On 10/19/18 9:47 AM, Daniil Titov wrote:
Hi Gary and Chris,

I am resending the previous email since the table in that email got corrupted.

Below is what output jdb prints when a breakpoint is hit depending on what 
suspended policy is used:

The current behavior.
SUSPEND_ALL:    Prompt is printed ( e.g. "main[1]"), location is printed
SUSPEND_EVENT_THREAD:    Prompt is not printed, location is not printed
SUSPEND_NONE:    Prompt is not printed, location is not printed

The fix changes this behavior as the following:

SUSPEND_ALL:    Prompt is printed ( e.g. "main[1]"), location is printed
SUSPEND_EVENT_THREAD:    Prompt is printed ( "> "), location is printed
SUSPEND_NONE:    Prompt is printed ( "> "), location is printed
I'm still in favor of this fix.
Could you please say is it OK for you or you want that the location was printed only for 
SUSPEND_ALL case?  Or probably just leave all behavior unchanged and close the bug as 
"not an issue"?

Regarding settable prompt...  As I understand Gary's original concern was that waiting in tests for 
a simple prompt " > " (>  ) could be unreliable if this substring 
somehow appears in the output of the test program and the suggestion was to use more specific 
patterns for the cases when the full prompt  (thread_name[frame_index]) is not printed ( e.g. when  
the current thread is not set). However, we need somehow pass this pattern to 
Jdb.command(JdbCommand) method otherwise it would keep waiting for the full prompt and fail with the 
timeout.  Probably I am missing something here...
Maybe we need a version of command() that takes a pattern to look for other than the prompt.

Chris
Thanks!
  --Daniil

On 10/19/18, 9:27 AM, "Daniil Titov" <daniil.x.ti...@oracle.com> wrote:

