[jdk17] RFR: 8271158: runtime/handshake/HandshakeTimeoutTest.java test doesn't check exit code

[Igor Ignatyev]

On Thu, 22 Jul 2021 19:43:46 GMT, Igor Ignatyev <iignatyev at openjdk.org> wrote:

>> test/hotspot/jtreg/runtime/handshake/HandshakeTimeoutTest.java line 63:
>> 
>>> 61:         output.reportDiagnosticSummary();
>>> 62:         // In rare cases the target wakes up and performs the handshake at the same time as we timeout.
>>> 63:         // Therefore it's not certain the timeout will find any thread.
>> 
>> The comment on L62-63 indicates that this line:
>> 
>>     L64: output.shouldMatch("has not cleared handshake op|No thread with an unfinished handshake op");
>> 
>> will sometimes finish with "No thread with an unfinished handshake op". In that case,
>> won't the test finish with an exit code of zero?
>> 
>> If I'm right about that, you've introduced a rare case where the test will
>> fail (because the exit code is 0) when it would have passed before.
>
> given `HandshakeTimeoutTest$Test` will work till it crashes, its exit code can't be 0. which, I *guess*, means we will always have "has not cleared handshake op".

actually, both `No thread with an unfinished handshake op` and `has not cleared handshake op` lead to a call of `fatal()`:
```open/src/hotspot/share/runtime/handshake.cpp:
180 static void handle_timeout(HandshakeOperation* op, JavaThread* target) {        
181   JavaThreadIteratorWithHandle jtiwh;                                           
182                                                                                 
183   log_error(handshake)("Handshake timeout: %s(" INTPTR_FORMAT "), pending threads: " INT32_FORMAT,
184                        op->name(), p2i(op), op->pending_threads());             
185                                                                                 
186   if (target == NULL) {                                                         
187     for ( ; JavaThread* thr = jtiwh.next(); ) {                                 
188       if (thr->handshake_state()->operation_pending(op)) {                      
189         log_error(handshake)("JavaThread " INTPTR_FORMAT " has not cleared handshake op: " INTPTR_FORMAT, p2i(thr), p2i(op));
190         // Remember the last one found for more diagnostics below.              
191         target = thr;                                                           
192       }                                                                         
193     }                                                                           
194   } else {                                                                      
195     log_error(handshake)("JavaThread " INTPTR_FORMAT " has not cleared handshake op: " INTPTR_FORMAT, p2i(target), p2i(op));
196   }                                                                             
197                                                                                 
198   if (target != NULL) {                                                         
199     if (os::signal_thread(target, SIGILL, "cannot be handshaked")) {            
200       // Give target a chance to report the error and terminate the VM.         
201       os::naked_sleep(3000);                                                    
202     }                                                                           
203   } else {                                                                      
204     log_error(handshake)("No thread with an unfinished handshake op(" INTPTR_FORMAT ") found.", p2i(op));
205   }                                                                             
206   fatal("Handshake timeout");                                                   
207 }

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PR: https://git.openjdk.java.net/jdk17/pull/270