jinkachy opened a new pull request, #50210:
URL: https://github.com/apache/spark/pull/50210
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### What changes were proposed in this pull request?
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This PR removes the redundant `synchronized` keyword from the `isTerminated`
method in `sameThreadExecutorService()` implementation within the `ThreadUtils`
class. The method was using both a `synchronized` block and an explicit
`ReentrantLock`, which is unnecessary and potentially problematic.
### Why are the changes needed?
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The changes are needed for several reasons:
1. **Eliminates redundant synchronization**: The current implementation uses
both `synchronized` keyword and explicit `ReentrantLock`, which is redundant
and creates unnecessary overhead.
2. **Reduces potential deadlock risks**: Using two different locking
mechanisms (built-in `synchronized` and explicit `ReentrantLock`) in the same
method could lead to complex lock ordering issues and increase deadlock risks.
Although the risk of deadlock in the current implementation is low, if
someone modifies the code in the future and adds a method that acquires these
two locks in a different order, it would introduce a deadlock risk.
3. **Improves performance**: Removing the unnecessary synchronization layer
reduces lock contention and context switching overhead.
4. **Code consistency**: Other methods in the same class only use
`ReentrantLock` for synchronization, so removing `synchronized` makes the code
style more consistent.
5. **More precise control**: `ReentrantLock` already provides all the
synchronization needed with more features than the implicit `synchronized`
keyword.
### Does this PR introduce _any_ user-facing change?
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No. This change is an internal implementation improvement that doesn't
affect any public APIs or user-visible behavior.
### How was this patch tested?
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The existing tests for `ThreadUtils` were run to ensure that the behavior of
`sameThreadExecutorService()` remains unchanged. No additional tests were added
as this is a straightforward removal of redundant synchronization that doesn't
alter the method's behavior or contract.
### Was this patch authored or co-authored using generative AI tooling?
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No.
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