play_pause, next_track, set_music_volume
The latter is the more interesting test — it writes a 0xcc byte (the x86-64 software breakpoint instruction) which will cause the kernel to deliver a SIGTRAP to our process if executed. This is literally changing the executable code of libc. So the next time we call getchar, if we get a SIGTRAP, we know that the write has succeeded.，推荐阅读新收录的资料获取更多信息
Has reasonably sound axioms (2 points)，推荐阅读新收录的资料获取更多信息
A composite B-tree is still a sorted tree, but now entries are ordered first by severity, and then by timestamp within each severity value. This works great for this query shape: Postgres can jump directly to the portion of the tree matching severity，详情可参考新收录的资料