Mercurial > hg > graal-compiler
diff src/share/vm/runtime/thread.hpp @ 1842:6e0aac35bfa9
6980838: G1: guarantee(false) failed: thread has an unexpected active value in its SATB queue
Summary: Under certain circumstances a safepoint could happen between a JavaThread object being created and that object being added to the Java threads list. This could cause the active field of that thread's SATB queue to get out-of-sync with respect to the other Java threads. The solution is to activate the SATB queue, when necessary, before adding the thread to the Java threads list, not when the JavaThread object is created. The changeset also includes a small fix to rename the surrogate locker thread from "Surrogate Locker Thread (CMS)" to "Surrogate Locker Thread (Concurrent GC)" since it's also used in G1.
Reviewed-by: iveresov, ysr, johnc, jcoomes
| author | tonyp |
|---|---|
| date | Fri, 01 Oct 2010 16:43:05 -0400 |
| parents | f4f596978298 |
| children | 0715f0cf171d |
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--- a/src/share/vm/runtime/thread.hpp Fri Oct 01 21:48:40 2010 -0700 +++ b/src/share/vm/runtime/thread.hpp Fri Oct 01 16:43:05 2010 -0400 @@ -1487,6 +1487,29 @@ } #endif // !SERIALGC + // This method initializes the SATB and dirty card queues before a + // JavaThread is added to the Java thread list. Right now, we don't + // have to do anything to the dirty card queue (it should have been + // activated when the thread was created), but we have to activate + // the SATB queue if the thread is created while a marking cycle is + // in progress. The activation / de-activation of the SATB queues at + // the beginning / end of a marking cycle is done during safepoints + // so we have to make sure this method is called outside one to be + // able to safely read the active field of the SATB queue set. Right + // now, it is called just before the thread is added to the Java + // thread list in the Threads::add() method. That method is holding + // the Threads_lock which ensures we are outside a safepoint. We + // cannot do the obvious and set the active field of the SATB queue + // when the thread is created given that, in some cases, safepoints + // might happen between the JavaThread constructor being called and the + // thread being added to the Java thread list (an example of this is + // when the structure for the DestroyJavaVM thread is created). +#ifndef SERIALGC + void initialize_queues(); +#else // !SERIALGC + void initialize_queues() { } +#endif // !SERIALGC + // Machine dependent stuff #include "incls/_thread_pd.hpp.incl"