     Hi Gary and Chris,
Below is the table that shows what jdb output is printed when a breakpoint is hit depending on what suspended policy is used: SUSPEND POLICY | PROMPT PRINTED | LOCATION PRINTED
     --------------------------------------- 
|---------------------------|--------------------------
     SUSPEND_ALL.                           | yes,  e.g. "main[1]" |            
yes
     --------------------------------------- |-------------------------- 
|--------------------------
     SUSPEND_EVENT_THREAD      | no                  |            no
     ----------------------------------------|------------------------ 
--|--------------------------
     SUSPEND_ALL.                           | no                              | 
           no
The fix changes this behavior as the following: SUSPEND POLICY | PROMPT PRINTED. | LOCATION PRINTED
     --------------------------------------- 
|----------------------------|--------------------------
     SUSPEND_ALL.                           | yes , e.g. "main[1]"  |           
 yes
     --------------------------------------- 
|----------------------------|--------------------------
     SUSPEND_EVENT_THREAD      | yes ,  ">"                    |            yes
     ----------------------------------------|--------------------------- 
|--------------------------
     SUSPEND_ALL.                           | yes,  ">".                    |   
         yes
Could you please say is it OK for you or you want that the location was printed only for SUSPEND_ALL case? Or probably just leave all behavior unchanged and close the bug as "not an issue"? Regarding settable prompt... As I understand Gary's original concern was that waiting in tests for a simple prompt " > " (&gt;&nbsp; ) could be unreliable if this substring somehow appears in the output of the test program and the suggestion was to use more specific patterns for the cases when the full prompt (thread_name[frame_index]) is not printed ( e.g. when the current thread is not set). However, we need somehow pass this pattern to Jdb.command(JdbCommand) method otherwise it would keep waiting for the full prompt and fail with the timeout. Probably I am missing something here... Thanks! Best regards,
     Daniil
On 10/19/18, 12:54 AM, "gary.ad...@oracle.com" <gary.ad...@oracle.com> wrote: It's not clear to me if the omitted location information for the non
         stopping
         cases was intentional or not. It may be sufficient to know that the
         event fired
         without the extra information.
I don't think a settable prompt is required either. There are plenty of
         jdb commands that
         could be used with the wait for message in tests that need to
         synchronize at a specific
         point in the test sequence.
I don't think we see wait for simple prompt in any of the tests, because it
         is not reliable enough.
On 10/18/18 11:53 AM, Daniil Titov wrote:
         > Hi Gary,
         >
         > Currently when a breakpoint is hit the message "Breakpoint hit:" is printed in 
the debugger output. What we do in this fix we just add more information about what exact breakpoint 
is hit. Do you suggest we should not print this line at all if suspend policy is SUSPEND_NONE? If so 
then it is not clear what is the use of the command "stop go ..." would be. Regarding 
waiting for the simple prompt, we could change JDbCommand to have a field to store a prompt pattern 
and use this pattern (if it was set) when waiting for command to complete. In tests when required we 
would set the pattern in JdbCommand to more complicated one matching a specific output we are 
expecting at this particular step. Do you think it would be a better approach?
         >
         > Thanks!
         >
         > Best regards,
         > Daniil
         >
         >
         >
         > On 10/18/18, 4:09 AM, "Gary Adams" <gary.ad...@oracle.com> wrote:
         >
         >      I'm not certain that we should be printing locations or prompts 
for
         >      events when the vm has not been suspended. This looks OK for the
         >      simple test case we are working on here, but in real life there 
may
         >      be a lot more output produced.
         >
         >      The user has to select a specific thread before additional 
commands
         >      can be performed in the correct context. e.g. threads, thread 
n, where, ...
         >      So the information is available to the user. It doesn't have to 
be
         >      produced at the time the event is processed.
         >
         >      I'm uncomfortable putting too much trust in waiting for the 
simple prompt,
         >      because there is too great a chance of false positives on such 
a small
         >      marker.
         >
         >
         >      On 10/17/18, 8:50 PM, Daniil Titov wrote:
         >      > Hi Chris, Alex and JC,
         >      >
         >      > I created a separate issue to deal with "non-atomic" jdb 
output at https://bugs.openjdk.java.net/browse/JDK-8212626 .
         >      >
         >      > Please review an updated fix that includes the changes Alex 
suggested.
         >      >
         >      > Webrev: http://cr.openjdk.java.net/~dtitov/8211736/webrev.04
         >      > Issue: https://bugs.openjdk.java.net/browse/JDK-8211736
         >      >
         >      > Thanks!
         >      > --Daniil
         >      >
         >      >
         >      > On 10/17/18, 5:06 PM, "Daniil 
Titov"<daniil.x.ti...@oracle.com>  wrote:
         >      >
         >      >      Hi Chris,
         >      >
         >      >      The previous email was accidentally fired before I 
managed to type anything in. Sorry for confusion.
         >      >
         >      >      Jdb constantly reads new commands from System.in despite 
whether the breakpoint is hit and/or the prompt is printed.
