53 lines
962 B
Go
53 lines
962 B
Go
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package sync
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import (
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"runtime"
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"sync"
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"time"
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)
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type Mutex struct {
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mu sync.Mutex
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hold *int // Unique value for passing to pprof.
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stack [32]uintptr // The stack for the current holder.
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start time.Time // When the lock was obtained.
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entries int // Number of entries returned from runtime.Callers.
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}
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func (m *Mutex) Lock() {
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if contentionOn {
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v := new(int)
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lockBlockers.Add(v, 0)
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m.mu.Lock()
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lockBlockers.Remove(v)
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m.hold = v
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lockHolders.Add(v, 0)
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} else {
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m.mu.Lock()
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}
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if lockTimesOn {
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m.entries = runtime.Callers(2, m.stack[:])
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m.start = time.Now()
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}
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}
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func (m *Mutex) Unlock() {
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if lockTimesOn {
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d := time.Since(m.start)
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var key [32]uintptr
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copy(key[:], m.stack[:m.entries])
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lockStatsMu.Lock()
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v, ok := lockStatsByStack[key]
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if !ok {
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v.Init()
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}
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v.Add(d)
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lockStatsByStack[key] = v
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lockStatsMu.Unlock()
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}
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if contentionOn {
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lockHolders.Remove(m.hold)
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}
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m.mu.Unlock()
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}
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