chore: refactor shutdown config, to prevent setting zero values

[kevwan]

No description provided.

[codecov]

Codecov Report

Attention: Patch coverage is 70.00000% with 6 lines in your changes missing coverage. Please review.

Project coverage is 94.56%. Comparing base (8690859) to head (c37d356).
Report is 196 commits behind head on master.

Files with missing lines	Patch %	Lines
core/proc/shutdown.go	68.42%	6 Missing ⚠️

Additional details and impacted files

Files with missing lines	Coverage Δ
core/service/serviceconf.go	90.32% <100.00%> (+0.32%)	⬆️
core/proc/shutdown.go	75.38% <68.42%> (+1.47%)	⬆️

... and 8 files with indirect coverage changes

[kevwan]

Recommendations

1. Documentation:

   • Ensure that the new ShutdownConf struct and its fields are well-documented to help future maintainers understand their purpose and usage.

2. Constants:

   • Consider adding comments to explain the purpose of default values for defaultWrapUpTime and defaultWaitTime.

3. Test Cases:

   • Add test cases to cover edge cases, such as setting WrapUpTime or WaitTime to zero or negative values and ensure the validation logic works as expected.

4. Thread Safety:

   • If wrapUpTime and waitTime can be modified concurrently, consider adding mutex protection to ensure thread safety.

Example Code Improvements

1. Adding Comments for Constants:

   const (
       // defaultWrapUpTime is the default time allowed for wrap-up listeners to complete.
       defaultWrapUpTime = time.Second
       // defaultWaitTime is the default waiting time before force quitting, used because most queues are blocking mode with a 5-second timeout.
       defaultWaitTime = 5500 * time.Millisecond
   )

2. Mutex Protection for Global Variables:

   var (
       mu sync.RWMutex
       wrapUpListeners   = new(listenerManager)
       shutdownListeners = new(listenerManager)
       wrapUpTime        = defaultWrapUpTime
       waitTime          = defaultWaitTime
   )
   
   func Setup(conf ShutdownConf) error {
       mu.Lock()
       defer mu.Unlock()
       if conf.WrapUpTime > 0 {
           wrapUpTime = conf.WrapUpTime
       }
       if conf.WaitTime > 0 {
           waitTime = conf.WaitTime
       }
       return nil
   }
   
   func SetTimeToForceQuit(duration time.Duration) {
       mu.Lock()
       defer mu.Unlock()
       waitTime = duration
   }

These improvements would enhance the code's robustness, readability, and maintainability.

[kevwan]

All recommendations finished.