RFR: 7904101: intermittent failure in StreamsTest.agentvm.ok [v3]

[Christian Stein]

On Mon, 27 Oct 2025 22:00:06 GMT, Vladimir Petko <vpetko at openjdk.org> wrote:

>> FileDescriptor test intermittently fails because the agent's process output capture lacks synchronisation. 
>> 
>> This PR fixes the issue:
>> - Agent VM prints the "process output separator" to stderr and stdout before and after action
>> - The main vm uses the marker to stop reading the stream for the current test result section (or a general agent log)
>> - The main vm restarts reading the log after updating the test section (or clearing it) until the next marker or the process is shut down.
>> 
>> Alternative:
>>  -Disable the test and make no assumptions about contents of the agent vm process output.
>> 
>> Testing: tier1 and tier2 tests on mainline jdk (Ubuntu Linux) in agentvm mode.
>> 
>> 
>> make test TEST=":tier1 :tier2" JTREG="TEST_MODE=agentvm"
>> 
>> ....
>> 
>> ==============================
>> Test summary
>> ==============================
>>    TEST                                              TOTAL  PASS  FAIL ERROR  SKIP   
>>    jtreg:test/hotspot/jtreg:tier1                     3124  2837     0     0   287   
>>    jtreg:test/jdk:tier1                               2519  2480     0     0    39   
>>    jtreg:test/langtools:tier1                         4670  4660     0     0    10   
>>    jtreg:test/jaxp:tier1                                 0     0     0     0     0   
>>    jtreg:test/lib-test:tier1                            38    38     0     0     0   
>>    jtreg:test/hotspot/jtreg:tier2                      960   913     0     0    47   
>>>> jtreg:test/jdk:tier2                               4455  4220     1     0   234 <<
>>    jtreg:test/langtools:tier2                           14    12     0     0     2   
>>    jtreg:test/jaxp:tier2                               517   516     0     0     1   
>>    jtreg:test/docs:tier2                                 4     0     0     0     4   
>> ==============================
>> TEST FAILURE
>> 
>> 
>> Unrelated failure: test/jdk/java/nio/channels/DatagramChannel/SendReceiveMaxSize.java
>> 
>> 
>> 
>> 
>> ---------System.out:(98/7409)----------
>> Seed from RandomFactory = 7590698091695474155L
>> [15:02:42.244] config SendReceiveMaxSize.setUp(): success [0ms]
>> [15:02:42.272] test SendReceiveMaxSize.testGetOption(SendReceiveMaxSize$$Lambda/0x00000000450736f8 at 8d234b9, 65507, /10.201.67.1): success [7ms]
>> [15:02:42.273] test SendReceiveMaxSize.testGetOption(SendReceiveMaxSize$$Lambda/0x0000000045073920 at 449629ff, 65507, /10.201.67.1): success [0ms]
>> [15:02:42.273] test SendReceiveMaxSize.testGetOption(SendReceiveMaxSize$$Lamb...
>
> Vladimir Petko has updated the pull request incrementally with four additional commits since the last revision:
> 
>  - fix: create sections in the main thread
>  - chore: propagate timeouts and exceptions
>  - fix: do not synchronize section output
>  - fix: allow marker to appear at the end of the line

> Alternative:
> -Disable the test and make no assumptions about contents of the agent vm process output.

Before looking deeper into the implementation, do I read this correctly, the a test makes "assumptions about contents of the agent vm process output"?

-------------

PR Comment: https://git.openjdk.org/jtreg/pull/295#issuecomment-3601702583