Michael Tharp
26cd25c14b
If the waiter goroutine completes before the section guarding canceledAcquireCount has run, then there is a deadlock because there is nothing that can unlock the mutex. Scheduling the second goroutine ensures that one of the two can release the lock and keep things moving.
Puddle
Puddle is a tiny generic resource pool library for Go that uses the standard context library to signal cancellation of acquires. It is designed to contain the minimum functionality required for a resource pool. It can be used directly or it can be used as the base for a domain specific resource pool. For example, a database connection pool may use puddle internally and implement health checks and keep-alive behavior without needing to implement any concurrent code of its own.
Features
- Acquire cancellation via context standard library
- Statistics API for monitoring pool pressure
- No dependencies outside of standard library
- High performance
- 100% test coverage
Example Usage
constructor := func(context.Context) (interface{}, error) {
return net.Dial("tcp", "127.0.0.1:8080")
}
destructor := func(value interface{}) {
value.(net.Conn).Close()
}
maxPoolSize := 10
pool := puddle.NewPool(constructor, destructor, maxPoolSize)
// Acquire resource from the pool.
res, err := pool.Acquire(context.Background())
if err != nil {
// ...
}
// Use resource.
_, err = res.Value().(net.Conn).Write([]byte{1})
if err != nil {
// ...
}
// Release when done.
res.Release()
License
MIT