Ever since February 2010, the body of the login coroutine function has been
enclosed in try/catch (...), with an llerrs message to try to crash more
informatively than the runtime's unhandled-exception termination. Over the
years this evolved to LL_ERRS and then to CRASH_ON_UNHANDLED_EXCEPTION.
This persisted despite the August 2016 addition of generic catch clauses in
the LLCoros::toplevel() function to serve the same purpose, and despite the
subsequent introduction of the LLCoros::Stop family of exceptions to
deliberately throw into waiting coroutines on viewer shutdown.
That's exactly what was happening. When the user closed the viewer while
waiting for the response from login.cgi, the waiting operation threw
LLCoros::Stopping, which was caught by that CRASH_ON_UNHANDLED_EXCEPTION,
which crashed the viewer with LL_ERRS rather than propagating up to the
toplevel() and cleanly terminating the coroutine.
Change CRASH_ON_UNHANDLED_EXCEPTION() to LOG_UNHANDLED_EXCEPTION() and
re-throw so toplevel() can handle.
The new LLCoros::Stop exception is intended to terminate long-lived coroutines
-- not interrupt mainstream shutdown processing. Only throw it on an
explicitly-launched coroutine.
Make LLCoros::getName() (used by the above test) static. As with other LLCoros
methods, it might be called after the LLCoros LLSingleton instance has been
deleted. Requiring the caller to call instance() implies a possible need to
also call wasDeleted(). Encapsulate that nuance into a static method instead.
The new LLCoros::Stop exception is intended to terminate long-lived coroutines
-- not interrupt mainstream shutdown processing. Only throw it on an
explicitly-launched coroutine.
Make LLCoros::getName() (used by the above test) static. As with other LLCoros
methods, it might be called after the LLCoros LLSingleton instance has been
deleted. Requiring the caller to call instance() implies a possible need to
also call wasDeleted(). Encapsulate that nuance into a static method instead.
Specifically, introduce an LLEventMailDrop("LoginSync"). When the updater
detects that an update is required, it will post to that rendezvous point.
When login.cgi responds with login failure, make the login coroutine wait (a
few seconds) for that ping from the updater.
If we receive that ping and if it contains a "reply" key, make the fail.login
listener respond to the updater with an indication of whether to proceed with
update.
If both login.cgi and the updater concur that an update is required, produce a
new confirmation message for the user and then (once user responds) tell the
updater to proceed. Otherwise, produce the usual login-failure message and
tell the updater never mind.
Introduce LLCoro::OverrideConsuming to provide temporary save/restore of the
set_consuming() / get_consuming() flag. It's a good idea to set the consuming
flag when retrieving data from an LLEventMailDrop.
Wrap coroutine call in try/catch in top-level coroutine wrapper function
LLCoros::toplevel(). Distinguish exception classes derived from
LLContinueError (log and continue) from all others (crash with LL_ERRS).
Enhance CRASH_ON_UNHANDLED_EXCEPTIONS() and LOG_UNHANDLED_EXCEPTIONS() macros
to accept a context string to supplement the log message. This lets us replace
many places that called boost::current_exception_diagnostic_information() with
LOG_UNHANDLED_EXCEPTIONS() instead, since the explicit calls were mostly to
log supplemental information.
Provide supplemental information (coroutine name, function parameters) for
some of the previous LOG_UNHANDLED_EXCEPTIONS() calls. This information
duplicates LL_DEBUGS() information at the top of these functions, but in a
typical log file we wouldn't see the LL_DEBUGS() message.
Eliminate a few catch (std::exception e) clauses: the information we get from
boost::current_exception_diagnostic_information() in a catch (...) clause
makes it unnecessary to distinguish.
In a few cases, add a final 'throw;' to a catch (...) clause: having logged
the local context info, propagate the exception to be caught by higher-level
try/catch.
In a couple places, couldn't resist reconciling indentation within a
particular function: tabs where the rest of the function uses tabs, spaces
where the rest of the function uses spaces.
In LLLogin::Impl::loginCoro(), eliminate some confusing comments about an
array of rewritten URIs that date back to a long-deleted implementation.
Turns out we have a surprising number of catch (...) clauses in the viewer
code base. If all we currently do is
LL_ERRS() << "unknown exception" << LL_ENDL;
then call CRASH_ON_UNHANDLED_EXCEPTION() instead. If what we do is
LL_WARNS() << "unknown exception" << LL_ENDL;
then call LOG_UNHANDLED_EXCEPTION() instead.
Since many places need LOG_UNHANDLED_EXCEPTION() and nobody catches
LLContinueError yet, eliminate LLContinueError& parameter from
LOG_UNHANDLED_EXCEPTION(). This permits us to use the same log message as
CRASH_ON_UNHANDLED_EXCEPTION(), just with a different severity level.
Where a catch (...) clause actually provides contextual information, or makes
an error string, add boost::current_exception_diagnostic_information() to try
to figure out actual exception class and message.
To date, the coroutine helper functions in lleventcoro.h have been in the
global namespace. Migrate them into llcoro namespace, and fix references.
Specifically, LLVoidListener => llcoro::VoidListener, and voidlistener(),
postAndWait(), both waitForEventOn(), postAndWait2(), errorException() and
errorLog() have been moved into llcoro.
Also migrate new LLCoros::get_self() and Suspending to llcoro:: namespace.
While at it, I realized that -- having converted several lleventcoro.h
functions from templates (for arbitrary 'self' parameter type) to ordinary
functions, having moved them from lleventcoro.h to lleventcoro.cpp, we can now
migrate their helpers from lleventcoro.h to lleventcoro.cpp as well. This
eliminates the need for the LLEventDetail namespace; the relevant helpers are
now in an anonymous namespace in the .cpp file: listenerNameForCoro(),
storeToLLSDPath(), WaitForEventOnHelper and wfeoh().
In autobuild.xml, specify today's build of the Boost package that includes the
Boost.Context library, and whose boost::dcoroutines library uses Boost.Context
exclusively instead of its previous context-switching underpinnings (source of
the ucontext.h dependency).
Add BOOST_CONTEXT_LIBRARY to Boost.cmake and Copy3rdPartyLibs.cmake. Link it
with the viewer and with the lllogin.cpp test executable.
Track new Boost package convention that our (early, unofficial) Boost.Coroutine
library is now accessed as boost/dcoroutine/etc.h and boost::dcoroutines::etc.
Remove #include <boost/coroutine/coroutine.hpp> from
llviewerprecompiledheaders.h and lllogin.cpp: old rule that Boost.Coroutine
header must be #included before anything else that might use ucontext.h is
gone now that we no longer depend on ucontext.h. In fact remove
-D_XOPEN_SOURCE in 00-Common.cmake because that was inserted specifically to
work around a known problem with the ucontext.h facilities.
This eliminates the timing hole (introduced by EXT-3934 fix) in which a
belated SRV response could confuse the XMLRPC response code.
Extend unit tests to positively drive the bug and validate the fix.
Added settings to config SRV request params
Increased timeout to 10 seconds
Changed timeout to generate login failure event instead of an error.
Added unit test to cover SRV failure event.
Ansariel