         >      >
         >      >      cat -n 
src/jdk.jdi/share/classes/com/sun/tools/example/debug/tty/TTY.java
         >      >
         >      >      786                    // Process interactive commands.
         >      >         787                 MessageOutput.printPrompt();
         >      >         788                 while (true) {
         >      >         789                     String ln = in.readLine();
         >      >         790                     if (ln == null) {
         >      >         791                         /*
         >      >         792                          *  Jdb is being shutdown 
because debuggee exited, ignore any 'null'
         >      >         793                          *  returned by 
readLine() during shutdown. JDK-8154144.
         >      >         794                          */
         >      >         795                         if (!isShuttingDown()) {
         >      >         796                             
MessageOutput.println("Input stream closed.");
         >      >         797                         }
         >      >         798                         ln = "quit";
         >      >         799                     }
         >      >         800     
         >      >         801                     if (ln.startsWith("!!")&&  
lastLine != null) {
         >      >         802                         ln = lastLine + 
ln.substring(2);
         >      >         803                         
MessageOutput.printDirectln(ln);// Special case: use printDirectln()
         >      >         804                     }
         >      >         805     
         >      >         806                     StringTokenizer t = new 
StringTokenizer(ln);
         >      >         807                     if (t.hasMoreTokens()) {
         >      >         808                         lastLine = ln;
         >      >         809                         executeCommand(t);
         >      >         810                     } else {
         >      >         811                         
MessageOutput.printPrompt();
         >      >         812                     }
         >      >         813                 }
         >      >         814             } catch (VMDisconnectedException e) {
         >      >         815                 
handler.handleDisconnectedException();
         >      >         816             }
         >      >
         >      >      Below is a sample debug session for the following test class that sends 
commands "threads" and "quit"
         >      >      1  public class LoopTest {
         >      >           2         public static void main(String[] args) 
throws Exception {
         >      >           3             Thread thread = 
Thread.currentThread();
         >      >           4             while(true) {
         >      >           5                 print(thread);
         >      >           6                 Thread.sleep(5000);
         >      >           7             }
         >      >           8         }
         >      >           9     
         >      >          10         public static void print(Object obj) {
         >      >          11             //System.out.println(obj);
         >      >          12         }
         >      >          13     }
         >      >
         >      >      datitov-mac:work datitov$ 
~/src/jdk-hs/build/macosx-x64-debug/images/jdk/bin/jdb LoopTest
         >      >      Initializing jdb ...
         >      >      >  stop go at LoopTest:6
         >      >      Deferring breakpoint LoopTest:6.
         >      >      It will be set after the class is loaded.
         >      >      >  run
         >      >      run LoopTest
         >      >      Set uncaught java.lang.Throwable
         >      >      Set deferred uncaught java.lang.Throwable
         >      >      >
         >      >      VM Started: Set deferred breakpoint LoopTest:6
         >      >
         >      >      Breakpoint hit: "thread=main", LoopTest.main(), line=6 
bci=8
         >      >      6                Thread.sleep(5000);
         >      >
         >      >      Breakpoint hit: "thread=main", LoopTest.main(), line=6 
bci=8
         >      >      6                Thread.sleep(5000);
         >      >      threads
         >      >      Group system:
         >      >        (java.lang.ref.Reference$ReferenceHandler)0x172 
Reference Handler running
         >      >        (java.lang.ref.Finalizer$FinalizerThread)0x173  
Finalizer         cond. waiting
         >      >        (java.lang.Thread)0x174                         Signal 
Dispatcher running
         >      >      Group main:
         >      >        (java.lang.Thread)0x1                           main   
           sleeping
         >      >      Group InnocuousThreadGroup:
         >      >        (jdk.internal.misc.InnocuousThread)0x197        
Common-Cleaner    cond. waiting
         >      >      >
         >      >      Breakpoint hit: "thread=main", LoopTest.main(), line=6 
bci=8
         >      >      6                Thread.sleep(5000);
         >      >
         >      >      Breakpoint hit: "thread=main", LoopTest.main(), line=6 
bci=8
         >      >      6                Thread.sleep(5000);
         >      >      quit
         >      >      Breakpoint hit: "thread=main", LoopTest.main(), line=6 
bci=8
         >      >      6                Thread.sleep(5000);
         >      >
         >      >      datitov-mac:work datitov$
         >      >
         >      >      I think we could print a simple prompt in this case as 
Alex suggested.
         >      >
         >      >      Best regards,
         >      >      Daniil
         >      >
         >      >      On 10/17/18, 3:52 PM, "Chris 
Plummer"<chris.plum...@oracle.com>  wrote:
         >      >
         >      >          What is the jdb state for a breakpoint with 
