Replaces calls to os::javaTimeMillis(), which does not (and cannot) guarantee monotonicity, in GC code to an equivalent expression that uses os::javaTimeNanos(). os::javaTimeNanos is guaranteed monotonically non-decreasing if the underlying platform provides a monotonic time source. Changes in OS files are to make use of the newly defined constants in globalDefinitions.hpp.
Reviewed-by: dholmes, ysr
Co-authored-by: Greg Lewis <glewis@eyesbeyond.com>
Co-authored-by: Jung-uk Kim <jkim@freebsd.org>
Co-authored-by: Christos Zoulas <christos@zoulas.com>
Co-authored-by: Landon Fuller <landonf@plausible.coop>
Co-authored-by: The FreeBSD Foundation <board@freebsdfoundation.org>
Co-authored-by: Michael Franz <mvfranz@gmail.com>
Co-authored-by: Roger Hoover <rhoover@apple.com>
Co-authored-by: Alexander Strange <astrange@apple.com>
Reviewed-by: kvn, twisti, jrose
G1 now uses two reference processors - one is used by concurrent marking and the other is used by STW GCs (both full and incremental evacuation pauses). In an evacuation pause, the reference processor is embedded into the closures used to scan objects. Doing so causes causes reference objects to be 'discovered' by the reference processor. At the end of the evacuation pause, these discovered reference objects are processed - preserving (and copying) referent objects (and their reachable graphs) as appropriate.
Reviewed-by: ysr, jwilhelm, brutisso, stefank, tonyp
Perform a heap verification after the first phase of G1's full GC using objects' mark words to determine liveness. The third parameter of the heap verification routines, which was used in G1 to determine which marking bitmap to use in liveness calculations, has been changed from a boolean to an enum with values defined for using the mark word, and the 'prev' and 'next' bitmaps.
Reviewed-by: tonyp, ysr
Use _max_num_q = max(discovery_degree, processing_degree), and let balance_queues() redistribute from discovery_degree to processing_degree of queues. This should also allow a more dynamic and flexible parallelism policy in the future.
Reviewed-by: jmasa, johnc
Age bits need not enter the mark-word preservation calculus; also affected, in addition to CMS, per CR synopsis above, were ParNew (but not DefNew), ParallelScavenge and G1, albeit to a lesser degree than CMS.
Reviewed-by: tonyp, johnc
Added an ifndef DONT_USE_PRECOMPILED_HEADER to precompiled.hpp. Set up DONT_USE_PRECOMPILED_HEADER when compiling with Sun Studio or when the user specifies USE_PRECOMPILED_HEADER=0. Fixed broken include dependencies.
Reviewed-by: coleenp, kvn
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
