Hi,
Is there a clean way for hotspot to export the assert mechanism so it
can be called from
the C based native JDK libraries?
Thanks, Roger
On 6/1/2017 8:26 AM, Thomas Stüfe wrote:
Hi David,
On Thu, Jun 1, 2017 at 2:09 PM, David Holmes <[email protected]>
wrote:
Hi Thomas,
On 1/06/2017 7:20 PM, Thomas Stüfe wrote:
Hi all,
so, we have the hotspot asserts with all the niceties of our error
reporting. But these asserts are only accessible from within hotspot
coding.
In the JDK, in a number of places, I see that we use the standard posix
assert()(
http://pubs.opengroup.org/onlinepubs/009695399/functions/assert.html).
This means that when we trigger the assert, we will only get a brief
message on stderr and a core, but no hs_err file.
It also means that -XX:+CreateCoredumpOnCrash is ignored, so it is not
possible to switch off those core dumps.
This is unfortunate and also easy to fix. We do not even have to call into
the hotspot to get hotspot asserts. We could just force a NULL pointer
access or send ourselves a SIGILL or something. Anything which triggers
the
hotspot signal handling would be fine.
What do you think?
Sending ourselves a fatal signal doesn't indicate what assertion failed.
The error handler won't know it was an assert, just a SEGV or SIGILL
??
David
Sure. But in many cases this still would be preferable to just a core. We'd
get a hs-err file - admittedly with a Segv instead of an assert message -
but we have a callstack and could deduce the error from there.
I am not saying that this is an ideal solution. Of course, a really good
solution may invoke the real hotspot assert or one might come up with a way
to transfer assert information (message, file, line etc) to the hotspot
error handler. E.g. store the assert message in a globally visible char
array one could resolve via dlsym to avoid having to add link dependencies.
..Thomas
Kind Regards, Thomas
