Unfortunately, the symbol resolution of boost::stacktrace is broken on
FreeBSD, therefore fall back to using backtrace_symbols() to print the
stack trace saved by Boost.
Additionally, -D_GNU_SOURCE is required on FreeBSD for the
_Unwind_Backtrace function used by boost::stacktrace.
This makes the format more similar to what the uncaught C++ and SEH
exception handlers write. Previously there was no indication in the
crash log that a SIGABRT happened.
Older versions of MSVC fail to rethrow an unhandled C++ exception (using
`throw;`) in the termination handler (`std::set_terminate`), however
Icinga relies on this behavior in its crash handler
(`Application::ExceptionHandler`).
Maybe this will save the next person who has to look at this code some
time. Please don't blame me for the implementation, I'm just trying to
reconstruct what it does.
The logic for selecting the traces to print stays the same, but there
are fewer nested ifs now. This changes the format of the returned string
a bit by adding a heading for both traces.
By default, DiagnosticInformation uses the stack trace saved when the
exception was thrown, but this mechanism is not in use on Windows.
Gathering a stacktrace in the terminate handler serves as a fallback.
On Windows, the termination handler is executed for uncaught C++
exceptions unless a SEH unhandled exception filter is also set. In this
case, this filter has to explicitly chain the default filter to keep
this behavior.
Previously, the initial config dump was started in a timer executed
every 15 seconds. During the first execution of the timer, the Redis
connection is typically not established yet. Therefore, this delayed the
initial sync by up to 15 seconds.
This commit instead triggers the sync from a callback that is executed
after the connection is successfully established.
The timer is removed completely. On first glance, it looks like it would
ensure that a lost connection is reestablished, but this is handled
internally by RedisConnection. After the config has been dumped once,
that timer wouldn't ever attempt a reconnect anyways.
Disregard passive check results while no active checks are being scheduled due to violated dependencies.
This copes with the fact that programs feeding passive check results into Icinga may have no notion of reachability and so drive a checkable into HARD state although dependencies have caused active check scheduling being suspended. This may prevent superflous problem notifications being emitted during recovery.
As disable_checks defaults to false, it was regarded OK (by @Al2Klimov) to make this behaviour (which resembles the active check case) unconditional and not conditionalize it on an additional attribute.
In the description of disable_checks, note that a value of true both disables scheduling of active checks and drops passive check results.
This delays the log message stating that the initial dump is done until
all queries are actually done and now logs a meaningful duration. In
addition, this delays the return of the function and therefore when
state variables are updated by the caller.