WebSocket and multiplexed protocols are always read interested.
It may happen that while the application is writing, the write
blocks, resulting in a call to changeInterests().
At the same time, the selector may detect data to read and call
onSelected(), so there is a possibility that onSelected() runs
concurrently with changeInterests().
The fix adds an additional state (PROCESSING) that isolates the
changes that onSelected() makes to _interestOps, spin-waiting if
changeInterests() is running concurrently.
Likewise, changeInterests() spin-waits until onSelected() is running
concurrently.
The race was happening when updateKey() lost the race with
changeInterests() to update the interests and subsequently the key.
In that case, the selector thread that called updateKey() was returning
while changeInterests() was executing the CHANGING state.
Since updateKey() lost the race, the actual key interests was still
(typically) OP_READ so the selector thread would select() and call
onSelected() while changeInterests() was still executing, causing the
IllegalStateException.
+ Adding SecuredRedirectHandler as option for those jetty embedded folks
to have a simple http -> https solution (can even be setup and bound
to specific connectors via the named virtualhosts concepts)
+ Since SCI adds filters, but init() isn't run till later, that means
the context attribute for the WebSocketUpgradeFilter isn't present
during jsr356 runs. Added ability for manual filter creation to call
setToAttribute() as a pre-init step, allowing the init() itself to
bypass the set to attribute for that specific filter instance.
+ This also means ServletException is now thrown out from the
various configureContext() static methods.
+ After talking it through with Simone, swapping out 'global' init-param
with a bit more robust 'contextAttributeKey' to handle the automatic
context.setAttribute() of the filter itself.
As simply having a filter in the web.xml makes it alive, but nothing
is wired up into it, and accessing the filter instance via the
context metadata seems impossible. So we made the init-param for
'contextAttributeKey' important and required, but with defaulting
and validation checks.
+ Making key also work inside of WEB-INF/web.xml via context params
+ Making WebSocketUpgradeFilter generic enough to be used in a
web.xml descriptor
+ Adding global={bool} init-param on WebSocketUpgradeFilter to aid
library developers and end users more ways to tweak the filter
order
Introduced parameter "dispatchIO" in the relevant factories so that
they can be configured by users and connections will be created
taking into account this parameter.
For less configurable connection factories, this parameter is
currently hardcoded to either true or false depending on the case.
For example, ALPN and NPN connections have it to false, since they
don't do any blocking operation in onFillable().
+ Fixing #!/usr/bin/env bash
(it had extra spaces at end which breaks env lookup on cygwin)
+ Using cygpath -w liberally to allow java started from cygwin
to find resources using windows specific path names.
