Fix leaky connections #223
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djc
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Thanks for your work on this! |
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Fixes djc#221 It's possible to trigger more approvals than are necessary, in turn grabbing more connections than we need. This happens when we drop a connection. The drop produces a notify, which doesn't get used until the pool is empty. The first `Pool::get()` call on an empty pool will spawn an connect task, immediately complete `notify.notified().await`, then spawn a second connect task. Both will connect and we'll end up with 1 more connection than we need. Rather than address the notify issue directly, this fix introduces some bookkeeping that tracks the number of open `pool.get()` requests we have waiting on connections. If the number of pending connections >= the number of pending gets, we will not spawn any additional connect tasks.
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See #226. |
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Fixes #221
It's possible to trigger more approvals than are necessary, in turn
grabbing more connections than we need. This happens when we drop a
connection. The drop produces a notify, which doesn't get used until the
pool is empty. The first
Pool::get()call on an empty pool will spawnan connect task, immediately complete
notify.notified().await, thenspawn a second connect task. Both will connect and we'll end up with 1
more connection than we need.
Rather than address the notify issue directly, this fix introduces some
bookkeeping that tracks the number of open
pool.get()requests we havewaiting on connections. If the number of pending connections >= the
number of pending gets, we will not spawn any additional connect tasks.
I have additionally changed
See #225notify.notify_waiters();to anotify.notify_one();call in the broken connection branch. A singlebroken connection should only need to notify one pending task to spawn a
new connect task, not all of them.