SUSPEND_NONE? Can you
         >      >          actually type in commands even though no threads are 
suspended?
         >      >
         >      >          Chris
         >      >
         >      >          On 10/17/18 3:31 PM, Alex Menkov wrote:
         >      >          >  Hi Daniil, Chris,
         >      >          >
         >      >          >  As far as I understand, the fix does not 
completely fixes all
         >      >          >  "non-atomic" output issues (at least 
TTY.executeCommand still prints
         >      >          >  prompt separately), so I agree that handle it as 
separate issue would
         >      >          >  be better.
         >      >          >  Unfortunately I don't know Gary's ideas for the 
issue.
         >      >          >
         >      >          >  About the fix for print prompt:
         >      >          >  1) TTY.java:
         >      >          >  +            // Print current location if suspend 
policy is SUSPEND_NONE
         >      >          >  I suppose you mean "Print breakpoint location"
         >      >          >
         >      >          >  2) Does it make sense to use printCurrentLocation 
for
         >      >          >  SUSPEND_EVENT_THREAD?
         >      >          >  Is it expected to print something different from 
printBreakpointLocation?
         >      >          >
         >      >          >  3) I don't quite understand why we don't print 
simple prompt for
         >      >          >  SUSPEND_NONE. IIUC jdb can accept new command in 
both
         >      >          >  SUSPEND_EVENT_THREAD and SUSPEND_NONE cases 
(prompt shows that jdb
         >      >          >  waits for next command, right?)
         >      >          >
         >      >          >  4) JdbStopThreadTest.java
         >      >          >  New line line in Java regexp is "\\R"
         >      >          >
         >      >          >  --alex
         >      >          >
         >      >          >  On 10/17/2018 10:47, Chris Plummer wrote:
         >      >          >>  Hi Alex,
         >      >          >>
         >      >          >>  I think the tty buffering should be a separate 
bug fix, and I'd also
         >      >          >>  like input from Gary on it since he had tried 
something similar at
         >      >          >>  one point. It should probably also include a 
multithread test to
         >      >          >>  prove the fix is working (after first getting 
the test to fail
         >      >          >>  without the changes).
         >      >          >>
         >      >          >>  thanks,
         >      >          >>
         >      >          >>  Chris
         >      >          >>
         >      >          >>  On 10/16/18 8:59 PM, Daniil Titov wrote:
         >      >          >>>  Hi Alex, Chris and JC,
         >      >          >>>
         >      >          >>>  Please review an updated version of the patch 
that addresses these
         >      >          >>>  issues.
         >      >          >>>
         >      >          >>>  Webrev: 
http://cr.openjdk.java.net/~dtitov/8211736/webrev.03/
         >      >          >>>  Issue:  
https://bugs.openjdk.java.net/browse/JDK-8211736
         >      >          >>>
         >      >          >>>  Thanks!
         >      >          >>>  --Daniil
         >      >          >>>
         >      >          >>>
         >      >          >>>  On 10/12/18, 9:52 AM, "Alex 
Menkov"<alexey.men...@oracle.com>  wrote:
         >      >          >>>
         >      >          >>>       Hi Daniil,
         >      >          >>>       1) +1 for printCurrentLocation when 
suspendPolicy != SUSPEND_ALL
         >      >          >>>       2) wrong indent in JdbStopThreadTest.java:
         >      >          >>>          36         import lib.jdb.JdbCommand;
         >      >          >>>          37         import lib.jdb.JdbTest;
         >      >          >>>       3) I think it would be better to make 
waitForSimplePrompt
         >      >          >>>  property of
         >      >          >>>       JdbCommand (like JdbCommand.allowExit)
         >      >          >>>       
jdb.command(JdbCommand.run().replyIsSimplePrompt());
         >      >          >>>       looks much clearer than
         >      >          >>>       jdb.command(JdbCommand.run(), true);
         >      >          >>>       4) (TTY.java)
         >      >          >>>           MessageOutput.lnprint("Breakpoint 
hit:");
         >      >          >>>       +  // Print current location and prompt if 
suspend policy is
         >      >          >>>       SUSPEND_EVENT_THREAD.
         >      >          >>>       +  // In case of SUSPEND_ALL policy this 
is handled by
         >      >          >>>  vmInterrupted()
         >      >          >>>       method.
         >      >          >>>       +  if (be.request().suspendPolicy() ==
         >      >          >>>  EventRequest.SUSPEND_EVENT_THREAD) {
         >      >          >>>       + 
printCurrentLocation(ThreadInfo.getThreadInfo(be.thread()));
         >      >          >>>       +      MessageOutput.printPrompt();
         >      >          >>>       +  }
         >      >          >>>       We have 3 separate outputs.
         >      >          >>>       If we have several concurrent threads, we 
can easy get mess of
         >      >          >>>  outputs
         >      >          >>>       from different threads.
         >      >          >>>       I think it would be better to print 
everything in a single chunk.
         >      >          >>>       I suppose TTY has other places with similar 
"non-atomic"
         >      >          >>>  output, so
         >      >          >>>       maybe revising TTY output should be 
handled by separate issue.
         >      >          >>>       --alex
         >      >          >>>       On 10/11/2018 22:00, Chris Plummer wrote:
