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The entire unix operating system is designed to abstract away async problems and turn them sync so you can write sane code (if, else, for). In my experience si

The entire unix operating system is designed to abstract away async problems and turn them sync so you can write sane code (if, else, for). In my experience simple blocking code is incredibly misunderstood. Most programmers stop their thinking at “blocking is slow and non blocking is fast!”

mschuster91 2y ago
> The entire unix operating system is designed to abstract away async problems and turn them sync so you can write sane code (if, else, for). That only works for workloads that can be independently parallelized. For stuff that cannot be - which is the majority of consumer workload - you're in for a world of pain with locking and whatnot other issues.
- liontwist 2y ago
  No. It’s almost all the time that your computer has more than one thing to do; - your browser uses a process per tab - your web server responds to multiple requests in parallel - your web app is going to launch other programs - your desktop ui is going to have a compositing server separate from each application - your compiler is going to work on multiple source files
mzimbres 2y ago
> In my experience simple blocking code is incredibly misunderstood. I don't think so. You can't even implement a full-duplex protocol properly with sync IO since reading and writing can't happen at the same time on the same thread. Splitting them to different threads also won't help since accessing shared state requires synchronization with e.g. mutex that kills again simultaneous reading and writing.
- liontwist 2y ago
  How do you propose to implement duplex IO? And what’s the example case? With threads the reading and writing can happen simultaneously. The synchronization is only on whatever data you need to share. Note that if reading and writing are dependent, then single thread actually makes sense because you can’t do one without the other. Otherwise the pattern of logic you will execute for reading or writing is completely different, which is why threading is the perfect abstraction.
  - samsquire 2y ago
    I implemented split IO with io_uring, epoll and eventfd and my own thread safe comm pattern You can write to an eventfd to wake up io_uring listening on an epoll instance.

mschuster91 2y ago

> The entire unix operating system is designed to abstract away async problems and turn them sync so you can write sane code (if, else, for). That only works for workloads that can be independently parallelized. For stuff that cannot be - which is the majority of consumer workload - you're in for a world of pain with locking and whatnot other issues.

liontwist 2y ago
No. It’s almost all the time that your computer has more than one thing to do; - your browser uses a process per tab - your web server responds to multiple requests in parallel - your web app is going to launch other programs - your desktop ui is going to have a compositing server separate from each application - your compiler is going to work on multiple source files

mzimbres 2y ago

> In my experience simple blocking code is incredibly misunderstood. I don't think so. You can't even implement a full-duplex protocol properly with sync IO since reading and writing can't happen at the same time on the same thread. Splitting them to different threads also won't help since accessing shared state requires synchronization with e.g. mutex that kills again simultaneous reading and writing.

liontwist 2y ago
How do you propose to implement duplex IO? And what’s the example case? With threads the reading and writing can happen simultaneously. The synchronization is only on whatever data you need to share. Note that if reading and writing are dependent, then single thread actually makes sense because you can’t do one without the other. Otherwise the pattern of logic you will execute for reading or writing is completely different, which is why threading is the perfect abstraction.
- samsquire 2y ago
  I implemented split IO with io_uring, epoll and eventfd and my own thread safe comm pattern You can write to an eventfd to wake up io_uring listening on an epoll instance.