Ping...
Thanks,
Serguei
On 10/7/19 5:25 PM, serguei.spit...@oracle.com wrote:
On 10/7/19 17:14, serguei.spit...@oracle.com wrote:
Hi Alex, Chris and David,
The mach5 testing in 100 runs loop on all platform discovered a race
in new test.
It is between the native suspendTestedThreads() called on the
suspender thread
and the checkSuspendedStatus() calling native
checkTestedThreadsSuspended().
It occurred that the iteration count and sleep time in
checkSuspendedStatus() can be not enough:
100 private boolean checkSuspendedStatus(ThreadToSuspend[] threads)
throws RuntimeException {
101 boolean success = false;
102
103 log("Main: checking all tested threads have been suspended");
104
105 // wait for tested threads to reach suspended status
106 for (int i = 0; !success && i < 20; i++) {
107 try {
108 Thread.sleep(10);
109 } catch (InterruptedException e) {
110 throw new RuntimeException("Main: sleep was
interrupted\n\t" + e);
111 }
112 success = checkTestedThreadsSuspended();
113 }
114 return success;
115 }
So, I've decided to refactor/update the test a little bit:
1. Now the checkSuspendedStatus() is:
100 private boolean checkSuspendedStatus() throws RuntimeException {
101 log("Main: checking all tested threads have been suspended");
102 return checkTestedThreadsSuspended();
103 }
2. A raw monitor agent_monitor is added to the native agent.
It is created and locked in the Java_ThreadToSuspend_init()
function called at
the beginning of the ThreadToSuspend.run() execution of the
suspender thread
and unlocked at the end of
Java_ThreadToSuspend_suspendTestedThreads().
The Java_SuspendWithCurrentThread_checkTestedThreadsSuspended()
grabs the agent_monitor
on the Main thread to wait until the suspendTestedThreads()
completes its work.
3. Also, the results[] array is always created and used locally in
the functions
where it is needed: suspendTestedThreads() and resumeTestedThreads().
Forgot to tell about one more change:
4. The releaseTestedThreads() is renamed to releaseTestedThreadsInfo()
and moved
to the end of the Main thread run() method.
Also wanted to thank Alex for sharing good suggestions on the sync
approaches.
Thanks,
Serguei
Updated webrev version:
http://cr.openjdk.java.net/~sspitsyn/webrevs/2019/8231595-jvmti-susp-tlist.4/
Testing:
One mach5 run with 100 rep counter successfully passed.
To be more confident, I've submitted one more mach5 job which is in
progress.
Thanks,
Serguei