         >      >          >>>       >  Hi Daniil,
         >      >          >>>       >
         >      >          >>>       >  Can you send output from an example jdb 
session?
         >      >          >>>       >
         >      >          >>>       >  Do you think maybe we should also call 
printCurrentLocation()
         >      >          >>>  when the
         >      >          >>>       >  suspend policy is NONE?
         >      >          >>>       >
         >      >          >>>       >  There's a typo in the following line. 
The space is on the
         >      >          >>>  wrong side of
         >      >          >>>       >  the comma.
         >      >          >>>       >
         >      >          >>>       >     72 
jdb.command(JdbCommand.stopThreadAt(DEBUGGEE_CLASS
         >      >          >>>  ,bpLine));
         >      >          >>>       >
         >      >          >>>       >  thanks,
         >      >          >>>       >
         >      >          >>>       >  Chris
         >      >          >>>       >
         >      >          >>>       >  On 10/11/18 8:02 PM, Daniil Titov wrote:
         >      >          >>>       >>
         >      >          >>>       >>  Thank you,  JC!
         >      >          >>>       >>
         >      >          >>>       >>  Please review an updated version of 
the patch that fixes
         >      >          >>>  newly added
         >      >          >>>       >>  test for Windows platform  (now it 
uses system dependent line
         >      >          >>>       >>  separator string).
         >      >          >>>       >>
         >      >          >>>       >>  
Webrev:http://cr.openjdk.java.net/~dtitov/8211736/webrev.02/
         >      >          >>>       >>  
<http://cr.openjdk.java.net/%7Edtitov/8211736/webrev.02/>
         >      >          >>>       >>
         >      >          >>>       >>  Issue: 
https://bugs.openjdk.java.net/browse/JDK-8211736
         >      >          >>>       >>
         >      >          >>>       >>  Best regards,
         >      >          >>>       >>
         >      >          >>>       >>  --Daniil
         >      >          >>>       >>
         >      >          >>>       >>  *From: *JC Beyler<jcbey...@google.com>
         >      >          >>>       >>  *Date: *Thursday, October 11, 2018 at 
7:17 PM
         >      >          >>>       >>  *To: *<daniil.x.ti...@oracle.com>
         >      >          >>>       >>  *Cc: 
*<serviceability-dev@openjdk.java.net>
         >      >          >>>       >>  *Subject: *Re: RFR 8211736: jdb 
doesn't print prompt when
         >      >          >>>  breakpoint
         >      >          >>>       >>  is hit and suspend policy is 
STOP_EVENT_THREAD
         >      >          >>>       >>
         >      >          >>>       >>  Hi Daniil,
         >      >          >>>       >>
         >      >          >>>       >>  Looks good to me. I saw a really small 
nit:
         >      >          >>>       >>
         >      >          >>>       >>
         >      >          >>>  
http://cr.openjdk.java.net/~dtitov/8211736/webrev.01/test/jdk/com/sun/jdi/JdbStopThreadTest.java.html
         >      >          >>>
         >      >          >>>       >>
         >      >          >>>  
<http://cr.openjdk.java.net/%7Edtitov/8211736/webrev.01/test/jdk/com/sun/jdi/JdbStopThreadTest.java.html>
         >      >          >>>
         >      >          >>>       >>
         >      >          >>>       >>  70  
jdb.command(JdbCommand.stopThreadAt( DEBUGGEE_CLASS
         >      >          >>>  ,bpLine));
         >      >          >>>       >>
         >      >          >>>       >>  There is a space after the '('.
         >      >          >>>       >>
         >      >          >>>       >>  No need to send a new webrev for that 
evidently :),
         >      >          >>>       >>
         >      >          >>>       >>  Jc
         >      >          >>>       >>
         >      >          >>>       >>  On Thu, Oct 11, 2018 at 5:07 PM Daniil 
Titov
         >      >          >>>       >>  <daniil.x.ti...@oracle.com
         >      >          >>>  <mailto:daniil.x.ti...@oracle.com>>  wrote:
         >      >          >>>       >>
         >      >          >>>       >>      Please review the change that 
fixes the issue with
         >      >          >>>  missing prompt
         >      >          >>>       >>      in jdb when a breakpoint is hit 
and the suspend policy
         >      >          >>>  is set to
         >      >          >>>       >>      stop the thread only.
         >      >          >>>       >>
         >      >          >>>       >>      Webrev:
         >      >          >>>  
http://cr.openjdk.java.net/~dtitov/8211736/webrev.01
         >      >          >>>       >>  
<http://cr.openjdk.java.net/%7Edtitov/8211736/webrev.01>
         >      >          >>>       >>      Issue: 
https://bugs.openjdk.java.net/browse/JDK-8211736
         >      >          >>>       >>
         >      >          >>>       >>      Thanks!
         >      >          >>>       >>      --Daniil
         >      >          >>>       >>
         >      >          >>>       >>
         >      >          >>>       >>
         >      >          >>>       >>  --
         >      >          >>>       >>
         >      >          >>>       >>  Thanks,
         >      >          >>>       >>
         >      >          >>>       >>  Jc
         >      >          >>>       >>
         >      >          >>>       >
         >      >          >>>
         >      >          >>>
         >      >          >>
         >      >          >>
         >      >
         >      >
         >      >
         >      >
         >      >
         >
         >
         >
         >



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