Tim Ellison wrote:
Regis wrote:
I have attached a patch for this issue on JIRA.
See comments elsewhere why the patch needs some tweaking.
I think that would be helpful to add file path in error messages when
throw FileNotFoundException, and that need to allocate new memory for
the new messages, I used hymem_allocate_memory to do this. But I don't
have chance to free that memory, since exception thrown, code back to
java. That may cause memory leak, I know define a enough large char
array could avoid this, but need more memory (path may be very long), is
there any other better way to do this? Thanks!
A code sample would be helpful to ensure I understand your situation
correctly.
For example, the system message is "No such file or directory", I just
like to append file path, like "No such file or directory: /home/a/c",
so I need a new block of memory for holding the new string.
But the 'throw' in native code does not cause a function return (think
of it as marking a pending throw upon return [1]). The ThrowNew JNI
call will copy the message string into a new Java String object, so you
can free it before the native returns, i.e.
That's a little surprise, I need to refresh my head about the native
code. Where can I find such details of JNI call? It seems JNI spec is so
brief that I can't find more useful things.
allocate memory
throw exception
free memory
return from native (causes throw to occur)
Of course, you can also just use a local var rather than allocate if you
want too.
Make sense?
Tim
Thanks Tim, that's very clear :)
[1] It's important to understand this, otherwise you'll be surprised
about code running after your "native throw". As a rule, you should
tidy-up and return quite soon after raising the exception for clarity.
