Hi Igor,
On 3/12/18 1:26 PM, Igor Ignatyev wrote:
On Mar 12, 2018, at 8:53 AM, Chris Plummer <chris.plum...@oracle.com
<mailto:chris.plum...@oracle.com>> wrote:
On 3/11/18 7:52 PM, David Holmes wrote:
Hi Chris,
On 10/03/2018 6:46 AM, Chris Plummer wrote:
Hello,
Please help review the following:
https://bugs.openjdk.java.net/browse/JDK-8198655
http://cr.openjdk.java.net/~cjplummer/8198655/webrev.00/webrev/
In the end there were two issues. The first was that the
pb.redirectError() call was redirecting the LingeredApp's stderr to
the console, which we don't want. The second was that nothing was
capturing the LingeredApp's output and sending it to the driver
app's output (jtr file). These changes make all the LingeredApp's
output end up in the jtr file.
It isn't clear to me how the interleaving of the two streams by the
two threads is handled in the copy routine. Are we guaranteed to get
complete lines of output from each stream before writing to System.out?
Hi David,
I'm hoping Igor will chime in here, since this is just cloned from
some closed code he wrote, and he recommended this fix. Perhaps we
are just doing something a bit non standard here. When spawning a
separate test process, don't we normally just dump stdout and stderr
separately via OutputAnalyzer.reportDiagnosticSummary() after the
test completes, and then only if there is an error. I'm not sure why
Igor felt LingeredApp tests should be handled differently.
I recommended this fix as one of possibilities and never claimed it's
the best solution ;) I don't know much of LingeredApp tests, so I
just suggested the patch which only solves the problem I noticed
(LingeredApp's cerr being printed into jtreg agent's cerr).
If by "into jtreg agent's cerr" you are referring to the presence of
JDWP "ERROR" messages in the jtreg console, that is fixed simply by
removing the following:
pb.redirectError(ProcessBuilder.Redirect.INHERIT);
And that is already part of this fix. But it actually makes the ERROR
messages completely disappear. The copy() part of the fix makes all the
LingeredApp output appear in the .jtr file (including the JDWP "ERROR"
messages).
OutputAnalyzer might not fit the use case of LingeredApp b/c it blocks
till the process is finished. again, I don't know much about
LingeredApp itself and the tests which use it.
My point was that other jtreg tests that use ProcessBuilder and
OutputAnalyzer don't print out anything from the spawned process/app
until it is done, and even then usually only if there was a test
failure. Why is there a need here to print out messages as they are
generated.
answering to David's question, copy routine handles interleaving of
two streams similarly to printf routine, it does not do that at all.
we are writing to System.out as we read data, the only guarantee we
have is all the bytes we read into buffer will be written together
(which might mean 1 byte at a time), no guarantees about lines. the
behavior is pretty much the same as you expect to get from an
interactive shell w/ both cout and cerr are being printed on the console.
Not quite. If a single threaded app is sending to both System.out and
System.err (and/or stdout and stderr) and does something to ensure
flushing after each print or each line, then the output should appear
cleanly in the order executed. By having two different threads read
these two streams, order might be changed, and possibly even interleaved
within lines.
cheers,
Chris
Thanks,
-- Igor
thanks,
Chris
Thanks,
David
-----
Tested by running all tests that use LingeredApp.
thanks,
Chris
