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@ -8,14 +8,15 @@ import ( |
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"sync" |
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) |
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// SingleInstancePool is a pool of non-identical instances
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// ExclusivePool is a pool of non-identical instances
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// that only one instance with same identity is in the pool at a time.
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// In other words, only instances with different identities can exist
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// at the same time.
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// In other words, only instances with different identities can be in
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// the pool the same time. If another instance with same identity tries
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// to get into the pool, it hangs until previous instance left the pool.
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//
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// This pool is particularly useful for performing tasks on same resource
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// on the file system in different goroutines.
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type SingleInstancePool struct { |
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type ExclusivePool struct { |
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lock sync.Mutex |
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// pool maintains locks for each instance in the pool.
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@ -29,9 +30,9 @@ type SingleInstancePool struct { |
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count map[string]int |
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} |
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// NewSingleInstancePool initializes and returns a new SingleInstancePool object.
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func NewSingleInstancePool() *SingleInstancePool { |
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return &SingleInstancePool{ |
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// NewExclusivePool initializes and returns a new ExclusivePool object.
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func NewExclusivePool() *ExclusivePool { |
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return &ExclusivePool{ |
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pool: make(map[string]*sync.Mutex), |
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count: make(map[string]int), |
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} |
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@ -39,7 +40,7 @@ func NewSingleInstancePool() *SingleInstancePool { |
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// CheckIn checks in an instance to the pool and hangs while instance
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// with same indentity is using the lock.
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func (p *SingleInstancePool) CheckIn(identity string) { |
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func (p *ExclusivePool) CheckIn(identity string) { |
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p.lock.Lock() |
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lock, has := p.pool[identity] |
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@ -55,7 +56,7 @@ func (p *SingleInstancePool) CheckIn(identity string) { |
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// CheckOut checks out an instance from the pool and releases the lock
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// to let other instances with same identity to grab the lock.
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func (p *SingleInstancePool) CheckOut(identity string) { |
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func (p *ExclusivePool) CheckOut(identity string) { |
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p.lock.Lock() |
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defer p.lock.Unlock() |
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