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
A collection of portability improvements including shared code support for PPC, ARM platforms, software floating point, cross compilation support and improvements in error crash detail.
Reviewed-by: phh, never, coleenp, dholmes
Move creating stack guard pages in jni attach thread before potential java call rather than after. Also cleanup stack guard pages when jni attach fails
Reviewed-by: never, dholmes
Rename can_post_exceptions support to can_post_on_exceptions. Add support for should_post_on_exceptions flag to permit per JavaThread optimizations.
Reviewed-by: never, kvn, dcubed
Deferred card marks are now flushed during the gc prologue. Parallel[Scavege,OldGC] and SerialGC no longer defer card marks generated by COMPILER2 as a result of ReduceInitialCardMarks. For these cases, introduced a diagnostic option to defer the card marks, only for the purposes of testing and diagnostics. CMS and G1 continue to defer card marks. Potential performance concern related to single-threaded flushing of deferred card marks in the gc prologue will be addressed in the future.
Reviewed-by: never, johnc
During the work for 6829187 we have fixed a number of basic bugs which are logically grouped with 6815692 and 6858164 but which must be reviewed and pushed separately.
Reviewed-by: kvn, never
6889757: G1: enable card mark elision for initializing writes from compiled code (ReduceInitialCardMarks)
Defer the (compiler-elided) card-mark upon a slow-path allocation until after the store and before the next subsequent safepoint; G1 now answers yes to can_elide_tlab_write_barriers().
Reviewed-by: jcoomes, kvn, never
6660573: G1: BigApps Failure : guarantee(satb_mq_set.completed_buffers_num() == 0,"invariant")
When exiting a mutator thread is removed from the thread list before it has a chance to flush its SATB and barrier queues. If GC happens at this moment the objects that are refererred from these queues can be moved, which will case a crash. The fix is simply to flush the buffers before removing a thread from the list.
Reviewed-by: jcoomes, tonyp
