How to solve the issue of invalidation of map iterators during traversal

If a map iterator becomes invalid during iteration, it may be because the structure of the map was modified while iterating, causing the iterator to become invalid.

To address this issue, one can take the following approaches:

1. Iterate using a for loop: instead of directly using the map iterator, use a for loop to iterate through the elements in the map. This way, modifying the map structure during iteration will not affect the effectiveness of the iterator.
2. Create a new map before making any changes to the existing map: when needing to modify the map structure, create a new map first, copy the necessary content to the new map, and then assign the new map to the original map.
3. When needing to read and write to a map simultaneously in multiple goroutines, it is recommended to use sync.Map, a concurrent-safe map type provided by the Go language. It includes built-in mechanisms for handling concurrency and allows for safe operations on the map in a concurrent environment.

The issue of map iterator traversal failure can be effectively resolved using the above method.