seaweedfs/weed/util/limited_executor.go

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2022-09-25 19:59:38 +00:00
package util
// initial version comes from https://github.com/korovkin/limiter/blob/master/limiter.go
// LimitedConcurrentExecutor object
type LimitedConcurrentExecutor struct {
limit int
tokenChan chan int
}
func NewLimitedConcurrentExecutor(limit int) *LimitedConcurrentExecutor {
// allocate a limiter instance
c := &LimitedConcurrentExecutor{
limit: limit,
tokenChan: make(chan int, limit),
}
// allocate the tokenChan:
for i := 0; i < c.limit; i++ {
c.tokenChan <- i
}
return c
}
// Execute adds a function to the execution queue.
// if num of go routines allocated by this instance is < limit
// launch a new go routine to execute job
// else wait until a go routine becomes available
func (c *LimitedConcurrentExecutor) Execute(job func()) {
token := <-c.tokenChan
go func() {
defer func() {
c.tokenChan <- token
}()
// run the job
job()
}()
}