I'm working on an image uploader and want to concurrently resize the image to different sizes. Once I've read the file as a []byte I'm passing a reference of that buffer to my resize functions that are being run concurrently.
Is this safe? I'm thinking by passing a reference of a large file to be read by resize functions will save me memory, and the concurrency will save me time.
Thank you!
分享 Read-only data is usually fine for concurrent access, but you have to be very careful when passing references (pointers, slices, maps and so on) around. Today maybe no one is modifying them while you're also reading, but tomorrow someone may be.
If this is a throwaway script, you'll be fine. But if it's part of a larger program, I'd recommend future-proofing your code by judiciously protecting concurrent access. In your case something like a reader-writer lock could be a good match - all the readers will be able to acquire the lock concurrently, so the performance impact is negligible. And then if you do decide in the future this data could be modified, you already have the proper groundwork laid down w.r.t. safety.
Don't forget to run your code with the race detector enabled.
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