Make reading via TCPConnection re-entrant safe #3175
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Port over bc6f78bcaad55156393753c540befe9f581065bc from wallaroo. There's a nasty possible bug in TCPConnection before applying this change. Because `_mute` and `_unmute` are synchronous methods on TCPConnection and because they can be called inside `_pending_reads` via code executing in `notify.received`, its possible to mute and unmute a source while executing `_pending_reads`. Prior to this change, if you were to unmute from inside a pending reads via the above scenario, `_unmute` would synchronously call `_pending_reads` to re-enter that function and start processing data out of order. Further, we could end up in an infinite loop so long as enough data existed.
SeanTAllen
approved these changes
Jun 9, 2019
SeanTAllen
approved these changes
Jun 9, 2019
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Port over bc6f78bcaad55156393753c540befe9f581065bc from wallaroo.
There's a nasty possible bug in TCPConnection before
applying this change.
Because
_muteand_unmuteare synchronous methods onTCPConnection and because they can be called inside
_pending_readsvia code executing innotify.received, itspossible to mute and unmute a source while executing
_pending_reads.Prior to this change, if you were to unmute from inside a pending
reads via the above scenario,
_unmutewould synchronously call_pending_readsto re-enter that function and start processingdata out of order. Further, we could end up in an infinite loop
so long as enough data existed.