Hi,
On 2015-10-28 21:59, Rachel Protacio wrote:
Including serviceability-dev. Recap:
Summary: In logging/log.hpp, the logging vwrite function previously
asserted that the buffer remains within 512 characters, which is
too short for logging message of non-pre-determined length, e.g. for
vtable and itable function names. Now, the function resizes the buffer
to the appropriate length, asserting only that the resulting buffer is
valid. Includes tag "logtest" to test that logging can print an output
of 518 characters.
Open webrev: http://cr.openjdk.java.net/~rprotacio/8138916.02
Bug: https://bugs.openjdk.java.net/browse/JDK-8138916
I don't like that the test log message is included in the product, or
that a completely new tag is introduced for it.
I think a much better approach would be to do the test logging in an
internal VM test, reusing the logging tag. This way it won't be logged
unless we are actually testing stuff, and we don't introduce a new tag.
Also it would look better if it were logged on develop level.
Thanks,
Marcus
Includes own acceptance test, and passes JPRT and remote hotspot/test
tests.
Thank you,
Rachel
On 10/28/2015 4:08 PM, Rachel Protacio wrote:
Thanks for the review and all the feedback!
Rachel
On 10/28/2015 4:05 PM, Dmitry Samersoff wrote:
Rachel,
Looks good for me!
-Dmitry
On 2015-10-28 20:50, Rachel Protacio wrote:
Thank you both. I've removed the re-declaration and added
prefix_len to
newbuf_len. As for line 115, that line is not for the sake of
recalculating prefix_len, but for writing the prefix to the buffer.
http://cr.openjdk.java.net/~rprotacio/8138916.02/
Thanks,
Rachel
On 10/28/2015 12:27 PM, Coleen Phillimore wrote:
Dmitry, Thank you for reviewing and providing comments. The second
version is better because of these things that I didn't notice until
you pointed it out.
The malloc won't be frequent. I think it'll be okay and follows
other
coding patterns in the jvm.
Thanks!
Coleen
On 10/28/15 12:09 PM, Dmitry Samersoff wrote:
Coleen,
OK. I'm leaving it in good hands ;)
-Dmitry
On 2015-10-28 18:54, Coleen Phillimore wrote:
Hi, I'm also reviewing this. I think this looks good. I
don't think
the solution to allocate a static buffer is very nice because it
still
has limits and we don't want to allocate something large on the
stack.
The malloc case is the infrequent case. If it becomes frequent
we can
increase LogBufferSize from 512.
I think 111 the assert is good because if the windows code is
wrong (or
the vscprintf does something wrong an unexpected) we can catch the
error
with the assert before writing over memory.
I agree 116 shouldn't redeclare 'ret'.
Otherwise, I think it looks really good and I don't need to see
another
revision.
Thanks!
Coleen
On 10/28/15 11:40 AM, Dmitry Samersoff wrote:
Rachel,
On 2015-10-28 17:48, Rachel Protacio wrote:
Thank you for the comments, both Dmitry and Mikael. Replies
inline.
Modified webrev:
http://cr.openjdk.java.net/~rprotacio/8138916.01/
111 Assert is never happens on Windows, so it's better to move
it to
os_posix
113 newbuf_len doesn't account prefix_len
115 you may consider to use pre-calculated at ll. 108 prefix
rather
than
calculate it again.
116 int ret redefined it causes a warning.
-Dmitry
(Retested and works fine.)
On 10/27/2015 7:52 AM, Dmitry Samersoff wrote:
Rachel,
In worst case (windows, overflow) the code would parse format
string
four times.
You're right. I've added a check. New amount of times
vnsprintf() is
called:
posix, fits => 1
posix, overflow => 2
windows, fits => 1
windows, overflow => 3 (the best performance we can get)
Also NEW_C_HEAP_ARRAY takes a lock and might become a
performance bottleneck.
POSIX equivalent of _vscprintf(fmt, args) is vsnprintf(NULL,
0, fmt,
args)
So it might be better to create os::log_vcprintf(fmt, args),
then
write
code at log.hpp as:
int buf_len = os::log_vcprintf(fmt, args);
assert(buf_len < 2*page_size, "Stack overflow in logging");
char buf[buf_len];
vsprintf(buf, fmt, args);
I don't think this would work anyway. A char[] needs a static
size.
Thanks,
Rachel
-Dmitry
On 2015-10-26 23:58, Rachel Protacio wrote:
Hello, all,
Please review this fix to the faulty write function from the
Unified
Logging framework.
Summary: In logging/log.hpp, the logging vwrite function
previously
asserted that the buffer remains within 512 characters,
which is
too
short for logging message of non-pre-determined length, e.g.
for
vtable
and itable function names. Now, the function resizes the buffer
to the
appropriate length, asserting only that the resulting buffer is
valid.
Includes tag "logtest" to test that logging can print an output
of 518
characters.
Open webrev:http://cr.openjdk.java.net/~rprotacio/8138916/
Bug:https://bugs.openjdk.java.net/browse/JDK-8138916
Includes own acceptance test, and passes JPRT and remote
hotspot/test
tests.
Thank you,
Rachel
